patch: Add JSON datatype to PostgreSQL (GSoC, WIP)

commit 4dec7762583cdbe5ad10ce683e7b16d38f1129f7
Author: Joey Adams <joeyadams3.14159@gmail.com>
Date:   Tue Aug 10 02:20:38 2010 -0400

    Added json contrib module.

diff --git a/contrib/json/Makefile b/contrib/json/Makefile
new file mode 100644
index 0000000..65e8b12
--- /dev/null
+++ b/contrib/json/Makefile
@@ -0,0 +1,17 @@
+MODULE_big = json
+OBJS = json.o jsonpath.o json_io.o json_op.o util.o
+
+DATA_built = json.sql
+DATA = uninstall_json.sql
+REGRESS = init json validate condense orig json_path json_get json_set array_to_json
+
+ifdef USE_PGXS
+PG_CONFIG = pg_config
+PGXS := $(shell $(PG_CONFIG) --pgxs)
+include $(PGXS)
+else
+subdir = contrib/json
+top_builddir = ../..
+include $(top_builddir)/src/Makefile.global
+include $(top_srcdir)/contrib/contrib-global.mk
+endif
diff --git a/contrib/json/expected/array_to_json.out b/contrib/json/expected/array_to_json.out
new file mode 100644
index 0000000..be408f3
--- /dev/null
+++ b/contrib/json/expected/array_to_json.out
@@ -0,0 +1,244 @@
+SELECT to_json(ARRAY[1,2,3]);
+ to_json 
+---------
+ [1,2,3]
+(1 row)
+
+SELECT to_json(ARRAY[[1],[2],[3]]);
+    to_json    
+---------------
+ [[1],[2],[3]]
+(1 row)
+
+SELECT to_json(ARRAY[[1,2],[2],[3]]);
+ERROR:  multidimensional arrays must have array expressions with matching dimensions
+SELECT to_json(ARRAY[[1,2],[3,4],[5,6]]);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,6]]
+(1 row)
+
+SELECT to_json(ARRAY[[],[],[]]);
+ERROR:  cannot determine type of empty array
+LINE 1: SELECT to_json(ARRAY[[],[],[]]);
+                             ^
+HINT:  Explicitly cast to the desired type, for example ARRAY[]::integer[].
+SELECT to_json(ARRAY[[],[],[]]::integer[][]);
+ to_json 
+---------
+ []
+(1 row)
+
+SELECT to_json(ARRAY['hello']);
+  to_json  
+-----------
+ ["hello"]
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world']);
+      to_json      
+-------------------
+ ["hello","world"]
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world', 5]);
+ERROR:  invalid input syntax for integer: "hello"
+LINE 1: SELECT to_json(ARRAY['hello', 'world', 5]);
+                             ^
+SELECT to_json(ARRAY['hello', 'world', 5]::text[]);
+        to_json        
+-----------------------
+ ["hello","world","5"]
+(1 row)
+
+SELECT to_json(ARRAY[ARRAY['hello', 'world', 5]]::text[][]);
+         to_json         
+-------------------------
+ [["hello","world","5"]]
+(1 row)
+
+SELECT to_json(ARRAY[]);
+ERROR:  cannot determine type of empty array
+LINE 1: SELECT to_json(ARRAY[]);
+                       ^
+HINT:  Explicitly cast to the desired type, for example ARRAY[]::integer[].
+SELECT to_json(ARRAY[]::text[]);
+ to_json 
+---------
+ []
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world', null]);
+        to_json         
+------------------------
+ ["hello","world",null]
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world', null, 5]);
+ERROR:  invalid input syntax for integer: "hello"
+LINE 1: SELECT to_json(ARRAY['hello', 'world', null, 5]);
+                             ^
+SELECT to_json(ARRAY['hello', 'world', null, '5']);
+          to_json           
+----------------------------
+ ["hello","world",null,"5"]
+(1 row)
+
+SELECT to_json(ARRAY[null]);
+ to_json 
+---------
+ [null]
+(1 row)
+
+SELECT to_json(ARRAY[null, null]);
+   to_json   
+-------------
+ [null,null]
+(1 row)
+
+SELECT to_json(ARRAY[[null],[null],[null]]);
+        to_json         
+------------------------
+ [[null],[null],[null]]
+(1 row)
+
+SELECT to_json(ARRAY[[null,null],[null,null],[null,null]]);
+                to_json                
+---------------------------------------
+ [[null,null],[null,null],[null,null]]
+(1 row)
+
+SELECT to_json(ARRAY[[[null,null]],[[null,null]],[[null,null]]]);
+                   to_json                   
+---------------------------------------------
+ [[[null,null]],[[null,null]],[[null,null]]]
+(1 row)
+
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]);
+ERROR:  ARRAY could not convert type integer[] to text[]
+LINE 1: SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]]...
+                                          ^
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]::int[][][]);
+                            to_json                            
+---------------------------------------------------------------
+ [[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]
+(1 row)
+
+SELECT to_json(array[1,2,3,4,5]::int2vector);
+   to_json   
+-------------
+ [1,2,3,4,5]
+(1 row)
+
+SELECT to_json(array[1,2,3,4,5]::oidvector);
+   to_json   
+-------------
+ [1,2,3,4,5]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],5]::oidvector);
+ERROR:  syntax error at or near "5"
+LINE 1: SELECT to_json(array[[1,2],[3,4],5]::oidvector);
+                                         ^
+SELECT to_json(array[[1,2],[3,4],[5]]::oidvector);
+ERROR:  multidimensional arrays must have array expressions with matching dimensions
+SELECT to_json(array[[1,2],[3,4],[5,5]]::oidvector);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,5]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,6]]::oidvector);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,6]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,6]]::int2vector);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,6]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,6000]]::int2vector);
+        to_json         
+------------------------
+ [[1,2],[3,4],[5,6000]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,60000]]::int2vector);
+ERROR:  smallint out of range
+SELECT to_json(array[[1,2],[3,4],[5,null]]::int2vector);
+        to_json         
+------------------------
+ [[1,2],[3,4],[5,null]]
+(1 row)
+
+SELECT to_json(array[[1,2],[null,4],[5,null]]::int2vector);
+          to_json          
+---------------------------
+ [[1,2],[null,4],[5,null]]
+(1 row)
+
+SELECT to_json(array[[1,2],[null,4],[5,null]]::oidvector);
+          to_json          
+---------------------------
+ [[1,2],[null,4],[5,null]]
+(1 row)
+
+SELECT to_json(array[[true,false],[false,true]]::bool[][]);
+           to_json           
+-----------------------------
+ [[true,false],[false,true]]
+(1 row)
+
+SELECT to_json(array[[true,false],[false,true],[null,null]]::bool[][]);
+                 to_json                 
+-----------------------------------------
+ [[true,false],[false,true],[null,null]]
+(1 row)
+
+SELECT to_json('{1,2,3}');
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json('{1,2,3}'::text); -- should form "{1,2,3}", not build an array
+  to_json  
+-----------
+ "{1,2,3}"
+(1 row)
+
+SELECT to_json('{1,2,3}'::int[]);
+ to_json 
+---------
+ [1,2,3]
+(1 row)
+
+SELECT to_json('{one,two,three}'::text[]);
+        to_json        
+-----------------------
+ ["one","two","three"]
+(1 row)
+
+SELECT to_json('{one,two,three,null}'::text[]);
+          to_json           
+----------------------------
+ ["one","two","three",null]
+(1 row)
+
+SELECT to_json('{one,two,three,null,five}'::text[]);
+              to_json              
+-----------------------------------
+ ["one","two","three",null,"five"]
+(1 row)
+
+SELECT to_json('{null}'::text[]);
+ to_json 
+---------
+ [null]
+(1 row)
+
+SELECT to_json('{{null}}'::text[][]);
+ to_json  
+----------
+ [[null]]
+(1 row)
+
diff --git a/contrib/json/expected/condense.out b/contrib/json/expected/condense.out
new file mode 100644
index 0000000..8ff95f6
--- /dev/null
+++ b/contrib/json/expected/condense.out
@@ -0,0 +1,59 @@
+SELECT json_condense('"hello"');
+ json_condense 
+---------------
+ "hello"
+(1 row)
+
+SELECT json_condense($$"hello\u266Bworld"$$);
+ json_condense 
+---------------
+ "hello♫world"
+(1 row)
+
+SELECT json_condense($$"hello\u266bworld"$$);
+ json_condense 
+---------------
+ "hello♫world"
+(1 row)
+
+SELECT json_condense($$"hello♫world"$$);
+ json_condense 
+---------------
+ "hello♫world"
+(1 row)
+
+SELECT json_condense($$      "hello world"    $$);
+ json_condense 
+---------------
+ "hello world"
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world"}    $$);
+   json_condense   
+-------------------
+ {"hello":"world"}
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world", "bye": 0.0001  }    $$);
+         json_condense          
+--------------------------------
+ {"hello":"world","bye":0.0001}
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world",
+								"bye": 0.0000001
+}    $$);
+           json_condense           
+-----------------------------------
+ {"hello":"world","bye":0.0000001}
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world"
+,
+"bye"
+: [-0.1234e1, 12345e0]		}    $$);
+                json_condense                
+---------------------------------------------
+ {"hello":"world","bye":[-0.1234e1,12345e0]}
+(1 row)
+
diff --git a/contrib/json/expected/init.out b/contrib/json/expected/init.out
new file mode 100644
index 0000000..43f11fa
--- /dev/null
+++ b/contrib/json/expected/init.out
@@ -0,0 +1,3 @@
+SET client_min_messages = warning;
+\set ECHO none
+RESET client_min_messages;
diff --git a/contrib/json/expected/json.out b/contrib/json/expected/json.out
new file mode 100644
index 0000000..63e7633
--- /dev/null
+++ b/contrib/json/expected/json.out
@@ -0,0 +1,623 @@
+SELECT '[]'::JSON;
+ json 
+------
+ []
+(1 row)
+
+SELECT '['::JSON;
+ERROR:  could not parse JSON value
+LINE 1: SELECT '['::JSON;
+               ^
+SELECT '[1,2,3]'::JSON;
+  json   
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[1,2,3]'::JSON::TEXT;
+  text   
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[1,2,3  ]'::JSON;
+   json    
+-----------
+ [1,2,3  ]
+(1 row)
+
+SELECT '[1,2,3  ,4]'::JSON;
+    json     
+-------------
+ [1,2,3  ,4]
+(1 row)
+
+SELECT '[1,2,3  ,4.0]'::JSON;
+     json      
+---------------
+ [1,2,3  ,4.0]
+(1 row)
+
+SELECT '[1,2,3  ,4]'::JSON;
+    json     
+-------------
+ [1,2,3  ,4]
+(1 row)
+
+SELECT 'true'::JSON;
+ json 
+------
+ true
+(1 row)
+
+SELECT 'true'::TEXT::JSON;
+ json 
+------
+ true
+(1 row)
+
+SELECT 'false'::JSON;
+ json  
+-------
+ false
+(1 row)
+
+SELECT 'null'::JSON;
+ json 
+------
+ null
+(1 row)
+
+SELECT '1.1'::JSON;
+ json 
+------
+ 1.1
+(1 row)
+
+SELECT '"string"'::JSON;
+   json   
+----------
+ "string"
+(1 row)
+
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+                json                
+------------------------------------
+ {"key1":"value1", "key2":"value2"}
+(1 row)
+
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+                json                
+------------------------------------
+ {"key1":"value1", "key2":"value2"}
+(1 row)
+
+SELECT 15::JSON;
+ json 
+------
+ 15
+(1 row)
+
+SELECT json_type('[]');
+ json_type 
+-----------
+ array
+(1 row)
+
+SELECT json_type('{}');
+ json_type 
+-----------
+ object
+(1 row)
+
+SELECT json_type('true');
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type('false');
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type('null');
+ json_type 
+-----------
+ null
+(1 row)
+
+CREATE TABLE testjson (j JSON);
+INSERT INTO testjson VALUES ('[1,2,3,4]');
+INSERT INTO testjson VALUES ('{"key":"value"}');
+INSERT INTO testjson VALUES ('{"key":"value"');
+ERROR:  could not parse JSON value
+LINE 1: INSERT INTO testjson VALUES ('{"key":"value"');
+                                     ^
+INSERT INTO testjson VALUES ('');
+ERROR:  could not parse JSON value
+LINE 1: INSERT INTO testjson VALUES ('');
+                                     ^
+INSERT INTO testjson VALUES ('""');
+INSERT INTO testjson VALUES ('true');
+INSERT INTO testjson VALUES ('false');
+INSERT INTO testjson VALUES ('null');
+INSERT INTO testjson VALUES ('[]');
+INSERT INTO testjson VALUES ('{}');
+SELECT * FROM testjson;
+        j        
+-----------------
+ [1,2,3,4]
+ {"key":"value"}
+ ""
+ true
+ false
+ null
+ []
+ {}
+(8 rows)
+
+SELECT json_type(j) FROM testjson;
+ json_type 
+-----------
+ array
+ object
+ string
+ bool
+ bool
+ null
+ array
+ object
+(8 rows)
+
+-- to_json: null
+SELECT to_json(NULL);
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json(NULL::INT);
+ to_json 
+---------
+ null
+(1 row)
+
+SELECT to_json(NULL::INT[]);
+ to_json 
+---------
+ null
+(1 row)
+
+SELECT to_json(NULL::VOID);
+ERROR:  to_json cannot convert void to JSON
+SELECT to_json(NULL::MONEY);
+ERROR:  to_json cannot convert money to JSON
+SELECT to_json('null'::text); -- should yield '"null"', not 'null'
+ to_json 
+---------
+ "null"
+(1 row)
+
+SELECT json_type(to_json(NULL));
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT json_type(to_json(NULL::INT));
+ json_type 
+-----------
+ null
+(1 row)
+
+SELECT json_type(to_json(NULL::VOID));
+ERROR:  to_json cannot convert void to JSON
+SELECT json_type(to_json(NULL::MONEY));
+ERROR:  to_json cannot convert money to JSON
+-- to_json: string
+SELECT to_json('');
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT json_type(to_json(''));
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json('string');
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT json_type(to_json('string'));
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json('string'::VARCHAR);
+ to_json  
+----------
+ "string"
+(1 row)
+
+SELECT json_type(to_json('string'::VARCHAR));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('string'::VARCHAR(3));
+ to_json 
+---------
+ "str"
+(1 row)
+
+SELECT json_type(to_json('string'::VARCHAR(3)));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('{1,2,3}'::TEXT);
+  to_json  
+-----------
+ "{1,2,3}"
+(1 row)
+
+SELECT json_type(to_json('{1,2,3}'::TEXT));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('"doubly-encoded"'::JSON);
+       to_json        
+----------------------
+ "\"doubly-encoded\""
+(1 row)
+
+SELECT json_type(to_json('"doubly-encoded"'::JSON));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('"nested quotes"'::TEXT);
+       to_json       
+---------------------
+ "\"nested quotes\""
+(1 row)
+
+SELECT json_type(to_json('"nested quotes"'::TEXT));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('"nested quotes"'::TEXT)::TEXT::JSON;
+       to_json       
+---------------------
+ "\"nested quotes\""
+(1 row)
+
+SELECT json_type(to_json('"nested quotes"'::TEXT)::TEXT::JSON);
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('h'::CHAR);
+ to_json 
+---------
+ "h"
+(1 row)
+
+SELECT json_type(to_json('h'::CHAR));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('hello world'::CHAR);
+ to_json 
+---------
+ "h"
+(1 row)
+
+SELECT json_type(to_json('hello world'::CHAR));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('hello world!'::CHAR(11));
+    to_json    
+---------------
+ "hello world"
+(1 row)
+
+SELECT json_type(to_json('hello world!'::CHAR(11)));
+ json_type 
+-----------
+ string
+(1 row)
+
+-- to_json: number
+SELECT to_json(12345);
+ to_json 
+---------
+ 12345
+(1 row)
+
+SELECT to_json(12345.678);
+  to_json  
+-----------
+ 12345.678
+(1 row)
+
+SELECT json_type(to_json(12345));
+ json_type 
+-----------
+ number
+(1 row)
+
+SELECT json_type(to_json(12345.678));
+ json_type 
+-----------
+ number
+(1 row)
+
+SELECT to_json(+1.23e100::FLOAT);
+  to_json  
+-----------
+ 1.23e+100
+(1 row)
+
+SELECT to_json('+1.23e100'::FLOAT);
+  to_json  
+-----------
+ 1.23e+100
+(1 row)
+
+SELECT to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890);
+                                                          to_json                                                          
+---------------------------------------------------------------------------------------------------------------------------
+ 123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890
+(1 row)
+
+SELECT json_type(to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890));
+ json_type 
+-----------
+ number
+(1 row)
+
+SELECT to_json('100'::MONEY);
+ERROR:  to_json cannot convert money to JSON
+-- to_json: bool
+SELECT to_json(TRUE);
+ to_json 
+---------
+ true
+(1 row)
+
+SELECT to_json(FALSE);
+ to_json 
+---------
+ false
+(1 row)
+
+SELECT to_json(1=1);
+ to_json 
+---------
+ true
+(1 row)
+
+SELECT to_json(1=2);
+ to_json 
+---------
+ false
+(1 row)
+
+SELECT json_type(to_json(TRUE));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type(to_json(FALSE));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type(to_json(1=1));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type(to_json(1=2));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT to_json(TRUE::TEXT)::TEXT = '"' || TRUE || '"';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT to_json(FALSE::TEXT)::TEXT = '"' || FALSE || '"';
+ ?column? 
+----------
+ t
+(1 row)
+
+-- to_json: array
+SELECT to_json(ARRAY[1,2,3]);
+ to_json 
+---------
+ [1,2,3]
+(1 row)
+
+-- more tests are in array_to_json.sql
+-- to_json: invalid types
+SELECT to_json(row(1,2));
+ERROR:  to_json cannot convert record to JSON
+SELECT to_json('127.0.0.1'::INET);
+ERROR:  to_json cannot convert inet to JSON
+-- from_json: null
+SELECT from_json(null);
+ from_json 
+-----------
+ 
+(1 row)
+
+SELECT from_json(NULL::TEXT);
+ERROR:  function from_json(text) does not exist
+LINE 1: SELECT from_json(NULL::TEXT);
+               ^
+HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
+SELECT from_json(NULL::JSON);
+ from_json 
+-----------
+ 
+(1 row)
+
+-- from_json: string
+SELECT from_json('"valid string"');
+  from_json   
+--------------
+ valid string
+(1 row)
+
+SELECT from_json($$ "hello\nworld" $$);
+ from_json 
+-----------
+ hello    +
+ world
+(1 row)
+
+SELECT from_json($$ "hello\u0000world" $$);
+ERROR:  could not convert JSON-encoded string to TEXT: contains \u0000
+DETAIL:  the string was:  "hello\u0000world" 
+-- from_json: number
+SELECT from_json('123');
+ from_json 
+-----------
+ 123
+(1 row)
+
+SELECT from_json('123')::INT;
+ from_json 
+-----------
+       123
+(1 row)
+
+SELECT from_json('123.456')::INT;
+ERROR:  invalid input syntax for integer: "123.456"
+SELECT from_json('123.456')::FLOAT;
+ from_json 
+-----------
+   123.456
+(1 row)
+
+SELECT from_json('123e-38');
+ from_json 
+-----------
+ 123e-38
+(1 row)
+
+SELECT from_json('123e-38')::FLOAT;
+ from_json 
+-----------
+  1.23e-36
+(1 row)
+
+SELECT from_json('1.23e-38')::FLOAT;
+ from_json 
+-----------
+  1.23e-38
+(1 row)
+
+SELECT from_json('1.23e-38');
+ from_json 
+-----------
+ 1.23e-38
+(1 row)
+
+SELECT from_json('1.23e-38')::NUMERIC;
+                 from_json                  
+--------------------------------------------
+ 0.0000000000000000000000000000000000000123
+(1 row)
+
+-- from_json: bool
+SELECT from_json('true')::JSON;
+ from_json 
+-----------
+ true
+(1 row)
+
+SELECT from_json('true');
+ from_json 
+-----------
+ true
+(1 row)
+
+SELECT from_json('true')::BOOLEAN;
+ from_json 
+-----------
+ t
+(1 row)
+
+SELECT from_json('true')::BOOLEAN::JSON;
+ERROR:  could not parse JSON value
+SELECT from_json('true')::BOOLEAN::TEXT::JSON;
+ from_json 
+-----------
+ true
+(1 row)
+
+SELECT from_json('false')::BOOLEAN::TEXT::JSON;
+ from_json 
+-----------
+ false
+(1 row)
+
+SELECT from_json('false');
+ from_json 
+-----------
+ false
+(1 row)
+
+SELECT from_json('f');
+ERROR:  could not parse JSON value
+LINE 1: SELECT from_json('f');
+                         ^
+SELECT from_json('t');
+ERROR:  could not parse JSON value
+LINE 1: SELECT from_json('t');
+                         ^
+SELECT from_json('f'::BOOLEAN::TEXT);
+ERROR:  function from_json(text) does not exist
+LINE 1: SELECT from_json('f'::BOOLEAN::TEXT);
+               ^
+HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
+SELECT from_json('f'::BOOLEAN::TEXT::JSON);
+ from_json 
+-----------
+ false
+(1 row)
+
+SELECT from_json('t'::BOOLEAN::TEXT::JSON);
+ from_json 
+-----------
+ true
+(1 row)
+
+-- from_json: object
+SELECT from_json('{"key": "value"}');
+ERROR:  from_json cannot be applied to JSON objects
+-- from_json: array
+SELECT from_json('[1,2,3]');
+ERROR:  from_json cannot be applied to JSON arrays
+-- from_json: invalid
+SELECT from_json('invalid');
+ERROR:  could not parse JSON value
+LINE 1: SELECT from_json('invalid');
+                         ^
+CREATE TABLE sample_query_text (json JSON);
+INSERT INTO sample_query_text VALUES ($$
+"SELECT pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c WHERE c.relkind IN ('i') AND substring(pg_catalog.quote_ident(c.relname),1,0)='' AND pg_catalog.pg_table_is_visible(c.oid) AND c.relnamespace <> (SELECT oid FROM pg_catalog.pg_namespace WHERE nspname = 'pg_catalog')\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' FROM pg_catalog.pg_namespace n WHERE substring(pg_catalog.quote_ident(n.nspname) || '.',1,0)='' AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) > 1\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n WHERE c.relnamespace = n.oid AND c.relkind IN ('i') AND substring(pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname),1,0)='' AND substring(pg_catalog.quote_ident(n.nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(n.nspname))+1) AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) = 1\n UNION SELECT 'ON' UNION SELECT 'CONCURRENTLY'\nLIMIT 1000"
+$$);
+SELECT md5(from_json(json)) FROM sample_query_text;
+               md5                
+----------------------------------
+ 1c0d28af72da21149acbdf305c197141
+(1 row)
+
diff --git a/contrib/json/expected/json_get.out b/contrib/json/expected/json_get.out
new file mode 100644
index 0000000..1fc6344
--- /dev/null
+++ b/contrib/json/expected/json_get.out
@@ -0,0 +1,59 @@
+SELECT json_get('{"key": "value", "key2": "value2"}', 'key');
+ json_get 
+----------
+ "value"
+(1 row)
+
+SELECT json_get('{"key": "value", "key": "value2"}', 'key');
+ERROR:  JSONPath expression matched multiple results
+/* These each return no result because 0 is a number
+   (indicating a numeric subscript),
+   not a string (indicating an object subscript). */
+SELECT json_get('{"0": "value", "key": "value"}', '0');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('{"0": "value", "0": "value"}', '[0]');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('{"0": "value", "0": "value"}', '.0');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('{"0": "value", "1": "value"}', '["0"]');
+ json_get 
+----------
+ "value"
+(1 row)
+
+SELECT json_get('{"0": "value", "0": "value"}', '["0"]');
+ERROR:  JSONPath expression matched multiple results
+SELECT json_get('[0,1,2,3]', '0');
+ json_get 
+----------
+ 0
+(1 row)
+
+SELECT json_get('[0,1,2,3]', '"0"');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('[0,1,2,3]', '*');
+ERROR:  JSONPath expression matched multiple results
+SELECT json_get('[0]', '*');
+ json_get 
+----------
+ 0
+(1 row)
+
+SELECT json_get('[[0]]', '..*');
+ERROR:  JSONPath expression matched multiple results
diff --git a/contrib/json/expected/json_path.out b/contrib/json/expected/json_path.out
new file mode 100644
index 0000000..22c0f10
--- /dev/null
+++ b/contrib/json/expected/json_path.out
@@ -0,0 +1,1049 @@
+SELECT parse_json_path('..');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('..*');
+ parse_json_path 
+-----------------
+ $..[*]
+(1 row)
+
+SELECT parse_json_path('.*');
+ parse_json_path 
+-----------------
+ $[*]
+(1 row)
+
+SELECT parse_json_path('');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('$.*');
+ parse_json_path 
+-----------------
+ $[*]
+(1 row)
+
+SELECT parse_json_path('$');
+ parse_json_path 
+-----------------
+ $
+(1 row)
+
+SELECT parse_json_path('$*');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('*');
+ parse_json_path 
+-----------------
+ $[*]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 025  ] $$);
+ parse_json_path 
+-----------------
+ $..[25]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 $$);
+ parse_json_path 
+-----------------
+ $[0][3]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0_3 $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ . 0.3 $$);
+ parse_json_path 
+-----------------
+ $[0][3]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 031  ] $$);
+ parse_json_path 
+-----------------
+ $..[31]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello $$);
+ parse_json_path  
+------------------
+ $[0][3]["hello"]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . "back\\slash" $$);
+         parse_json_path         
+---------------------------------
+ $[0][3]["hello"]["back\\slash"]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . ["back\\slash"] $$);
+         parse_json_path         
+---------------------------------
+ $[0][3]["hello"]["back\\slash"]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . back\slash $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . backslash $$);
+        parse_json_path        
+-------------------------------
+ $[0][3]["hello"]["backslash"]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 0x31  ] $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ [ 0x31  ] $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ _3 $$);
+ parse_json_path 
+-----------------
+ $["_3"]
+(1 row)
+
+SELECT parse_json_path($$ _3_ $$);
+ parse_json_path 
+-----------------
+ $["_3_"]
+(1 row)
+
+SELECT parse_json_path($$ [ _3 ] $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ _3 $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ . _3 $$);
+ parse_json_path 
+-----------------
+ $["_3"]
+(1 row)
+
+SELECT parse_json_path('..["5"]');
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path('..[5]');
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path('..5');
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path($$ .. [ -5  ] $$);
+ parse_json_path 
+-----------------
+ $..[-5]
+(1 row)
+
+SELECT parse_json_path($$ .. [ "5"  ] $$);
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path($$ .. [ +5  ] $$);
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 5  ] $$);
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path($$ .. ["5"] $$);
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path($$ ..["5"] $$);
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path($$ [ "5" ] $$);
+ parse_json_path 
+-----------------
+ $["5"]
+(1 row)
+
+SELECT parse_json_path($$ [ 5 ] $$);
+ parse_json_path 
+-----------------
+ $[5]
+(1 row)
+
+SELECT parse_json_path('."hello"');
+ parse_json_path 
+-----------------
+ $["hello"]
+(1 row)
+
+SELECT parse_json_path('.hello');
+ parse_json_path 
+-----------------
+ $["hello"]
+(1 row)
+
+SELECT parse_json_path('...["hello world"]');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('..["hello world"]');
+  parse_json_path   
+--------------------
+ $..["hello world"]
+(1 row)
+
+SELECT parse_json_path('."hello world"');
+ parse_json_path  
+------------------
+ $["hello world"]
+(1 row)
+
+SELECT parse_json_path('.["hello world"]');
+ parse_json_path  
+------------------
+ $["hello world"]
+(1 row)
+
+SELECT parse_json_path('.hello world');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('..["hello world"]["5"]');
+     parse_json_path     
+-------------------------
+ $..["hello world"]["5"]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]');
+    parse_json_path    
+-----------------------
+ $..["hello world"][5]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]..*.[*]');
+          parse_json_path           
+------------------------------------
+ $..["hello world"][5]..[3]..[*][*]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]..*');
+         parse_json_path         
+---------------------------------
+ $..["hello world"][5]..[3]..[*]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]');
+      parse_json_path       
+----------------------------
+ $..["hello world"][5]..[3]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]*');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$
+	.. [ '"hello"\\"world"' ]
+	[ 5 ] .. [3] . * [ * ]
+$$);
+              parse_json_path              
+-------------------------------------------
+ $..["\"hello\"\\\"world\""][5]..[3][*][*]
+(1 row)
+
+select parse_json_path('$char');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('$.char');
+ parse_json_path 
+-----------------
+ $["char"]
+(1 row)
+
+select parse_json_path('$.char()');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('$.char(5)');
+ parse_json_path 
+-----------------
+ $.char(5)
+(1 row)
+
+select parse_json_path('$.char(  -1  )');
+ parse_json_path 
+-----------------
+ $.char(-1)
+(1 row)
+
+select parse_json_path('$.char(  -1  )  . char(0)');
+  parse_json_path   
+--------------------
+ $.char(-1).char(0)
+(1 row)
+
+select parse_json_path('$.char(  -1  )  . char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $.char(-1).char(0)
+(1 row)
+
+select parse_json_path('$.char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('$ . char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('$ .. char(  +1  )  . char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $..char(1).char(0)
+(1 row)
+
+select parse_json_path('$ .. char(  +1  )  .. char  ( 0 )  ');
+   parse_json_path   
+---------------------
+ $..char(1)..char(0)
+(1 row)
+
+select parse_json_path('$ . char(  +1  )  .. char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $.char(1)..char(0)
+(1 row)
+
+select parse_json_path('$ . char(  +1  )  char  ( 0 )  ');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('$ char(  +1  )  char  ( 0 )  ');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('.char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('..char(  +1  )  . char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $..char(1).char(0)
+(1 row)
+
+select parse_json_path('...char(  +1  )  . char  ( 0 )  ');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('[char(5)]');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(0)');
+ json_path 
+-----------
+ "⁰"
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(1)');
+ json_path 
+-----------
+ "¹"
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(2)');
+ json_path 
+-----------
+ "\u0000"
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(3)');
+ json_path 
+-----------
+ "³"
+(1 row)
+
+SELECT json_path('"0123"', 'char(-1)');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('"0123"', 'char(0)');
+ json_path 
+-----------
+ "0"
+(1 row)
+
+SELECT json_path('"0123"', 'char(1)');
+ json_path 
+-----------
+ "1"
+(1 row)
+
+SELECT json_path('"0123"', 'char(2)');
+ json_path 
+-----------
+ "2"
+(1 row)
+
+SELECT json_path('"0123"', 'char(3)');
+ json_path 
+-----------
+ "3"
+(1 row)
+
+SELECT json_path('"0123"', 'char(4)');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('"⁰¹²³"', 'char(0)');
+ json_path 
+-----------
+ "⁰"
+(1 row)
+
+SELECT json_path('"⁰¹²³"', 'char(1)');
+ json_path 
+-----------
+ "¹"
+(1 row)
+
+SELECT json_path('"⁰¹²³"', 'char(2)');
+ json_path 
+-----------
+ "²"
+(1 row)
+
+SELECT json_path('"⁰¹²³"', 'char(3)');
+ json_path 
+-----------
+ "³"
+(1 row)
+
+SELECT json_path('[1,2,3]', '$');
+ json_path 
+-----------
+ [1,2,3]
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.+1');
+ json_path 
+-----------
+ 2
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.-1');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('[1,2,3]', '$.0');
+ json_path 
+-----------
+ 1
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.1');
+ json_path 
+-----------
+ 2
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.2');
+ json_path 
+-----------
+ 3
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.3');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('[1,2,3]', '*');
+ json_path 
+-----------
+ 1
+ 2
+ 3
+(3 rows)
+
+SELECT json_path('[1,2,3]', '[0]');
+ json_path 
+-----------
+ 1
+(1 row)
+
+SELECT json_path('[1,2,3]', '[1]');
+ json_path 
+-----------
+ 2
+(1 row)
+
+SELECT json_path('[1,2,3]', '[2]');
+ json_path 
+-----------
+ 3
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', $$['2']$$);
+ json_path 
+-----------
+ "two"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["0"]');
+ json_path 
+-----------
+ "zero"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["1"]');
+ json_path 
+-----------
+ "one"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["2"]');
+ json_path 
+-----------
+ "two"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[0]');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[1]');
+ json_path 
+-----------
+(0 rows)
+
+-- Multiple JSONPath results are listed in BFS order
+-- (just because it's easier to implement efficiently than DFS)
+SELECT json_path('[0,1,[2, [3,4 , 5],6,[7,8],9],10]', '$..*');
+        json_path         
+--------------------------
+ 0
+ 1
+ [2, [3,4 , 5],6,[7,8],9]
+ 10
+ 2
+ [3,4 , 5]
+ 6
+ [7,8]
+ 9
+ 3
+ 4
+ 5
+ 7
+ 8
+(14 rows)
+
+CREATE TABLE sample (json JSON);
+INSERT INTO sample VALUES ($$
+{
+	"store": {
+		"books": [
+			{
+				"title": "book 0",
+				"author": "author 0",
+				"prices": [1,2,3]
+			}, {
+				"title": "book 1",
+				"author": "author 1",
+				"prices": [4,5,6]
+			}, {
+				"title": "book 2",
+				"author": "author 2",
+				"prices": [7,8,9]
+			}
+		],
+		"toys": [
+			"Yo-yo",
+			"Boomerang",
+			"Basketball"
+		]
+	}
+}
+$$);
+SELECT json_path(json, 'store.books[*]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].title') FROM sample;
+ json_path 
+-----------
+ "book 0"
+ "book 1"
+ "book 2"
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].author') FROM sample;
+ json_path  
+------------
+ "author 0"
+ "author 1"
+ "author 2"
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].prices') FROM sample;
+ json_path 
+-----------
+ [1,2,3]
+ [4,5,6]
+ [7,8,9]
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].prices[*]') FROM sample;
+ json_path 
+-----------
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+(9 rows)
+
+SELECT json_path(json, 'store.toys[*]') FROM sample;
+  json_path   
+--------------
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(3 rows)
+
+SELECT json_path(json, 'store.toys[*][0]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, 'store.toys[*][1]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, 'store.toys[*][0][0]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, 'store.toys[*][0][1]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '..books') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ [                                                    +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ]
+(1 row)
+
+SELECT json_path(json, '..books[*]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+(3 rows)
+
+SELECT json_path(json, '..title') FROM sample;
+ json_path 
+-----------
+ "book 0"
+ "book 1"
+ "book 2"
+(3 rows)
+
+SELECT json_path(json, '..author') FROM sample;
+ json_path  
+------------
+ "author 0"
+ "author 1"
+ "author 2"
+(3 rows)
+
+SELECT json_path(json, '..prices[*]') FROM sample;
+ json_path 
+-----------
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+(9 rows)
+
+SELECT json_path(json, '..toys[*]') FROM sample;
+  json_path   
+--------------
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(3 rows)
+
+SELECT json_path(json, '..toys..[*]') FROM sample;
+  json_path   
+--------------
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(3 rows)
+
+SELECT json_path(json, '..[-1]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '..[0]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ 1
+ 4
+ 7
+ "Yo-yo"
+(5 rows)
+
+SELECT json_path(json, '..[1]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ 2
+ 5
+ 8
+ "Boomerang"
+(5 rows)
+
+SELECT json_path(json, '..[2]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+ 3
+ 6
+ 9
+ "Basketball"
+(5 rows)
+
+SELECT json_path(json, '..[3]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '$') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+         "store": {                                   +
+                 "books": [                           +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ],                                   +
+                 "toys": [                            +
+                         "Yo-yo",                     +
+                         "Boomerang",                 +
+                         "Basketball"                 +
+                 ]                                    +
+         }                                            +
+ }
+(1 row)
+
+SELECT json_path(json, '..*') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                 "books": [                           +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ],                                   +
+                 "toys": [                            +
+                         "Yo-yo",                     +
+                         "Boomerang",                 +
+                         "Basketball"                 +
+                 ]                                    +
+         }
+ [                                                    +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ]
+ [                                                    +
+                         "Yo-yo",                     +
+                         "Boomerang",                 +
+                         "Basketball"                 +
+                 ]
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+ "book 0"
+ "author 0"
+ [1,2,3]
+ 1
+ 2
+ 3
+ "book 1"
+ "author 1"
+ [4,5,6]
+ 4
+ 5
+ 6
+ "book 2"
+ "author 2"
+ [7,8,9]
+ 7
+ 8
+ 9
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(27 rows)
+
+SELECT json_path(json, '..char(-1)') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '..char(0)') FROM sample;
+ json_path 
+-----------
+ "b"
+ "a"
+ "b"
+ "a"
+ "b"
+ "a"
+ "Y"
+ "B"
+ "B"
+(9 rows)
+
+SELECT json_path(json, '..char(1)') FROM sample;
+ json_path 
+-----------
+ "o"
+ "u"
+ "o"
+ "u"
+ "o"
+ "u"
+ "o"
+ "o"
+ "a"
+(9 rows)
+
+SELECT json_path(json, '..char(2)') FROM sample;
+ json_path 
+-----------
+ "o"
+ "t"
+ "o"
+ "t"
+ "o"
+ "t"
+ "-"
+ "o"
+ "s"
+(9 rows)
+
+SELECT json_path(json, '..char(3)') FROM sample;
+ json_path 
+-----------
+ "k"
+ "h"
+ "k"
+ "h"
+ "k"
+ "h"
+ "y"
+ "m"
+ "k"
+(9 rows)
+
+SELECT json_path(json, '..char(100)') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
diff --git a/contrib/json/expected/json_set.out b/contrib/json/expected/json_set.out
new file mode 100644
index 0000000..cc14f80
--- /dev/null
+++ b/contrib/json/expected/json_set.out
@@ -0,0 +1,164 @@
+SELECT json_set('[1,2,3]', '[1]', 5::json);
+ json_set 
+----------
+ [1,5,3]
+(1 row)
+
+SELECT json_set('[1,2,3]', '[3]', 5::json);
+ json_set 
+----------
+ [1,2,3]
+(1 row)
+
+SELECT json_set('[1,2,3]', '[2]', 5::json);
+ json_set 
+----------
+ [1,2,5]
+(1 row)
+
+SELECT json_set('[1,2,3]', '[2]', '[0,1]'::json);
+  json_set   
+-------------
+ [1,2,[0,1]]
+(1 row)
+
+SELECT json_set('  [ 1 ,   2,3]', '1', '5');
+    json_set    
+----------------
+   [ 1 ,   5,3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [2,3],3]', '1', '5');
+    json_set    
+----------------
+   [ 1 ,   5,3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  5 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[5][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[4][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[3][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[2][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '   5  ');
+           json_set            
+-------------------------------
+   [ 1 ,   [  5 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1][0]', '   5  ');
+              json_set               
+-------------------------------------
+   [ 1 ,   [  5 ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '   5  ');
+              json_set               
+-------------------------------------
+   [ 1 ,   [  5 ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '     5  ');
+              json_set               
+-------------------------------------
+   [ 1 ,   [  5 ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\tworld"  $$);
+                     json_set                     
+--------------------------------------------------
+   [ 1 ,   [  "hello\tworld" ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\u0009world"  $$);
+                       json_set                       
+------------------------------------------------------
+   [ 1 ,   [  "hello\u0009world" ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][*]', $$     "hello\u0009world"  $$);
+                               json_set                                
+-----------------------------------------------------------------------
+   [ 1 ,   [  "hello\u0009world" ,   "hello\u0009world"     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+       json_set        
+-----------------------
+   "hello\u0009world" 
+(1 row)
+
+SELECT json_set('       [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+          json_set          
+----------------------------
+        "hello\u0009world" 
+(1 row)
+
+-- Since JavaScript doesn't do anything when you assign to a character subscript,
+-- neither will json_set.
+SELECT json_set('"hello"', '[0]', '"H"');
+ json_set 
+----------
+ "hello"
+(1 row)
+
+SELECT json_set('"hello"', '[0][0]', '"H"');
+ json_set 
+----------
+ "hello"
+(1 row)
+
+SELECT json_set('["hello"]', '[0][0]', '"H"');
+ json_set  
+-----------
+ ["hello"]
+(1 row)
+
+SELECT json_set('["hello"]', '[0][0][0]', '"H"');
+ json_set  
+-----------
+ ["hello"]
+(1 row)
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*]', '["set"]');
+                 json_set                  
+-------------------------------------------
+ [["set"],["set"],["set"],["set"],["set"]]
+(1 row)
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*][*]', '["set"]');
+              json_set               
+-------------------------------------
+ [0,1,2,[["set"],["set"],["set"]],4]
+(1 row)
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$..[*]', '["set"]');
+                 json_set                  
+-------------------------------------------
+ [["set"],["set"],["set"],["set"],["set"]]
+(1 row)
+
diff --git a/contrib/json/expected/orig.out b/contrib/json/expected/orig.out
new file mode 100644
index 0000000..95a768f
--- /dev/null
+++ b/contrib/json/expected/orig.out
@@ -0,0 +1,14 @@
+/* Make sure creating an array literal and subscripting
+ * preserves the original string exactly
+ * (except for trimming surrounding whitespace). */
+SELECT bool_and(btrim(before, E'\t\n\r ') = after) FROM (
+	SELECT
+		string AS before,
+		json_path(('  [ ' || string || '  ] ')::json, '$.[0]')::text AS after
+	FROM valid_test_strings
+) AS subquery;
+ bool_and 
+----------
+ t
+(1 row)
+
diff --git a/contrib/json/expected/validate.out b/contrib/json/expected/validate.out
new file mode 100644
index 0000000..3ff190b
--- /dev/null
+++ b/contrib/json/expected/validate.out
@@ -0,0 +1,220 @@
+SELECT json_validate(string), string FROM test_strings;
+ json_validate |                          string                          
+---------------+----------------------------------------------------------
+ f             | 
+ f             |   
+ f             | "
+ f             | [,]
+ f             | [)
+ f             | []]
+ f             | [}
+ f             | {,}
+ f             | {]
+ f             | ["1":2]
+ f             | [1,2,]
+ f             | [1:2}
+ f             | {"1":2,}
+ f             | {1:2}
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7 ]}]}
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7]}]}
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]]
+ f             | {"1":2, "3":4
+ f             | "1\u2"
+ f             | [,2]
+ f             | "3
+ f             | "3" "4"
+ f             | [3[4]
+ f             | [3[4]]
+ f             | [3, [4, [5], 6] 7, 8 9]
+ f             | [3, [4, [5], 6] 7, 8, 9]
+ f             | [3, [4, [5], 6], 7, 8 9]
+ f             | {"hello":true, "bye":false, null}
+ f             | {"hello":true, "bye":false, null:null}
+ f             | "hi
+ f             | "hi"""
+ f             | {"hi": "bye"]
+ f             | "\uD800\uD800"
+ f             | "\uD800\uDBFF"
+ f             | "\UD834\UDD1E"
+ f             | "\uDB00"
+ f             | "\uDB00\uDBFF"
+ t             | "\uFFFE"
+ t             | "\uFFFF"
+ f             | .
+ t             | ""
+ t             | []
+ t             | {}
+ f             | +.
+ t             | 0.5
+ f             | 0.e1
+ t             | {"1":{}}
+ t             | {"1":2}
+ t             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"]}]}
+ t             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]}
+ t             | 1234
+ t             | -1234
+ t             | {"1":2, "3":4}
+ f             | +1234
+ f             | ++1234
+ t             | 123.456e14234
+ t             | 123.456e-14234
+ t             | 123.456e+14234
+ f             | 123.e-14234
+ t             | "1\u2000"
+ t             | "1\u20001"
+ t             | 2
+ f             | .246e-14234
+ f             | .2e-14234
+ t             | 3
+ f             | .3
+ t             | "3"
+ t             | [3]
+ f             | +3.
+ t             | 3.2e+1
+ t             | [3, [4]]
+ t             | [3, [4, [5]]]
+ t             | [3, [4, [5], 6]]
+ t             | [3, [4, [5], 6], 7]
+ t             | [3, [4, [5], 6], 7, 8]
+ t             | [3, [4, [5], 6], 7, 8, 9]
+ f             | +3.5
+ f             | .3e
+ f             | .3e1
+ f             | .3e-1
+ f             | .3e+1
+ f             | 3.e1
+ f             | 3.e+1
+ t             | 3e+1
+ f             | .5
+ f             | +.5
+ f             | .5e+1
+ t             | [ 7]
+ t             | [7 ]
+ t             | [7]
+ f             | .e-14234
+ t             | "hello"
+ t             | ["hello"]
+ t             | ["hello", "bye"]
+ t             | ["hello", "bye\n"]
+ t             | ["hello", "bye\n\r\t"]
+ t             | ["hello", "bye\n\r\t\b"]
+ t             | ["hello", "bye\n\r\t\b",true]
+ t             | ["hello", "bye\n\r\t\b",true , false]
+ t             | ["hello", "bye\n\r\t\b",true , false,    null]
+ f             | ["hello", "bye\n\r\t\v"]
+ t             | {"hello":true}
+ t             | {"hello":true, "bye":false}
+ t             | {"hello":true, "bye":false, "foo":["one","two","three"]}
+ t             | "hi"
+ t             | ["hi"]
+ t             | ["hi", "bye"]
+ t             | {"hi": "bye"}
+ t             | ["hi", "bye", 3]
+ t             | ["hi", "bye[", 3]
+ t             | "\u0007"
+ t             | "\u0008"
+ t             | "\u0009"
+ t             | "\u0010"
+ t             | "\u0020"
+ t             | "\u10000"
+ t             | "\u1234"
+ t             | "\u99999"
+ t             | "\ud800\udc00"
+ t             | "\uD800\uDC00"
+ t             | "\uD834\uDD1E"
+ t             | "\uDBFF\uDFFF"
+ t             | "\uFFFD"
+ t             | "\uFFFF"
+ f             | hello
+ t             | [32, 1]
+ f             | [32, 
+ t             | "\uD800\uDC00"
+ t             | "\n"
+ t             | "hello"
+ t             | "hello\u0009world"
+ t             | "hello"
+ t             | "hello\n"
+ t             | "hello"
+ t             | 3
+ f             | 3.
+ f             | .3
+ t             | 0.3
+ f             | 0.3e
+ f             | 0.3e+
+ t             | 0.3e+5
+ t             | 0.3e-5
+ t             | 0.3e5
+ t             | "hello"
+ f             | +3
+ t             | -3
+ f             | -3.
+ t             | -3.1
+ f             | .5
+ f             | 5.
+ f             | 5.e1
+ t             | 0.5
+ f             | .3e1
+ f             | .3e+1
+ f             | .3e-1
+ f             | .3e-1 .5
+ f             | .3e-1.5
+ f             | .3e+1.5
+ f             | .3e+.
+ f             | .3e+.5
+ f             | .3e+1.5
+ f             | 9.3e+1.5
+ f             | 9.e+1.5
+ f             | 9.e+
+ f             | 9.e+1
+ t             | "\""
+ t             | "\"3.5"
+ t             | "\"."
+ f             | "\".".
+ t             | "\"....."
+ f             | "\"\"\"\"""
+ f             | ["\"\"\"\"", .5]
+ f             | [.5]
+ t             | ["\"\"\"\"", 0.5]
+ f             | ["\"\"\"\"", .5]
+ f             | ["\"\"\"\"",.5]
+ f             | ["\"",.5]
+ f             | ["\".5",.5]
+ f             | ["\".5",".5\"".5]
+ f             | ["\".5",".5\"", .5]
+ f             | ["\".5",".5\"",.5]
+ t             | ["\".5",".5\"",0.5]
+ f             | {"key":/*comment*/"value"}
+ f             | {"key":/*comment"value"}
+ f             | {"key":"value"}/*
+ f             | {"key":"value"}/**/
+ f             | {"key":"value"}/***/
+ f             | {"key":"value"}/**//
+ f             | {"key":"value"}/**///
+ f             | {"key":"value"}/**///----
+ f             | {"key":"value"}#
+ f             | {"key":"value"}#{
+ f             | {"key":"value"}#{}
+ f             | {"key":"value"}#,
+ f             | {"key":"value"/**/, "k2":"v2"}
+ t             | "\u0027"
+ f             | "hello\'"
+ f             | 'hello\''
+ f             | 'hello'
+ f             | 'hell\'o'
+ f             | '\'hello'
+ f             | '\'hello\''
+ f             | \'hello\'
+ f             | 'hello\'
+ f             | ['hello\']
+ f             | ['hello\'']
+ f             | ['hello"']
+ f             | ['hello\"']
+ f             | ['hello"o']
+ f             | ['"']
+ f             | '"'
+ f             | '"hello"'
+ f             | '"hello'
+ f             | '"hi"'
+(215 rows)
+
diff --git a/contrib/json/json.c b/contrib/json/json.c
new file mode 100644
index 0000000..3aa6ddd
--- /dev/null
+++ b/contrib/json/json.c
@@ -0,0 +1,1202 @@
+/*-------------------------------------------------------------------------
+ *
+ * json.c
+ *	  Core JSON manipulation routines used by JSON data type support.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "json.h"
+#include "util.h"
+
+#include <ctype.h>
+
+#include "mb/pg_wchar.h"
+
+#define is_internal(node) ((node)->type == JSON_ARRAY || (node)->type == JSON_OBJECT)
+
+/* We can't use isspace() because it also accepts \v and \f, which
+   aren't legal whitespace characters in strict JSON. */
+#define is_whitespace(c) ((c)==' ' || (c)=='\t' || (c)=='\n' || (c)=='\r')
+
+static void
+skip_whitespace(const char **sp)
+{
+	const char *s = *sp;
+
+	while (is_whitespace(*s))
+		s++;
+	*sp = s;
+}
+
+static char
+end_parenthesis(JSON * node)
+{
+	Assert(node != NULL);
+
+	switch (node->type)
+	{
+		case JSON_ARRAY:
+			return ']';
+		case JSON_OBJECT:
+			return '}';
+		default:
+			Assert(false);
+			return '\0';
+	}
+}
+
+/*
+ * Reads exactly 4 hex characters (capital or lowercase).
+ * Writes the result to *out .
+ * Returns true on success, false if any input chars are not [0-9A-Fa-f] .
+ */
+static bool
+read_hex16(const char *in, unsigned int *out)
+{
+	unsigned int i;
+	unsigned int tmp;
+	char		c;
+
+	*out = 0;
+
+	for (i = 0; i < 4; i++)
+	{
+		c = *in++;
+		if (c >= '0' && c <= '9')
+			tmp = c - '0';
+		else if (c >= 'A' && c <= 'F')
+			tmp = c - 'A' + 10;
+		else if (c >= 'a' && c <= 'f')
+			tmp = c - 'a' + 10;
+		else
+			return false;
+
+		*out <<= 4;
+		*out += tmp;
+	}
+
+	return true;
+}
+
+/*
+ * Encodes a 16-bit number into hexadecimal,
+ * writing exactly 4 hex chars.
+ */
+static void
+write_hex16(char *out, unsigned int val)
+{
+	const char *hex = "0123456789ABCDEF";
+
+	*out++ = hex[(val >> 12) & 0xF];
+	*out++ = hex[(val >> 8) & 0xF];
+	*out++ = hex[(val >> 4) & 0xF];
+	*out++ = hex[val & 0xF];
+}
+
+
+/*********** JSON creation, manipulation, and deletion **********/
+
+JSON *
+json_mknode(json_type type)
+{
+	JSON	   *node = palloc(sizeof(*node));
+
+	memset(node, 0, sizeof(*node));
+	node->type = type;
+	return node;
+}
+
+JSON *
+json_mkbool(bool v_bool)
+{
+	JSON	   *node = json_mknode(JSON_BOOL);
+
+	node->v.v_bool = v_bool;
+	return node;
+}
+
+JSON *
+json_mkstring(const char *str, size_t length)
+{
+	JSON	   *node = json_mknode(JSON_STRING);
+
+	if (str)
+	{
+		node->v.string.str = pnstrdup(str, length);
+		node->v.string.length = length;
+	}
+	return node;
+}
+
+JSON *
+json_mknumber(const char *number, size_t length)
+{
+	JSON	   *node = json_mknode(JSON_NUMBER);
+
+	if (number)
+		node->v.number = pnstrdup(number, length);
+	return node;
+}
+
+/*
+ * Indicate that the node's value has changed,
+ * marking ancestors as necessary.
+ *
+ * Call json_touch_value so that json_encode(..., JSONOPT_ORIG)
+ * will encode the new value rather than using original text.
+ */
+void
+json_touch_value(JSON * node)
+{
+	while (node && node->orig.value.start)
+	{
+		node->orig.value.start = NULL;
+		node = node->parent;
+	}
+}
+
+/*
+ * Add child to parent, but don't clear orig pointers of ancestors.
+ *
+ * This is used by json_decode to ensure that original text segments
+ * are preserved while building the JSON tree.
+ */
+static void
+json_append_notouch(JSON * parent, JSON * child)
+{
+	Assert(parent->type == JSON_ARRAY || parent->type == JSON_OBJECT);
+	Assert(child->parent == NULL);
+
+	parent->v.children.count++;
+	child->parent = parent;
+	child->prev = parent->v.children.tail;
+	child->next = NULL;
+
+	if (parent->v.children.tail)
+	{
+		parent->v.children.tail->next = child;
+		parent->v.children.tail = child;
+	}
+	else
+	{
+		parent->v.children.head = parent->v.children.tail = child;
+	}
+}
+
+/*
+ * json_append
+ *	  Add child to parent, putting it at the end of its child list.
+ *
+ *	  Child must not already have another parent.
+ */
+void
+json_append(JSON * parent, JSON * child)
+{
+	json_append_notouch(parent, child);
+	json_touch_value(parent);
+}
+
+/*
+ * json_remove
+ *	  Remove node from its parent, but do not delete it.
+ */
+void
+json_remove(JSON * node)
+{
+	JSON	   *parent = node->parent;
+
+	if (parent == NULL)
+		return;
+	Assert(parent->type == JSON_ARRAY || parent->type == JSON_OBJECT);
+	Assert(parent->v.children.count > 0);
+
+	if (node->prev)
+		node->prev->next = node->next;
+	else
+		parent->v.children.head = node->next;
+	if (node->next)
+		node->next->prev = node->prev;
+	else
+		parent->v.children.tail = node->prev;
+
+	parent->v.children.count--;
+	node->parent = NULL;
+	node->prev = NULL;
+	node->next = NULL;
+
+	json_touch_value(parent);
+}
+
+/*
+ * Update the value of a node, preserving position and key information.
+ *
+ * Note well: If replacement is an array or object with children, the parent
+ *			  pointers of those children will be incorrect
+ *			  (they'll still refer to their original parent).
+ *
+ *			  Untrustworthy parent pointers is the price to pay for
+ *			  being able to copy JSON values by reference.
+ */
+void
+json_replace_value(JSON * node, JSON * replacement)
+{
+	node->type = replacement->type;
+	node->v = replacement->v;
+	node->orig.value = replacement->orig.value;
+
+	if (node->parent)
+		json_touch_value(node->parent);
+}
+
+const char *
+json_get_string(JSON * node, size_t *length_out)
+{
+	Assert(node->type == JSON_STRING);
+	if (length_out)
+		*length_out = node->v.string.length;
+	return node->v.string.str;
+}
+
+void
+json_set_string(JSON * node, const char *str, size_t length)
+{
+	Assert(node->type == JSON_STRING);
+	if (node->v.string.str)
+		pfree(node->v.string.str);
+	if (str)
+	{
+		node->v.string.str = pnstrdup(str, length);
+		node->v.string.length = length;
+	}
+	else
+	{
+		node->v.string.str = NULL;
+		node->v.string.length = 0;
+	}
+	json_touch_value(node);
+}
+
+const char *
+json_get_number(JSON * node)
+{
+	Assert(node->type == JSON_NUMBER);
+	return node->v.number;
+}
+
+void
+json_set_number(JSON * node, const char *number, size_t length)
+{
+	Assert(node->type == JSON_NUMBER);
+	if (node->v.number)
+		pfree(node->v.number);
+	if (number)
+		node->v.number = pnstrdup(number, length);
+	else
+		node->v.number = NULL;
+	json_touch_value(node);
+}
+
+/* Non-recursively free a node */
+static void
+free_node(JSON * node)
+{
+	if (node->type == JSON_STRING)
+	{
+		if (node->v.string.str)
+			pfree(node->v.string.str);
+	}
+	else if (node->type == JSON_NUMBER)
+	{
+		if (node->v.number)
+			pfree(node->v.number);
+	}
+
+	if (node->key)
+		pfree(node->key);
+
+	pfree(node);
+}
+
+/*
+ * Free a JSON node and all its descendants.
+ *
+ * Do not use this function if you have performed json_replace_value on
+ * a descendant, as this function relies on each node's ->parent field
+ * being trustworthy.
+ */
+static void
+json_delete(JSON * node)
+{
+	JSON	   *parent,
+			   *next;
+
+	if (node == NULL)
+		return;
+
+	/* Remove node from parent (if it has one). */
+	json_remove(node);
+
+descend:
+	while (is_internal(node) && node->v.children.head)
+		node = node->v.children.head;
+
+advance:
+	parent = node->parent;
+	next = node->next;
+	free_node(node);
+	node = next;
+
+	if (node != NULL)
+	{
+		goto descend;
+	}
+	else
+	{
+		node = parent;
+		if (node != NULL)
+			goto advance;
+		else
+			return;
+	}
+}
+
+
+/*********************** Parsing and validation **********************/
+
+static JSON *decode_leaf(const char **sp);
+static JSON *decode_number(const char **sp);
+
+/*
+ * json_decode_string has a different signature than its friends
+ * because it's also used to parse object member keys.
+ * It's also useful outside of json.c, such as in jsonpath.c .
+ */
+char	   *json_decode_string(const char **sp, size_t *length, bool strict);
+
+/*
+ * json_validate
+ *	  Make sure the given UTF-8 string is valid JSON.
+ *
+ * TODO: Consider making a dedicated function for this so we don't have to
+ *		 convert to UTF-8, build a JSON node, then free both
+ *		 whenever we need to validate (such as in json_in and json_recv).
+ */
+bool
+json_validate(const char *str)
+{
+	JSON	   *node = json_decode(str);
+
+	if (node == NULL)
+		return false;
+	json_delete(node);
+	return true;
+}
+
+/*
+ * json_validate_server_encoded
+ *	  Variant of json_validate that takes a server-encoded string
+ *	  rather than a UTF-8 string.
+ *
+ *	  Note that a dedicated json_validate (described in the TODO above)
+ *	  would be able to handle both encodings natively, since both are
+ *	  ASCII-compatible.
+ */
+bool
+json_validate_server_encoded(const char *str)
+{
+	char	   *str_utf8 = server_to_utf8(str, strlen(str));
+	bool		result = json_validate(str_utf8);
+
+	if (str_utf8 != str)
+		pfree(str_utf8);
+
+	return result;
+}
+
+/*
+ * json_decode
+ *	  Convert a JSON-encoded string to a JSON node.
+ *	  @str must be valid UTF-8.
+ */
+JSON *
+json_decode(const char *str)
+{
+	JSON	   *root = NULL,
+			   *parent = NULL,
+			   *node = NULL;
+	const char *s = str;
+	char	   *key;
+	size_t		key_length;
+	struct json_orig orig;
+	bool		expect_endp;
+
+	if (str == NULL)
+		return NULL;
+
+	Assert(utf8_validate(str, strlen(str)));
+
+	expect_endp = false;
+	goto item;
+
+item:							/* Expect a value (set expect_endp before goto
+								 * item; ) */
+	key = NULL;
+	key_length = 0;
+	memset(&orig, 0, sizeof(orig));
+
+	orig.key_left_space.start = s;
+	orig.left_space.start = s;
+
+	skip_whitespace(&s);
+
+	if (expect_endp)
+	{
+		if (*s == ']' || *s == '}')
+			goto endp;
+	}
+
+	if (parent != NULL && parent->type == JSON_OBJECT)
+	{
+		/* Parse member key string. */
+		orig.key_left_space.end = s;
+		orig.key.start = s;
+
+		key = json_decode_string(&s, &key_length, true);
+		if (key == NULL)
+			goto failed;
+
+		orig.key.end = s;
+		orig.key_right_space.start = s;
+
+		/* Eat the " : " */
+		skip_whitespace(&s);
+		if (*s != ':')
+			goto failed;
+
+		orig.key_right_space.end = s;
+		s++;
+		orig.left_space.start = s;
+
+		skip_whitespace(&s);
+	}
+
+	/*
+	 * The way orig.value and company are initialized is a bit funky. If this
+	 * node has children, we have to finish parsing the node's children before
+	 * we know where it ends.  Hence, initialization of orig.value_end and
+	 * after will be deferred if this node has children.
+	 */
+
+	orig.left_space.end = s;
+	orig.value.start = s;
+
+	node = decode_leaf(&s);
+	if (node == NULL)
+	{
+		if (*s == '[')
+			node = json_mknode(JSON_ARRAY);
+		else if (*s == '{')
+			node = json_mknode(JSON_OBJECT);
+		else
+			goto failed;
+		s++;
+
+		/*
+		 * orig.value.end and later are dangling (actually NULL) for now, but
+		 * will be initialized when we get to state 'endp' .
+		 */
+	}
+	else
+	{
+		orig.value.end = s;
+		orig.right_space.start = s;
+
+		skip_whitespace(&s);
+
+		orig.right_space.end = s;
+	}
+
+	node->key = key;
+	node->key_length = key_length;
+
+	/*
+	 * The key now belongs to the node.  This prevents a double free on
+	 * failure (see the failed: label).
+	 */
+	key = NULL;
+
+	node->orig = orig;
+
+	if (parent != NULL)
+		json_append_notouch(parent, node);
+	else
+		root = node;
+
+	if (is_internal(node))
+	{
+		/*
+		 * "push" node onto the "stack".  Nodes point up to their parents,
+		 * which is why this function doesn't need a "stack" per se.
+		 */
+		parent = node;
+
+		expect_endp = true;
+		goto item;
+	}
+
+	if (parent != NULL)
+		goto comma_endp;
+	else
+		goto end;
+
+comma_endp:						/* Expect a comma or end bracket/brace */
+	if (*s == ',')
+	{
+		s++;
+
+		expect_endp = false;
+		goto item;
+	}
+	if (*s == ']' || *s == '}')
+		goto endp;
+
+	goto failed;
+
+endp:							/* Handle an end bracket/brace */
+	if (*s != end_parenthesis(parent))
+		goto failed;
+	s++;
+
+	/* "pop" a node from the "stack" */
+	node = parent;
+	parent = parent->parent;
+
+	/*
+	 * The other pointers were set when we started parsing this node in the
+	 * 'item' state.
+	 */
+	node->orig.value.end = s;
+	node->orig.right_space.start = s;
+
+	skip_whitespace(&s);
+
+	node->orig.right_space.end = s;
+
+	if (parent != NULL)
+		goto comma_endp;
+	else
+		goto end;
+
+end:							/* Expect end of text */
+	if (*s != '\0')
+		goto failed;
+	return node;
+
+failed:					/* Handle failure */
+	if (key != NULL)
+		pfree(key);
+	json_delete(root);
+	return NULL;
+}
+
+/*
+ * Decode and skip a node that does not have children.
+ * Whitespace is not skipped first (it is done in the primary decode loop).
+ *
+ * Returns NULL if next character is '[', '{', or invalid.
+ */
+static JSON *
+decode_leaf(const char **sp)
+{
+	char		c = **sp;
+
+	if (c == '"')
+	{
+		size_t		length;
+		char	   *str = json_decode_string(sp, &length, true);
+
+		if (str != NULL)
+		{
+			JSON	   *node = json_mknode(JSON_STRING);
+
+			node->v.string.str = str;
+			node->v.string.length = length;
+			return node;
+		}
+
+		return NULL;
+	}
+	if ((c >= '0' && c <= '9') || c == '-')
+		return decode_number(sp);
+	if (strncmp(*sp, "true", 4) == 0)
+	{
+		(*sp) += 4;
+		return json_mkbool(true);
+	}
+	if (strncmp(*sp, "false", 5) == 0)
+	{
+		(*sp) += 5;
+		return json_mkbool(false);
+	}
+	if (strncmp(*sp, "null", 4) == 0)
+	{
+		(*sp) += 4;
+		return json_mknode(JSON_NULL);
+	}
+
+	return NULL;
+}
+
+/*
+ * The JSON spec says that a number shall follow this precise pattern
+ * (spaces and quotes added for readability):
+ *	 '-'? (0 | [1-9][0-9]*) ('.' [0-9]+)? ([Ee] [+-]? [0-9]+)?
+ *
+ * However, some JSON parsers are more liberal.  For instance, PHP accepts
+ * '.5' and '1.'.  JSON.parse accepts '+3'.
+ *
+ * This function takes the strict approach.
+ */
+static bool
+validate_number(const char **sp)
+{
+	const char *s = *sp;
+
+	/* '-'? */
+	if (*s == '-')
+		s++;
+
+	/* (0 | [1-9][0-9]*) */
+	if (*s == '0')
+	{
+		s++;
+	}
+	else
+	{
+		if (!isdigit(*s))
+			return false;
+		do
+			s++;
+		while (isdigit(*s));
+	}
+
+	/* ('.' [0-9]+)? */
+	if (*s == '.')
+	{
+		s++;
+		if (!isdigit(*s))
+			return false;
+		do
+			s++;
+		while (isdigit(*s));
+	}
+
+	/* ([Ee] [+-]? [0-9]+)? */
+	if (*s == 'E' || *s == 'e')
+	{
+		s++;
+		if (*s == '+' || *s == '-')
+			s++;
+		if (!isdigit(*s))
+			return false;
+		do
+			s++;
+		while (isdigit(*s));
+	}
+
+	*sp = s;
+	return true;
+}
+
+static JSON *
+decode_number(const char **sp)
+{
+	const char *start,
+			   *end;
+
+	start = *sp;
+	if (!validate_number(sp))
+		return NULL;
+	end = *sp;
+
+	return json_mknumber(start, end - start);
+}
+
+/*
+ * json_decode_string
+ *	  If you're interested in the decoding JSON in general, see json_decode.
+ *
+ *	  Decodes a JSON string literal (e.g. "\"hello\"").
+ *
+ *	  If strict is true, string must be double-quoted,
+ *	  as is required by the JSON RFC.
+ *	  Otherwise (e.g. if parsing something JSON-like, such as JSONPath),
+ *	  the string may be single- or double-quoted.
+ *
+ *	  Also, no whitespace skipping is done, so the caller should only
+ *	  call this function when it expects **sp to be either " or '
+ *
+ *	  On success, returns the decoded string, passes the decoded string's
+ *	  length through *length (which must not be NULL), and advances *sp to point
+ *	  to the end of string literal (after the closing quote character).
+ *
+ *	  On failure (parse error), returns NULL and
+ *	  leaves *length and *sp untouched.
+ */
+char *
+json_decode_string(const char **sp, size_t *length, bool strict)
+{
+	const char *s = *sp;
+	StringInfoData ret;
+	char		buf[4];
+	int			len;
+	char		quote;
+
+	Assert(length != NULL);
+
+	initStringInfo(&ret);
+
+	quote = *s++;
+	if (strict)
+	{
+		if (quote != '"')
+			return NULL;
+	}
+	else
+	{
+		if (quote != '"' && quote != '\'')
+			return NULL;
+	}
+
+	while (*s != '\0' && *s != quote)
+	{
+		unsigned char c = *s++;
+		unsigned int uc;
+		unsigned int lc;
+
+		if (c == '\\')
+		{
+			c = *s++;
+			switch (c)
+			{
+				case '\\':
+				case '/':
+					break;
+				case 'b':
+					c = '\b';
+					break;
+				case 'f':
+					c = '\f';
+					break;
+				case 'n':
+					c = '\n';
+					break;
+				case 'r':
+					c = '\r';
+					break;
+				case 't':
+					c = '\t';
+					break;
+				case 'u':
+					if (!read_hex16(s, &uc))
+						goto failed;
+					s += 4;
+
+					if (uc >= 0xD800 && uc <= 0xDFFF)
+					{
+						/* Handle UTF-16 surrogate pair. */
+
+						if (uc >= 0xDC00)
+							goto failed;		/* Second surrogate not
+												 * preceded by first
+												 * surrogate. */
+
+						if (s[0] != '\\' || s[1] != 'u'
+							|| !read_hex16(s + 2, &lc)
+							|| !(lc >= 0xDC00 && lc <= 0xDFFF))
+							goto failed;		/* First surrogate not
+												 * followed by second
+												 * surrogate. */
+
+						s += 6;
+
+						uc = 0x10000 | ((uc & 0x3FF) << 10) | (lc & 0x3FF);
+					}
+
+					unicode_to_utf8(uc, (unsigned char *) buf);
+					len = pg_utf_mblen((unsigned char *) buf);
+
+					Assert(len > 0);
+
+					appendBinaryStringInfo(&ret, buf, len);
+
+					continue;	/* Continue the enclosing while loop to skip
+								 * the str_append below. */
+				default:		/* Invalid escape */
+					if (c == quote)
+						break;
+					if (!strict && (c == '"' || c == '\''))
+						break;
+					goto failed;	/* Invalid escape */
+			}
+		}
+		else if (c <= 0x1F)
+		{
+			/* Control characters not allowed in string literals. */
+			goto failed;
+		}
+		appendStringInfoChar(&ret, c);
+	}
+
+	if (*s++ != quote)
+		goto failed;
+
+	*length = ret.len;
+	*sp = s;
+	return ret.data;
+
+failed:
+	pfree(ret.data);
+	return NULL;
+}
+
+/*
+ * json_text_type
+ *	  Determines the type of a JSON string without fully decoding it.
+ *	  Expects the given string to be valid JSON.
+ *	  Might return JSON_INVALID if something is wrong with the input.
+ */
+json_type
+json_text_type(const char *str, size_t nbytes)
+{
+	const char *s = str;
+	const char *e = str + nbytes;
+	char		c;
+
+	/* Skip whitespace characters. */
+	while (s < e && is_whitespace(*s))
+		s++;
+
+	/* Get first non-white character, making sure it's in bounds. */
+	if (s >= e)
+		return JSON_INVALID;
+	c = *s;
+
+	switch (c)
+	{
+		case 'n':
+			return JSON_NULL;
+		case '"':
+			return JSON_STRING;
+		case 't':
+		case 'f':
+			return JSON_BOOL;
+		case '{':
+			return JSON_OBJECT;
+		case '[':
+			return JSON_ARRAY;
+		default:
+			if (c == '-' || (c >= '0' && c <= '9'))
+				return JSON_NUMBER;
+			return JSON_INVALID;
+	}
+}
+
+
+/****************************** Encoding *****************************/
+
+/*
+ * encode_string
+ *	  Variant of json_encode_string that writes its output to a StringInfo.
+ */
+static void
+encode_string(StringInfo out, const char *string, size_t length, char quote,
+			  bool escape_unicode)
+{
+	const char *s = string;
+	const char *e = s + length;
+
+	Assert(quote != '\\');
+	if (escape_unicode)
+		Assert(utf8_validate(string, length));
+
+	appendStringInfoChar(out, quote);
+
+	while (s < e)
+	{
+		unsigned char c = *s++;
+		unsigned char endchar;
+
+		switch (c)
+		{
+			case '\\':
+				endchar = '\\';
+				break;
+			case '\b':
+				endchar = 'b';
+				break;
+			case '\f':
+				endchar = 'f';
+				break;
+			case '\n':
+				endchar = 'n';
+				break;
+			case '\r':
+				endchar = 'r';
+				break;
+			case '\t':
+				endchar = 't';
+				break;
+			default:
+				{
+					if (c == quote)
+					{
+						endchar = quote;
+						break;
+					}
+					if (c < 0x1F || (c >= 0x80 && escape_unicode))
+					{
+						/* Encode using \u.... */
+						pg_wchar	uc;
+						unsigned int lc;
+						char		txt[13];
+
+						s--;
+						uc = utf8_decode_char(&s);
+
+						txt[0] = '\\';
+						txt[1] = 'u';
+						txt[6] = '\\';
+						txt[7] = 'u';
+						if (uc <= 0xFFFF)
+						{
+							write_hex16(txt + 2, uc);
+							txt[6] = '\0';
+						}
+						else
+						{
+							uc -= 0x10000;
+							lc = uc & 0x3FF;
+							uc = uc >> 10;
+							uc |= 0xD800;
+							lc |= 0xDC00;
+							write_hex16(txt + 2, uc);
+							write_hex16(txt + 8, lc);
+							txt[12] = '\0';
+						}
+
+						appendStringInfoString(out, txt);
+						continue;		/* Skip backslash-encoding code below. */
+					}
+					endchar = '\0';
+				}
+		}
+
+		appendStringInfoChar(out, endchar ? '\\' : c);
+		if (endchar != '\0')
+			appendStringInfoChar(out, endchar);
+	}
+
+	appendStringInfoChar(out, quote);
+}
+
+static bool
+encode_number(StringInfo out, const char *string)
+{
+	const char *s = string;
+	const char *start,
+			   *end;
+
+	if (string == NULL)
+		return false;
+
+	/* Validate number, trimming whitespace. */
+	skip_whitespace(&s);
+	start = s;
+	if (!validate_number(&s))
+		return false;
+	end = s;
+	skip_whitespace(&s);
+	if (*s != '\0')
+		return false;
+
+	/* Append number to out */
+	appendBinaryStringInfo(out, start, end - start);
+
+	return true;
+}
+
+typedef struct
+{
+	StringInfoData str;
+	bool		use_orig;
+	bool		escape_unicode;
+	bool		trim;
+}	json_encode_ctx;
+
+static bool json_encode_recurse(JSON * node, json_encode_ctx * ctx);
+
+/*
+ * json_encode
+ *	  Encode a JSON node.
+ *
+ *	  The JSONOPT_ESCAPE_UNICODE option may only be used
+ *	  if the strings in the JSON tree are UTF-8-encoded.
+ */
+char *
+json_encode(JSON * node, int options)
+{
+	json_encode_ctx ctx;
+
+	initStringInfo(&ctx.str);
+	ctx.use_orig = !!(options & JSONOPT_USE_ORIG);
+	ctx.escape_unicode = !!(options & JSONOPT_ESCAPE_UNICODE);
+	ctx.trim = !(options & JSONOPT_NO_TRIM);
+
+	if (!json_encode_recurse(node, &ctx))
+	{
+		pfree(ctx.str.data);
+		return NULL;
+	}
+
+	return ctx.str.data;
+}
+
+static bool
+json_encode_recurse(JSON * node, json_encode_ctx * ctx)
+{
+#define has_orig(field) \
+		(use_orig && node->orig.field.start)
+#define push_orig(field) \
+		appendBinaryStringInfo(&ctx->str, node->orig.field.start, \
+							node->orig.field.end - node->orig.field.start)
+
+	bool		use_orig = ctx->use_orig;
+	bool		trim = ctx->trim;
+
+	ctx->trim = false;			/* Don't trim internal nodes, just the root
+								 * node. */
+
+	if (!trim && has_orig(left_space))
+		push_orig(left_space);
+
+	if (has_orig(value))
+	{
+		push_orig(value);
+	}
+	else
+	{
+		const char *txt = NULL;
+		JSON	   *child;
+
+		switch (node->type)
+		{
+			case JSON_NULL:
+				txt = "null";
+				break;
+			case JSON_BOOL:
+				if (node->v.v_bool)
+					txt = "true";
+				else
+					txt = "false";
+				break;
+			case JSON_STRING:
+				encode_string(&ctx->str,
+							  node->v.string.str, node->v.string.length,
+							  '"', ctx->escape_unicode);
+				break;
+			case JSON_NUMBER:
+				if (!encode_number(&ctx->str, node->v.number))
+					return false;
+				break;
+			case JSON_ARRAY:
+				appendStringInfoChar(&ctx->str, '[');
+
+				json_foreach(child, node)
+				{
+					json_encode_recurse(child, ctx);
+					if (child->next != NULL)
+						appendStringInfoChar(&ctx->str, ',');
+				}
+
+				appendStringInfoChar(&ctx->str, ']');
+				break;
+			case JSON_OBJECT:
+				appendStringInfoChar(&ctx->str, '{');
+
+				json_foreach(child, node)
+				{
+					/*
+					 * Shadows the parent node (assigned to the variable
+					 * @node) so we can use our macros on the child node
+					 * instead. Hurray for lexical scoping!
+					 */
+					JSON	   *node = child;
+
+					if (has_orig(key_left_space))
+						push_orig(key_left_space);
+
+					if (has_orig(key))
+						push_orig(key);
+					else
+						encode_string(&ctx->str, node->key, node->key_length,
+									  '"', ctx->escape_unicode);
+
+					if (has_orig(key_right_space))
+						push_orig(key_right_space);
+
+					appendStringInfoChar(&ctx->str, ':');
+
+					json_encode_recurse(node, ctx);
+
+					if (node->next != NULL)
+						appendStringInfoChar(&ctx->str, ',');
+				}
+
+				appendStringInfoChar(&ctx->str, '}');
+				break;
+			default:
+				return false;
+		}
+
+		if (txt != NULL)
+			appendStringInfoString(&ctx->str, txt);
+	}
+
+	if (!trim && has_orig(right_space))
+		push_orig(right_space);
+
+	return true;
+
+#undef has_orig
+#undef push_orig
+}
+
+/*
+ * json_encode_string
+ *	  If you're interested in encoding JSON in general, see json_encode .
+ *
+ *	  Encodes a string literal JSON-style using the given quote character.
+ *	  Note that using anything but '"' as the quote character will result
+ *	  in invalid JSON.
+ *
+ *	  If escape_unicode is true, str must be valid UTF-8.
+ *	  In any case, str may contain null characters (hence the length argument).
+ *
+ *	  quote must not be a backslash.
+ */
+char *
+json_encode_string(const char *str, size_t length, char quote,
+				   bool escape_unicode)
+{
+	StringInfoData ret;
+
+	initStringInfo(&ret);
+	encode_string(&ret, str, length, quote, escape_unicode);
+
+	return ret.data;
+}
diff --git a/contrib/json/json.h b/contrib/json/json.h
new file mode 100644
index 0000000..16654ed
--- /dev/null
+++ b/contrib/json/json.h
@@ -0,0 +1,220 @@
+/*-------------------------------------------------------------------------
+ *
+ * json.h
+ *	  Core JSON manipulation routines used by JSON data type support,
+ *	  along with miscellaneous declarations and includes.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef JSON_H
+#define JSON_H
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/htup.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "libpq/pqformat.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+#include "utils/typcache.h"
+
+typedef struct varlena jsontype;
+
+#define DatumGetJSONP(X)	((jsontype *) PG_DETOAST_DATUM(X))
+#define JSONPGetDatum(X)	PointerGetDatum(X)
+
+#define PG_GETARG_JSON_P(n) DatumGetJSONP(PG_GETARG_DATUM(n))
+#define PG_RETURN_JSON_P(x) PG_RETURN_POINTER(x)
+
+void		report_corrupt_json(void);
+
+/* Keep the order of these enum entries in sync with
+ * enum_type_names[] in json_ops.c . */
+typedef enum
+{
+	JSON_NULL,
+	JSON_STRING,
+	JSON_NUMBER,
+	JSON_BOOL,
+	JSON_OBJECT,
+	JSON_ARRAY,
+	JSON_TYPE_COUNT = JSON_ARRAY + 1,
+
+	JSON_INVALID
+}	json_type;
+
+#define json_type_is_valid(type) ((type) >= 0 && (type) < JSON_TYPE_COUNT)
+
+typedef struct JSON JSON;
+
+/*
+ * All strings in JSON nodes are UTF-8-encoded, not server encoded.
+ * The reason for this is because we need to encode/decode individual
+ * Unicode codepoints when dealing with escape characters, but there
+ * are no functions for efficiently converting between Unicode code points
+ * and any server encoding.
+ *
+ * As an exception to the rule, if you only use node factory functions and
+ * json_encode without the JSONOPT_ESCAPE_UNICODE option, you may operate
+ * in the server encoding instead.
+ */
+struct JSON
+{
+	json_type	type;
+
+	union
+	{
+		/* JSON_BOOL */
+		bool		v_bool;
+
+		/* JSON_STRING */
+		struct
+		{
+			char	   *str;
+			size_t		length;
+		}			string;
+
+		/*
+		 * JSON_NUMBER
+		 *
+		 * Numbers are encoded as strings to avoid unnecessary precision loss.
+		 */
+		char	   *number;
+
+		/* JSON_ARRAY or JSON_OBJECT (children) */
+		struct
+		{
+			JSON	   *head;
+			JSON	   *tail;
+			size_t		count;
+		}			children;
+	}			v;
+
+	JSON	   *parent;
+	JSON	   *prev;
+	JSON	   *next;
+
+	/*
+	 * If node is a member of an object, key will be set. Otherwise, key will
+	 * be null.
+	 */
+	char	   *key;
+	size_t		key_length;
+
+	struct json_orig
+	{
+		/* These only apply if this node is a member of an object. */
+		struct
+		{
+			const char *start;
+			const char *end;
+		}			key_left_space, key, key_right_space;
+
+		struct
+		{
+			const char *start;
+			const char *end;
+		}			left_space, value, right_space;
+	}			orig;
+
+	/* Used by jp_set to indicate we should not visit this node again. */
+	bool		jp_changed;
+};
+
+
+/*** Encoding / decoding / validation ***/
+
+bool		json_validate(const char *str);
+bool		json_validate_server_encoded(const char *str);
+JSON	   *json_decode(const char *str);
+
+#define JSONOPT_USE_ORIG		1
+#define JSONOPT_ESCAPE_UNICODE	2
+#define JSONOPT_NO_TRIM			4
+char	   *json_encode(JSON * node, int options);
+
+json_type	json_text_type(const char *str, size_t nbytes);
+
+
+/*** Lookup / traversal ***/
+
+#define json_foreach(child, parent) \
+	for ((child) = json_head(parent); (child) != NULL; (child) = (child)->next)
+
+static inline JSON *
+json_head(JSON * parent)
+{
+	switch (parent->type)
+	{
+		case JSON_ARRAY:
+		case JSON_OBJECT:
+			return parent->v.children.head;
+		default:
+			return NULL;
+	}
+}
+
+
+/*** Parent/child manipulation ***/
+
+void		json_append(JSON * parent, JSON * child);
+void		json_remove(JSON * node);
+
+
+/*** Node factory functions ***/
+
+JSON	   *json_mknode(json_type type);
+JSON	   *json_mkbool(bool v_bool);
+JSON	   *json_mkstring(const char *str, size_t length);
+JSON	   *json_mknumber(const char *number, size_t length);
+static inline JSON *
+json_mkarray(void)
+{
+	return json_mknode(JSON_ARRAY);
+}
+static inline JSON *
+json_mkobject(void)
+{
+	return json_mknode(JSON_OBJECT);
+}
+
+
+/*** Value get/set functions ***/
+
+void		json_touch_value(JSON * node);
+
+static inline bool
+json_get_bool(JSON * node)
+{
+	Assert(node->type == JSON_BOOL);
+	return node->v.v_bool;
+}
+static inline void
+json_set_bool(JSON * node, bool v_bool)
+{
+	Assert(node->type == JSON_BOOL);
+	node->v.v_bool = v_bool;
+	json_touch_value(node);
+}
+const char *json_get_string(JSON * node, size_t *length_out);
+void		json_set_string(JSON * node, const char *str, size_t length);
+const char *json_get_number(JSON * node);
+void		json_set_number(JSON * node, const char *number, size_t length);
+
+void		json_replace_value(JSON * node, JSON * replacement);
+
+
+/*** Miscellaneous utility functions ***/
+
+char	   *json_decode_string(const char **sp, size_t *length, bool strict);
+char	   *json_encode_string(const char *str, size_t length, char quote, bool escape_unicode);
+
+#endif
diff --git a/contrib/json/json.sql.in b/contrib/json/json.sql.in
new file mode 100644
index 0000000..7176e4b
--- /dev/null
+++ b/contrib/json/json.sql.in
@@ -0,0 +1,85 @@
+-- Adjust this setting to control where the objects get created.
+SET search_path = public;
+
+CREATE TYPE json;
+
+CREATE OR REPLACE FUNCTION json_in(cstring)
+RETURNS json
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_out(json)
+RETURNS cstring
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_recv(internal)
+RETURNS json
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_send(json)
+RETURNS bytea
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE TYPE json (
+	INPUT = json_in,
+	OUTPUT = json_out,
+	RECEIVE = json_recv,
+	SEND = json_send,
+	INTERNALLENGTH = VARIABLE,
+	STORAGE = extended,
+	
+	-- make it a non-preferred member of string type category, as citext does
+	CATEGORY       = 'S',
+	PREFERRED      = false
+);
+
+-- Keep the labels of this enum in sync with enum_type_names[] in json_ops.c .
+CREATE TYPE json_type_t AS ENUM ('null', 'string', 'number', 'bool', 'object', 'array');
+
+CREATE OR REPLACE FUNCTION json_type(json)
+RETURNS json_type_t
+AS 'MODULE_PATHNAME','json_get_type'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_validate(text)
+RETURNS boolean
+AS 'MODULE_PATHNAME','json_validate_f'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION from_json(json)
+RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION to_json(anyelement)
+RETURNS json
+AS 'MODULE_PATHNAME'
+LANGUAGE C IMMUTABLE; -- not STRICT; allows to_json(NULL) to return 'null'::json.
+
+CREATE OR REPLACE FUNCTION json_get(json, json_path text)
+RETURNS json
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_set(json, json_path text, json)
+RETURNS json
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_path(json, json_path text)
+RETURNS SETOF json
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION json_condense(json)
+RETURNS json
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
+
+CREATE OR REPLACE FUNCTION parse_json_path(text)
+RETURNS text
+AS 'MODULE_PATHNAME'
+LANGUAGE C STRICT IMMUTABLE;
diff --git a/contrib/json/json_io.c b/contrib/json/json_io.c
new file mode 100644
index 0000000..2510d49
--- /dev/null
+++ b/contrib/json/json_io.c
@@ -0,0 +1,465 @@
+/*-------------------------------------------------------------------------
+ *
+ * json_io.c
+ *	  Primary input/output and conversion procedures
+ *	  for JSON data type.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "json.h"
+#include "util.h"
+
+#include "utils/array.h"
+#include "mb/pg_wchar.h"
+
+PG_MODULE_MAGIC;
+
+static json_type decide_json_type(Oid type, char category);
+static const char *datum_to_json(Datum datum, TypeInfo *typeInfo,
+			  json_type target_type);
+static const char *array_to_json(Datum datum);
+static const char *build_array_string(const char **values,
+				   const int *dim, int ndim);
+static void build_array_string_recurse(StringInfo string, const char ***values,
+						   const int *dim, int ndim);
+
+void
+report_corrupt_json(void)
+{
+	ereport(ERROR,
+			(errcode(ERRCODE_DATA_CORRUPTED),
+			 errmsg("corrupt JSON content")));
+}
+
+PG_FUNCTION_INFO_V1(json_in);
+Datum		json_in(PG_FUNCTION_ARGS);
+Datum
+json_in(PG_FUNCTION_ARGS)
+{
+	char	   *string = PG_GETARG_CSTRING(0);
+	jsontype   *vardata;
+
+	if (!json_validate_server_encoded(string))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("could not parse JSON value")));
+
+	vardata = cstring_to_text(string);
+	PG_RETURN_JSON_P(vardata);
+}
+
+PG_FUNCTION_INFO_V1(json_out);
+Datum		json_out(PG_FUNCTION_ARGS);
+Datum
+json_out(PG_FUNCTION_ARGS)
+{
+	jsontype   *vardata = PG_GETARG_JSON_P(0);
+	char	   *string = text_to_cstring((text *) vardata);
+
+	Assert(json_validate_server_encoded(string));
+
+	PG_RETURN_CSTRING(string);
+}
+
+PG_FUNCTION_INFO_V1(json_recv);
+Datum		json_recv(PG_FUNCTION_ARGS);
+Datum
+json_recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	char	   *str;
+	int			nbytes;
+	jsontype   *result;
+
+	str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
+
+	if (!json_validate_server_encoded(str))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+				 errmsg("could not parse JSON value")));
+
+	result = cstring_to_text_with_len(str, nbytes);
+	pfree(str);
+
+	PG_RETURN_JSON_P(result);
+}
+
+PG_FUNCTION_INFO_V1(json_send);
+Datum		json_send(PG_FUNCTION_ARGS);
+Datum
+json_send(PG_FUNCTION_ARGS)
+{
+	jsontype   *t = PG_GETARG_JSON_P(0);
+	StringInfoData buf;
+
+#ifdef USE_ASSERT_CHECKING
+	{
+		char	   *string = text_to_cstring(t);
+
+		Assert(json_validate_server_encoded(string));
+
+		pfree(string);
+	}
+#endif
+
+	pq_begintypsend(&buf);
+	pq_sendtext(&buf, VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/*
+ * Performs JSON value extraction in UTF-8 C-String land.
+ *
+ * If the input was JSON-encoded NULL, this function returns NULL
+ * (indicating that we want from_json to yield actual SQL NULL).
+ */
+static const char *
+from_json_cstring(const char *input)
+{
+	size_t		len;
+	JSON	   *json = json_decode(input);
+	const char *cstring_out = NULL;
+
+	if (json == NULL)
+		report_corrupt_json();
+
+	switch (json->type)
+	{
+		case JSON_NULL:
+			cstring_out = NULL;
+			break;
+		case JSON_STRING:
+			cstring_out = json_get_string(json, &len);
+			if (strlen(cstring_out) != len)
+				ereport(ERROR,
+						(errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
+						 errmsg("could not convert JSON-encoded string to TEXT: contains \\u0000"),
+						 errdetail("the string was: %s", utf8_to_server(input, strlen(input)))));
+
+			/*
+			 * todo: suggest using from_json_as_bytea instead when that is
+			 * available.
+			 */
+			break;
+		case JSON_NUMBER:
+			cstring_out = json_get_number(json);
+			break;
+		case JSON_BOOL:
+			cstring_out = json_get_bool(json) ? "true" : "false";
+			break;
+		case JSON_OBJECT:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("from_json cannot be applied to JSON objects")));
+			break;
+		case JSON_ARRAY:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("from_json cannot be applied to JSON arrays")));
+			break;
+		default:
+			Assert(false);
+	}
+
+	return cstring_out;
+}
+
+PG_FUNCTION_INFO_V1(from_json);
+Datum		from_json(PG_FUNCTION_ARGS);
+Datum
+from_json(PG_FUNCTION_ARGS)
+{
+	char	   *cstring_in = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	const char *cstring_out = from_json_cstring(cstring_in);
+	text	   *vardata_out;
+
+	pfree(cstring_in);
+
+	if (cstring_out != NULL)
+	{
+		vardata_out = utf8_cstring_to_text(cstring_out);
+		PG_RETURN_TEXT_P(vardata_out);
+	}
+	else
+	{
+		PG_RETURN_NULL();
+	}
+}
+
+PG_FUNCTION_INFO_V1(to_json);
+Datum		to_json(PG_FUNCTION_ARGS);
+Datum
+to_json(PG_FUNCTION_ARGS)
+{
+	Oid			argtype = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	TypeInfo   *typeInfo;
+	json_type	target_type;
+
+	typeInfo = FN_EXTRA();
+	if (typeInfo == NULL)
+	{
+		typeInfo = FN_EXTRA_ALLOC(sizeof(TypeInfo));
+		getTypeInfo(typeInfo, argtype, IOFunc_output, FN_MCXT());
+	}
+	else if (typeInfo->type != argtype)
+	{
+		getTypeInfo(typeInfo, argtype, IOFunc_output, FN_MCXT());
+	}
+
+	target_type = decide_json_type(argtype, typeInfo->typcategory);
+
+	/*
+	 * If NULL argument is given, return the string "null", not actual NULL.
+	 * The null check is done after the type check so users can identify type
+	 * bugs earlier.
+	 */
+	if (PG_ARGISNULL(0))
+		PG_RETURN_JSON_P(cstring_to_text("null"));
+
+	PG_RETURN_JSON_P(utf8_cstring_to_text(
+				  datum_to_json(PG_GETARG_DATUM(0), typeInfo, target_type)));
+}
+
+/*
+ * decide_json_type
+ *
+ * Given a type and its corresponding typcategory, determine what
+ * JSON type to encode it to.  If it's not possible to encode the type
+ * (or if support for the type isn't implemented yet), report an error.
+ */
+static json_type
+decide_json_type(Oid type, char category)
+{
+	switch (category)
+	{
+		case 'S':
+			return JSON_STRING;
+		case 'P':
+			if (type == CSTRINGOID)
+				return JSON_STRING;
+			goto invalid;
+		case 'N':
+			if (type == CASHOID)
+				goto invalid;
+			return JSON_NUMBER;
+		case 'B':
+			if (type == BOOLOID)
+				return JSON_BOOL;
+			goto invalid;
+		case 'A':
+			return JSON_ARRAY;
+		default:
+			goto invalid;
+	}
+
+invalid:
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+		 errmsg("to_json cannot convert %s to JSON", format_type_be(type))));
+	return JSON_INVALID;
+}
+
+/*
+ * datum_to_json
+ *	  Converts a datum to a UTF-8-encoded JSON string.
+ *
+ *	  typeInfo comes from the getTypeInfo function, and
+ *	  target_type comes from decide_json_type .
+ *
+ *	  See to_json and array_to_json for examples of
+ *	  how to invoke this function.
+ */
+static const char *
+datum_to_json(Datum datum, TypeInfo *typeInfo, json_type target_type)
+{
+	char	   *cstring;
+	char	   *cstring_utf8;
+	JSON	   *node;
+	char	   *encoded_utf8;
+
+	switch (target_type)
+	{
+		case JSON_STRING:
+		case JSON_NUMBER:
+			cstring = OutputFunctionCall(&typeInfo->proc, datum);
+			cstring_utf8 = server_to_utf8(cstring, strlen(cstring));
+
+			if (cstring != cstring_utf8)
+				pfree(cstring);
+
+			if (target_type == JSON_STRING)
+				node = json_mkstring(cstring_utf8, strlen(cstring_utf8));
+			else
+				node = json_mknumber(cstring_utf8, strlen(cstring_utf8));
+
+			encoded_utf8 = json_encode(node, 0);
+			if (encoded_utf8 == NULL)
+			{
+				/*
+				 * Currently, we assume that output conversion for all types
+				 * in category 'N' (excluding CASH) will, by coincidence,
+				 * always give a valid JSON-encoded number.
+				 *
+				 * If this error message appears, it means the assumption is
+				 * incorrect, and we need to either blacklist the type in
+				 * decide_json_type (like we did with CASH), or add code that
+				 * can parse the number type.
+				 */
+				ereport(ERROR,
+						(errcode(ERRCODE_INTERNAL_ERROR),
+						 errmsg("to_json failed to convert %s \"%s\" to a valid JSON %s.\n",
+								format_type_be(typeInfo->type),
+								cstring,
+						 target_type == JSON_STRING ? "string" : "number")));
+			}
+
+			return encoded_utf8;
+
+		case JSON_BOOL:
+			return DatumGetBool(datum) ? "true" : "false";
+
+		case JSON_ARRAY:
+			return array_to_json(datum);
+
+		default:
+			Assert(false);
+			return NULL;
+	}
+}
+
+/*
+ * array_to_json
+ *	  Converts a PostgreSQL array datum to a UTF-8-encoded JSON string.
+ *
+ *	  Note: We assume that any type with typcategory = 'A'
+ *			is compatible with array_out.
+ */
+static const char *
+array_to_json(Datum datum)
+{
+	ArrayType  *v = DatumGetArrayTypeP(datum);
+	Oid			element_type = ARR_ELEMTYPE(v);
+	TypeInfo	element_typeinfo;
+	json_type	target_type;
+	int		   *dim;
+	int			ndim;
+	int			nitems;
+	int			i;
+	char	   *s;
+	bits8	   *bitmap;
+	int			bitmask;
+	Datum		elt;
+	const char **values;
+	const char *ret;
+
+	/*
+	 * todo: Consider caching the TypeInfo of array items (which we're
+	 * computing now) in the fcinfo->flinfo->fn_mcxt of to_json like we do
+	 * with the TypeInfo of the array itself.
+	 */
+	getTypeInfo(&element_typeinfo, element_type, IOFunc_output, CurrentMemoryContext);
+
+	target_type = decide_json_type(element_type, element_typeinfo.typcategory);
+
+	ndim = ARR_NDIM(v);
+	dim = ARR_DIMS(v);
+	nitems = ArrayGetNItems(ndim, dim);
+
+	/*
+	 * Unfortunately, we can't make SELECT
+	 * to_json(ARRAY[[],[],[]]::integer[][]); yield '[[],[],[]]' because ndim
+	 * is set to 0 when the array has no items.
+	 */
+	if (nitems <= 0)
+		return "[]";
+
+	values = palloc(nitems * sizeof(const char *));
+
+	s = ARR_DATA_PTR(v);
+	bitmap = ARR_NULLBITMAP(v);
+	bitmask = 1;
+
+	for (i = 0; i < nitems; i++)
+	{
+		if (bitmap != NULL && (*bitmap & bitmask) == 0)
+		{
+			values[i] = NULL;
+		}
+		else
+		{
+			elt = fetch_att(s, element_typeinfo.typbyval, element_typeinfo.typlen);
+			s = att_addlength_datum(s, element_typeinfo.typlen, elt);
+			s = (char *) att_align_nominal(s, element_typeinfo.typalign);
+
+			values[i] = datum_to_json(elt, &element_typeinfo, target_type);
+		}
+
+		if (bitmap != NULL)
+		{
+			bitmask <<= 1;
+			if (bitmask == 0x100)
+			{
+				bitmap++;
+				bitmask = 1;
+			}
+		}
+	}
+
+	ret = build_array_string(values, dim, ndim);
+
+	pfree(values);
+
+	return ret;
+}
+
+/*
+ * build_array_string
+ *	  Takes a multidimensional array of (JSON-formatted) strings and
+ *	  converts it to JSON by wrapping the strings in array brackets and commas.
+ */
+static const char *
+build_array_string(const char **values, const int *dim, int ndim)
+{
+	StringInfoData string[1];
+
+	initStringInfo(string);
+	build_array_string_recurse(string, &values, dim, ndim);
+
+	return string->data;
+}
+
+static void
+build_array_string_recurse(StringInfo string, const char ***values,
+						   const int *dim, int ndim)
+{
+	int			i,
+				count = dim[0];
+
+	appendStringInfoChar(string, '[');
+
+	for (i = 0; i < count; i++)
+	{
+		if (ndim > 1)
+		{
+			build_array_string_recurse(string, values, dim + 1, ndim - 1);
+		}
+		else
+		{
+			const char *value = *(*values)++;
+
+			if (value != NULL)
+				appendStringInfoString(string, value);
+			else
+				appendStringInfoString(string, "null");
+		}
+
+		if (i + 1 < count)
+			appendStringInfoChar(string, ',');
+	}
+
+	appendStringInfoChar(string, ']');
+}
diff --git a/contrib/json/json_op.c b/contrib/json/json_op.c
new file mode 100644
index 0000000..f0a3ed2
--- /dev/null
+++ b/contrib/json/json_op.c
@@ -0,0 +1,253 @@
+/*-------------------------------------------------------------------------
+ *
+ * json_op.c
+ *	  Manipulation procedures for JSON data type.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "json.h"
+#include "jsonpath.h"
+#include "util.h"
+
+static EnumLabel enum_labels[JSON_TYPE_COUNT] =
+{
+	{JSON_NULL, "null"},
+	{JSON_STRING, "string"},
+	{JSON_NUMBER, "number"},
+	{JSON_BOOL, "bool"},
+	{JSON_OBJECT, "object"},
+	{JSON_ARRAY, "array"}
+};
+
+/* json_validate(text).  Renamed to avoid clashing
+ * with the C function json_validate. */
+PG_FUNCTION_INFO_V1(json_validate_f);
+Datum		json_validate_f(PG_FUNCTION_ARGS);
+Datum
+json_validate_f(PG_FUNCTION_ARGS)
+{
+	char	   *string;
+	bool		ret;
+
+	string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	ret = json_validate(string);
+	pfree(string);
+
+	PG_RETURN_BOOL(ret);
+}
+
+/* json_type(json).  Renamed to avoid clashing
+ * with the typedef enum of the same name. */
+PG_FUNCTION_INFO_V1(json_get_type);
+Datum		json_get_type(PG_FUNCTION_ARGS);
+Datum
+json_get_type(PG_FUNCTION_ARGS)
+{
+	jsontype   *t = PG_GETARG_JSON_P(0);
+	json_type	type;
+	Oid		   *label_oids;
+
+	/*
+	 * No need to convert to UTF-8 before calling json_text_type, as it looks
+	 * solely at ASCII characters.
+	 */
+	type = json_text_type(VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
+
+	if (!json_type_is_valid(type))
+		report_corrupt_json();
+
+	label_oids = FN_EXTRA();
+	if (label_oids == NULL)
+	{
+		label_oids = FN_EXTRA_ALLOC(JSON_TYPE_COUNT * sizeof(Oid));
+		getEnumLabelOids("json_type_t", enum_labels, label_oids, JSON_TYPE_COUNT);
+	}
+
+	PG_RETURN_OID(label_oids[type]);
+}
+
+PG_FUNCTION_INFO_V1(json_condense);
+Datum		json_condense(PG_FUNCTION_ARGS);
+Datum
+json_condense(PG_FUNCTION_ARGS)
+{
+	char	   *string;
+	JSON	   *json;
+	char	   *condensed;
+
+	string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	json = json_decode(string);
+	condensed = json_encode(json, 0);
+
+	if (condensed == NULL)
+		report_corrupt_json();
+
+	PG_RETURN_JSON_P(utf8_cstring_to_text(condensed));
+}
+
+/*
+ * json_path_base
+ *	  Given the function call info of a PostgreSQL function
+ *	  with arguments (JSON, jsonpath TEXT [, ...]),
+ *	  match the JSONPath string given in the second argument
+ *	  against the JSON tree given in the first argument.
+ *
+ *	  This returns a List of JPRef* items, just like jp_match.
+ *	  jpref_encode() is used to convert them to JSON-formatted strings.
+ */
+static List *
+json_path_base(FunctionCallInfo fcinfo)
+{
+	char	   *json_string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	char	   *path_string = text_to_utf8_cstring(PG_GETARG_TEXT_PP(1));
+	JSONPath   *jpath = jp_parse(path_string);
+	JSON	   *json = json_decode(json_string);
+	List	   *result_list;
+
+	if (jpath == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid JSONPath expression")));
+	if (json == NULL)
+		report_corrupt_json();
+
+	result_list = jp_match(jpath, json);
+
+	return result_list;
+}
+
+PG_FUNCTION_INFO_V1(json_get);
+Datum		json_get(PG_FUNCTION_ARGS);
+Datum
+json_get(PG_FUNCTION_ARGS)
+{
+	List	   *result_list = json_path_base(fcinfo);
+	ListCell   *result;
+	char	   *rs_json;
+	jsontype   *result_vardata;
+	int			length = list_length(result_list);
+
+	if (length == 0)
+	{
+		PG_RETURN_NULL();
+	}
+	else if (length == 1)
+	{
+		result = list_head(result_list);
+		rs_json = jpref_encode(lfirst(result));
+
+		Assert(rs_json != NULL);
+		Assert(json_validate(rs_json) == true);
+
+		result_vardata = (jsontype *) utf8_cstring_to_text(rs_json);
+
+		pfree(rs_json);
+
+		PG_RETURN_JSON_P(result_vardata);
+	}
+	else
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("JSONPath expression matched multiple results")));
+		PG_RETURN_NULL();
+	}
+}
+
+PG_FUNCTION_INFO_V1(json_set);
+Datum		json_set(PG_FUNCTION_ARGS);
+Datum
+json_set(PG_FUNCTION_ARGS)
+{
+	char	   *json_string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	char	   *path_string = text_to_utf8_cstring(PG_GETARG_TEXT_PP(1));
+	char	   *rvalue_string = text_to_utf8_cstring(PG_GETARG_JSON_P(2));
+	JSONPath   *jpath = jp_parse(path_string);
+	JSON	   *json = json_decode(json_string);
+	JSON	   *rvalue = json_decode(rvalue_string);
+	char	   *result;
+	jsontype   *result_text;
+
+	if (jpath == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid JSONPath expression")));
+
+	if (json == NULL || rvalue == NULL)
+		report_corrupt_json();
+
+	jp_set(jpath, json, rvalue);
+
+	result = json_encode(json, JSONOPT_USE_ORIG | JSONOPT_NO_TRIM);
+	result_text = utf8_cstring_to_text(result);
+
+	pfree(result);
+
+	PG_RETURN_JSON_P(result_text);
+}
+
+PG_FUNCTION_INFO_V1(json_path);
+Datum		json_path(PG_FUNCTION_ARGS);
+Datum
+json_path(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	ListCell   *result;
+
+	/* TODO: consider returning the entire result set in one call. */
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		MemoryContext oldcontext;
+		List	   *results;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		results = json_path_base(fcinfo);
+		funcctx->user_fctx = list_head(results);
+
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	result = funcctx->user_fctx;
+
+	if (result != NULL)
+	{
+		char	   *json_string;
+		jsontype   *json_text;
+
+		json_string = jpref_encode(lfirst(result));
+		Assert(json_string != NULL);
+		Assert(json_validate(json_string) == true);
+
+		json_text = utf8_cstring_to_text(json_string);
+
+		funcctx->user_fctx = lnext(result);
+
+		SRF_RETURN_NEXT(funcctx, JSONPGetDatum(json_text));
+	}
+
+	SRF_RETURN_DONE(funcctx);
+}
+
+PG_FUNCTION_INFO_V1(parse_json_path);
+Datum		parse_json_path(PG_FUNCTION_ARGS);
+Datum
+parse_json_path(PG_FUNCTION_ARGS)
+{
+	char	   *string = text_to_utf8_cstring(PG_GETARG_TEXT_PP(0));
+	JSONPath   *jpath = jp_parse(string);
+	char	   *normalized;
+
+	if (jpath == NULL)
+		PG_RETURN_NULL();
+
+	normalized = jp_show(jpath);
+	PG_RETURN_TEXT_P(utf8_cstring_to_text(normalized));
+}
diff --git a/contrib/json/jsonpath.c b/contrib/json/jsonpath.c
new file mode 100644
index 0000000..edfa6e8
--- /dev/null
+++ b/contrib/json/jsonpath.c
@@ -0,0 +1,596 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonpath.c
+ *	  JSONPath implementation routines for JSON data type support.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "jsonpath.h"
+#include "util.h"
+
+#include <ctype.h>
+
+/* NB: These macros evaluate their argument multiple times. */
+
+#define isletter(c) (((c) >= 'A' && (c) <= 'Z') || ((c) >= 'a' && (c) <= 'z'))
+ /* isalpha() is locale-specific.  This simply matches [A-Za-z] . */
+#define isextended(c) ((unsigned char)(c) > 127)
+
+/* Note that Unicode characters are allowed in identifiers. */
+#define identifier_start(c) (isletter(c) || (c) == '_' || (c) == '$' || isextended(c))
+#define identifier_char(c) (identifier_start(c) || isdigit(c))
+
+#define integer_start(c) (isdigit(c) || (c) == '+' || (c) == '-')
+
+/*
+ * In a valid JSONPath list, the first element is always of type JP_ROOT.
+ * This element is used so an otherwise empty JSONPath list won't be NULL.
+ * This allows us to use NULL to indicate an invalid JSONPath.
+ *
+ * This function returns the first cell,
+ * making sure it is of type JP_ROOT.
+ */
+static ListCell *
+jp_root(JSONPath * jp)
+{
+	ListCell   *cell;
+	jp_element *elem;
+
+	Assert(jp != NULL);
+
+	cell = list_head(jp);
+	elem = lfirst(cell);
+	Assert(elem->type == JP_ROOT);
+
+	return cell;
+}
+
+/*
+ * This function returns the second cell of a JSONPath list
+ * (the first cell after the JP_ROOT).
+ */
+static ListCell *
+jp_head(JSONPath * jp)
+{
+	return lnext(jp_root(jp));
+}
+
+/*
+ * Note that skip_spaces differs from skip_whitespace in json.c
+ * in that this function treats '\f' and '\v' as whitespace.
+ * This is because JSON does not accept these characters as
+ * whitespace, but since this is JSONPath,
+ * we can do whatever we want here :-)
+ */
+static void
+skip_spaces(const char **sp)
+{
+	const char *s = *sp;
+
+	while (isspace(*s))
+		s++;
+	*sp = s;
+}
+
+static jp_element *
+mkElement(jp_element_type type, bool rd)
+{
+	jp_element *elem = palloc0(sizeof(*elem));
+
+	elem->type = type;
+	elem->recursive_descent = rd;
+	return elem;
+}
+
+static jp_element *
+mkRoot(void)
+{
+	jp_element *elem = mkElement(JP_ROOT, false);
+
+	return elem;
+}
+
+static jp_element *
+mkWildcard(bool rd)
+{
+	jp_element *elem = mkElement(JP_WILDCARD, rd);
+
+	return elem;
+}
+
+static jp_element *
+mkIndexSubscript(long index, bool rd)
+{
+	jp_element *elem = mkElement(JP_INDEX_SUBSCRIPT, rd);
+
+	elem->data.index = index;
+	return elem;
+}
+
+static jp_element *
+mkKeySubscript(char *key, size_t length, bool rd)
+{
+	jp_element *elem = mkElement(JP_KEY_SUBSCRIPT, rd);
+
+	elem->data.key.ptr = key;
+	elem->data.key.length = length;
+	return elem;
+}
+
+static jp_element *
+mkCallChar(long index, bool rd)
+{
+	jp_element *elem = mkElement(JP_CALL_CHAR, rd);
+
+	elem->data.index = index;
+	return elem;
+}
+
+static JPRef *
+mkRef(JPRefType type)
+{
+	JPRef	   *ref = palloc0(sizeof(*ref));
+
+	ref->type = type;
+	return ref;
+}
+
+static JPRef *
+mkRefNode(JSON * node)
+{
+	JPRef	   *ref = mkRef(JP_REF_NODE);
+
+	ref->u.node = node;
+	return ref;
+}
+
+static JPRef *
+mkRefChar(const char *bytes, size_t length)
+{
+	JPRef	   *ref = mkRef(JP_REF_CHAR);
+	ref->u.chr. bytes = bytes;
+	ref->u.chr. length = length;
+
+	return ref;
+}
+
+/*
+ * jp_show
+ *	  Unparse a JSONPath expression.  This is used by parse_json_path
+ *	  to stringify successfully parsed JSONPaths.
+ */
+char *
+jp_show(JSONPath * jp)
+{
+	StringInfoData string[1];
+	ListCell   *cell;
+	jp_element *elem;
+	bool		rd;
+	char	   *tmp;
+
+	initStringInfo(string);
+
+	foreach(cell, jp)
+	{
+		elem = lfirst(cell);
+		rd = elem->recursive_descent;
+
+		switch (elem->type)
+		{
+			case JP_ROOT:
+				appendStringInfoChar(string, '$');
+				break;
+			case JP_WILDCARD:
+				appendStringInfoString(string, rd ? "..[*]" : "[*]");
+				break;
+			case JP_INDEX_SUBSCRIPT:
+				appendStringInfo(string, "%s[%ld]", rd ? ".." : "", elem->data.index);
+				break;
+			case JP_KEY_SUBSCRIPT:
+				tmp = json_encode_string(elem->data.key.ptr, elem->data.key.length, '"', false);
+				appendStringInfo(string, "%s[%s]", rd ? ".." : "", tmp);
+				pfree(tmp);
+				break;
+			case JP_CALL_CHAR:
+				appendStringInfo(string, "%s(%ld)", rd ? "..char" : ".char", elem->data.index);
+				break;
+			default:
+				Assert(false);
+		}
+	}
+
+	return string->data;
+}
+
+/*
+ * Parse a long starting at *s .
+ *
+ * On success, return true and update *s to point to the end of the number.
+ * On failure, return false and leave *s untouched.
+ */
+static bool
+parse_long(const char **s, long *out)
+{
+	const char *p = *s;
+
+	errno = 0;
+	*out = strtol(*s, (char **) &p, 10);
+	if (p <= *s || errno != 0)
+		return false;
+
+	*s = p;
+	return true;
+}
+
+/*
+ * jp_parse
+ *	  Parse a JSONPath expression (into a List of jp_element items).
+ *
+ *	  TODO: Get rid of all those gotos.  The parser uses constant space,
+ *			so there's no chance of a stack overflow anyway.
+ */
+JSONPath *
+jp_parse(const char *pattern)
+{
+	JSONPath   *jp = NIL;
+	const char *s = pattern;
+	const char *start;
+	const char *end;
+	bool		recursive_descent = false;
+	bool		bracket = false;
+	const char *err_msg = NULL;
+	long		index;
+	char	   *key;
+	size_t		key_length;
+
+	skip_spaces(&s);
+
+	/* pattern may not be empty */
+	if (*s == '\0')
+		return NULL;
+
+	jp = lappend(jp, mkRoot());
+
+	if (*s == '$')
+	{
+		s++;
+		goto begin_element;
+	}
+	else if (*s != '.')
+	{
+		goto dot_subscript;
+		/* implicit '.' at beginning */
+	}
+
+begin_element:
+	skip_spaces(&s);
+begin_element_noskip:
+
+	recursive_descent = false;
+	bracket = false;
+
+	if (*s == '\0')
+		goto end;
+	if (s[0] == '.' && s[1] == '.')
+	{
+		recursive_descent = true;
+		s += 2;
+		goto dot_subscript;
+	}
+	if (s[0] == '.')
+	{
+		s++;
+		goto dot_subscript;
+	}
+	if (s[0] == '[')
+	{
+		s++;
+		goto bracket_subscript;
+	}
+
+	goto failed;
+
+next_element:
+	if (bracket)
+	{
+		skip_spaces(&s);
+		if (*s != ']')
+			goto failed;
+		s++;
+	}
+	goto begin_element;
+
+dot_subscript:
+	skip_spaces(&s);
+
+	if (*s == '*')
+		goto wildcard;
+	if (integer_start(*s))
+		goto integer;
+	if (identifier_start(*s))
+		goto identifier;
+	if (*s == '"' || *s == '\'')
+		goto string;
+	if (*s == '[')
+	{
+		s++;
+		goto bracket_subscript;
+	}
+
+	goto failed;
+
+bracket_subscript:
+	skip_spaces(&s);
+
+	bracket = true;
+
+	if (*s == '*')
+		goto wildcard;
+	if (integer_start(*s))
+		goto integer;
+	if (identifier_start(*s))
+	{
+		err_msg = "Identifiers may not be bracketed.  This syntax is reserved for future use.";
+		goto failed;
+	}
+	if (*s == '"' || *s == '\'')
+		goto string;
+
+	goto failed;
+
+wildcard:
+	s++;
+	jp = lappend(jp, mkWildcard(recursive_descent));
+	goto next_element;
+
+integer:
+	if (!parse_long(&s, &index))
+		goto failed;
+
+	jp = lappend(jp, mkIndexSubscript(index, recursive_descent));
+	goto next_element;
+
+identifier:
+	start = s;
+	while (identifier_char(*s))
+		s++;
+	end = s;
+
+	skip_spaces(&s);
+
+	if (*s == '(')
+	{
+		if (end - start == 4 && memcmp(start, "char", 4) == 0)
+		{
+			s++;
+			skip_spaces(&s);
+			goto call_char;
+		}
+
+		goto failed;
+	}
+
+	key = pnstrdup(start, end - start);
+	key_length = end - start;
+
+	jp = lappend(jp, mkKeySubscript(key, key_length, recursive_descent));
+	goto begin_element_noskip;
+
+string:
+	key = json_decode_string(&s, &key_length, false);
+	if (key == NULL)
+		goto failed;
+
+	jp = lappend(jp, mkKeySubscript(key, key_length, recursive_descent));
+	goto next_element;
+
+call_char:
+	if (!parse_long(&s, &index))
+		goto failed;
+
+	skip_spaces(&s);
+
+	if (*s++ != ')')
+		goto failed;
+
+	jp = lappend(jp, mkCallChar(index, recursive_descent));
+	goto begin_element;
+
+end:
+	return jp;
+
+failed:
+	return NULL;
+}
+
+/*
+ * Currently, a lot of JPRef nodes are allocated just to pass JSON pointers
+ * to match_recurse.  If this becomes a memory/performance issue in the future,
+ * JPRef could merged with JSON by adding JPRef's specialty types to the
+ * json_type enum and JSON union.	JPRef is currently not merged with
+ * JSON in an attempt to keep the codebase tidy and easier to extend.
+ */
+static void match_recurse(void on_match(void *ctx, JPRef * ref), void *ctx,
+									  ListCell *path, JPRef * ref)
+{
+	jp_element *elem;
+	JSON	   *json,
+			   *child;
+
+	if (path == NULL)
+	{
+		/* The end of the JSONPath list is the "accept" state. */
+		on_match(ctx, ref);
+		return;
+	}
+
+	elem = lfirst(path);
+
+	if (ref->type == JP_REF_NODE)
+		json = ref->u.node;
+	else
+		json = NULL;
+
+	switch (elem->type)
+	{
+		case JP_WILDCARD:
+			if (json != NULL)
+			{
+				json_foreach(child, json)
+					match_recurse(on_match, ctx, lnext(path), mkRefNode(child));
+			}
+			break;
+
+		case JP_INDEX_SUBSCRIPT:
+			if (json != NULL && json->type == JSON_ARRAY &&
+				elem->data.index >= 0 &&
+				(size_t) elem->data.index < json->v.children.count)
+			{
+				size_t		i;
+
+				for (child = json->v.children.head, i = 0;
+					 child != NULL && i < (size_t) elem->data.index;
+					 child = child->next, i++)
+				{
+				}
+
+				/*
+				 * If this fails, it means json->v.children.count was greater
+				 * than the actual number of children.
+				 */
+				Assert(i == elem->data.index && child != NULL);
+
+				match_recurse(on_match, ctx, lnext(path), mkRefNode(child));
+			}
+			break;
+
+		case JP_KEY_SUBSCRIPT:
+			if (json != NULL && json->type == JSON_OBJECT)
+			{
+				json_foreach(child, json)
+				{
+					if (child->key != NULL &&
+						child->key_length == elem->data.key.length &&
+						memcmp(child->key, elem->data.key.ptr, child->key_length) == 0)
+					{
+						match_recurse(on_match, ctx, lnext(path), mkRefNode(child));
+					}
+				}
+			}
+			break;
+
+		case JP_CALL_CHAR:
+			if (json != NULL && json->type == JSON_STRING &&
+				elem->data.index >= 0)
+			{
+				const char *sub_start;
+				size_t		sub_bytes;
+				size_t		sub_length;
+
+				sub_length = utf8_substring(
+								   json->v.string.str, json->v.string.length,
+											elem->data.index, 1,
+											&sub_start, &sub_bytes);
+
+				if (sub_length == 1)
+					match_recurse(on_match, ctx, lnext(path), mkRefChar(sub_start, sub_bytes));
+			}
+			else if (ref->type == JP_REF_CHAR && elem->data.index == 0)
+			{
+				/* char(0) on a character yields itself. */
+				match_recurse(on_match, ctx, lnext(path), ref);
+			}
+			break;
+
+		default:;
+	}
+
+	if (elem->recursive_descent && json != NULL)
+	{
+		json_foreach(child, json)
+		{
+			if (!child->jp_changed)
+				match_recurse(on_match, ctx, path, mkRefNode(child));
+		}
+	}
+}
+
+static void
+jp_match_callback(List **results, JPRef * ref)
+{
+	*results = lappend(*results, ref);
+}
+
+/*
+ * jp_match
+ *	  Match a parsed JSONPath expression against a JSON tree,
+ *	  yielding a List of JPRef* items.
+ *
+ *	  To convert the JPRef* items to JSON-formatted strings, use jpref_encode.
+ */
+List *
+jp_match(JSONPath * jp, JSON * json)
+{
+	ListCell   *lc = jp_head(jp);
+	List	   *results = NIL;
+
+	match_recurse((void *) jp_match_callback, &results, lc, mkRefNode(json));
+
+	return results;
+}
+
+static void
+jp_set_callback(JSON * value, JPRef * ref)
+{
+	switch (ref->type)
+	{
+		case JP_REF_NODE:
+			json_replace_value(ref->u.node, value);
+			ref->u.node->jp_changed = true;
+			break;
+
+		default:;				/* Do nothing if ref is immutable. */
+	}
+}
+
+/*
+ * jp_set
+ *	  Set all elements that match a parsed JSONPath expression
+ *	  in a JSON tree to a new value.
+ *
+ *	  Note that jp_set uses json_replace_value so it doesn't have to deep-copy
+ *	  on every assignment if @value is a tree.	This means that parent pointers
+ *	  of the resulting tree will not be trustworthy.
+ */
+void
+jp_set(JSONPath * jp, JSON * json, JSON * value)
+{
+	ListCell   *lc = jp_head(jp);
+
+	match_recurse((void *) jp_set_callback, value, lc, mkRefNode(json));
+}
+
+/*
+ * jpref_encode
+ *	  Convert a JPRef to a JSON-formatted string.
+ */
+char *
+jpref_encode(JPRef * ref)
+{
+	switch (ref->type)
+	{
+		case JP_REF_NODE:
+			return json_encode(ref->u.node, JSONOPT_USE_ORIG);
+
+		case JP_REF_CHAR:
+			return json_encode_string(ref->u.chr.bytes, ref->u.chr.length, '"', false);
+
+		default:
+			Assert(false);
+			return NULL;
+	}
+}
diff --git a/contrib/json/jsonpath.h b/contrib/json/jsonpath.h
new file mode 100644
index 0000000..4be498d
--- /dev/null
+++ b/contrib/json/jsonpath.h
@@ -0,0 +1,103 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonpath.h
+ *	  JSONPath implementation routines for JSON data type support.
+ *
+ *	  The "JSONPath" implemented here is similar to, but not exactly the same as,
+ *	  the JSONPath described at http://goessner.net/articles/JsonPath/ .
+ *	  The main differences are stronger subscripting rules, special methods
+ *	  via function-call notation (currently, the only one provided is .char()),
+ *	  and that the '$' at the beginning of a JSONPath expression is optional.
+ *	  Also, array indices as a set (e.g. [0,1]) and filters/scripts are currently
+ *	  not implemented.	Array indices are a planned feature.  True filters
+ *	  would require an honest-to-goodness JavaScript engine, so perhaps
+ *	  someone will write a module for that in the future.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef JSONPATH_H
+#define JSONPATH_H
+
+#include "json.h"
+
+#include "nodes/pg_list.h"
+
+typedef enum
+{
+	JP_ROOT,
+	JP_WILDCARD,
+	JP_INDEX_SUBSCRIPT,
+	JP_KEY_SUBSCRIPT,
+	JP_CALL_CHAR
+}	jp_element_type;
+
+/*
+ * A jp_element is a single piece of a JSONPath expression
+ * (e.g. [3], .foo, .char(3), ..*).  It represents subscripting
+ * down one level in a JSON tree, or invoking a special method
+ * (like .char() ).  However, if recursive_descent is set to true,
+ * the subscript applies to a value and all of its descendants.
+ */
+typedef struct
+{
+	jp_element_type type;
+
+	union
+	{
+		long		index;
+		struct
+		{
+			char	   *ptr;
+			size_t		length;
+		}			key;
+	}			data;
+
+	/* If element was preceded by ".." in pattern */
+	bool		recursive_descent;
+}	jp_element;
+
+typedef enum
+{
+	JP_REF_NODE,
+	JP_REF_CHAR
+}	JPRefType;
+
+/*
+ * A JPRef is a reference to some part of a JSON tree,
+ * typically a value (but not always).
+ *
+ * JPRef* is really a "subclass" of JSON* .  In the future, this structure
+ * will likely be merged into the JSON structure to improve performance.
+ */
+typedef struct
+{
+	JPRefType	type;
+
+	union
+	{
+		JSON	   *node;
+
+		struct
+		{
+			const char *bytes;
+			size_t		length;
+		} chr;
+	}			u;
+}	JPRef;
+
+typedef List /* jp_element* */ JSONPath;
+
+JSONPath   *jp_parse(const char *pattern);
+char	   *jp_show(JSONPath * jp);
+
+List /* JPRef* */ *jp_match(JSONPath * jp, JSON * json);
+void		jp_set(JSONPath * jp, JSON * json, JSON * value);
+
+/* Returns the JSON encoding of the given reference. */
+char	   *jpref_encode(JPRef * ref);
+
+#endif
diff --git a/contrib/json/sql/array_to_json.sql b/contrib/json/sql/array_to_json.sql
new file mode 100644
index 0000000..ba07ea4
--- /dev/null
+++ b/contrib/json/sql/array_to_json.sql
@@ -0,0 +1,45 @@
+SELECT to_json(ARRAY[1,2,3]);
+SELECT to_json(ARRAY[[1],[2],[3]]);
+SELECT to_json(ARRAY[[1,2],[2],[3]]);
+SELECT to_json(ARRAY[[1,2],[3,4],[5,6]]);
+SELECT to_json(ARRAY[[],[],[]]);
+SELECT to_json(ARRAY[[],[],[]]::integer[][]);
+SELECT to_json(ARRAY['hello']);
+SELECT to_json(ARRAY['hello', 'world']);
+SELECT to_json(ARRAY['hello', 'world', 5]);
+SELECT to_json(ARRAY['hello', 'world', 5]::text[]);
+SELECT to_json(ARRAY[ARRAY['hello', 'world', 5]]::text[][]);
+SELECT to_json(ARRAY[]);
+SELECT to_json(ARRAY[]::text[]);
+SELECT to_json(ARRAY['hello', 'world', null]);
+SELECT to_json(ARRAY['hello', 'world', null, 5]);
+SELECT to_json(ARRAY['hello', 'world', null, '5']);
+SELECT to_json(ARRAY[null]);
+SELECT to_json(ARRAY[null, null]);
+SELECT to_json(ARRAY[[null],[null],[null]]);
+SELECT to_json(ARRAY[[null,null],[null,null],[null,null]]);
+SELECT to_json(ARRAY[[[null,null]],[[null,null]],[[null,null]]]);
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]);
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]::int[][][]);
+SELECT to_json(array[1,2,3,4,5]::int2vector);
+SELECT to_json(array[1,2,3,4,5]::oidvector);
+SELECT to_json(array[[1,2],[3,4],5]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5]]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5,5]]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5,6]]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5,6]]::int2vector);
+SELECT to_json(array[[1,2],[3,4],[5,6000]]::int2vector);
+SELECT to_json(array[[1,2],[3,4],[5,60000]]::int2vector);
+SELECT to_json(array[[1,2],[3,4],[5,null]]::int2vector);
+SELECT to_json(array[[1,2],[null,4],[5,null]]::int2vector);
+SELECT to_json(array[[1,2],[null,4],[5,null]]::oidvector);
+SELECT to_json(array[[true,false],[false,true]]::bool[][]);
+SELECT to_json(array[[true,false],[false,true],[null,null]]::bool[][]);
+SELECT to_json('{1,2,3}');
+SELECT to_json('{1,2,3}'::text); -- should form "{1,2,3}", not build an array
+SELECT to_json('{1,2,3}'::int[]);
+SELECT to_json('{one,two,three}'::text[]);
+SELECT to_json('{one,two,three,null}'::text[]);
+SELECT to_json('{one,two,three,null,five}'::text[]);
+SELECT to_json('{null}'::text[]);
+SELECT to_json('{{null}}'::text[][]);
diff --git a/contrib/json/sql/condense.sql b/contrib/json/sql/condense.sql
new file mode 100644
index 0000000..7ad563b
--- /dev/null
+++ b/contrib/json/sql/condense.sql
@@ -0,0 +1,14 @@
+SELECT json_condense('"hello"');
+SELECT json_condense($$"hello\u266Bworld"$$);
+SELECT json_condense($$"hello\u266bworld"$$);
+SELECT json_condense($$"hello♫world"$$);
+SELECT json_condense($$      "hello world"    $$);
+SELECT json_condense($$    {  "hello" : "world"}    $$);
+SELECT json_condense($$    {  "hello" : "world", "bye": 0.0001  }    $$);
+SELECT json_condense($$    {  "hello" : "world",
+								"bye": 0.0000001
+}    $$);
+SELECT json_condense($$    {  "hello" : "world"
+,
+"bye"
+: [-0.1234e1, 12345e0]		}    $$);
diff --git a/contrib/json/sql/init.sql b/contrib/json/sql/init.sql
new file mode 100644
index 0000000..9ce0d6b
--- /dev/null
+++ b/contrib/json/sql/init.sql
@@ -0,0 +1,10 @@
+SET client_min_messages = warning;
+\set ECHO none
+\i json.sql
+
+\i sql/test_strings.sql
+CREATE TABLE valid_test_strings AS
+	SELECT string FROM test_strings WHERE json_validate(string);
+
+\set ECHO all
+RESET client_min_messages;
diff --git a/contrib/json/sql/json.sql b/contrib/json/sql/json.sql
new file mode 100644
index 0000000..1e98d6c
--- /dev/null
+++ b/contrib/json/sql/json.sql
@@ -0,0 +1,159 @@
+SELECT '[]'::JSON;
+SELECT '['::JSON;
+SELECT '[1,2,3]'::JSON;
+SELECT '[1,2,3]'::JSON::TEXT;
+SELECT '[1,2,3  ]'::JSON;
+SELECT '[1,2,3  ,4]'::JSON;
+SELECT '[1,2,3  ,4.0]'::JSON;
+SELECT '[1,2,3  ,4]'::JSON;
+SELECT 'true'::JSON;
+SELECT 'true'::TEXT::JSON;
+SELECT 'false'::JSON;
+SELECT 'null'::JSON;
+SELECT '1.1'::JSON;
+SELECT '"string"'::JSON;
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+SELECT 15::JSON;
+
+SELECT json_type('[]');
+SELECT json_type('{}');
+SELECT json_type('true');
+SELECT json_type('false');
+SELECT json_type('null');
+
+CREATE TABLE testjson (j JSON);
+INSERT INTO testjson VALUES ('[1,2,3,4]');
+INSERT INTO testjson VALUES ('{"key":"value"}');
+INSERT INTO testjson VALUES ('{"key":"value"');
+INSERT INTO testjson VALUES ('');
+INSERT INTO testjson VALUES ('""');
+INSERT INTO testjson VALUES ('true');
+INSERT INTO testjson VALUES ('false');
+INSERT INTO testjson VALUES ('null');
+INSERT INTO testjson VALUES ('[]');
+INSERT INTO testjson VALUES ('{}');
+
+SELECT * FROM testjson;
+
+SELECT json_type(j) FROM testjson;
+
+
+-- to_json: null
+SELECT to_json(NULL);
+SELECT to_json(NULL::INT);
+SELECT to_json(NULL::INT[]);
+SELECT to_json(NULL::VOID);
+SELECT to_json(NULL::MONEY);
+SELECT to_json('null'::text); -- should yield '"null"', not 'null'
+SELECT json_type(to_json(NULL));
+SELECT json_type(to_json(NULL::INT));
+SELECT json_type(to_json(NULL::VOID));
+SELECT json_type(to_json(NULL::MONEY));
+
+-- to_json: string
+SELECT to_json('');
+SELECT json_type(to_json(''));
+SELECT to_json('string');
+SELECT json_type(to_json('string'));
+SELECT to_json('string'::VARCHAR);
+SELECT json_type(to_json('string'::VARCHAR));
+SELECT to_json('string'::VARCHAR(3));
+SELECT json_type(to_json('string'::VARCHAR(3)));
+SELECT to_json('{1,2,3}'::TEXT);
+SELECT json_type(to_json('{1,2,3}'::TEXT));
+SELECT to_json('"doubly-encoded"'::JSON);
+SELECT json_type(to_json('"doubly-encoded"'::JSON));
+SELECT to_json('"nested quotes"'::TEXT);
+SELECT json_type(to_json('"nested quotes"'::TEXT));
+SELECT to_json('"nested quotes"'::TEXT)::TEXT::JSON;
+SELECT json_type(to_json('"nested quotes"'::TEXT)::TEXT::JSON);
+SELECT to_json('h'::CHAR);
+SELECT json_type(to_json('h'::CHAR));
+SELECT to_json('hello world'::CHAR);
+SELECT json_type(to_json('hello world'::CHAR));
+SELECT to_json('hello world!'::CHAR(11));
+SELECT json_type(to_json('hello world!'::CHAR(11)));
+
+-- to_json: number
+SELECT to_json(12345);
+SELECT to_json(12345.678);
+SELECT json_type(to_json(12345));
+SELECT json_type(to_json(12345.678));
+SELECT to_json(+1.23e100::FLOAT);
+SELECT to_json('+1.23e100'::FLOAT);
+SELECT to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890);
+SELECT json_type(to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890));
+SELECT to_json('100'::MONEY);
+
+-- to_json: bool
+SELECT to_json(TRUE);
+SELECT to_json(FALSE);
+SELECT to_json(1=1);
+SELECT to_json(1=2);
+SELECT json_type(to_json(TRUE));
+SELECT json_type(to_json(FALSE));
+SELECT json_type(to_json(1=1));
+SELECT json_type(to_json(1=2));
+SELECT to_json(TRUE::TEXT)::TEXT = '"' || TRUE || '"';
+SELECT to_json(FALSE::TEXT)::TEXT = '"' || FALSE || '"';
+
+-- to_json: array
+SELECT to_json(ARRAY[1,2,3]);
+-- more tests are in array_to_json.sql
+
+-- to_json: invalid types
+SELECT to_json(row(1,2));
+SELECT to_json('127.0.0.1'::INET);
+
+
+-- from_json: null
+SELECT from_json(null);
+SELECT from_json(NULL::TEXT);
+SELECT from_json(NULL::JSON);
+
+-- from_json: string
+SELECT from_json('"valid string"');
+SELECT from_json($$ "hello\nworld" $$);
+SELECT from_json($$ "hello\u0000world" $$);
+
+-- from_json: number
+SELECT from_json('123');
+SELECT from_json('123')::INT;
+SELECT from_json('123.456')::INT;
+SELECT from_json('123.456')::FLOAT;
+SELECT from_json('123e-38');
+SELECT from_json('123e-38')::FLOAT;
+SELECT from_json('1.23e-38')::FLOAT;
+SELECT from_json('1.23e-38');
+SELECT from_json('1.23e-38')::NUMERIC;
+
+-- from_json: bool
+SELECT from_json('true')::JSON;
+SELECT from_json('true');
+SELECT from_json('true')::BOOLEAN;
+SELECT from_json('true')::BOOLEAN::JSON;
+SELECT from_json('true')::BOOLEAN::TEXT::JSON;
+SELECT from_json('false')::BOOLEAN::TEXT::JSON;
+SELECT from_json('false');
+SELECT from_json('f');
+SELECT from_json('t');
+SELECT from_json('f'::BOOLEAN::TEXT);
+SELECT from_json('f'::BOOLEAN::TEXT::JSON);
+SELECT from_json('t'::BOOLEAN::TEXT::JSON);
+
+-- from_json: object
+SELECT from_json('{"key": "value"}');
+
+-- from_json: array
+SELECT from_json('[1,2,3]');
+
+-- from_json: invalid
+SELECT from_json('invalid');
+
+CREATE TABLE sample_query_text (json JSON);
+INSERT INTO sample_query_text VALUES ($$
+"SELECT pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c WHERE c.relkind IN ('i') AND substring(pg_catalog.quote_ident(c.relname),1,0)='' AND pg_catalog.pg_table_is_visible(c.oid) AND c.relnamespace <> (SELECT oid FROM pg_catalog.pg_namespace WHERE nspname = 'pg_catalog')\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' FROM pg_catalog.pg_namespace n WHERE substring(pg_catalog.quote_ident(n.nspname) || '.',1,0)='' AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) > 1\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n WHERE c.relnamespace = n.oid AND c.relkind IN ('i') AND substring(pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname),1,0)='' AND substring(pg_catalog.quote_ident(n.nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(n.nspname))+1) AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) = 1\n UNION SELECT 'ON' UNION SELECT 'CONCURRENTLY'\nLIMIT 1000"
+$$);
+
+SELECT md5(from_json(json)) FROM sample_query_text;
diff --git a/contrib/json/sql/json_get.sql b/contrib/json/sql/json_get.sql
new file mode 100644
index 0000000..1427d47
--- /dev/null
+++ b/contrib/json/sql/json_get.sql
@@ -0,0 +1,18 @@
+SELECT json_get('{"key": "value", "key2": "value2"}', 'key');
+SELECT json_get('{"key": "value", "key": "value2"}', 'key');
+
+/* These each return no result because 0 is a number
+   (indicating a numeric subscript),
+   not a string (indicating an object subscript). */
+SELECT json_get('{"0": "value", "key": "value"}', '0');
+SELECT json_get('{"0": "value", "0": "value"}', '[0]');
+SELECT json_get('{"0": "value", "0": "value"}', '.0');
+
+SELECT json_get('{"0": "value", "1": "value"}', '["0"]');
+SELECT json_get('{"0": "value", "0": "value"}', '["0"]');
+
+SELECT json_get('[0,1,2,3]', '0');
+SELECT json_get('[0,1,2,3]', '"0"');
+SELECT json_get('[0,1,2,3]', '*');
+SELECT json_get('[0]', '*');
+SELECT json_get('[[0]]', '..*');
diff --git a/contrib/json/sql/json_path.sql b/contrib/json/sql/json_path.sql
new file mode 100644
index 0000000..01d972b
--- /dev/null
+++ b/contrib/json/sql/json_path.sql
@@ -0,0 +1,173 @@
+SELECT parse_json_path('..');
+SELECT parse_json_path('..*');
+SELECT parse_json_path('.*');
+SELECT parse_json_path('');
+SELECT parse_json_path('$.*');
+SELECT parse_json_path('$');
+SELECT parse_json_path('$*');
+SELECT parse_json_path('*');
+SELECT parse_json_path($$ .. [ 025  ] $$);
+SELECT parse_json_path($$ $ . 0 . 3 $$);
+SELECT parse_json_path($$ $ . 0_3 $$);
+SELECT parse_json_path($$ $ . 0.3 $$);
+SELECT parse_json_path($$ .. [ 031  ] $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . "back\\slash" $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . ["back\\slash"] $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . back\slash $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . backslash $$);
+SELECT parse_json_path($$ .. [ 0x31  ] $$);
+SELECT parse_json_path($$ [ 0x31  ] $$);
+SELECT parse_json_path($$ _3 $$);
+SELECT parse_json_path($$ _3_ $$);
+SELECT parse_json_path($$ [ _3 ] $$);
+SELECT parse_json_path($$ $ _3 $$);
+SELECT parse_json_path($$ $ . _3 $$);
+SELECT parse_json_path('..["5"]');
+SELECT parse_json_path('..[5]');
+SELECT parse_json_path('..5');
+SELECT parse_json_path($$ .. [ -5  ] $$);
+SELECT parse_json_path($$ .. [ "5"  ] $$);
+SELECT parse_json_path($$ .. [ +5  ] $$);
+SELECT parse_json_path($$ .. [ 5  ] $$);
+SELECT parse_json_path($$ .. ["5"] $$);
+SELECT parse_json_path($$ ..["5"] $$);
+SELECT parse_json_path($$ [ "5" ] $$);
+SELECT parse_json_path($$ [ 5 ] $$);
+SELECT parse_json_path('."hello"');
+SELECT parse_json_path('.hello');
+SELECT parse_json_path('...["hello world"]');
+SELECT parse_json_path('..["hello world"]');
+SELECT parse_json_path('."hello world"');
+SELECT parse_json_path('.["hello world"]');
+SELECT parse_json_path('.hello world');
+SELECT parse_json_path('..["hello world"]["5"]');
+SELECT parse_json_path('..["hello world"][5]');
+SELECT parse_json_path('..["hello world"][5]..[3]..*.[*]');
+SELECT parse_json_path('..["hello world"][5]..[3]..*');
+SELECT parse_json_path('..["hello world"][5]..[3]');
+SELECT parse_json_path('..["hello world"][5]..[3]*');
+SELECT parse_json_path($$
+	.. [ '"hello"\\"world"' ]
+	[ 5 ] .. [3] . * [ * ]
+$$);
+
+select parse_json_path('$char');
+select parse_json_path('$.char');
+select parse_json_path('$.char()');
+select parse_json_path('$.char(5)');
+select parse_json_path('$.char(  -1  )');
+select parse_json_path('$.char(  -1  )  . char(0)');
+select parse_json_path('$.char(  -1  )  . char  ( 0 )  ');
+select parse_json_path('$.char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('$ . char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('$ .. char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('$ .. char(  +1  )  .. char  ( 0 )  ');
+select parse_json_path('$ . char(  +1  )  .. char  ( 0 )  ');
+select parse_json_path('$ . char(  +1  )  char  ( 0 )  ');
+select parse_json_path('$ char(  +1  )  char  ( 0 )  ');
+select parse_json_path('char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('.char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('..char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('...char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('[char(5)]');
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(0)');
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(1)');
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(2)');
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(3)');
+SELECT json_path('"0123"', 'char(-1)');
+SELECT json_path('"0123"', 'char(0)');
+SELECT json_path('"0123"', 'char(1)');
+SELECT json_path('"0123"', 'char(2)');
+SELECT json_path('"0123"', 'char(3)');
+SELECT json_path('"0123"', 'char(4)');
+SELECT json_path('"⁰¹²³"', 'char(0)');
+SELECT json_path('"⁰¹²³"', 'char(1)');
+SELECT json_path('"⁰¹²³"', 'char(2)');
+SELECT json_path('"⁰¹²³"', 'char(3)');
+SELECT json_path('[1,2,3]', '$');
+SELECT json_path('[1,2,3]', '$.+1');
+SELECT json_path('[1,2,3]', '$.-1');
+SELECT json_path('[1,2,3]', '$.0');
+SELECT json_path('[1,2,3]', '$.1');
+SELECT json_path('[1,2,3]', '$.2');
+SELECT json_path('[1,2,3]', '$.3');
+SELECT json_path('[1,2,3]', '*');
+SELECT json_path('[1,2,3]', '[0]');
+SELECT json_path('[1,2,3]', '[1]');
+SELECT json_path('[1,2,3]', '[2]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', $$['2']$$);
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["0"]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["1"]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["2"]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[0]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[1]');
+
+-- Multiple JSONPath results are listed in BFS order
+-- (just because it's easier to implement efficiently than DFS)
+SELECT json_path('[0,1,[2, [3,4 , 5],6,[7,8],9],10]', '$..*');
+
+
+CREATE TABLE sample (json JSON);
+INSERT INTO sample VALUES ($$
+{
+	"store": {
+		"books": [
+			{
+				"title": "book 0",
+				"author": "author 0",
+				"prices": [1,2,3]
+			}, {
+				"title": "book 1",
+				"author": "author 1",
+				"prices": [4,5,6]
+			}, {
+				"title": "book 2",
+				"author": "author 2",
+				"prices": [7,8,9]
+			}
+		],
+		"toys": [
+			"Yo-yo",
+			"Boomerang",
+			"Basketball"
+		]
+	}
+}
+$$);
+
+SELECT json_path(json, 'store.books[*]') FROM sample;
+SELECT json_path(json, 'store.books[*].title') FROM sample;
+SELECT json_path(json, 'store.books[*].author') FROM sample;
+SELECT json_path(json, 'store.books[*].prices') FROM sample;
+SELECT json_path(json, 'store.books[*].prices[*]') FROM sample;
+SELECT json_path(json, 'store.toys[*]') FROM sample;
+SELECT json_path(json, 'store.toys[*][0]') FROM sample;
+SELECT json_path(json, 'store.toys[*][1]') FROM sample;
+SELECT json_path(json, 'store.toys[*][0][0]') FROM sample;
+SELECT json_path(json, 'store.toys[*][0][1]') FROM sample;
+
+SELECT json_path(json, '..books') FROM sample;
+SELECT json_path(json, '..books[*]') FROM sample;
+SELECT json_path(json, '..title') FROM sample;
+SELECT json_path(json, '..author') FROM sample;
+SELECT json_path(json, '..prices[*]') FROM sample;
+SELECT json_path(json, '..toys[*]') FROM sample;
+SELECT json_path(json, '..toys..[*]') FROM sample;
+
+SELECT json_path(json, '..[-1]') FROM sample;
+SELECT json_path(json, '..[0]') FROM sample;
+SELECT json_path(json, '..[1]') FROM sample;
+SELECT json_path(json, '..[2]') FROM sample;
+SELECT json_path(json, '..[3]') FROM sample;
+
+SELECT json_path(json, '$') FROM sample;
+SELECT json_path(json, '..*') FROM sample;
+
+SELECT json_path(json, '..char(-1)') FROM sample;
+SELECT json_path(json, '..char(0)') FROM sample;
+SELECT json_path(json, '..char(1)') FROM sample;
+SELECT json_path(json, '..char(2)') FROM sample;
+SELECT json_path(json, '..char(3)') FROM sample;
+SELECT json_path(json, '..char(100)') FROM sample;
diff --git a/contrib/json/sql/json_set.sql b/contrib/json/sql/json_set.sql
new file mode 100644
index 0000000..71c7a4c
--- /dev/null
+++ b/contrib/json/sql/json_set.sql
@@ -0,0 +1,31 @@
+SELECT json_set('[1,2,3]', '[1]', 5::json);
+SELECT json_set('[1,2,3]', '[3]', 5::json);
+SELECT json_set('[1,2,3]', '[2]', 5::json);
+SELECT json_set('[1,2,3]', '[2]', '[0,1]'::json);
+SELECT json_set('  [ 1 ,   2,3]', '1', '5');
+SELECT json_set('  [ 1 ,   [2,3],3]', '1', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[5][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[4][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[3][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[2][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '   5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1][0]', '   5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '   5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '     5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\tworld"  $$);
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\u0009world"  $$);
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][*]', $$     "hello\u0009world"  $$);
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+SELECT json_set('       [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+
+-- Since JavaScript doesn't do anything when you assign to a character subscript,
+-- neither will json_set.
+SELECT json_set('"hello"', '[0]', '"H"');
+SELECT json_set('"hello"', '[0][0]', '"H"');
+SELECT json_set('["hello"]', '[0][0]', '"H"');
+SELECT json_set('["hello"]', '[0][0][0]', '"H"');
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*]', '["set"]');
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*][*]', '["set"]');
+SELECT json_set('[0,1,2,[3,4,5],4]', '$..[*]', '["set"]');
diff --git a/contrib/json/sql/orig.sql b/contrib/json/sql/orig.sql
new file mode 100644
index 0000000..7dad00e
--- /dev/null
+++ b/contrib/json/sql/orig.sql
@@ -0,0 +1,10 @@
+
+/* Make sure creating an array literal and subscripting
+ * preserves the original string exactly
+ * (except for trimming surrounding whitespace). */
+SELECT bool_and(btrim(before, E'\t\n\r ') = after) FROM (
+	SELECT
+		string AS before,
+		json_path(('  [ ' || string || '  ] ')::json, '$.[0]')::text AS after
+	FROM valid_test_strings
+) AS subquery;
diff --git a/contrib/json/sql/test_strings.sql b/contrib/json/sql/test_strings.sql
new file mode 100644
index 0000000..074080b
--- /dev/null
+++ b/contrib/json/sql/test_strings.sql
@@ -0,0 +1,216 @@
+CREATE TABLE test_strings (string TEXT);
+INSERT INTO test_strings VALUES ($$$$);
+INSERT INTO test_strings VALUES ($$  $$);
+INSERT INTO test_strings VALUES ($$"$$);
+INSERT INTO test_strings VALUES ($$[,]$$);
+INSERT INTO test_strings VALUES ($$[)$$);
+INSERT INTO test_strings VALUES ($$[]]$$);
+INSERT INTO test_strings VALUES ($$[}$$);
+INSERT INTO test_strings VALUES ($${,}$$);
+INSERT INTO test_strings VALUES ($${]$$);
+INSERT INTO test_strings VALUES ($$["1":2]$$);
+INSERT INTO test_strings VALUES ($$[1,2,]$$);
+INSERT INTO test_strings VALUES ($$[1:2}$$);
+INSERT INTO test_strings VALUES ($${"1":2,}$$);
+INSERT INTO test_strings VALUES ($${1:2}$$);
+INSERT INTO test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7 ]}]}$$);
+INSERT INTO test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7]}]}$$);
+INSERT INTO test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]$$);
+INSERT INTO test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]]$$);
+INSERT INTO test_strings VALUES ($${"1":2, "3":4$$);
+INSERT INTO test_strings VALUES ($$"1\u2"$$);
+INSERT INTO test_strings VALUES ($$[,2]$$);
+INSERT INTO test_strings VALUES ($$"3$$);
+INSERT INTO test_strings VALUES ($$"3" "4"$$);
+INSERT INTO test_strings VALUES ($$[3[4]$$);
+INSERT INTO test_strings VALUES ($$[3[4]]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6] 7, 8 9]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6] 7, 8, 9]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6], 7, 8 9]$$);
+INSERT INTO test_strings VALUES ($${"hello":true, "bye":false, null}$$);
+INSERT INTO test_strings VALUES ($${"hello":true, "bye":false, null:null}$$);
+INSERT INTO test_strings VALUES ($$"hi$$);
+INSERT INTO test_strings VALUES ($$"hi"""$$);
+INSERT INTO test_strings VALUES ($${"hi": "bye"]$$);
+INSERT INTO test_strings VALUES ($$"\uD800\uD800"$$);
+INSERT INTO test_strings VALUES ($$"\uD800\uDBFF"$$);
+INSERT INTO test_strings VALUES ($$"\UD834\UDD1E"$$);
+INSERT INTO test_strings VALUES ($$"\uDB00"$$);
+INSERT INTO test_strings VALUES ($$"\uDB00\uDBFF"$$);
+INSERT INTO test_strings VALUES ($$"\uFFFE"$$);
+INSERT INTO test_strings VALUES ($$"\uFFFF"$$);
+INSERT INTO test_strings VALUES ($$.$$);
+INSERT INTO test_strings VALUES ($$""$$);
+INSERT INTO test_strings VALUES ($$[]$$);
+INSERT INTO test_strings VALUES ($${}$$);
+INSERT INTO test_strings VALUES ($$+.$$);
+INSERT INTO test_strings VALUES ($$0.5$$);
+INSERT INTO test_strings VALUES ($$0.e1$$);
+INSERT INTO test_strings VALUES ($${"1":{}}$$);
+INSERT INTO test_strings VALUES ($${"1":2}$$);
+INSERT INTO test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"]}]}$$);
+INSERT INTO test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]}$$);
+INSERT INTO test_strings VALUES ($$1234$$);
+INSERT INTO test_strings VALUES ($$-1234$$);
+INSERT INTO test_strings VALUES ($${"1":2, "3":4}$$);
+INSERT INTO test_strings VALUES ($$+1234$$);
+INSERT INTO test_strings VALUES ($$++1234$$);
+INSERT INTO test_strings VALUES ($$123.456e14234$$);
+INSERT INTO test_strings VALUES ($$123.456e-14234$$);
+INSERT INTO test_strings VALUES ($$123.456e+14234$$);
+INSERT INTO test_strings VALUES ($$123.e-14234$$);
+INSERT INTO test_strings VALUES ($$"1\u2000"$$);
+INSERT INTO test_strings VALUES ($$"1\u20001"$$);
+INSERT INTO test_strings VALUES ($$2$$);
+INSERT INTO test_strings VALUES ($$.246e-14234$$);
+INSERT INTO test_strings VALUES ($$.2e-14234$$);
+INSERT INTO test_strings VALUES ($$3$$);
+INSERT INTO test_strings VALUES ($$.3$$);
+INSERT INTO test_strings VALUES ($$"3"$$);
+INSERT INTO test_strings VALUES ($$[3]$$);
+INSERT INTO test_strings VALUES ($$+3.$$);
+INSERT INTO test_strings VALUES ($$3.2e+1$$);
+INSERT INTO test_strings VALUES ($$[3, [4]]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5]]]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6]]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6], 7]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6], 7, 8]$$);
+INSERT INTO test_strings VALUES ($$[3, [4, [5], 6], 7, 8, 9]$$);
+INSERT INTO test_strings VALUES ($$+3.5$$);
+INSERT INTO test_strings VALUES ($$.3e$$);
+INSERT INTO test_strings VALUES ($$.3e1$$);
+INSERT INTO test_strings VALUES ($$.3e-1$$);
+INSERT INTO test_strings VALUES ($$.3e+1$$);
+INSERT INTO test_strings VALUES ($$3.e1$$);
+INSERT INTO test_strings VALUES ($$3.e+1$$);
+INSERT INTO test_strings VALUES ($$3e+1$$);
+INSERT INTO test_strings VALUES ($$.5$$);
+INSERT INTO test_strings VALUES ($$+.5$$);
+INSERT INTO test_strings VALUES ($$.5e+1$$);
+INSERT INTO test_strings VALUES ($$[ 7]$$);
+INSERT INTO test_strings VALUES ($$[7 ]$$);
+INSERT INTO test_strings VALUES ($$[7]$$);
+INSERT INTO test_strings VALUES ($$.e-14234$$);
+INSERT INTO test_strings VALUES ($$"hello"$$);
+INSERT INTO test_strings VALUES ($$["hello"]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye"]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n"]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n\r\t"]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n\r\t\b"]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n\r\t\b",true]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n\r\t\b",true , false]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n\r\t\b",true , false,    null]$$);
+INSERT INTO test_strings VALUES ($$["hello", "bye\n\r\t\v"]$$);
+INSERT INTO test_strings VALUES ($${"hello":true}$$);
+INSERT INTO test_strings VALUES ($${"hello":true, "bye":false}$$);
+INSERT INTO test_strings VALUES ($${"hello":true, "bye":false, "foo":["one","two","three"]}$$);
+INSERT INTO test_strings VALUES ($$"hi"$$);
+INSERT INTO test_strings VALUES ($$["hi"]$$);
+INSERT INTO test_strings VALUES ($$["hi", "bye"]$$);
+INSERT INTO test_strings VALUES ($${"hi": "bye"}$$);
+INSERT INTO test_strings VALUES ($$["hi", "bye", 3]$$);
+INSERT INTO test_strings VALUES ($$["hi", "bye[", 3]$$);
+INSERT INTO test_strings VALUES ($$"\u0007"$$);
+INSERT INTO test_strings VALUES ($$"\u0008"$$);
+INSERT INTO test_strings VALUES ($$"\u0009"$$);
+INSERT INTO test_strings VALUES ($$"\u0010"$$);
+INSERT INTO test_strings VALUES ($$"\u0020"$$);
+INSERT INTO test_strings VALUES ($$"\u10000"$$);
+INSERT INTO test_strings VALUES ($$"\u1234"$$);
+INSERT INTO test_strings VALUES ($$"\u99999"$$);
+INSERT INTO test_strings VALUES ($$"\ud800\udc00"$$);
+INSERT INTO test_strings VALUES ($$"\uD800\uDC00"$$);
+INSERT INTO test_strings VALUES ($$"\uD834\uDD1E"$$);
+INSERT INTO test_strings VALUES ($$"\uDBFF\uDFFF"$$);
+INSERT INTO test_strings VALUES ($$"\uFFFD"$$);
+INSERT INTO test_strings VALUES ($$"\uFFFF"$$);
+INSERT INTO test_strings VALUES ($$hello$$);
+INSERT INTO test_strings VALUES ($$[32, 1]$$);
+INSERT INTO test_strings VALUES ($$[32, $$);
+INSERT INTO test_strings VALUES ($$"\uD800\uDC00"$$);
+INSERT INTO test_strings VALUES ($$"\n"$$);
+INSERT INTO test_strings VALUES ($$"hello"$$);
+INSERT INTO test_strings VALUES ($$"hello\u0009world"$$);
+INSERT INTO test_strings VALUES ($$"hello"$$);
+INSERT INTO test_strings VALUES ($$"hello\n"$$);
+INSERT INTO test_strings VALUES ($$"hello"$$);
+INSERT INTO test_strings VALUES ($$3$$);
+INSERT INTO test_strings VALUES ($$3.$$);
+INSERT INTO test_strings VALUES ($$.3$$);
+INSERT INTO test_strings VALUES ($$0.3$$);
+INSERT INTO test_strings VALUES ($$0.3e$$);
+INSERT INTO test_strings VALUES ($$0.3e+$$);
+INSERT INTO test_strings VALUES ($$0.3e+5$$);
+INSERT INTO test_strings VALUES ($$0.3e-5$$);
+INSERT INTO test_strings VALUES ($$0.3e5$$);
+INSERT INTO test_strings VALUES ($$"hello"$$);
+INSERT INTO test_strings VALUES ($$+3$$);
+INSERT INTO test_strings VALUES ($$-3$$);
+INSERT INTO test_strings VALUES ($$-3.$$);
+INSERT INTO test_strings VALUES ($$-3.1$$);
+INSERT INTO test_strings VALUES ($$.5$$);
+INSERT INTO test_strings VALUES ($$5.$$);
+INSERT INTO test_strings VALUES ($$5.e1$$);
+INSERT INTO test_strings VALUES ($$0.5$$);
+INSERT INTO test_strings VALUES ($$.3e1$$);
+INSERT INTO test_strings VALUES ($$.3e+1$$);
+INSERT INTO test_strings VALUES ($$.3e-1$$);
+INSERT INTO test_strings VALUES ($$.3e-1 .5$$);
+INSERT INTO test_strings VALUES ($$.3e-1.5$$);
+INSERT INTO test_strings VALUES ($$.3e+1.5$$);
+INSERT INTO test_strings VALUES ($$.3e+.$$);
+INSERT INTO test_strings VALUES ($$.3e+.5$$);
+INSERT INTO test_strings VALUES ($$.3e+1.5$$);
+INSERT INTO test_strings VALUES ($$9.3e+1.5$$);
+INSERT INTO test_strings VALUES ($$9.e+1.5$$);
+INSERT INTO test_strings VALUES ($$9.e+$$);
+INSERT INTO test_strings VALUES ($$9.e+1$$);
+INSERT INTO test_strings VALUES ($$"\""$$);
+INSERT INTO test_strings VALUES ($$"\"3.5"$$);
+INSERT INTO test_strings VALUES ($$"\"."$$);
+INSERT INTO test_strings VALUES ($$"\".".$$);
+INSERT INTO test_strings VALUES ($$"\"....."$$);
+INSERT INTO test_strings VALUES ($$"\"\"\"\"""$$);
+INSERT INTO test_strings VALUES ($$["\"\"\"\"", .5]$$);
+INSERT INTO test_strings VALUES ($$[.5]$$);
+INSERT INTO test_strings VALUES ($$["\"\"\"\"", 0.5]$$);
+INSERT INTO test_strings VALUES ($$["\"\"\"\"", .5]$$);
+INSERT INTO test_strings VALUES ($$["\"\"\"\"",.5]$$);
+INSERT INTO test_strings VALUES ($$["\"",.5]$$);
+INSERT INTO test_strings VALUES ($$["\".5",.5]$$);
+INSERT INTO test_strings VALUES ($$["\".5",".5\"".5]$$);
+INSERT INTO test_strings VALUES ($$["\".5",".5\"", .5]$$);
+INSERT INTO test_strings VALUES ($$["\".5",".5\"",.5]$$);
+INSERT INTO test_strings VALUES ($$["\".5",".5\"",0.5]$$);
+INSERT INTO test_strings VALUES ($${"key":/*comment*/"value"}$$);
+INSERT INTO test_strings VALUES ($${"key":/*comment"value"}$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}/*$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}/**/$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}/***/$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}/**//$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}/**///$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}/**///----$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}#$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}#{$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}#{}$$);
+INSERT INTO test_strings VALUES ($${"key":"value"}#,$$);
+INSERT INTO test_strings VALUES ($${"key":"value"/**/, "k2":"v2"}$$);
+INSERT INTO test_strings VALUES ($$"\u0027"$$);
+INSERT INTO test_strings VALUES ($$"hello\'"$$);
+INSERT INTO test_strings VALUES ($$'hello\''$$);
+INSERT INTO test_strings VALUES ($$'hello'$$);
+INSERT INTO test_strings VALUES ($$'hell\'o'$$);
+INSERT INTO test_strings VALUES ($$'\'hello'$$);
+INSERT INTO test_strings VALUES ($$'\'hello\''$$);
+INSERT INTO test_strings VALUES ($$\'hello\'$$);
+INSERT INTO test_strings VALUES ($$'hello\'$$);
+INSERT INTO test_strings VALUES ($$['hello\']$$);
+INSERT INTO test_strings VALUES ($$['hello\'']$$);
+INSERT INTO test_strings VALUES ($$['hello"']$$);
+INSERT INTO test_strings VALUES ($$['hello\"']$$);
+INSERT INTO test_strings VALUES ($$['hello"o']$$);
+INSERT INTO test_strings VALUES ($$['"']$$);
+INSERT INTO test_strings VALUES ($$'"'$$);
+INSERT INTO test_strings VALUES ($$'"hello"'$$);
+INSERT INTO test_strings VALUES ($$'"hello'$$);
+INSERT INTO test_strings VALUES ($$'"hi"'$$);
diff --git a/contrib/json/sql/validate.sql b/contrib/json/sql/validate.sql
new file mode 100644
index 0000000..32da7f7
--- /dev/null
+++ b/contrib/json/sql/validate.sql
@@ -0,0 +1 @@
+SELECT json_validate(string), string FROM test_strings;
diff --git a/contrib/json/uninstall_json.sql b/contrib/json/uninstall_json.sql
new file mode 100644
index 0000000..52abb1b
--- /dev/null
+++ b/contrib/json/uninstall_json.sql
@@ -0,0 +1,8 @@
+-- Adjust this setting to control where the objects get dropped.
+SET search_path = public;
+
+DROP TYPE json CASCADE;
+DROP TYPE json_type_t;
+
+DROP FUNCTION json_validate(text);
+DROP FUNCTION parse_json_path(text);
diff --git a/contrib/json/util.c b/contrib/json/util.c
new file mode 100644
index 0000000..97c08d4
--- /dev/null
+++ b/contrib/json/util.c
@@ -0,0 +1,351 @@
+/*-------------------------------------------------------------------------
+ *
+ * util.c
+ *	  General purpose routines used by JSON data type support.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "util.h"
+
+#include "catalog/namespace.h"
+#include "catalog/pg_enum.h"
+#include "utils/syscache.h"
+
+/*
+ * getTypeInfo
+ *	  Retrieve information about a type, along with either its
+ *	  input, output, binary receive, or binary send procedure.
+ *
+ *	  which_func should be one of:
+ *		  IOFunc_input
+ *		  IOFunc_output
+ *		  IOFunc_receive
+ *		  IOFunc_send
+ *
+ *	  mcxt is the memory context the IO function selected will use to store
+ *	  subsidiary data.	The memory context should live at least as long as
+ *	  the TypeInfo structure you specify.
+ */
+void
+getTypeInfo(TypeInfo *d, Oid type, IOFuncSelector which_func, MemoryContext mcxt)
+{
+	d->type = type;
+	d->which_func = which_func;
+	d->mcxt = mcxt;
+
+	get_type_io_data(type, which_func,
+					 &d->typlen, &d->typbyval, &d->typalign,
+					 &d->typdelim, &d->typioparam, &d->typiofunc);
+	fmgr_info_cxt(d->typiofunc, &d->proc, d->mcxt);
+
+	get_type_category_preferred(type,
+								&d->typcategory, &d->typispreferred);
+}
+
+static int
+enum_label_cmp(const void *left, const void *right)
+{
+	const char *l = ((EnumLabel *) left)->label;
+	const char *r = ((EnumLabel *) right)->label;
+
+	return strcmp(l, r);
+}
+
+/*
+ * getEnumLabelOids
+ *	  Look up the OIDs of enum labels.	Enum label OIDs are needed to
+ *	  return values of a custom enum type from a C function.
+ *
+ *	  Callers should typically cache the OIDs produced by this function
+ *	  using FN_EXTRA, as retrieving enum label OIDs is somewhat expensive.
+ *
+ *	  Every labels[i].index must be between 0 and count, and oid_out
+ *	  must be allocated to hold count items.  Note that getEnumLabelOids
+ *	  sorts the labels[] array passed to it.
+ *
+ *	  Any labels not found in the enum will have their corresponding
+ *	  oid_out entries set to InvalidOid.
+ *
+ *	  Sample usage:
+ *
+ *	  -- SQL --
+ *	  CREATE TYPE colors AS ENUM ('red', 'green', 'blue');
+ *
+ *	  -- C --
+ *	  enum Colors {RED, GREEN, BLUE, COLOR_COUNT};
+ *
+ *	  static EnumLabel enum_labels[COLOR_COUNT] =
+ *	  {
+ *		  {RED,   "red"},
+ *		  {GREEN, "green"},
+ *		  {BLUE,  "blue"}
+ *	  };
+ *
+ *	  Oid *label_oids = palloc(COLOR_COUNT * sizeof(Oid));
+ *	  getEnumLabelOids("colors", enum_labels, label_oids, COLOR_COUNT);
+ *
+ *	  PG_RETURN_OID(label_oids[GREEN]);
+ */
+void
+getEnumLabelOids(const char *typname, EnumLabel labels[], Oid oid_out[], int count)
+{
+	CatCList   *list;
+	Oid			enumtypoid;
+	int			total;
+	int			i;
+	EnumLabel	key;
+	EnumLabel  *found;
+
+	enumtypoid = TypenameGetTypid(typname);
+	Assert(OidIsValid(enumtypoid));
+
+	qsort(labels, count, sizeof(EnumLabel), enum_label_cmp);
+
+	for (i = 0; i < count; i++)
+		oid_out[i] = InvalidOid;
+
+	list = SearchSysCacheList1(ENUMTYPOIDNAME,
+							   ObjectIdGetDatum(enumtypoid));
+	total = list->n_members;
+
+	for (i = 0; i < total; i++)
+	{
+		HeapTuple	tup = &list->members[i]->tuple;
+		Oid			oid = HeapTupleGetOid(tup);
+		Form_pg_enum en = (Form_pg_enum) GETSTRUCT(tup);
+
+		key.label = NameStr(en->enumlabel);
+		found = bsearch(&key, labels, count, sizeof(EnumLabel), enum_label_cmp);
+		if (found != NULL)
+		{
+			Assert(found->index >= 0 && found->index < count);
+			oid_out[found->index] = oid;
+		}
+	}
+
+	ReleaseCatCacheList(list);
+}
+
+/*
+ * utf8_substring
+ *	  Find substring bounds in a UTF-8-encoded string.
+ *
+ *	  @src and @srcbytes are the start and byte length of the input string.
+ *	  @start and @length are the start and number of characters requested.
+ *
+ *	  Writes the bounds of the substring to
+ *	  *out_start (start) and *out_bytes (byte length).
+ *	  Returns the number of characters (not bytes) in the string.
+ *
+ *	  Example:
+ *		 const char *out_start;
+ *		 int		 out_bytes;
+ *		 int		 out_chars;
+ *
+ *		 out_chars =
+ *			 unicode_substring("⁰¹²³", 9,
+ *							   1, 100,
+ *							   &out_start, &out_bytes);
+ *
+ *	  out_chars will be 3.
+ *	  out_start will point to the "¹".
+ *	  out_bytes will be 6.
+ */
+size_t
+utf8_substring(
+			   const char *src, size_t srcbytes,
+			   size_t start, size_t length,
+			   const char **out_start, size_t *out_bytes)
+{
+	const char *e = src + srcbytes;
+	const char *sub_start;
+	const char *sub_end;
+	size_t		sub_length;
+
+	sub_start = src;
+	while (start > 0 && sub_start < e)
+	{
+		sub_start += pg_utf_mblen((const unsigned char *) sub_start);
+		start--;
+	}
+
+	sub_end = sub_start;
+	sub_length = 0;
+	while (sub_length < length && sub_end < e)
+	{
+		sub_end += pg_utf_mblen((const unsigned char *) sub_end);
+		sub_length++;
+	}
+
+	/* Make sure the input didn't have a clipped UTF-8 character */
+	if (sub_start > e)
+	{
+		Assert(false);
+		sub_start = sub_end = e;
+	}
+	else if (sub_end > e)
+	{
+		Assert(false);
+		sub_end = e;
+	}
+
+	*out_start = sub_start;
+	*out_bytes = sub_end - sub_start;
+	return sub_length;
+}
+
+static const bool utf8_allow_surrogates = false;
+
+/*
+ * utf8_decode_char
+ *	  Decodes a UTF-8 character, advancing *sp to point to the end of it.
+ *	  Returns the Unicode code point of the character.
+ *
+ *	  This function will go away when a utf8_to_unicode
+ *	  function becomes available.
+ */
+pg_wchar
+utf8_decode_char(const char **sp)
+{
+	const unsigned char *s = (const unsigned char *) *sp;
+	unsigned char c = *s++;
+	unsigned int len;
+	unsigned char sf[4] = {0xFF, 0x1F, 0xF, 0x7};
+	pg_wchar	uc;
+
+	if (c < 0x80)
+		len = 0;
+	else if (c < 0xE0)
+		len = 1;
+	else if (c < 0xF0)
+		len = 2;
+	else
+		len = 3;
+
+	uc = c & sf[len];
+	while (len--)
+	{
+		uc <<= 6;
+		uc |= *s++ & 0x3F;
+	}
+
+	*sp = (const char *) s;
+	return uc;
+}
+
+/*
+ * utf8_validate
+ *	  Essentially a variant of pg_verify_mbstr(PG_UTF8, str, length, true)
+ *	  that allows '\0' characters.
+ */
+bool
+utf8_validate(const char *str, size_t length)
+{
+	const unsigned char *s = (const unsigned char *) str;
+	const unsigned char *e = s + length;
+	int			len;
+
+	while (s < e)
+	{
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			s++;
+			continue;
+		}
+
+		len = pg_utf_mblen(s);
+		if (s + len > e)
+			return false;
+
+		if (!pg_utf8_islegal(s, len))
+			return false;
+
+		s += len;
+	}
+
+	return true;
+}
+
+char *
+server_to_utf8(const char *str, int len)
+{
+	return (char *) pg_do_encoding_conversion(
+				 (unsigned char *) str, len, GetDatabaseEncoding(), PG_UTF8);
+}
+
+char *
+utf8_to_server(const char *str, int len)
+{
+	return (char *) pg_do_encoding_conversion(
+				 (unsigned char *) str, len, PG_UTF8, GetDatabaseEncoding());
+}
+
+/*
+ * text_to_utf8_cstring
+ *	  Just like text_to_cstring, but yields a C string
+ *	  encoded in UTF-8 instead of the server encoding.
+ */
+char *
+text_to_utf8_cstring(const text *t)
+{
+	/* must cast away the const, just like in text_to_cstring */
+	text	   *tunpacked = pg_detoast_datum_packed((struct varlena *) t);
+	const char *data = VARDATA_ANY(tunpacked);
+	int			len = VARSIZE_ANY_EXHDR(tunpacked);
+	char	   *result;
+
+	result = server_to_utf8(data, len);
+	if (result == data)
+		result = pnstrdup(data, len);
+
+	if (tunpacked != t)
+		pfree(tunpacked);
+
+	return result;
+}
+
+/*
+ * text_to_utf8_cstring
+ *	  Just like cstring_to_text, but takes a C string
+ *	  encoded in UTF-8 instead of the server encoding.
+ */
+text *
+utf8_cstring_to_text(const char *s)
+{
+	return utf8_cstring_to_text_with_len(s, strlen(s));
+}
+
+/*
+ * utf8_cstring_to_text_with_len
+ *	  Just like cstring_to_text_with_len, but takes a C string
+ *	  encoded in UTF-8 instead of the server encoding.
+ *
+ *	  The input string should not contain null characters.
+ */
+text *
+utf8_cstring_to_text_with_len(const char *s, int len)
+{
+	char	   *cstring;
+	int			cstring_len;
+	text	   *result;
+
+	cstring = utf8_to_server(s, len);
+	if (cstring == s)
+		cstring_len = len;
+	else
+		cstring_len = strlen(cstring);
+
+	result = (text *) palloc(len + VARHDRSZ);
+
+	SET_VARSIZE(result, len + VARHDRSZ);
+	memcpy(VARDATA(result), cstring, cstring_len);
+
+	if (cstring != s)
+		pfree(cstring);
+
+	return result;
+}
diff --git a/contrib/json/util.h b/contrib/json/util.h
new file mode 100644
index 0000000..6877ab5
--- /dev/null
+++ b/contrib/json/util.h
@@ -0,0 +1,115 @@
+/*-------------------------------------------------------------------------
+ *
+ * util.h
+ *	  General purpose routines used by JSON data type support.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef JSON_UTIL_H
+#define JSON_UTIL_H
+
+#include "postgres.h"
+
+#include "funcapi.h"
+#include "mb/pg_wchar.h"
+#include "utils/lsyscache.h"
+
+typedef struct
+{
+	Oid			type;
+	IOFuncSelector which_func;
+	MemoryContext mcxt;
+
+	int16		typlen;
+	bool		typbyval;
+	char		typalign;
+	char		typdelim;
+	Oid			typioparam;
+	Oid			typiofunc;
+	FmgrInfo	proc;
+
+	char		typcategory;
+	bool		typispreferred;
+} TypeInfo;
+
+typedef struct
+{
+	int			index;
+	const char *label;
+}	EnumLabel;
+
+/*
+ * FN_EXTRA, FN_EXTRA_ALLOC, FN_MCXT
+ *	   Macros for manipulating context preserved across function calls.
+ *
+ *	   FN_EXTRA is typically used for caching lookups and other nontrivial
+ *	   operations across multiple calls of a user-defined function.
+ *
+ *	   Do not use FN_EXTRA in a set-returning function.  Use user_fctx instead.
+ *
+ *	   Typical usage looks like:
+ *
+ *	   my_extra = FN_EXTRA();
+ *	   if (my_extra == NULL)
+ *	   {
+ *		   my_extra = FN_EXTRA_ALLOC(sizeof(MyExtra));
+ *		   my_extra->type_name = NULL;
+ *	   }
+ *
+ *	   if (my_extra->type_name == NULL ||
+ *		   strcmp(my_extra->type_name, type_name) != 0)
+ *	   {
+ *		   my_extra->type_name = MemoryContextStrdup(FN_MCXT(), type_name);
+ *		   my_extra->type_id   = TypenameGetTypid(my_extra->type_name);
+ *	   }
+ */
+#define FN_EXTRA() (fcinfo->flinfo->fn_extra)
+#define FN_EXTRA_ALLOC(size) \
+	(fcinfo->flinfo->fn_extra = MemoryContextAlloc(fcinfo->flinfo->fn_mcxt, size))
+
+/*
+ * Data allocated inside of FN_EXTRA() should be allocated into FN_MCXT()
+ * so it is preserved across calls
+ */
+#define FN_MCXT() (fcinfo->flinfo->fn_mcxt)
+
+void		getTypeInfo(TypeInfo *d, Oid type, IOFuncSelector which_func, MemoryContext mcxt);
+
+void		getEnumLabelOids(const char *typname, EnumLabel labels[], Oid oid_out[], int count);
+
+size_t utf8_substring(const char *src, size_t srcbytes,
+			   size_t start, size_t length,
+			   const char **out_start, size_t *out_bytes);
+pg_wchar	utf8_decode_char(const char **sp);
+bool		utf8_validate(const char *str, size_t length);
+
+/*
+ * Adaptations of pg_do_encoding_conversion for simplifying UTF-8 conversions.
+ *
+ * These are used frequently in the JSON code because JSON nodes are encoded
+ * in UTF-8.  The reason they are encoded in UTF-8 is because we need to
+ * be able to handle Unicode escapes, but there is
+ * no simple and efficient way to do that with the server encoding.
+ *
+ * Just like pg_do_encoding_conversion, if no conversion is done, the original
+ * pointer given is returned.
+ */
+char	   *server_to_utf8(const char *str, int len);
+char	   *utf8_to_server(const char *str, int len);
+
+/*
+ * Variants of text_to_cstring and cstring_to_text for simplifying UTF-8 conversions.
+ *
+ * Just like text_to_cstring, text_to_utf8_cstring will always return a palloc'd,
+ * null-terminated C-string.
+ */
+char	   *text_to_utf8_cstring(const text *t);
+text	   *utf8_cstring_to_text(const char *s);
+text	   *utf8_cstring_to_text_with_len(const char *s, int len);
+
+
+#endif
diff --git a/doc/src/sgml/contrib.sgml b/doc/src/sgml/contrib.sgml
index 3ea383c..f3bbc52 100644
--- a/doc/src/sgml/contrib.sgml
+++ b/doc/src/sgml/contrib.sgml
@@ -96,6 +96,7 @@ psql -d dbname -f <replaceable>SHAREDIR</>/contrib/<replaceable>module</>.sql
  &intagg;
  &intarray;
  &isn;
+ &json;
  &lo;
  &ltree;
  &oid2name;
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 98f7470..7b44f15 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -108,6 +108,7 @@
 <!entity intagg          SYSTEM "intagg.sgml">
 <!entity intarray        SYSTEM "intarray.sgml">
 <!entity isn             SYSTEM "isn.sgml">
+<!entity json            SYSTEM "json.sgml">
 <!entity lo              SYSTEM "lo.sgml">
 <!entity ltree           SYSTEM "ltree.sgml">
 <!entity oid2name        SYSTEM "oid2name.sgml">
diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
new file mode 100644
index 0000000..ad48a2f
--- /dev/null
+++ b/doc/src/sgml/json.sgml
@@ -0,0 +1,177 @@
+<sect1 id="json">
+ <title>json</title>
+
+ <indexterm zone="json">
+  <primary>json</primary>
+ </indexterm>
+
+ <para>
+  This module implements the <type>json</> data type for storing <ulink url="http://www.json.org/">JSON</ulink> content in <productname>PostgreSQL</>.  The advantage of using the <type>json</> type over storing JSON content in a <type>text</> field is that it makes sure input values are valid JSON, and there are several type-safe functions for manipulating JSON content.
+ </para>
+
+ <para>
+  The <type>json</> type stores valid JSON <quote>values</quote> as defined by <ulink url="http://json.org/">json.org</ulink>.  That is, a <type>json</> field can hold a string, number, object, array, 'true', 'false', or 'null'.
+ </para>
+
+ <para>
+  The <type>json</> datatype should be thought of as a specialization of <type>text</type> rather than a wrapper around <type>text</>, <type>int</>, <type>float</>, etc.  For instance, <literal>' "string" '::json::text</literal> will simply yield <literal>' "string" '</literal>.  Also, bear in mind that JSON null (<literal>'null'::json</literal>) and SQL NULL (<literal>NULL::json</literal>) are two different things.
+ </para>
+
+ <para>
+  The json module is currently under development.
+ </para>
+
+ <sect2>
+  <title><type>json</> Functions</title>
+
+  <table id="json-func-table">
+   <title><type>json</type> Functions</title>
+
+   <tgroup cols="5">
+    <thead>
+     <row>
+      <entry>Function</entry>
+      <entry>Return Type</entry>
+      <entry>Description</entry>
+      <entry>Example</entry>
+      <entry>Result</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry morerows="1"><function>to_json(anyelement)</function></entry>
+      <entry morerows="1"><type>json</type></entry>
+      <entry morerows="1">Encode a value as JSON.</entry>
+      <entry><literal>to_json('string'::TEXT)</literal></entry>
+      <entry><literal>'"string"'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>to_json(array['one','two','three',null]::text[])</literal></entry>
+      <entry><literal>'["one","two","three",null]'</literal></entry>
+     </row>
+     <row>
+      <entry><function>from_json(json)</function></entry>
+      <entry><type>text</type></entry>
+      <entry>Decode a JSON-encoded value.</entry>
+      <entry><literal>from_json('"string"')</literal></entry>
+      <entry><literal>'string'</literal></entry>
+     </row>
+     <row>
+      <entry morerows="1"><function>json_validate(text)</function></entry>
+      <entry morerows="1"><type>boolean</type></entry>
+      <entry morerows="1">Determine if text is valid JSON.</entry>
+      <entry><literal>json_validate('{key: "value"}')</literal></entry>
+      <entry><literal>false</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_validate('{"key": "value"}')</literal></entry>
+      <entry><literal>true</literal></entry>
+     </row>
+     <row>
+      <entry morerows="2"><function>json_get(json, jsonpath text)</function></entry>
+      <entry morerows="2"><type>json</type></entry>
+      <entry morerows="2">Select a single value from a JSON tree using a JSONPath expression.</entry>
+      <entry><literal>json_get('[0,1,2]', '$[1]')</literal></entry>
+      <entry><literal>'1'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_get('[0,1,2]', '$[100]')</literal></entry>
+      <entry><literal>NULL</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_get('[0,1,2]', '$[*]')</literal></entry>
+      <entry><literal>Error</literal></entry>
+     </row>
+     <row>
+      <entry morerows="2"><function>json_set(json, jsonpath text, json)</function></entry>
+      <entry morerows="2"><type>json</type></entry>
+      <entry morerows="2">Set items in a JSON tree that match a JSONPath expression.</entry>
+      <entry><literal>json_set('[0,1,2]', '$[1]', '"x"')</literal></entry>
+      <entry><literal>'[0,"x",2]'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_set('[0,1,2]', '$[100]', '"x"')</literal></entry>
+      <entry><literal>'[0,1,2]'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_set('[0,1,2]', '$[*]', '"x"')</literal></entry>
+      <entry><literal>'["x","x","x"]'</literal></entry>
+     </row>
+     <row>
+      <entry morerows="2"><function>json_path(json, jsonpath text)</function></entry>
+      <entry morerows="2"><type>setof json</type></entry>
+      <entry morerows="2">Select multiple values from a JSON tree using a JSONPath expression.</entry>
+      <entry><literal>json_path('[0,1,2]', '$[1]')</literal></entry>
+      <entry>
+<programlisting>
+ 1
+(1 row)
+</programlisting>
+      </entry>
+     </row>
+     <row>
+      <entry><literal>json_path('[0,1,2]', '$[100]')</literal></entry>
+      <entry>
+<programlisting>
+(0 rows)
+</programlisting>
+      </entry>
+     </row>
+     <row>
+      <entry><literal>json_path('[0,1,2]', '$[*]')</literal></entry>
+      <entry>
+<programlisting>
+ 0
+ 1
+ 2
+(3 rows)
+</programlisting>
+      </entry>
+     </row>
+     <row>
+      <entry morerows="1"><function>json_condense(json)</function></entry>
+      <entry morerows="1"><type>json</type></entry>
+      <entry morerows="1">Re-encodes JSON to form a string with minimal length (mainly removes whitespace).</entry>
+      <entry><literal>json_condense('    {  "key" : "value"}    ')</literal></entry>
+      <entry><literal>'{"key":"value"}'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_condense($$  "\u266B"  $$)</literal></entry>
+      <entry><literal>'"&#9835;"' -- if encoding supports Unicode</literal></entry>
+     </row>
+     <row>
+      <entry><function>json_type(json)</function></entry>
+      <entry><type>json_type_t</type>&nbsp;-&nbsp;&nbsp;one&nbsp;of:
+<programlisting>
+'null'
+'string'
+'number'
+'bool'
+'object'
+'array'
+</programlisting>
+      </entry>
+      <entry>Get the type of a <type>json</type> value.</entry>
+      <entry><literal>json_type('{"pi": "3.14159", "e": "2.71828"}')</literal></entry>
+      <entry><literal>'object'</literal></entry>
+     </row>
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
+ <sect2>
+  <title>Author</title>
+
+  <para>
+   Joey Adams <email>joeyadams3.14159@gmail.com</email>
+  </para>
+  
+  <para>
+   Development of this module was sponsored by Google through its Google Summer of Code program (<ulink url="http://code.google.com/soc">code.google.com/soc</ulink>).
+  </para>
+ </sect2>
+
+</sect1>

diff --git a/doc/src/sgml/datatype.sgml b/doc/src/sgml/datatype.sgml
index 548a3d7..59063f3 100644
--- a/doc/src/sgml/datatype.sgml
+++ b/doc/src/sgml/datatype.sgml
@@ -137,6 +137,12 @@
       </row>
 
       <row>
+       <entry><type>json</type></entry>
+       <entry></entry>
+       <entry>JSON-encoded value</entry>
+      </row>
+
+      <row>
        <entry><type>line</type></entry>
        <entry></entry>
        <entry>infinite line on a plane</entry>
@@ -4121,6 +4127,8 @@ SET xmloption TO { DOCUMENT | CONTENT };
    </para>
    </sect2>
   </sect1>
+  
+  &json;
 
   &array;
 
diff --git a/doc/src/sgml/filelist.sgml b/doc/src/sgml/filelist.sgml
index 98f7470..f871328 100644
--- a/doc/src/sgml/filelist.sgml
+++ b/doc/src/sgml/filelist.sgml
@@ -22,6 +22,7 @@
 <!entity dml        SYSTEM "dml.sgml">
 <!entity func       SYSTEM "func.sgml">
 <!entity indices    SYSTEM "indices.sgml">
+<!entity json       SYSTEM "json.sgml">
 <!entity mvcc       SYSTEM "mvcc.sgml">
 <!entity perform    SYSTEM "perform.sgml">
 <!entity queries    SYSTEM "queries.sgml">
diff --git a/doc/src/sgml/json.sgml b/doc/src/sgml/json.sgml
new file mode 100644
index 0000000..4e9402f
--- /dev/null
+++ b/doc/src/sgml/json.sgml
@@ -0,0 +1,173 @@
+<sect1 id="datatype-json">
+ <title><acronym>JSON</> Type</title>
+
+ <indexterm zone="datatype-json">
+  <primary>JSON</primary>
+ </indexterm>
+
+ <para>
+  The <type>json</> data type can be used to store <ulink url="http://www.json.org/">JSON</ulink> data in <productname>PostgreSQL</>.  Its advantage over storing JSON data in a <type>text</> field is that it ensures input is valid JSON, and there are several type-safe functions for manipulating JSON content.
+ </para>
+
+ <para>
+  The <type>json</> type stores valid JSON <quote>values</quote> as defined by <ulink url="http://json.org/">json.org</ulink>.  This means that it can hold a string, number, object, array, 'true', 'false', or 'null'.  Note that the <ulink url="http://www.ietf.org/rfc/rfc4627.txt">JSON RFC</ulink> states that a JSON text can only be an object or array, and that some applications do not handle bare JSON values (values not wrapped in an object or array) well or at all.  The reason the <type>json</> type allows encoding bare values is because selection operations like <literal>json_get('[1,2,3]', '[0]')</literal> wouldn't make much sense otherwise.
+ </para>
+
+ <para>
+  The <type>json</> data type should be thought of as a specialization of <type>text</type> rather than a wrapper around <type>text</>, <type>int</>, <type>float</>, etc.  For instance, <literal>' "string" '::json::text</literal> will simply yield <literal>' "string" '</literal>.  Also, bear in mind that JSON null (<literal>'null'::json</literal>) and SQL NULL (<literal>NULL::json</literal>) are two different things.
+ </para>
+
+ <sect2>
+  <title><type>json</> Functions</title>
+
+  <table id="json-func-table">
+   <title><type>json</type> Functions</title>
+
+   <tgroup cols="5">
+    <thead>
+     <row>
+      <entry>Function</entry>
+      <entry>Return Type</entry>
+      <entry>Description</entry>
+      <entry>Example</entry>
+      <entry>Result</entry>
+     </row>
+    </thead>
+
+    <tbody>
+     <row>
+      <entry morerows="1"><function>to_json(anyelement)</function></entry>
+      <entry morerows="1"><type>json</type></entry>
+      <entry morerows="1">Encode a value as JSON.</entry>
+      <entry><literal>to_json('string'::TEXT)</literal></entry>
+      <entry><literal>'"string"'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>to_json(array['one','two','three',null]::text[])</literal></entry>
+      <entry><literal>'["one","two","three",null]'</literal></entry>
+     </row>
+     <row>
+      <entry><function>from_json(json)</function></entry>
+      <entry><type>text</type></entry>
+      <entry>Decode a JSON-encoded value.</entry>
+      <entry><literal>from_json('"string"')</literal></entry>
+      <entry><literal>'string'</literal></entry>
+     </row>
+     <row>
+      <entry morerows="1"><function>json_validate(text)</function></entry>
+      <entry morerows="1"><type>boolean</type></entry>
+      <entry morerows="1">Determine if text is valid JSON.</entry>
+      <entry><literal>json_validate('{key: "value"}')</literal></entry>
+      <entry><literal>false</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_validate('{"key": "value"}')</literal></entry>
+      <entry><literal>true</literal></entry>
+     </row>
+     <row>
+      <entry morerows="2"><function>json_get(json, jsonpath text)</function></entry>
+      <entry morerows="2"><type>json</type></entry>
+      <entry morerows="2">Select a single value from a JSON tree using a JSONPath expression.</entry>
+      <entry><literal>json_get('[0,1,2]', '$[1]')</literal></entry>
+      <entry><literal>'1'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_get('[0,1,2]', '$[100]')</literal></entry>
+      <entry><literal>NULL</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_get('[0,1,2]', '$[*]')</literal></entry>
+      <entry><literal>Error</literal></entry>
+     </row>
+     <row>
+      <entry morerows="2"><function>json_set(json, jsonpath text, json)</function></entry>
+      <entry morerows="2"><type>json</type></entry>
+      <entry morerows="2">Set items in a JSON tree that match a JSONPath expression.</entry>
+      <entry><literal>json_set('[0,1,2]', '$[1]', '"x"')</literal></entry>
+      <entry><literal>'[0,"x",2]'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_set('[0,1,2]', '$[100]', '"x"')</literal></entry>
+      <entry><literal>'[0,1,2]'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_set('[0,1,2]', '$[*]', '"x"')</literal></entry>
+      <entry><literal>'["x","x","x"]'</literal></entry>
+     </row>
+     <row>
+      <entry morerows="2"><function>json_path(json, jsonpath text)</function></entry>
+      <entry morerows="2"><type>setof json</type></entry>
+      <entry morerows="2">Select multiple values from a JSON tree using a JSONPath expression.</entry>
+      <entry><literal>json_path('[0,1,2]', '$[1]')</literal></entry>
+      <entry>
+<programlisting>
+ 1
+(1 row)
+</programlisting>
+      </entry>
+     </row>
+     <row>
+      <entry><literal>json_path('[0,1,2]', '$[100]')</literal></entry>
+      <entry>
+<programlisting>
+(0 rows)
+</programlisting>
+      </entry>
+     </row>
+     <row>
+      <entry><literal>json_path('[0,1,2]', '$[*]')</literal></entry>
+      <entry>
+<programlisting>
+ 0
+ 1
+ 2
+(3 rows)
+</programlisting>
+      </entry>
+     </row>
+     <row>
+      <entry morerows="1"><function>json_condense(json)</function></entry>
+      <entry morerows="1"><type>json</type></entry>
+      <entry morerows="1">Re-encodes JSON to form a string with minimal length (mainly removes whitespace).</entry>
+      <entry><literal>json_condense('    {  "key" : "value"}    ')</literal></entry>
+      <entry><literal>'{"key":"value"}'</literal></entry>
+     </row>
+     <row>
+      <entry><literal>json_condense($$  "\u266B"  $$)</literal></entry>
+      <entry><literal>'"&#9835;"' -- if encoding supports Unicode</literal></entry>
+     </row>
+     <row>
+      <entry><function>json_type(json)</function></entry>
+      <entry><type>json_type_t</type>&nbsp;-&nbsp;&nbsp;one&nbsp;of:
+<programlisting>
+'null'
+'string'
+'number'
+'bool'
+'object'
+'array'
+</programlisting>
+      </entry>
+      <entry>Get the type of a <type>json</type> value.</entry>
+      <entry><literal>json_type('{"pi": "3.14159", "e": "2.71828"}')</literal></entry>
+      <entry><literal>'object'</literal></entry>
+     </row>
+    </tbody>
+   </tgroup>
+  </table>
+
+ </sect2>
+
+ <sect2>
+  <title>Author</title>
+
+  <para>
+   Joey Adams <email>joeyadams3.14159@gmail.com</email>
+  </para>
+  
+  <para>
+   Development of this data type was sponsored by Google through its Google Summer of Code program (<ulink url="http://code.google.com/soc">code.google.com/soc</ulink>).
+  </para>
+ </sect2>
+
+</sect1>
diff --git a/src/backend/utils/adt/Makefile b/src/backend/utils/adt/Makefile
index 70e21b9..141f114 100644
--- a/src/backend/utils/adt/Makefile
+++ b/src/backend/utils/adt/Makefile
@@ -29,7 +29,8 @@ OBJS = acl.o arrayfuncs.o array_userfuncs.o arrayutils.o bool.o \
 	tsginidx.o tsgistidx.o tsquery.o tsquery_cleanup.o tsquery_gist.o \
 	tsquery_op.o tsquery_rewrite.o tsquery_util.o tsrank.o \
 	tsvector.o tsvector_op.o tsvector_parser.o \
-	txid.o uuid.o windowfuncs.o xml.o
+	txid.o uuid.o windowfuncs.o xml.o \
+	json.o json_io.o json_op.o jsonpath.o
 
 like.o: like.c like_match.c
 
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
new file mode 100644
index 0000000..0090411
--- /dev/null
+++ b/src/backend/utils/adt/json.c
@@ -0,0 +1,1276 @@
+/*-------------------------------------------------------------------------
+ *
+ * json.c
+ *	  Core JSON manipulation routines used by JSON data type support.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "utils/json.h"
+
+#include <ctype.h>
+
+#include "mb/pg_wchar.h"
+
+#define is_internal(node) ((node)->type == JSON_ARRAY || (node)->type == JSON_OBJECT)
+
+/* We can't use isspace() because it also accepts \v and \f, which
+   aren't legal whitespace characters in strict JSON. */
+#define is_whitespace(c) ((c)==' ' || (c)=='\t' || (c)=='\n' || (c)=='\r')
+
+static void
+skip_whitespace(const char **sp)
+{
+	const char *s = *sp;
+
+	while (is_whitespace(*s))
+		s++;
+	*sp = s;
+}
+
+static char
+end_parenthesis(JSON * node)
+{
+	Assert(node != NULL);
+
+	switch (node->type)
+	{
+		case JSON_ARRAY:
+			return ']';
+		case JSON_OBJECT:
+			return '}';
+		default:
+			Assert(false);
+			return '\0';
+	}
+}
+
+/*
+ * Reads exactly 4 hex characters (capital or lowercase).
+ * Writes the result to *out .
+ * Returns true on success, false if any input chars are not [0-9A-Fa-f] .
+ */
+static bool
+read_hex16(const char *in, unsigned int *out)
+{
+	unsigned int i;
+	unsigned int tmp;
+	char		c;
+
+	*out = 0;
+
+	for (i = 0; i < 4; i++)
+	{
+		c = *in++;
+		if (c >= '0' && c <= '9')
+			tmp = c - '0';
+		else if (c >= 'A' && c <= 'F')
+			tmp = c - 'A' + 10;
+		else if (c >= 'a' && c <= 'f')
+			tmp = c - 'a' + 10;
+		else
+			return false;
+
+		*out <<= 4;
+		*out += tmp;
+	}
+
+	return true;
+}
+
+/*
+ * Encodes a 16-bit number into hexadecimal,
+ * writing exactly 4 hex chars.
+ */
+static void
+write_hex16(char *out, unsigned int val)
+{
+	const char *hex = "0123456789ABCDEF";
+
+	*out++ = hex[(val >> 12) & 0xF];
+	*out++ = hex[(val >> 8) & 0xF];
+	*out++ = hex[(val >> 4) & 0xF];
+	*out++ = hex[val & 0xF];
+}
+
+/*
+ * utf8_decode_char
+ *	  Decodes a UTF-8 character, advancing *sp to point to the end of it.
+ *	  Returns the Unicode code point of the character.
+ *
+ *	  This function will go away when a utf8_to_unicode
+ *	  function becomes available.
+ */
+static pg_wchar
+utf8_decode_char(const char **sp)
+{
+	const unsigned char *s = (const unsigned char *) *sp;
+	unsigned char c = *s++;
+	unsigned int len;
+	unsigned char sf[4] = {0xFF, 0x1F, 0xF, 0x7};
+	pg_wchar	uc;
+
+	if (c < 0x80)
+		len = 0;
+	else if (c < 0xE0)
+		len = 1;
+	else if (c < 0xF0)
+		len = 2;
+	else
+		len = 3;
+
+	uc = c & sf[len];
+	while (len--)
+	{
+		uc <<= 6;
+		uc |= *s++ & 0x3F;
+	}
+
+	*sp = (const char *) s;
+	return uc;
+}
+
+#ifdef USE_ASSERT_CHECKING
+
+/*
+ * utf8_validate
+ *	  Essentially a variant of pg_verify_mbstr(PG_UTF8, str, length, true)
+ *	  that allows '\0' characters.
+ *
+ *	  This function is only used by assertions.
+ */
+static bool
+utf8_validate(const char *str, size_t length)
+{
+	const unsigned char *s = (const unsigned char *) str;
+	const unsigned char *e = s + length;
+	int			len;
+
+	while (s < e)
+	{
+		if (!IS_HIGHBIT_SET(*s))
+		{
+			s++;
+			continue;
+		}
+
+		len = pg_utf_mblen(s);
+		if (s + len > e)
+			return false;
+
+		if (!pg_utf8_islegal(s, len))
+			return false;
+
+		s += len;
+	}
+
+	return true;
+}
+#endif
+
+
+/*********** JSON creation, manipulation, and deletion **********/
+
+JSON *
+json_mknode(json_type type)
+{
+	JSON	   *node = palloc(sizeof(*node));
+
+	memset(node, 0, sizeof(*node));
+	node->type = type;
+	return node;
+}
+
+JSON *
+json_mkbool(bool v_bool)
+{
+	JSON	   *node = json_mknode(JSON_BOOL);
+
+	node->v.v_bool = v_bool;
+	return node;
+}
+
+JSON *
+json_mkstring(const char *str, size_t length)
+{
+	JSON	   *node = json_mknode(JSON_STRING);
+
+	if (str)
+	{
+		node->v.string.str = pnstrdup(str, length);
+		node->v.string.length = length;
+	}
+	return node;
+}
+
+JSON *
+json_mknumber(const char *number, size_t length)
+{
+	JSON	   *node = json_mknode(JSON_NUMBER);
+
+	if (number)
+		node->v.number = pnstrdup(number, length);
+	return node;
+}
+
+/*
+ * Indicate that the node's value has changed,
+ * marking ancestors as necessary.
+ *
+ * Call json_touch_value so that json_encode(..., JSONOPT_ORIG)
+ * will encode the new value rather than using original text.
+ */
+void
+json_touch_value(JSON * node)
+{
+	while (node && node->orig.value.start)
+	{
+		node->orig.value.start = NULL;
+		node = node->parent;
+	}
+}
+
+/*
+ * Add child to parent, but don't clear orig pointers of ancestors.
+ *
+ * This is used by json_decode to ensure that original text segments
+ * are preserved while building the JSON tree.
+ */
+static void
+json_append_notouch(JSON * parent, JSON * child)
+{
+	Assert(parent->type == JSON_ARRAY || parent->type == JSON_OBJECT);
+	Assert(child->parent == NULL);
+
+	parent->v.children.count++;
+	child->parent = parent;
+	child->prev = parent->v.children.tail;
+	child->next = NULL;
+
+	if (parent->v.children.tail)
+	{
+		parent->v.children.tail->next = child;
+		parent->v.children.tail = child;
+	}
+	else
+	{
+		parent->v.children.head = parent->v.children.tail = child;
+	}
+}
+
+/*
+ * json_append
+ *	  Add child to parent, putting it at the end of its child list.
+ *
+ *	  Child must not already have another parent.
+ */
+void
+json_append(JSON * parent, JSON * child)
+{
+	json_append_notouch(parent, child);
+	json_touch_value(parent);
+}
+
+/*
+ * json_remove
+ *	  Remove node from its parent, but do not delete it.
+ */
+void
+json_remove(JSON * node)
+{
+	JSON	   *parent = node->parent;
+
+	if (parent == NULL)
+		return;
+	Assert(parent->type == JSON_ARRAY || parent->type == JSON_OBJECT);
+	Assert(parent->v.children.count > 0);
+
+	if (node->prev)
+		node->prev->next = node->next;
+	else
+		parent->v.children.head = node->next;
+	if (node->next)
+		node->next->prev = node->prev;
+	else
+		parent->v.children.tail = node->prev;
+
+	parent->v.children.count--;
+	node->parent = NULL;
+	node->prev = NULL;
+	node->next = NULL;
+
+	json_touch_value(parent);
+}
+
+/*
+ * Update the value of a node, preserving position and key information.
+ *
+ * Note well: If replacement is an array or object with children, the parent
+ *			  pointers of those children will be incorrect
+ *			  (they'll still refer to their original parent).
+ *
+ *			  Untrustworthy parent pointers is the price to pay for
+ *			  being able to copy JSON values by reference.
+ */
+void
+json_replace_value(JSON * node, JSON * replacement)
+{
+	node->type = replacement->type;
+	node->v = replacement->v;
+	node->orig.value = replacement->orig.value;
+
+	if (node->parent)
+		json_touch_value(node->parent);
+}
+
+const char *
+json_get_string(JSON * node, size_t *length_out)
+{
+	Assert(node->type == JSON_STRING);
+	if (length_out)
+		*length_out = node->v.string.length;
+	return node->v.string.str;
+}
+
+void
+json_set_string(JSON * node, const char *str, size_t length)
+{
+	Assert(node->type == JSON_STRING);
+	if (node->v.string.str)
+		pfree(node->v.string.str);
+	if (str)
+	{
+		node->v.string.str = pnstrdup(str, length);
+		node->v.string.length = length;
+	}
+	else
+	{
+		node->v.string.str = NULL;
+		node->v.string.length = 0;
+	}
+	json_touch_value(node);
+}
+
+const char *
+json_get_number(JSON * node)
+{
+	Assert(node->type == JSON_NUMBER);
+	return node->v.number;
+}
+
+void
+json_set_number(JSON * node, const char *number, size_t length)
+{
+	Assert(node->type == JSON_NUMBER);
+	if (node->v.number)
+		pfree(node->v.number);
+	if (number)
+		node->v.number = pnstrdup(number, length);
+	else
+		node->v.number = NULL;
+	json_touch_value(node);
+}
+
+/* Non-recursively free a node */
+static void
+free_node(JSON * node)
+{
+	if (node->type == JSON_STRING)
+	{
+		if (node->v.string.str)
+			pfree(node->v.string.str);
+	}
+	else if (node->type == JSON_NUMBER)
+	{
+		if (node->v.number)
+			pfree(node->v.number);
+	}
+
+	if (node->key)
+		pfree(node->key);
+
+	pfree(node);
+}
+
+/*
+ * Free a JSON node and all its descendants.
+ *
+ * Do not use this function if you have performed json_replace_value on
+ * a descendant, as this function relies on each node's ->parent field
+ * being trustworthy.
+ */
+static void
+json_delete(JSON * node)
+{
+	JSON	   *parent,
+			   *next;
+
+	if (node == NULL)
+		return;
+
+	/* Remove node from parent (if it has one). */
+	json_remove(node);
+
+descend:
+	while (is_internal(node) && node->v.children.head)
+		node = node->v.children.head;
+
+advance:
+	parent = node->parent;
+	next = node->next;
+	free_node(node);
+	node = next;
+
+	if (node != NULL)
+	{
+		goto descend;
+	}
+	else
+	{
+		node = parent;
+		if (node != NULL)
+			goto advance;
+		else
+			return;
+	}
+}
+
+
+/*********************** Parsing and validation **********************/
+
+static JSON *decode_leaf(const char **sp);
+static JSON *decode_number(const char **sp);
+
+/*
+ * json_decode_string has a different signature than its friends
+ * because it's also used to parse object member keys.
+ * It's also useful outside of json.c, such as in jsonpath.c .
+ */
+char	   *json_decode_string(const char **sp, size_t *length, bool strict);
+
+/*
+ * json_validate
+ *	  Make sure the given UTF-8 string is valid JSON.
+ *
+ * TODO: Consider making a dedicated function for this so we don't have to
+ *		 convert to UTF-8, build a JSON node, then free both
+ *		 whenever we need to validate (such as in json_in and json_recv).
+ */
+bool
+json_validate(const char *str)
+{
+	JSON	   *node = json_decode(str);
+
+	if (node == NULL)
+		return false;
+	json_delete(node);
+	return true;
+}
+
+/*
+ * json_validate_server_encoded
+ *	  Variant of json_validate that takes a server-encoded string
+ *	  rather than a UTF-8 string.
+ *
+ *	  Note that a dedicated json_validate (described in the TODO above)
+ *	  would be able to handle both encodings natively, since both are
+ *	  ASCII-compatible.
+ */
+bool
+json_validate_server_encoded(const char *str)
+{
+	char	   *str_utf8 = server_to_utf8(str, strlen(str));
+	bool		result = json_validate(str_utf8);
+
+	if (str_utf8 != str)
+		pfree(str_utf8);
+
+	return result;
+}
+
+/*
+ * json_decode
+ *	  Convert a JSON-encoded string to a JSON node.
+ *	  @str must be valid UTF-8.
+ */
+JSON *
+json_decode(const char *str)
+{
+	JSON	   *root = NULL,
+			   *parent = NULL,
+			   *node = NULL;
+	const char *s = str;
+	char	   *key;
+	size_t		key_length;
+	struct json_orig orig;
+	bool		expect_endp;
+
+	if (str == NULL)
+		return NULL;
+
+	Assert(utf8_validate(str, strlen(str)));
+
+	expect_endp = false;
+	goto item;
+
+item:							/* Expect a value (set expect_endp before goto
+								 * item; ) */
+	key = NULL;
+	key_length = 0;
+	memset(&orig, 0, sizeof(orig));
+
+	orig.key_left_space.start = s;
+	orig.left_space.start = s;
+
+	skip_whitespace(&s);
+
+	if (expect_endp)
+	{
+		if (*s == ']' || *s == '}')
+			goto endp;
+	}
+
+	if (parent != NULL && parent->type == JSON_OBJECT)
+	{
+		/* Parse member key string. */
+		orig.key_left_space.end = s;
+		orig.key.start = s;
+
+		key = json_decode_string(&s, &key_length, true);
+		if (key == NULL)
+			goto failed;
+
+		orig.key.end = s;
+		orig.key_right_space.start = s;
+
+		/* Eat the " : " */
+		skip_whitespace(&s);
+		if (*s != ':')
+			goto failed;
+
+		orig.key_right_space.end = s;
+		s++;
+		orig.left_space.start = s;
+
+		skip_whitespace(&s);
+	}
+
+	/*
+	 * The way orig.value and company are initialized is a bit funky. If this
+	 * node has children, we have to finish parsing the node's children before
+	 * we know where it ends.  Hence, initialization of orig.value_end and
+	 * after will be deferred if this node has children.
+	 */
+
+	orig.left_space.end = s;
+	orig.value.start = s;
+
+	node = decode_leaf(&s);
+	if (node == NULL)
+	{
+		if (*s == '[')
+			node = json_mknode(JSON_ARRAY);
+		else if (*s == '{')
+			node = json_mknode(JSON_OBJECT);
+		else
+			goto failed;
+		s++;
+
+		/*
+		 * orig.value.end and later are dangling (actually NULL) for now, but
+		 * will be initialized when we get to state 'endp' .
+		 */
+	}
+	else
+	{
+		orig.value.end = s;
+		orig.right_space.start = s;
+
+		skip_whitespace(&s);
+
+		orig.right_space.end = s;
+	}
+
+	node->key = key;
+	node->key_length = key_length;
+
+	/*
+	 * The key now belongs to the node.  This prevents a double free on
+	 * failure (see the failed: label).
+	 */
+	key = NULL;
+
+	node->orig = orig;
+
+	if (parent != NULL)
+		json_append_notouch(parent, node);
+	else
+		root = node;
+
+	if (is_internal(node))
+	{
+		/*
+		 * "push" node onto the "stack".  Nodes point up to their parents,
+		 * which is why this function doesn't need a "stack" per se.
+		 */
+		parent = node;
+
+		expect_endp = true;
+		goto item;
+	}
+
+	if (parent != NULL)
+		goto comma_endp;
+	else
+		goto end;
+
+comma_endp:						/* Expect a comma or end bracket/brace */
+	if (*s == ',')
+	{
+		s++;
+
+		expect_endp = false;
+		goto item;
+	}
+	if (*s == ']' || *s == '}')
+		goto endp;
+
+	goto failed;
+
+endp:							/* Handle an end bracket/brace */
+	if (*s != end_parenthesis(parent))
+		goto failed;
+	s++;
+
+	/* "pop" a node from the "stack" */
+	node = parent;
+	parent = parent->parent;
+
+	/*
+	 * The other pointers were set when we started parsing this node in the
+	 * 'item' state.
+	 */
+	node->orig.value.end = s;
+	node->orig.right_space.start = s;
+
+	skip_whitespace(&s);
+
+	node->orig.right_space.end = s;
+
+	if (parent != NULL)
+		goto comma_endp;
+	else
+		goto end;
+
+end:							/* Expect end of text */
+	if (*s != '\0')
+		goto failed;
+	return node;
+
+failed:					/* Handle failure */
+	if (key != NULL)
+		pfree(key);
+	json_delete(root);
+	return NULL;
+}
+
+/*
+ * Decode and skip a node that does not have children.
+ * Whitespace is not skipped first (it is done in the primary decode loop).
+ *
+ * Returns NULL if next character is '[', '{', or invalid.
+ */
+static JSON *
+decode_leaf(const char **sp)
+{
+	char		c = **sp;
+
+	if (c == '"')
+	{
+		size_t		length;
+		char	   *str = json_decode_string(sp, &length, true);
+
+		if (str != NULL)
+		{
+			JSON	   *node = json_mknode(JSON_STRING);
+
+			node->v.string.str = str;
+			node->v.string.length = length;
+			return node;
+		}
+
+		return NULL;
+	}
+	if ((c >= '0' && c <= '9') || c == '-')
+		return decode_number(sp);
+	if (strncmp(*sp, "true", 4) == 0)
+	{
+		(*sp) += 4;
+		return json_mkbool(true);
+	}
+	if (strncmp(*sp, "false", 5) == 0)
+	{
+		(*sp) += 5;
+		return json_mkbool(false);
+	}
+	if (strncmp(*sp, "null", 4) == 0)
+	{
+		(*sp) += 4;
+		return json_mknode(JSON_NULL);
+	}
+
+	return NULL;
+}
+
+/*
+ * The JSON spec says that a number shall follow this precise pattern
+ * (spaces and quotes added for readability):
+ *	 '-'? (0 | [1-9][0-9]*) ('.' [0-9]+)? ([Ee] [+-]? [0-9]+)?
+ *
+ * However, some JSON parsers are more liberal.  For instance, PHP accepts
+ * '.5' and '1.'.  JSON.parse accepts '+3'.
+ *
+ * This function takes the strict approach.
+ */
+static bool
+validate_number(const char **sp)
+{
+	const char *s = *sp;
+
+	/* '-'? */
+	if (*s == '-')
+		s++;
+
+	/* (0 | [1-9][0-9]*) */
+	if (*s == '0')
+	{
+		s++;
+	}
+	else
+	{
+		if (!isdigit(*s))
+			return false;
+		do
+			s++;
+		while (isdigit(*s));
+	}
+
+	/* ('.' [0-9]+)? */
+	if (*s == '.')
+	{
+		s++;
+		if (!isdigit(*s))
+			return false;
+		do
+			s++;
+		while (isdigit(*s));
+	}
+
+	/* ([Ee] [+-]? [0-9]+)? */
+	if (*s == 'E' || *s == 'e')
+	{
+		s++;
+		if (*s == '+' || *s == '-')
+			s++;
+		if (!isdigit(*s))
+			return false;
+		do
+			s++;
+		while (isdigit(*s));
+	}
+
+	*sp = s;
+	return true;
+}
+
+static JSON *
+decode_number(const char **sp)
+{
+	const char *start,
+			   *end;
+
+	start = *sp;
+	if (!validate_number(sp))
+		return NULL;
+	end = *sp;
+
+	return json_mknumber(start, end - start);
+}
+
+/*
+ * json_decode_string
+ *	  If you're interested in the decoding JSON in general, see json_decode.
+ *
+ *	  Decodes a JSON string literal (e.g. "\"hello\"").
+ *
+ *	  If strict is true, string must be double-quoted,
+ *	  as is required by the JSON RFC.
+ *	  Otherwise (e.g. if parsing something JSON-like, such as JSONPath),
+ *	  the string may be single- or double-quoted.
+ *
+ *	  Also, no whitespace skipping is done, so the caller should only
+ *	  call this function when it expects **sp to be either " or '
+ *
+ *	  On success, returns the decoded string, passes the decoded string's
+ *	  length through *length (which must not be NULL), and advances *sp to point
+ *	  to the end of string literal (after the closing quote character).
+ *
+ *	  On failure (parse error), returns NULL and
+ *	  leaves *length and *sp untouched.
+ */
+char *
+json_decode_string(const char **sp, size_t *length, bool strict)
+{
+	const char *s = *sp;
+	StringInfoData ret;
+	char		buf[4];
+	int			len;
+	char		quote;
+
+	Assert(length != NULL);
+
+	initStringInfo(&ret);
+
+	quote = *s++;
+	if (strict)
+	{
+		if (quote != '"')
+			return NULL;
+	}
+	else
+	{
+		if (quote != '"' && quote != '\'')
+			return NULL;
+	}
+
+	while (*s != '\0' && *s != quote)
+	{
+		unsigned char c = *s++;
+		unsigned int uc;
+		unsigned int lc;
+
+		if (c == '\\')
+		{
+			c = *s++;
+			switch (c)
+			{
+				case '\\':
+				case '/':
+					break;
+				case 'b':
+					c = '\b';
+					break;
+				case 'f':
+					c = '\f';
+					break;
+				case 'n':
+					c = '\n';
+					break;
+				case 'r':
+					c = '\r';
+					break;
+				case 't':
+					c = '\t';
+					break;
+				case 'u':
+					if (!read_hex16(s, &uc))
+						goto failed;
+					s += 4;
+
+					if (uc >= 0xD800 && uc <= 0xDFFF)
+					{
+						/* Handle UTF-16 surrogate pair. */
+
+						if (uc >= 0xDC00)
+							goto failed;		/* Second surrogate not
+												 * preceded by first
+												 * surrogate. */
+
+						if (s[0] != '\\' || s[1] != 'u'
+							|| !read_hex16(s + 2, &lc)
+							|| !(lc >= 0xDC00 && lc <= 0xDFFF))
+							goto failed;		/* First surrogate not
+												 * followed by second
+												 * surrogate. */
+
+						s += 6;
+
+						uc = 0x10000 | ((uc & 0x3FF) << 10) | (lc & 0x3FF);
+					}
+
+					unicode_to_utf8(uc, (unsigned char *) buf);
+					len = pg_utf_mblen((unsigned char *) buf);
+
+					Assert(len > 0);
+
+					appendBinaryStringInfo(&ret, buf, len);
+
+					continue;	/* Continue the enclosing while loop to skip
+								 * the str_append below. */
+				default:		/* Invalid escape */
+					if (c == quote)
+						break;
+					if (!strict && (c == '"' || c == '\''))
+						break;
+					goto failed;	/* Invalid escape */
+			}
+		}
+		else if (c <= 0x1F)
+		{
+			/* Control characters not allowed in string literals. */
+			goto failed;
+		}
+		appendStringInfoChar(&ret, c);
+	}
+
+	if (*s++ != quote)
+		goto failed;
+
+	*length = ret.len;
+	*sp = s;
+	return ret.data;
+
+failed:
+	pfree(ret.data);
+	return NULL;
+}
+
+/*
+ * json_text_type
+ *	  Determines the type of a JSON string without fully decoding it.
+ *	  Expects the given string to be valid JSON.
+ *	  Might return JSON_INVALID if something is wrong with the input.
+ */
+json_type
+json_text_type(const char *str, size_t nbytes)
+{
+	const char *s = str;
+	const char *e = str + nbytes;
+	char		c;
+
+	/* Skip whitespace characters. */
+	while (s < e && is_whitespace(*s))
+		s++;
+
+	/* Get first non-white character, making sure it's in bounds. */
+	if (s >= e)
+		return JSON_INVALID;
+	c = *s;
+
+	switch (c)
+	{
+		case 'n':
+			return JSON_NULL;
+		case '"':
+			return JSON_STRING;
+		case 't':
+		case 'f':
+			return JSON_BOOL;
+		case '{':
+			return JSON_OBJECT;
+		case '[':
+			return JSON_ARRAY;
+		default:
+			if (c == '-' || (c >= '0' && c <= '9'))
+				return JSON_NUMBER;
+			return JSON_INVALID;
+	}
+}
+
+
+/****************************** Encoding *****************************/
+
+/*
+ * encode_string
+ *	  Variant of json_encode_string that writes its output to a StringInfo.
+ */
+static void
+encode_string(StringInfo out, const char *string, size_t length, char quote,
+			  bool escape_unicode)
+{
+	const char *s = string;
+	const char *e = s + length;
+
+	Assert(quote != '\\');
+	if (escape_unicode)
+		Assert(utf8_validate(string, length));
+
+	appendStringInfoChar(out, quote);
+
+	while (s < e)
+	{
+		unsigned char c = *s++;
+		unsigned char endchar;
+
+		switch (c)
+		{
+			case '\\':
+				endchar = '\\';
+				break;
+			case '\b':
+				endchar = 'b';
+				break;
+			case '\f':
+				endchar = 'f';
+				break;
+			case '\n':
+				endchar = 'n';
+				break;
+			case '\r':
+				endchar = 'r';
+				break;
+			case '\t':
+				endchar = 't';
+				break;
+			default:
+				{
+					if (c == quote)
+					{
+						endchar = quote;
+						break;
+					}
+					if (c < 0x1F || (c >= 0x80 && escape_unicode))
+					{
+						/* Encode using \u.... */
+						pg_wchar	uc;
+						unsigned int lc;
+						char		txt[13];
+
+						s--;
+						uc = utf8_decode_char(&s);
+
+						txt[0] = '\\';
+						txt[1] = 'u';
+						txt[6] = '\\';
+						txt[7] = 'u';
+						if (uc <= 0xFFFF)
+						{
+							write_hex16(txt + 2, uc);
+							txt[6] = '\0';
+						}
+						else
+						{
+							uc -= 0x10000;
+							lc = uc & 0x3FF;
+							uc = uc >> 10;
+							uc |= 0xD800;
+							lc |= 0xDC00;
+							write_hex16(txt + 2, uc);
+							write_hex16(txt + 8, lc);
+							txt[12] = '\0';
+						}
+
+						appendStringInfoString(out, txt);
+						continue;		/* Skip backslash-encoding code below. */
+					}
+					endchar = '\0';
+				}
+		}
+
+		appendStringInfoChar(out, endchar ? '\\' : c);
+		if (endchar != '\0')
+			appendStringInfoChar(out, endchar);
+	}
+
+	appendStringInfoChar(out, quote);
+}
+
+static bool
+encode_number(StringInfo out, const char *string)
+{
+	const char *s = string;
+	const char *start,
+			   *end;
+
+	if (string == NULL)
+		return false;
+
+	/* Validate number, trimming whitespace. */
+	skip_whitespace(&s);
+	start = s;
+	if (!validate_number(&s))
+		return false;
+	end = s;
+	skip_whitespace(&s);
+	if (*s != '\0')
+		return false;
+
+	/* Append number to out */
+	appendBinaryStringInfo(out, start, end - start);
+
+	return true;
+}
+
+typedef struct
+{
+	StringInfoData str;
+	bool		use_orig;
+	bool		escape_unicode;
+	bool		trim;
+}	json_encode_ctx;
+
+static bool json_encode_recurse(JSON * node, json_encode_ctx * ctx);
+
+/*
+ * json_encode
+ *	  Encode a JSON node.
+ *
+ *	  The JSONOPT_ESCAPE_UNICODE option may only be used
+ *	  if the strings in the JSON tree are UTF-8-encoded.
+ */
+char *
+json_encode(JSON * node, int options)
+{
+	json_encode_ctx ctx;
+
+	initStringInfo(&ctx.str);
+	ctx.use_orig = !!(options & JSONOPT_USE_ORIG);
+	ctx.escape_unicode = !!(options & JSONOPT_ESCAPE_UNICODE);
+	ctx.trim = !(options & JSONOPT_NO_TRIM);
+
+	if (!json_encode_recurse(node, &ctx))
+	{
+		pfree(ctx.str.data);
+		return NULL;
+	}
+
+	return ctx.str.data;
+}
+
+static bool
+json_encode_recurse(JSON * node, json_encode_ctx * ctx)
+{
+#define has_orig(field) \
+		(use_orig && node->orig.field.start)
+#define push_orig(field) \
+		appendBinaryStringInfo(&ctx->str, node->orig.field.start, \
+							node->orig.field.end - node->orig.field.start)
+
+	bool		use_orig = ctx->use_orig;
+	bool		trim = ctx->trim;
+
+	ctx->trim = false;			/* Don't trim internal nodes, just the root
+								 * node. */
+
+	if (!trim && has_orig(left_space))
+		push_orig(left_space);
+
+	if (has_orig(value))
+	{
+		push_orig(value);
+	}
+	else
+	{
+		const char *txt = NULL;
+		JSON	   *child;
+
+		switch (node->type)
+		{
+			case JSON_NULL:
+				txt = "null";
+				break;
+			case JSON_BOOL:
+				if (node->v.v_bool)
+					txt = "true";
+				else
+					txt = "false";
+				break;
+			case JSON_STRING:
+				encode_string(&ctx->str,
+							  node->v.string.str, node->v.string.length,
+							  '"', ctx->escape_unicode);
+				break;
+			case JSON_NUMBER:
+				if (!encode_number(&ctx->str, node->v.number))
+					return false;
+				break;
+			case JSON_ARRAY:
+				appendStringInfoChar(&ctx->str, '[');
+
+				json_foreach(child, node)
+				{
+					json_encode_recurse(child, ctx);
+					if (child->next != NULL)
+						appendStringInfoChar(&ctx->str, ',');
+				}
+
+				appendStringInfoChar(&ctx->str, ']');
+				break;
+			case JSON_OBJECT:
+				appendStringInfoChar(&ctx->str, '{');
+
+				json_foreach(child, node)
+				{
+					/*
+					 * Shadows the parent node (assigned to the variable
+					 * @node) so we can use our macros on the child node
+					 * instead. Hurray for lexical scoping!
+					 */
+					JSON	   *node = child;
+
+					if (has_orig(key_left_space))
+						push_orig(key_left_space);
+
+					if (has_orig(key))
+						push_orig(key);
+					else
+						encode_string(&ctx->str, node->key, node->key_length,
+									  '"', ctx->escape_unicode);
+
+					if (has_orig(key_right_space))
+						push_orig(key_right_space);
+
+					appendStringInfoChar(&ctx->str, ':');
+
+					json_encode_recurse(node, ctx);
+
+					if (node->next != NULL)
+						appendStringInfoChar(&ctx->str, ',');
+				}
+
+				appendStringInfoChar(&ctx->str, '}');
+				break;
+			default:
+				return false;
+		}
+
+		if (txt != NULL)
+			appendStringInfoString(&ctx->str, txt);
+	}
+
+	if (!trim && has_orig(right_space))
+		push_orig(right_space);
+
+	return true;
+
+#undef has_orig
+#undef push_orig
+}
+
+/*
+ * json_encode_string
+ *	  If you're interested in encoding JSON in general, see json_encode .
+ *
+ *	  Encodes a string literal JSON-style using the given quote character.
+ *	  Note that using anything but '"' as the quote character will result
+ *	  in invalid JSON.
+ *
+ *	  If escape_unicode is true, str must be valid UTF-8.
+ *	  In any case, str may contain null characters (hence the length argument).
+ *
+ *	  quote must not be a backslash.
+ */
+char *
+json_encode_string(const char *str, size_t length, char quote,
+				   bool escape_unicode)
+{
+	StringInfoData ret;
+
+	initStringInfo(&ret);
+	encode_string(&ret, str, length, quote, escape_unicode);
+
+	return ret.data;
+}
diff --git a/src/backend/utils/adt/json_io.c b/src/backend/utils/adt/json_io.c
new file mode 100644
index 0000000..c73a708
--- /dev/null
+++ b/src/backend/utils/adt/json_io.c
@@ -0,0 +1,464 @@
+/*-------------------------------------------------------------------------
+ *
+ * json_io.c
+ *	  Primary input/output and conversion procedures
+ *	  for JSON data type.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "utils/json.h"
+
+#include "utils/array.h"
+#include "mb/pg_wchar.h"
+
+PG_MODULE_MAGIC;
+
+static json_type decide_json_type(Oid type, char category);
+static const char *datum_to_json(Datum datum, TypeInfo *typeInfo,
+			  json_type target_type);
+static const char *array_to_json(Datum datum);
+static const char *build_array_string(const char **values,
+				   const int *dim, int ndim);
+static void build_array_string_recurse(StringInfo string, const char ***values,
+						   const int *dim, int ndim);
+
+void
+report_corrupt_json(void)
+{
+	ereport(ERROR,
+			(errcode(ERRCODE_DATA_CORRUPTED),
+			 errmsg("corrupt JSON content")));
+}
+
+PG_FUNCTION_INFO_V1(json_in);
+Datum		json_in(PG_FUNCTION_ARGS);
+Datum
+json_in(PG_FUNCTION_ARGS)
+{
+	char	   *string = PG_GETARG_CSTRING(0);
+	jsontype   *vardata;
+
+	if (!json_validate_server_encoded(string))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_TEXT_REPRESENTATION),
+				 errmsg("could not parse JSON value")));
+
+	vardata = cstring_to_text(string);
+	PG_RETURN_JSON_P(vardata);
+}
+
+PG_FUNCTION_INFO_V1(json_out);
+Datum		json_out(PG_FUNCTION_ARGS);
+Datum
+json_out(PG_FUNCTION_ARGS)
+{
+	jsontype   *vardata = PG_GETARG_JSON_P(0);
+	char	   *string = text_to_cstring((text *) vardata);
+
+	Assert(json_validate_server_encoded(string));
+
+	PG_RETURN_CSTRING(string);
+}
+
+PG_FUNCTION_INFO_V1(json_recv);
+Datum		json_recv(PG_FUNCTION_ARGS);
+Datum
+json_recv(PG_FUNCTION_ARGS)
+{
+	StringInfo	buf = (StringInfo) PG_GETARG_POINTER(0);
+	char	   *str;
+	int			nbytes;
+	jsontype   *result;
+
+	str = pq_getmsgtext(buf, buf->len - buf->cursor, &nbytes);
+
+	if (!json_validate_server_encoded(str))
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_BINARY_REPRESENTATION),
+				 errmsg("could not parse JSON value")));
+
+	result = cstring_to_text_with_len(str, nbytes);
+	pfree(str);
+
+	PG_RETURN_JSON_P(result);
+}
+
+PG_FUNCTION_INFO_V1(json_send);
+Datum		json_send(PG_FUNCTION_ARGS);
+Datum
+json_send(PG_FUNCTION_ARGS)
+{
+	jsontype   *t = PG_GETARG_JSON_P(0);
+	StringInfoData buf;
+
+#ifdef USE_ASSERT_CHECKING
+	{
+		char	   *string = text_to_cstring(t);
+
+		Assert(json_validate_server_encoded(string));
+
+		pfree(string);
+	}
+#endif
+
+	pq_begintypsend(&buf);
+	pq_sendtext(&buf, VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
+	PG_RETURN_BYTEA_P(pq_endtypsend(&buf));
+}
+
+/*
+ * Performs JSON value extraction in UTF-8 C-String land.
+ *
+ * If the input was JSON-encoded NULL, this function returns NULL
+ * (indicating that we want from_json to yield actual SQL NULL).
+ */
+static const char *
+from_json_cstring(const char *input)
+{
+	size_t		len;
+	JSON	   *json = json_decode(input);
+	const char *cstring_out = NULL;
+
+	if (json == NULL)
+		report_corrupt_json();
+
+	switch (json->type)
+	{
+		case JSON_NULL:
+			cstring_out = NULL;
+			break;
+		case JSON_STRING:
+			cstring_out = json_get_string(json, &len);
+			if (strlen(cstring_out) != len)
+				ereport(ERROR,
+						(errcode(ERRCODE_UNTRANSLATABLE_CHARACTER),
+						 errmsg("could not convert JSON-encoded string to TEXT: contains \\u0000"),
+						 errdetail("the string was: %s", utf8_to_server(input, strlen(input)))));
+
+			/*
+			 * todo: suggest using from_json_as_bytea instead when that is
+			 * available.
+			 */
+			break;
+		case JSON_NUMBER:
+			cstring_out = json_get_number(json);
+			break;
+		case JSON_BOOL:
+			cstring_out = json_get_bool(json) ? "true" : "false";
+			break;
+		case JSON_OBJECT:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("from_json cannot be applied to JSON objects")));
+			break;
+		case JSON_ARRAY:
+			ereport(ERROR,
+					(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+					 errmsg("from_json cannot be applied to JSON arrays")));
+			break;
+		default:
+			Assert(false);
+	}
+
+	return cstring_out;
+}
+
+PG_FUNCTION_INFO_V1(from_json);
+Datum		from_json(PG_FUNCTION_ARGS);
+Datum
+from_json(PG_FUNCTION_ARGS)
+{
+	char	   *cstring_in = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	const char *cstring_out = from_json_cstring(cstring_in);
+	text	   *vardata_out;
+
+	pfree(cstring_in);
+
+	if (cstring_out != NULL)
+	{
+		vardata_out = utf8_cstring_to_text(cstring_out);
+		PG_RETURN_TEXT_P(vardata_out);
+	}
+	else
+	{
+		PG_RETURN_NULL();
+	}
+}
+
+PG_FUNCTION_INFO_V1(to_json);
+Datum		to_json(PG_FUNCTION_ARGS);
+Datum
+to_json(PG_FUNCTION_ARGS)
+{
+	Oid			argtype = get_fn_expr_argtype(fcinfo->flinfo, 0);
+	TypeInfo   *typeInfo;
+	json_type	target_type;
+
+	typeInfo = FN_EXTRA();
+	if (typeInfo == NULL)
+	{
+		typeInfo = FN_EXTRA_ALLOC(sizeof(TypeInfo));
+		getTypeInfo(typeInfo, argtype, IOFunc_output, FN_MCXT());
+	}
+	else if (typeInfo->type != argtype)
+	{
+		getTypeInfo(typeInfo, argtype, IOFunc_output, FN_MCXT());
+	}
+
+	target_type = decide_json_type(argtype, typeInfo->typcategory);
+
+	/*
+	 * If NULL argument is given, return the string "null", not actual NULL.
+	 * The null check is done after the type check so users can identify type
+	 * bugs earlier.
+	 */
+	if (PG_ARGISNULL(0))
+		PG_RETURN_JSON_P(cstring_to_text("null"));
+
+	PG_RETURN_JSON_P(utf8_cstring_to_text(
+				  datum_to_json(PG_GETARG_DATUM(0), typeInfo, target_type)));
+}
+
+/*
+ * decide_json_type
+ *
+ * Given a type and its corresponding typcategory, determine what
+ * JSON type to encode it to.  If it's not possible to encode the type
+ * (or if support for the type isn't implemented yet), report an error.
+ */
+static json_type
+decide_json_type(Oid type, char category)
+{
+	switch (category)
+	{
+		case 'S':
+			return JSON_STRING;
+		case 'P':
+			if (type == CSTRINGOID)
+				return JSON_STRING;
+			goto invalid;
+		case 'N':
+			if (type == CASHOID)
+				goto invalid;
+			return JSON_NUMBER;
+		case 'B':
+			if (type == BOOLOID)
+				return JSON_BOOL;
+			goto invalid;
+		case 'A':
+			return JSON_ARRAY;
+		default:
+			goto invalid;
+	}
+
+invalid:
+	ereport(ERROR,
+			(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
+		 errmsg("to_json cannot convert %s to JSON", format_type_be(type))));
+	return JSON_INVALID;
+}
+
+/*
+ * datum_to_json
+ *	  Converts a datum to a UTF-8-encoded JSON string.
+ *
+ *	  typeInfo comes from the getTypeInfo function, and
+ *	  target_type comes from decide_json_type .
+ *
+ *	  See to_json and array_to_json for examples of
+ *	  how to invoke this function.
+ */
+static const char *
+datum_to_json(Datum datum, TypeInfo *typeInfo, json_type target_type)
+{
+	char	   *cstring;
+	char	   *cstring_utf8;
+	JSON	   *node;
+	char	   *encoded_utf8;
+
+	switch (target_type)
+	{
+		case JSON_STRING:
+		case JSON_NUMBER:
+			cstring = OutputFunctionCall(&typeInfo->proc, datum);
+			cstring_utf8 = server_to_utf8(cstring, strlen(cstring));
+
+			if (cstring != cstring_utf8)
+				pfree(cstring);
+
+			if (target_type == JSON_STRING)
+				node = json_mkstring(cstring_utf8, strlen(cstring_utf8));
+			else
+				node = json_mknumber(cstring_utf8, strlen(cstring_utf8));
+
+			encoded_utf8 = json_encode(node, 0);
+			if (encoded_utf8 == NULL)
+			{
+				/*
+				 * Currently, we assume that output conversion for all types
+				 * in category 'N' (excluding CASH) will, by coincidence,
+				 * always give a valid JSON-encoded number.
+				 *
+				 * If this error message appears, it means the assumption is
+				 * incorrect, and we need to either blacklist the type in
+				 * decide_json_type (like we did with CASH), or add code that
+				 * can parse the number type.
+				 */
+				ereport(ERROR,
+						(errcode(ERRCODE_INTERNAL_ERROR),
+						 errmsg("to_json failed to convert %s \"%s\" to a valid JSON %s.\n",
+								format_type_be(typeInfo->type),
+								cstring,
+						 target_type == JSON_STRING ? "string" : "number")));
+			}
+
+			return encoded_utf8;
+
+		case JSON_BOOL:
+			return DatumGetBool(datum) ? "true" : "false";
+
+		case JSON_ARRAY:
+			return array_to_json(datum);
+
+		default:
+			Assert(false);
+			return NULL;
+	}
+}
+
+/*
+ * array_to_json
+ *	  Converts a PostgreSQL array datum to a UTF-8-encoded JSON string.
+ *
+ *	  Note: We assume that any type with typcategory = 'A'
+ *			is compatible with array_out.
+ */
+static const char *
+array_to_json(Datum datum)
+{
+	ArrayType  *v = DatumGetArrayTypeP(datum);
+	Oid			element_type = ARR_ELEMTYPE(v);
+	TypeInfo	element_typeinfo;
+	json_type	target_type;
+	int		   *dim;
+	int			ndim;
+	int			nitems;
+	int			i;
+	char	   *s;
+	bits8	   *bitmap;
+	int			bitmask;
+	Datum		elt;
+	const char **values;
+	const char *ret;
+
+	/*
+	 * todo: Consider caching the TypeInfo of array items (which we're
+	 * computing now) in the fcinfo->flinfo->fn_mcxt of to_json like we do
+	 * with the TypeInfo of the array itself.
+	 */
+	getTypeInfo(&element_typeinfo, element_type, IOFunc_output, CurrentMemoryContext);
+
+	target_type = decide_json_type(element_type, element_typeinfo.typcategory);
+
+	ndim = ARR_NDIM(v);
+	dim = ARR_DIMS(v);
+	nitems = ArrayGetNItems(ndim, dim);
+
+	/*
+	 * Unfortunately, we can't make SELECT
+	 * to_json(ARRAY[[],[],[]]::integer[][]); yield '[[],[],[]]' because ndim
+	 * is set to 0 when the array has no items.
+	 */
+	if (nitems <= 0)
+		return "[]";
+
+	values = palloc(nitems * sizeof(const char *));
+
+	s = ARR_DATA_PTR(v);
+	bitmap = ARR_NULLBITMAP(v);
+	bitmask = 1;
+
+	for (i = 0; i < nitems; i++)
+	{
+		if (bitmap != NULL && (*bitmap & bitmask) == 0)
+		{
+			values[i] = NULL;
+		}
+		else
+		{
+			elt = fetch_att(s, element_typeinfo.typbyval, element_typeinfo.typlen);
+			s = att_addlength_datum(s, element_typeinfo.typlen, elt);
+			s = (char *) att_align_nominal(s, element_typeinfo.typalign);
+
+			values[i] = datum_to_json(elt, &element_typeinfo, target_type);
+		}
+
+		if (bitmap != NULL)
+		{
+			bitmask <<= 1;
+			if (bitmask == 0x100)
+			{
+				bitmap++;
+				bitmask = 1;
+			}
+		}
+	}
+
+	ret = build_array_string(values, dim, ndim);
+
+	pfree(values);
+
+	return ret;
+}
+
+/*
+ * build_array_string
+ *	  Takes a multidimensional array of (JSON-formatted) strings and
+ *	  converts it to JSON by wrapping the strings in array brackets and commas.
+ */
+static const char *
+build_array_string(const char **values, const int *dim, int ndim)
+{
+	StringInfoData string[1];
+
+	initStringInfo(string);
+	build_array_string_recurse(string, &values, dim, ndim);
+
+	return string->data;
+}
+
+static void
+build_array_string_recurse(StringInfo string, const char ***values,
+						   const int *dim, int ndim)
+{
+	int			i,
+				count = dim[0];
+
+	appendStringInfoChar(string, '[');
+
+	for (i = 0; i < count; i++)
+	{
+		if (ndim > 1)
+		{
+			build_array_string_recurse(string, values, dim + 1, ndim - 1);
+		}
+		else
+		{
+			const char *value = *(*values)++;
+
+			if (value != NULL)
+				appendStringInfoString(string, value);
+			else
+				appendStringInfoString(string, "null");
+		}
+
+		if (i + 1 < count)
+			appendStringInfoChar(string, ',');
+	}
+
+	appendStringInfoChar(string, ']');
+}
diff --git a/src/backend/utils/adt/json_op.c b/src/backend/utils/adt/json_op.c
new file mode 100644
index 0000000..577c4ee
--- /dev/null
+++ b/src/backend/utils/adt/json_op.c
@@ -0,0 +1,252 @@
+/*-------------------------------------------------------------------------
+ *
+ * json_op.c
+ *	  Manipulation procedures for JSON data type.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "utils/json.h"
+#include "utils/jsonpath.h"
+
+static EnumLabel enum_labels[JSON_TYPE_COUNT] =
+{
+	{JSON_NULL, "null"},
+	{JSON_STRING, "string"},
+	{JSON_NUMBER, "number"},
+	{JSON_BOOL, "bool"},
+	{JSON_OBJECT, "object"},
+	{JSON_ARRAY, "array"}
+};
+
+/* json_validate(text).  Renamed to avoid clashing
+ * with the C function json_validate. */
+PG_FUNCTION_INFO_V1(json_validate_f);
+Datum		json_validate_f(PG_FUNCTION_ARGS);
+Datum
+json_validate_f(PG_FUNCTION_ARGS)
+{
+	char	   *string;
+	bool		ret;
+
+	string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	ret = json_validate(string);
+	pfree(string);
+
+	PG_RETURN_BOOL(ret);
+}
+
+/* json_type(json).  Renamed to avoid clashing
+ * with the typedef enum of the same name. */
+PG_FUNCTION_INFO_V1(json_get_type);
+Datum		json_get_type(PG_FUNCTION_ARGS);
+Datum
+json_get_type(PG_FUNCTION_ARGS)
+{
+	jsontype   *t = PG_GETARG_JSON_P(0);
+	json_type	type;
+	Oid		   *label_oids;
+
+	/*
+	 * No need to convert to UTF-8 before calling json_text_type, as it looks
+	 * solely at ASCII characters.
+	 */
+	type = json_text_type(VARDATA_ANY(t), VARSIZE_ANY_EXHDR(t));
+
+	if (!json_type_is_valid(type))
+		report_corrupt_json();
+
+	label_oids = FN_EXTRA();
+	if (label_oids == NULL)
+	{
+		label_oids = FN_EXTRA_ALLOC(JSON_TYPE_COUNT * sizeof(Oid));
+		getEnumLabelOids("json_type_t", enum_labels, label_oids, JSON_TYPE_COUNT);
+	}
+
+	PG_RETURN_OID(label_oids[type]);
+}
+
+PG_FUNCTION_INFO_V1(json_condense);
+Datum		json_condense(PG_FUNCTION_ARGS);
+Datum
+json_condense(PG_FUNCTION_ARGS)
+{
+	char	   *string;
+	JSON	   *json;
+	char	   *condensed;
+
+	string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	json = json_decode(string);
+	condensed = json_encode(json, 0);
+
+	if (condensed == NULL)
+		report_corrupt_json();
+
+	PG_RETURN_JSON_P(utf8_cstring_to_text(condensed));
+}
+
+/*
+ * json_path_base
+ *	  Given the function call info of a PostgreSQL function
+ *	  with arguments (JSON, jsonpath TEXT [, ...]),
+ *	  match the JSONPath string given in the second argument
+ *	  against the JSON tree given in the first argument.
+ *
+ *	  This returns a List of JPRef* items, just like jp_match.
+ *	  jpref_encode() is used to convert them to JSON-formatted strings.
+ */
+static List *
+json_path_base(FunctionCallInfo fcinfo)
+{
+	char	   *json_string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	char	   *path_string = text_to_utf8_cstring(PG_GETARG_TEXT_PP(1));
+	JSONPath   *jpath = jp_parse(path_string);
+	JSON	   *json = json_decode(json_string);
+	List	   *result_list;
+
+	if (jpath == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid JSONPath expression")));
+	if (json == NULL)
+		report_corrupt_json();
+
+	result_list = jp_match(jpath, json);
+
+	return result_list;
+}
+
+PG_FUNCTION_INFO_V1(json_get);
+Datum		json_get(PG_FUNCTION_ARGS);
+Datum
+json_get(PG_FUNCTION_ARGS)
+{
+	List	   *result_list = json_path_base(fcinfo);
+	ListCell   *result;
+	char	   *rs_json;
+	jsontype   *result_vardata;
+	int			length = list_length(result_list);
+
+	if (length == 0)
+	{
+		PG_RETURN_NULL();
+	}
+	else if (length == 1)
+	{
+		result = list_head(result_list);
+		rs_json = jpref_encode(lfirst(result));
+
+		Assert(rs_json != NULL);
+		Assert(json_validate(rs_json) == true);
+
+		result_vardata = (jsontype *) utf8_cstring_to_text(rs_json);
+
+		pfree(rs_json);
+
+		PG_RETURN_JSON_P(result_vardata);
+	}
+	else
+	{
+		ereport(ERROR,
+				(errcode(ERRCODE_DATA_EXCEPTION),
+				 errmsg("JSONPath expression matched multiple results")));
+		PG_RETURN_NULL();
+	}
+}
+
+PG_FUNCTION_INFO_V1(json_set);
+Datum		json_set(PG_FUNCTION_ARGS);
+Datum
+json_set(PG_FUNCTION_ARGS)
+{
+	char	   *json_string = text_to_utf8_cstring(PG_GETARG_JSON_P(0));
+	char	   *path_string = text_to_utf8_cstring(PG_GETARG_TEXT_PP(1));
+	char	   *rvalue_string = text_to_utf8_cstring(PG_GETARG_JSON_P(2));
+	JSONPath   *jpath = jp_parse(path_string);
+	JSON	   *json = json_decode(json_string);
+	JSON	   *rvalue = json_decode(rvalue_string);
+	char	   *result;
+	jsontype   *result_text;
+
+	if (jpath == NULL)
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("invalid JSONPath expression")));
+
+	if (json == NULL || rvalue == NULL)
+		report_corrupt_json();
+
+	jp_set(jpath, json, rvalue);
+
+	result = json_encode(json, JSONOPT_USE_ORIG | JSONOPT_NO_TRIM);
+	result_text = utf8_cstring_to_text(result);
+
+	pfree(result);
+
+	PG_RETURN_JSON_P(result_text);
+}
+
+PG_FUNCTION_INFO_V1(json_path);
+Datum		json_path(PG_FUNCTION_ARGS);
+Datum
+json_path(PG_FUNCTION_ARGS)
+{
+	FuncCallContext *funcctx;
+	ListCell   *result;
+
+	/* TODO: consider returning the entire result set in one call. */
+
+	if (SRF_IS_FIRSTCALL())
+	{
+		MemoryContext oldcontext;
+		List	   *results;
+
+		funcctx = SRF_FIRSTCALL_INIT();
+		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
+
+		results = json_path_base(fcinfo);
+		funcctx->user_fctx = list_head(results);
+
+		MemoryContextSwitchTo(oldcontext);
+	}
+
+	funcctx = SRF_PERCALL_SETUP();
+	result = funcctx->user_fctx;
+
+	if (result != NULL)
+	{
+		char	   *json_string;
+		jsontype   *json_text;
+
+		json_string = jpref_encode(lfirst(result));
+		Assert(json_string != NULL);
+		Assert(json_validate(json_string) == true);
+
+		json_text = utf8_cstring_to_text(json_string);
+
+		funcctx->user_fctx = lnext(result);
+
+		SRF_RETURN_NEXT(funcctx, JSONPGetDatum(json_text));
+	}
+
+	SRF_RETURN_DONE(funcctx);
+}
+
+PG_FUNCTION_INFO_V1(parse_json_path);
+Datum		parse_json_path(PG_FUNCTION_ARGS);
+Datum
+parse_json_path(PG_FUNCTION_ARGS)
+{
+	char	   *string = text_to_utf8_cstring(PG_GETARG_TEXT_PP(0));
+	JSONPath   *jpath = jp_parse(string);
+	char	   *normalized;
+
+	if (jpath == NULL)
+		PG_RETURN_NULL();
+
+	normalized = jp_show(jpath);
+	PG_RETURN_TEXT_P(utf8_cstring_to_text(normalized));
+}
diff --git a/src/backend/utils/adt/jsonpath.c b/src/backend/utils/adt/jsonpath.c
new file mode 100644
index 0000000..70b67a6
--- /dev/null
+++ b/src/backend/utils/adt/jsonpath.c
@@ -0,0 +1,596 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonpath.c
+ *	  JSONPath implementation routines for JSON data type support.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#include "utils/jsonpath.h"
+#include "mb/pg_wchar.h"
+
+#include <ctype.h>
+
+/* NB: These macros evaluate their argument multiple times. */
+
+#define isletter(c) (((c) >= 'A' && (c) <= 'Z') || ((c) >= 'a' && (c) <= 'z'))
+ /* isalpha() is locale-specific.  This simply matches [A-Za-z] . */
+#define isextended(c) ((unsigned char)(c) > 127)
+
+/* Note that Unicode characters are allowed in identifiers. */
+#define identifier_start(c) (isletter(c) || (c) == '_' || (c) == '$' || isextended(c))
+#define identifier_char(c) (identifier_start(c) || isdigit(c))
+
+#define integer_start(c) (isdigit(c) || (c) == '+' || (c) == '-')
+
+/*
+ * In a valid JSONPath list, the first element is always of type JP_ROOT.
+ * This element is used so an otherwise empty JSONPath list won't be NULL.
+ * This allows us to use NULL to indicate an invalid JSONPath.
+ *
+ * This function returns the first cell,
+ * making sure it is of type JP_ROOT.
+ */
+static ListCell *
+jp_root(JSONPath * jp)
+{
+	ListCell   *cell;
+	jp_element *elem;
+
+	Assert(jp != NULL);
+
+	cell = list_head(jp);
+	elem = lfirst(cell);
+	Assert(elem->type == JP_ROOT);
+
+	return cell;
+}
+
+/*
+ * This function returns the second cell of a JSONPath list
+ * (the first cell after the JP_ROOT).
+ */
+static ListCell *
+jp_head(JSONPath * jp)
+{
+	return lnext(jp_root(jp));
+}
+
+/*
+ * Note that skip_spaces differs from skip_whitespace in json.c
+ * in that this function treats '\f' and '\v' as whitespace.
+ * This is because JSON does not accept these characters as
+ * whitespace, but since this is JSONPath,
+ * we can do whatever we want here :-)
+ */
+static void
+skip_spaces(const char **sp)
+{
+	const char *s = *sp;
+
+	while (isspace(*s))
+		s++;
+	*sp = s;
+}
+
+static jp_element *
+mkElement(jp_element_type type, bool rd)
+{
+	jp_element *elem = palloc0(sizeof(*elem));
+
+	elem->type = type;
+	elem->recursive_descent = rd;
+	return elem;
+}
+
+static jp_element *
+mkRoot(void)
+{
+	jp_element *elem = mkElement(JP_ROOT, false);
+
+	return elem;
+}
+
+static jp_element *
+mkWildcard(bool rd)
+{
+	jp_element *elem = mkElement(JP_WILDCARD, rd);
+
+	return elem;
+}
+
+static jp_element *
+mkIndexSubscript(long index, bool rd)
+{
+	jp_element *elem = mkElement(JP_INDEX_SUBSCRIPT, rd);
+
+	elem->data.index = index;
+	return elem;
+}
+
+static jp_element *
+mkKeySubscript(char *key, size_t length, bool rd)
+{
+	jp_element *elem = mkElement(JP_KEY_SUBSCRIPT, rd);
+
+	elem->data.key.ptr = key;
+	elem->data.key.length = length;
+	return elem;
+}
+
+static jp_element *
+mkCallChar(long index, bool rd)
+{
+	jp_element *elem = mkElement(JP_CALL_CHAR, rd);
+
+	elem->data.index = index;
+	return elem;
+}
+
+static JPRef *
+mkRef(JPRefType type)
+{
+	JPRef	   *ref = palloc0(sizeof(*ref));
+
+	ref->type = type;
+	return ref;
+}
+
+static JPRef *
+mkRefNode(JSON * node)
+{
+	JPRef	   *ref = mkRef(JP_REF_NODE);
+
+	ref->u.node = node;
+	return ref;
+}
+
+static JPRef *
+mkRefChar(const char *bytes, size_t length)
+{
+	JPRef	   *ref = mkRef(JP_REF_CHAR);
+	ref->u.chr. bytes = bytes;
+	ref->u.chr. length = length;
+
+	return ref;
+}
+
+/*
+ * jp_show
+ *	  Unparse a JSONPath expression.  This is used by parse_json_path
+ *	  to stringify successfully parsed JSONPaths.
+ */
+char *
+jp_show(JSONPath * jp)
+{
+	StringInfoData string[1];
+	ListCell   *cell;
+	jp_element *elem;
+	bool		rd;
+	char	   *tmp;
+
+	initStringInfo(string);
+
+	foreach(cell, jp)
+	{
+		elem = lfirst(cell);
+		rd = elem->recursive_descent;
+
+		switch (elem->type)
+		{
+			case JP_ROOT:
+				appendStringInfoChar(string, '$');
+				break;
+			case JP_WILDCARD:
+				appendStringInfoString(string, rd ? "..[*]" : "[*]");
+				break;
+			case JP_INDEX_SUBSCRIPT:
+				appendStringInfo(string, "%s[%ld]", rd ? ".." : "", elem->data.index);
+				break;
+			case JP_KEY_SUBSCRIPT:
+				tmp = json_encode_string(elem->data.key.ptr, elem->data.key.length, '"', false);
+				appendStringInfo(string, "%s[%s]", rd ? ".." : "", tmp);
+				pfree(tmp);
+				break;
+			case JP_CALL_CHAR:
+				appendStringInfo(string, "%s(%ld)", rd ? "..char" : ".char", elem->data.index);
+				break;
+			default:
+				Assert(false);
+		}
+	}
+
+	return string->data;
+}
+
+/*
+ * Parse a long starting at *s .
+ *
+ * On success, return true and update *s to point to the end of the number.
+ * On failure, return false and leave *s untouched.
+ */
+static bool
+parse_long(const char **s, long *out)
+{
+	const char *p = *s;
+
+	errno = 0;
+	*out = strtol(*s, (char **) &p, 10);
+	if (p <= *s || errno != 0)
+		return false;
+
+	*s = p;
+	return true;
+}
+
+/*
+ * jp_parse
+ *	  Parse a JSONPath expression (into a List of jp_element items).
+ *
+ *	  TODO: Get rid of all those gotos.  The parser uses constant space,
+ *			so there's no chance of a stack overflow anyway.
+ */
+JSONPath *
+jp_parse(const char *pattern)
+{
+	JSONPath   *jp = NIL;
+	const char *s = pattern;
+	const char *start;
+	const char *end;
+	bool		recursive_descent = false;
+	bool		bracket = false;
+	const char *err_msg = NULL;
+	long		index;
+	char	   *key;
+	size_t		key_length;
+
+	skip_spaces(&s);
+
+	/* pattern may not be empty */
+	if (*s == '\0')
+		return NULL;
+
+	jp = lappend(jp, mkRoot());
+
+	if (*s == '$')
+	{
+		s++;
+		goto begin_element;
+	}
+	else if (*s != '.')
+	{
+		goto dot_subscript;
+		/* implicit '.' at beginning */
+	}
+
+begin_element:
+	skip_spaces(&s);
+begin_element_noskip:
+
+	recursive_descent = false;
+	bracket = false;
+
+	if (*s == '\0')
+		goto end;
+	if (s[0] == '.' && s[1] == '.')
+	{
+		recursive_descent = true;
+		s += 2;
+		goto dot_subscript;
+	}
+	if (s[0] == '.')
+	{
+		s++;
+		goto dot_subscript;
+	}
+	if (s[0] == '[')
+	{
+		s++;
+		goto bracket_subscript;
+	}
+
+	goto failed;
+
+next_element:
+	if (bracket)
+	{
+		skip_spaces(&s);
+		if (*s != ']')
+			goto failed;
+		s++;
+	}
+	goto begin_element;
+
+dot_subscript:
+	skip_spaces(&s);
+
+	if (*s == '*')
+		goto wildcard;
+	if (integer_start(*s))
+		goto integer;
+	if (identifier_start(*s))
+		goto identifier;
+	if (*s == '"' || *s == '\'')
+		goto string;
+	if (*s == '[')
+	{
+		s++;
+		goto bracket_subscript;
+	}
+
+	goto failed;
+
+bracket_subscript:
+	skip_spaces(&s);
+
+	bracket = true;
+
+	if (*s == '*')
+		goto wildcard;
+	if (integer_start(*s))
+		goto integer;
+	if (identifier_start(*s))
+	{
+		err_msg = "Identifiers may not be bracketed.  This syntax is reserved for future use.";
+		goto failed;
+	}
+	if (*s == '"' || *s == '\'')
+		goto string;
+
+	goto failed;
+
+wildcard:
+	s++;
+	jp = lappend(jp, mkWildcard(recursive_descent));
+	goto next_element;
+
+integer:
+	if (!parse_long(&s, &index))
+		goto failed;
+
+	jp = lappend(jp, mkIndexSubscript(index, recursive_descent));
+	goto next_element;
+
+identifier:
+	start = s;
+	while (identifier_char(*s))
+		s++;
+	end = s;
+
+	skip_spaces(&s);
+
+	if (*s == '(')
+	{
+		if (end - start == 4 && memcmp(start, "char", 4) == 0)
+		{
+			s++;
+			skip_spaces(&s);
+			goto call_char;
+		}
+
+		goto failed;
+	}
+
+	key = pnstrdup(start, end - start);
+	key_length = end - start;
+
+	jp = lappend(jp, mkKeySubscript(key, key_length, recursive_descent));
+	goto begin_element_noskip;
+
+string:
+	key = json_decode_string(&s, &key_length, false);
+	if (key == NULL)
+		goto failed;
+
+	jp = lappend(jp, mkKeySubscript(key, key_length, recursive_descent));
+	goto next_element;
+
+call_char:
+	if (!parse_long(&s, &index))
+		goto failed;
+
+	skip_spaces(&s);
+
+	if (*s++ != ')')
+		goto failed;
+
+	jp = lappend(jp, mkCallChar(index, recursive_descent));
+	goto begin_element;
+
+end:
+	return jp;
+
+failed:
+	return NULL;
+}
+
+/*
+ * Currently, a lot of JPRef nodes are allocated just to pass JSON pointers
+ * to match_recurse.  If this becomes a memory/performance issue in the future,
+ * JPRef could merged with JSON by adding JPRef's specialty types to the
+ * json_type enum and JSON union.	JPRef is currently not merged with
+ * JSON in an attempt to keep the codebase tidy and easier to extend.
+ */
+static void match_recurse(void on_match(void *ctx, JPRef * ref), void *ctx,
+									  ListCell *path, JPRef * ref)
+{
+	jp_element *elem;
+	JSON	   *json,
+			   *child;
+
+	if (path == NULL)
+	{
+		/* The end of the JSONPath list is the "accept" state. */
+		on_match(ctx, ref);
+		return;
+	}
+
+	elem = lfirst(path);
+
+	if (ref->type == JP_REF_NODE)
+		json = ref->u.node;
+	else
+		json = NULL;
+
+	switch (elem->type)
+	{
+		case JP_WILDCARD:
+			if (json != NULL)
+			{
+				json_foreach(child, json)
+					match_recurse(on_match, ctx, lnext(path), mkRefNode(child));
+			}
+			break;
+
+		case JP_INDEX_SUBSCRIPT:
+			if (json != NULL && json->type == JSON_ARRAY &&
+				elem->data.index >= 0 &&
+				(size_t) elem->data.index < json->v.children.count)
+			{
+				size_t		i;
+
+				for (child = json->v.children.head, i = 0;
+					 child != NULL && i < (size_t) elem->data.index;
+					 child = child->next, i++)
+				{
+				}
+
+				/*
+				 * If this fails, it means json->v.children.count was greater
+				 * than the actual number of children.
+				 */
+				Assert(i == elem->data.index && child != NULL);
+
+				match_recurse(on_match, ctx, lnext(path), mkRefNode(child));
+			}
+			break;
+
+		case JP_KEY_SUBSCRIPT:
+			if (json != NULL && json->type == JSON_OBJECT)
+			{
+				json_foreach(child, json)
+				{
+					if (child->key != NULL &&
+						child->key_length == elem->data.key.length &&
+						memcmp(child->key, elem->data.key.ptr, child->key_length) == 0)
+					{
+						match_recurse(on_match, ctx, lnext(path), mkRefNode(child));
+					}
+				}
+			}
+			break;
+
+		case JP_CALL_CHAR:
+			if (json != NULL && json->type == JSON_STRING &&
+				elem->data.index >= 0)
+			{
+				const char *sub_start;
+				int			sub_bytes;
+				int			sub_length;
+
+				pg_encoding_substring(PG_UTF8,
+								   json->v.string.str, json->v.string.length,
+									  elem->data.index, 1,
+									  &sub_start, &sub_bytes, &sub_length);
+
+				if (sub_length == 1)
+					match_recurse(on_match, ctx, lnext(path), mkRefChar(sub_start, sub_bytes));
+			}
+			else if (ref->type == JP_REF_CHAR && elem->data.index == 0)
+			{
+				/* char(0) on a character yields itself. */
+				match_recurse(on_match, ctx, lnext(path), ref);
+			}
+			break;
+
+		default:;
+	}
+
+	if (elem->recursive_descent && json != NULL)
+	{
+		json_foreach(child, json)
+		{
+			if (!child->jp_changed)
+				match_recurse(on_match, ctx, path, mkRefNode(child));
+		}
+	}
+}
+
+static void
+jp_match_callback(List **results, JPRef * ref)
+{
+	*results = lappend(*results, ref);
+}
+
+/*
+ * jp_match
+ *	  Match a parsed JSONPath expression against a JSON tree,
+ *	  yielding a List of JPRef* items.
+ *
+ *	  To convert the JPRef* items to JSON-formatted strings, use jpref_encode.
+ */
+List *
+jp_match(JSONPath * jp, JSON * json)
+{
+	ListCell   *lc = jp_head(jp);
+	List	   *results = NIL;
+
+	match_recurse((void *) jp_match_callback, &results, lc, mkRefNode(json));
+
+	return results;
+}
+
+static void
+jp_set_callback(JSON * value, JPRef * ref)
+{
+	switch (ref->type)
+	{
+		case JP_REF_NODE:
+			json_replace_value(ref->u.node, value);
+			ref->u.node->jp_changed = true;
+			break;
+
+		default:;				/* Do nothing if ref is immutable. */
+	}
+}
+
+/*
+ * jp_set
+ *	  Set all elements that match a parsed JSONPath expression
+ *	  in a JSON tree to a new value.
+ *
+ *	  Note that jp_set uses json_replace_value so it doesn't have to deep-copy
+ *	  on every assignment if @value is a tree.	This means that parent pointers
+ *	  of the resulting tree will not be trustworthy.
+ */
+void
+jp_set(JSONPath * jp, JSON * json, JSON * value)
+{
+	ListCell   *lc = jp_head(jp);
+
+	match_recurse((void *) jp_set_callback, value, lc, mkRefNode(json));
+}
+
+/*
+ * jpref_encode
+ *	  Convert a JPRef to a JSON-formatted string.
+ */
+char *
+jpref_encode(JPRef * ref)
+{
+	switch (ref->type)
+	{
+		case JP_REF_NODE:
+			return json_encode(ref->u.node, JSONOPT_USE_ORIG);
+
+		case JP_REF_CHAR:
+			return json_encode_string(ref->u.chr.bytes, ref->u.chr.length, '"', false);
+
+		default:
+			Assert(false);
+			return NULL;
+	}
+}
diff --git a/src/include/catalog/pg_enum.h b/src/include/catalog/pg_enum.h
index 826b8bd..2409fcd 100644
--- a/src/include/catalog/pg_enum.h
+++ b/src/include/catalog/pg_enum.h
@@ -52,11 +52,26 @@ typedef FormData_pg_enum *Form_pg_enum;
 #define Anum_pg_enum_enumtypid			1
 #define Anum_pg_enum_enumlabel			2
 
+#define JSON_NULL_OID					3880
+#define JSON_STRING_OID					3881
+#define JSON_NUMBER_OID					3882
+#define JSON_BOOL_OID					3883
+#define JSON_OBJECT_OID					3884
+#define JSON_ARRAY_OID					3885
+
 /* ----------------
- *		pg_enum has no initial contents
+ *		initial contents of pg_enum
  * ----------------
  */
 
+/* json_type_t */
+DATA(insert OID = 3880 (146, null));
+DATA(insert OID = 3881 (146, string));
+DATA(insert OID = 3882 (146, number));
+DATA(insert OID = 3883 (146, bool));
+DATA(insert OID = 3884 (146, object));
+DATA(insert OID = 3885 (146, array));
+
 /*
  * prototypes for functions in pg_enum.c
  */
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
index d613038..f834eb5 100644
--- a/src/include/catalog/pg_proc.h
+++ b/src/include/catalog/pg_proc.h
@@ -4416,7 +4416,7 @@ DESCR("evaluate XPath expression, with namespaces support");
 DATA(insert OID = 2932 (  xpath		 PGNSP PGUID 14 1 0 0 f f f t f i 2 0 143 "25 142" _null_ _null_ _null_ _null_ "select pg_catalog.xpath($1, $2, ''{}''::pg_catalog.text[])" _null_ _null_ _null_ ));
 DESCR("evaluate XPath expression");
 
-DATA(insert OID = 2614 (  xmlexists	 PGNSP PGUID 12 1 0 0 f f f t f i 2 0 16 "25 142" _null_ _null_ _null_ _null_ xmlexists _null_ _null_ _null_ ));
+DATA(insert OID = 2614 (  xmlexists  PGNSP PGUID 12 1 0 0 f f f t f i 2 0 16 "25 142" _null_ _null_ _null_ _null_ xmlexists _null_ _null_ _null_ ));
 DESCR("test XML value against XPath expression");
 
 DATA(insert OID = 3049 (  xpath_exists	 PGNSP PGUID 12 1 0 0 f f f t f i 3 0 16 "25 142 1009" _null_ _null_ _null_ _null_ xpath_exists _null_ _null_ _null_ ));
@@ -4424,6 +4424,33 @@ DESCR("test XML value against XPath expression, with namespace support");
 DATA(insert OID = 3050 (  xpath_exists	 PGNSP PGUID 14 1 0 0 f f f t f i 2 0 16 "25 142" _null_ _null_ _null_ _null_ "select pg_catalog.xpath_exists($1, $2, ''{}''::pg_catalog.text[])" _null_ _null_ _null_ ));
 DESCR("test XML value against XPath expression");
 
+/* JSON support */
+DATA(insert OID = 3850 (  json_in			PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 144  "2275"		  _null_ _null_ _null_					_null_ json_in		   _null_ _null_ _null_ ));
+DESCR("I/O");
+DATA(insert OID = 3851 (  json_out			PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 2275 "144"		  _null_ _null_ _null_					_null_ json_out		   _null_ _null_ _null_ ));
+DESCR("I/O");
+DATA(insert OID = 3852 (  json_recv			PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 144  "2281"		  _null_ _null_ _null_					_null_ json_recv	   _null_ _null_ _null_ ));
+DESCR("I/O");
+DATA(insert OID = 3853 (  json_send			PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 17	 "144"		  _null_ _null_ _null_					_null_ json_send	   _null_ _null_ _null_ ));
+DESCR("I/O");
+DATA(insert OID = 3854 (  json_type			PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 146  "144"		  _null_ _null_ _null_					_null_ json_get_type   _null_ _null_ _null_ ));
+DESCR("get type of a JSON value");
+DATA(insert OID = 3855 (  json_validate		PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 16	 "25"		  _null_ _null_ _null_					_null_ json_validate_f _null_ _null_ _null_ ));
+DESCR("determine if text is valid JSON");
+DATA(insert OID = 3856 (  from_json			PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 25	 "144"		  _null_ _null_ _null_					_null_ from_json	   _null_ _null_ _null_ ));
+DESCR("decode a JSON value");
+DATA(insert OID = 3857 (  to_json			PGNSP PGUID 12 1 0	  0 f f f f f i 1 0 144  "2283"		  _null_ _null_ _null_					_null_ to_json		   _null_ _null_ _null_ ));
+DESCR("encode a value as JSON");
+DATA(insert OID = 3858 (  json_get			PGNSP PGUID 12 1 0	  0 f f f t f i 2 0 144  "144 25"	  _null_ _null_ "{null,json_path}"		_null_ json_get		   _null_ _null_ _null_ ));
+DESCR("get a single element matching a JSONPath expression");
+DATA(insert OID = 3859 (  json_set			PGNSP PGUID 12 1 0	  0 f f f t f i 3 0 144  "144 25 144" _null_ _null_ "{null,json_path,null}" _null_ json_set		   _null_ _null_ _null_ ));
+DESCR("set all elements matching a JSONPath expression to a new value");
+DATA(insert OID = 3860 (  json_path			PGNSP PGUID 12 1 1000 0 f f f t t i 2 0 144  "144 25"	  _null_ _null_ "{null,json_path}"		_null_ json_path	   _null_ _null_ _null_ ));
+DESCR("get all elements matching a JSONPath expression as a set");
+DATA(insert OID = 3861 (  json_condense		PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 144  "144"		  _null_ _null_ _null_					_null_ json_condense   _null_ _null_ _null_ ));
+DESCR("remove whitespace and unnecessary escapes in a JSON value");
+DATA(insert OID = 3862 (  parse_json_path	PGNSP PGUID 12 1 0	  0 f f f t f i 1 0 25	 "25"		  _null_ _null_ _null_					_null_ parse_json_path _null_ _null_ _null_ ));
+
 /* uuid */
 DATA(insert OID = 2952 (  uuid_in		   PGNSP PGUID 12 1 0 0 f f f t f i 1 0 2950 "2275" _null_ _null_ _null_ _null_ uuid_in _null_ _null_ _null_ ));
 DESCR("I/O");
diff --git a/src/include/catalog/pg_type.h b/src/include/catalog/pg_type.h
index c22aacc..f4a3fdb 100644
--- a/src/include/catalog/pg_type.h
+++ b/src/include/catalog/pg_type.h
@@ -343,6 +343,16 @@ DESCR("XML content");
 #define XMLOID 142
 DATA(insert OID = 143 ( _xml	   PGNSP PGUID -1 f b A f t \054 0 142 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
 
+
+DATA(insert OID = 144 ( json	   PGNSP PGUID -1 f b S f t \054 0 0 145 json_in json_out json_recv json_send - - - i x f 0 -1 0 _null_ _null_ ));
+DESCR("JSON content");
+DATA(insert OID = 145 ( _json	   PGNSP PGUID -1 f b A f t \054 0 144 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
+
+DATA(insert OID = 146 ( json_type_t  PGNSP PGUID 4	t e E f t \054 0 0 147 enum_in enum_out enum_recv enum_send - - - i p f 0 -1 0 _null_ _null_ ));
+DESCR("type of JSON value, as given by the json_type function");
+DATA(insert OID = 147 ( _json_type_t PGNSP PGUID -1 f b A f t \054 0 146 0 array_in array_out array_recv array_send - - - i x f 0 -1 0 _null_ _null_ ));
+
+
 /* OIDS 200 - 299 */
 
 DATA(insert OID = 210 (  smgr	   PGNSP PGUID 2 t b U f t \054 0 0 0 smgrin smgrout - - - - - s p f 0 -1 0 _null_ _null_ ));
diff --git a/src/include/utils/json.h b/src/include/utils/json.h
new file mode 100644
index 0000000..16654ed
--- /dev/null
+++ b/src/include/utils/json.h
@@ -0,0 +1,220 @@
+/*-------------------------------------------------------------------------
+ *
+ * json.h
+ *	  Core JSON manipulation routines used by JSON data type support,
+ *	  along with miscellaneous declarations and includes.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef JSON_H
+#define JSON_H
+
+#include "postgres.h"
+
+#include "access/heapam.h"
+#include "access/htup.h"
+#include "catalog/namespace.h"
+#include "catalog/pg_type.h"
+#include "funcapi.h"
+#include "libpq/pqformat.h"
+#include "utils/builtins.h"
+#include "utils/lsyscache.h"
+#include "utils/syscache.h"
+#include "utils/typcache.h"
+
+typedef struct varlena jsontype;
+
+#define DatumGetJSONP(X)	((jsontype *) PG_DETOAST_DATUM(X))
+#define JSONPGetDatum(X)	PointerGetDatum(X)
+
+#define PG_GETARG_JSON_P(n) DatumGetJSONP(PG_GETARG_DATUM(n))
+#define PG_RETURN_JSON_P(x) PG_RETURN_POINTER(x)
+
+void		report_corrupt_json(void);
+
+/* Keep the order of these enum entries in sync with
+ * enum_type_names[] in json_ops.c . */
+typedef enum
+{
+	JSON_NULL,
+	JSON_STRING,
+	JSON_NUMBER,
+	JSON_BOOL,
+	JSON_OBJECT,
+	JSON_ARRAY,
+	JSON_TYPE_COUNT = JSON_ARRAY + 1,
+
+	JSON_INVALID
+}	json_type;
+
+#define json_type_is_valid(type) ((type) >= 0 && (type) < JSON_TYPE_COUNT)
+
+typedef struct JSON JSON;
+
+/*
+ * All strings in JSON nodes are UTF-8-encoded, not server encoded.
+ * The reason for this is because we need to encode/decode individual
+ * Unicode codepoints when dealing with escape characters, but there
+ * are no functions for efficiently converting between Unicode code points
+ * and any server encoding.
+ *
+ * As an exception to the rule, if you only use node factory functions and
+ * json_encode without the JSONOPT_ESCAPE_UNICODE option, you may operate
+ * in the server encoding instead.
+ */
+struct JSON
+{
+	json_type	type;
+
+	union
+	{
+		/* JSON_BOOL */
+		bool		v_bool;
+
+		/* JSON_STRING */
+		struct
+		{
+			char	   *str;
+			size_t		length;
+		}			string;
+
+		/*
+		 * JSON_NUMBER
+		 *
+		 * Numbers are encoded as strings to avoid unnecessary precision loss.
+		 */
+		char	   *number;
+
+		/* JSON_ARRAY or JSON_OBJECT (children) */
+		struct
+		{
+			JSON	   *head;
+			JSON	   *tail;
+			size_t		count;
+		}			children;
+	}			v;
+
+	JSON	   *parent;
+	JSON	   *prev;
+	JSON	   *next;
+
+	/*
+	 * If node is a member of an object, key will be set. Otherwise, key will
+	 * be null.
+	 */
+	char	   *key;
+	size_t		key_length;
+
+	struct json_orig
+	{
+		/* These only apply if this node is a member of an object. */
+		struct
+		{
+			const char *start;
+			const char *end;
+		}			key_left_space, key, key_right_space;
+
+		struct
+		{
+			const char *start;
+			const char *end;
+		}			left_space, value, right_space;
+	}			orig;
+
+	/* Used by jp_set to indicate we should not visit this node again. */
+	bool		jp_changed;
+};
+
+
+/*** Encoding / decoding / validation ***/
+
+bool		json_validate(const char *str);
+bool		json_validate_server_encoded(const char *str);
+JSON	   *json_decode(const char *str);
+
+#define JSONOPT_USE_ORIG		1
+#define JSONOPT_ESCAPE_UNICODE	2
+#define JSONOPT_NO_TRIM			4
+char	   *json_encode(JSON * node, int options);
+
+json_type	json_text_type(const char *str, size_t nbytes);
+
+
+/*** Lookup / traversal ***/
+
+#define json_foreach(child, parent) \
+	for ((child) = json_head(parent); (child) != NULL; (child) = (child)->next)
+
+static inline JSON *
+json_head(JSON * parent)
+{
+	switch (parent->type)
+	{
+		case JSON_ARRAY:
+		case JSON_OBJECT:
+			return parent->v.children.head;
+		default:
+			return NULL;
+	}
+}
+
+
+/*** Parent/child manipulation ***/
+
+void		json_append(JSON * parent, JSON * child);
+void		json_remove(JSON * node);
+
+
+/*** Node factory functions ***/
+
+JSON	   *json_mknode(json_type type);
+JSON	   *json_mkbool(bool v_bool);
+JSON	   *json_mkstring(const char *str, size_t length);
+JSON	   *json_mknumber(const char *number, size_t length);
+static inline JSON *
+json_mkarray(void)
+{
+	return json_mknode(JSON_ARRAY);
+}
+static inline JSON *
+json_mkobject(void)
+{
+	return json_mknode(JSON_OBJECT);
+}
+
+
+/*** Value get/set functions ***/
+
+void		json_touch_value(JSON * node);
+
+static inline bool
+json_get_bool(JSON * node)
+{
+	Assert(node->type == JSON_BOOL);
+	return node->v.v_bool;
+}
+static inline void
+json_set_bool(JSON * node, bool v_bool)
+{
+	Assert(node->type == JSON_BOOL);
+	node->v.v_bool = v_bool;
+	json_touch_value(node);
+}
+const char *json_get_string(JSON * node, size_t *length_out);
+void		json_set_string(JSON * node, const char *str, size_t length);
+const char *json_get_number(JSON * node);
+void		json_set_number(JSON * node, const char *number, size_t length);
+
+void		json_replace_value(JSON * node, JSON * replacement);
+
+
+/*** Miscellaneous utility functions ***/
+
+char	   *json_decode_string(const char **sp, size_t *length, bool strict);
+char	   *json_encode_string(const char *str, size_t length, char quote, bool escape_unicode);
+
+#endif
diff --git a/src/include/utils/jsonpath.h b/src/include/utils/jsonpath.h
new file mode 100644
index 0000000..3caf0ab
--- /dev/null
+++ b/src/include/utils/jsonpath.h
@@ -0,0 +1,103 @@
+/*-------------------------------------------------------------------------
+ *
+ * jsonpath.h
+ *	  JSONPath implementation routines for JSON data type support.
+ *
+ *	  The "JSONPath" implemented here is similar to, but not exactly the same as,
+ *	  the JSONPath described at http://goessner.net/articles/JsonPath/ .
+ *	  The main differences are stronger subscripting rules, special methods
+ *	  via function-call notation (currently, the only one provided is .char()),
+ *	  and that the '$' at the beginning of a JSONPath expression is optional.
+ *	  Also, array indices as a set (e.g. [0,1]) and filters/scripts are currently
+ *	  not implemented.	Array indices are a planned feature.  True filters
+ *	  would require an honest-to-goodness JavaScript engine, so perhaps
+ *	  someone will write a module for that in the future.
+ *
+ * Copyright (c) 2010, PostgreSQL Global Development Group
+ * Written by Joey Adams <joeyadams3.14159@gmail.com>.
+ *
+ *-------------------------------------------------------------------------
+ */
+
+#ifndef JSONPATH_H
+#define JSONPATH_H
+
+#include "utils/json.h"
+
+#include "nodes/pg_list.h"
+
+typedef enum
+{
+	JP_ROOT,
+	JP_WILDCARD,
+	JP_INDEX_SUBSCRIPT,
+	JP_KEY_SUBSCRIPT,
+	JP_CALL_CHAR
+}	jp_element_type;
+
+/*
+ * A jp_element is a single piece of a JSONPath expression
+ * (e.g. [3], .foo, .char(3), ..*).  It represents subscripting
+ * down one level in a JSON tree, or invoking a special method
+ * (like .char() ).  However, if recursive_descent is set to true,
+ * the subscript applies to a value and all of its descendants.
+ */
+typedef struct
+{
+	jp_element_type type;
+
+	union
+	{
+		long		index;
+		struct
+		{
+			char	   *ptr;
+			size_t		length;
+		}			key;
+	}			data;
+
+	/* If element was preceded by ".." in pattern */
+	bool		recursive_descent;
+}	jp_element;
+
+typedef enum
+{
+	JP_REF_NODE,
+	JP_REF_CHAR
+}	JPRefType;
+
+/*
+ * A JPRef is a reference to some part of a JSON tree,
+ * typically a value (but not always).
+ *
+ * JPRef* is really a "subclass" of JSON* .  In the future, this structure
+ * will likely be merged into the JSON structure to improve performance.
+ */
+typedef struct
+{
+	JPRefType	type;
+
+	union
+	{
+		JSON	   *node;
+
+		struct
+		{
+			const char *bytes;
+			size_t		length;
+		} chr;
+	}			u;
+}	JPRef;
+
+typedef List /* jp_element* */ JSONPath;
+
+JSONPath   *jp_parse(const char *pattern);
+char	   *jp_show(JSONPath * jp);
+
+List /* JPRef* */ *jp_match(JSONPath * jp, JSON * json);
+void		jp_set(JSONPath * jp, JSON * json, JSON * value);
+
+/* Returns the JSON encoding of the given reference. */
+char	   *jpref_encode(JPRef * ref);
+
+#endif
diff --git a/src/test/regress/expected/json.out b/src/test/regress/expected/json.out
new file mode 100644
index 0000000..157298d
--- /dev/null
+++ b/src/test/regress/expected/json.out
@@ -0,0 +1,2440 @@
+SET client_min_messages = warning;
+\set ECHO none
+RESET client_min_messages;
+SELECT '[]'::JSON;
+ json 
+------
+ []
+(1 row)
+
+SELECT '['::JSON;
+ERROR:  could not parse JSON value
+LINE 1: SELECT '['::JSON;
+               ^
+SELECT '[1,2,3]'::JSON;
+  json   
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[1,2,3]'::JSON::TEXT;
+  text   
+---------
+ [1,2,3]
+(1 row)
+
+SELECT '[1,2,3  ]'::JSON;
+   json    
+-----------
+ [1,2,3  ]
+(1 row)
+
+SELECT '[1,2,3  ,4]'::JSON;
+    json     
+-------------
+ [1,2,3  ,4]
+(1 row)
+
+SELECT '[1,2,3  ,4.0]'::JSON;
+     json      
+---------------
+ [1,2,3  ,4.0]
+(1 row)
+
+SELECT '[1,2,3  ,4]'::JSON;
+    json     
+-------------
+ [1,2,3  ,4]
+(1 row)
+
+SELECT 'true'::JSON;
+ json 
+------
+ true
+(1 row)
+
+SELECT 'true'::TEXT::JSON;
+ json 
+------
+ true
+(1 row)
+
+SELECT 'false'::JSON;
+ json  
+-------
+ false
+(1 row)
+
+SELECT 'null'::JSON;
+ json 
+------
+ null
+(1 row)
+
+SELECT '1.1'::JSON;
+ json 
+------
+ 1.1
+(1 row)
+
+SELECT '"string"'::JSON;
+   json   
+----------
+ "string"
+(1 row)
+
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+                json                
+------------------------------------
+ {"key1":"value1", "key2":"value2"}
+(1 row)
+
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+                json                
+------------------------------------
+ {"key1":"value1", "key2":"value2"}
+(1 row)
+
+SELECT 15::JSON;
+ json 
+------
+ 15
+(1 row)
+
+SELECT json_type('[]');
+ json_type 
+-----------
+ array
+(1 row)
+
+SELECT json_type('{}');
+ json_type 
+-----------
+ object
+(1 row)
+
+SELECT json_type('true');
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type('false');
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type('null');
+ json_type 
+-----------
+ null
+(1 row)
+
+CREATE TABLE testjson (j JSON);
+INSERT INTO testjson VALUES ('[1,2,3,4]');
+INSERT INTO testjson VALUES ('{"key":"value"}');
+INSERT INTO testjson VALUES ('{"key":"value"');
+ERROR:  could not parse JSON value
+LINE 1: INSERT INTO testjson VALUES ('{"key":"value"');
+                                     ^
+INSERT INTO testjson VALUES ('');
+ERROR:  could not parse JSON value
+LINE 1: INSERT INTO testjson VALUES ('');
+                                     ^
+INSERT INTO testjson VALUES ('""');
+INSERT INTO testjson VALUES ('true');
+INSERT INTO testjson VALUES ('false');
+INSERT INTO testjson VALUES ('null');
+INSERT INTO testjson VALUES ('[]');
+INSERT INTO testjson VALUES ('{}');
+SELECT * FROM testjson;
+        j        
+-----------------
+ [1,2,3,4]
+ {"key":"value"}
+ ""
+ true
+ false
+ null
+ []
+ {}
+(8 rows)
+
+SELECT json_type(j) FROM testjson;
+ json_type 
+-----------
+ array
+ object
+ string
+ bool
+ bool
+ null
+ array
+ object
+(8 rows)
+
+-- to_json: null
+SELECT to_json(NULL);
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json(NULL::INT);
+ to_json 
+---------
+ null
+(1 row)
+
+SELECT to_json(NULL::INT[]);
+ to_json 
+---------
+ null
+(1 row)
+
+SELECT to_json(NULL::VOID);
+ERROR:  to_json cannot convert void to JSON
+SELECT to_json(NULL::MONEY);
+ERROR:  to_json cannot convert money to JSON
+SELECT to_json('null'::text); -- should yield '"null"', not 'null'
+ to_json 
+---------
+ "null"
+(1 row)
+
+SELECT json_type(to_json(NULL));
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT json_type(to_json(NULL::INT));
+ json_type 
+-----------
+ null
+(1 row)
+
+SELECT json_type(to_json(NULL::VOID));
+ERROR:  to_json cannot convert void to JSON
+SELECT json_type(to_json(NULL::MONEY));
+ERROR:  to_json cannot convert money to JSON
+-- to_json: string
+SELECT to_json('');
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT json_type(to_json(''));
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json('string');
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT json_type(to_json('string'));
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json('string'::VARCHAR);
+ to_json  
+----------
+ "string"
+(1 row)
+
+SELECT json_type(to_json('string'::VARCHAR));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('string'::VARCHAR(3));
+ to_json 
+---------
+ "str"
+(1 row)
+
+SELECT json_type(to_json('string'::VARCHAR(3)));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('{1,2,3}'::TEXT);
+  to_json  
+-----------
+ "{1,2,3}"
+(1 row)
+
+SELECT json_type(to_json('{1,2,3}'::TEXT));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('"doubly-encoded"'::JSON);
+       to_json        
+----------------------
+ "\"doubly-encoded\""
+(1 row)
+
+SELECT json_type(to_json('"doubly-encoded"'::JSON));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('"nested quotes"'::TEXT);
+       to_json       
+---------------------
+ "\"nested quotes\""
+(1 row)
+
+SELECT json_type(to_json('"nested quotes"'::TEXT));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('"nested quotes"'::TEXT)::TEXT::JSON;
+       to_json       
+---------------------
+ "\"nested quotes\""
+(1 row)
+
+SELECT json_type(to_json('"nested quotes"'::TEXT)::TEXT::JSON);
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('h'::CHAR);
+ to_json 
+---------
+ "h"
+(1 row)
+
+SELECT json_type(to_json('h'::CHAR));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('hello world'::CHAR);
+ to_json 
+---------
+ "h"
+(1 row)
+
+SELECT json_type(to_json('hello world'::CHAR));
+ json_type 
+-----------
+ string
+(1 row)
+
+SELECT to_json('hello world!'::CHAR(11));
+    to_json    
+---------------
+ "hello world"
+(1 row)
+
+SELECT json_type(to_json('hello world!'::CHAR(11)));
+ json_type 
+-----------
+ string
+(1 row)
+
+-- to_json: number
+SELECT to_json(12345);
+ to_json 
+---------
+ 12345
+(1 row)
+
+SELECT to_json(12345.678);
+  to_json  
+-----------
+ 12345.678
+(1 row)
+
+SELECT json_type(to_json(12345));
+ json_type 
+-----------
+ number
+(1 row)
+
+SELECT json_type(to_json(12345.678));
+ json_type 
+-----------
+ number
+(1 row)
+
+SELECT to_json(+1.23e100::FLOAT);
+  to_json  
+-----------
+ 1.23e+100
+(1 row)
+
+SELECT to_json('+1.23e100'::FLOAT);
+  to_json  
+-----------
+ 1.23e+100
+(1 row)
+
+SELECT to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890);
+                                                          to_json                                                          
+---------------------------------------------------------------------------------------------------------------------------
+ 123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890
+(1 row)
+
+SELECT json_type(to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890));
+ json_type 
+-----------
+ number
+(1 row)
+
+SELECT to_json('100'::MONEY);
+ERROR:  to_json cannot convert money to JSON
+-- to_json: bool
+SELECT to_json(TRUE);
+ to_json 
+---------
+ true
+(1 row)
+
+SELECT to_json(FALSE);
+ to_json 
+---------
+ false
+(1 row)
+
+SELECT to_json(1=1);
+ to_json 
+---------
+ true
+(1 row)
+
+SELECT to_json(1=2);
+ to_json 
+---------
+ false
+(1 row)
+
+SELECT json_type(to_json(TRUE));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type(to_json(FALSE));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type(to_json(1=1));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT json_type(to_json(1=2));
+ json_type 
+-----------
+ bool
+(1 row)
+
+SELECT to_json(TRUE::TEXT)::TEXT = '"' || TRUE || '"';
+ ?column? 
+----------
+ t
+(1 row)
+
+SELECT to_json(FALSE::TEXT)::TEXT = '"' || FALSE || '"';
+ ?column? 
+----------
+ t
+(1 row)
+
+-- to_json: array
+SELECT to_json(ARRAY[1,2,3]);
+ to_json 
+---------
+ [1,2,3]
+(1 row)
+
+SELECT to_json(ARRAY[1,2,3]);
+ to_json 
+---------
+ [1,2,3]
+(1 row)
+
+SELECT to_json(ARRAY[[1],[2],[3]]);
+    to_json    
+---------------
+ [[1],[2],[3]]
+(1 row)
+
+SELECT to_json(ARRAY[[1,2],[2],[3]]);
+ERROR:  multidimensional arrays must have array expressions with matching dimensions
+SELECT to_json(ARRAY[[1,2],[3,4],[5,6]]);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,6]]
+(1 row)
+
+SELECT to_json(ARRAY[[],[],[]]);
+ERROR:  cannot determine type of empty array
+LINE 1: SELECT to_json(ARRAY[[],[],[]]);
+                             ^
+HINT:  Explicitly cast to the desired type, for example ARRAY[]::integer[].
+SELECT to_json(ARRAY[[],[],[]]::integer[][]);
+ to_json 
+---------
+ []
+(1 row)
+
+SELECT to_json(ARRAY['hello']);
+  to_json  
+-----------
+ ["hello"]
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world']);
+      to_json      
+-------------------
+ ["hello","world"]
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world', 5]);
+ERROR:  invalid input syntax for integer: "hello"
+LINE 1: SELECT to_json(ARRAY['hello', 'world', 5]);
+                             ^
+SELECT to_json(ARRAY['hello', 'world', 5]::text[]);
+        to_json        
+-----------------------
+ ["hello","world","5"]
+(1 row)
+
+SELECT to_json(ARRAY[ARRAY['hello', 'world', 5]]::text[][]);
+         to_json         
+-------------------------
+ [["hello","world","5"]]
+(1 row)
+
+SELECT to_json(ARRAY[]);
+ERROR:  cannot determine type of empty array
+LINE 1: SELECT to_json(ARRAY[]);
+                       ^
+HINT:  Explicitly cast to the desired type, for example ARRAY[]::integer[].
+SELECT to_json(ARRAY[]::text[]);
+ to_json 
+---------
+ []
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world', null]);
+        to_json         
+------------------------
+ ["hello","world",null]
+(1 row)
+
+SELECT to_json(ARRAY['hello', 'world', null, 5]);
+ERROR:  invalid input syntax for integer: "hello"
+LINE 1: SELECT to_json(ARRAY['hello', 'world', null, 5]);
+                             ^
+SELECT to_json(ARRAY['hello', 'world', null, '5']);
+          to_json           
+----------------------------
+ ["hello","world",null,"5"]
+(1 row)
+
+SELECT to_json(ARRAY[null]);
+ to_json 
+---------
+ [null]
+(1 row)
+
+SELECT to_json(ARRAY[null, null]);
+   to_json   
+-------------
+ [null,null]
+(1 row)
+
+SELECT to_json(ARRAY[[null],[null],[null]]);
+        to_json         
+------------------------
+ [[null],[null],[null]]
+(1 row)
+
+SELECT to_json(ARRAY[[null,null],[null,null],[null,null]]);
+                to_json                
+---------------------------------------
+ [[null,null],[null,null],[null,null]]
+(1 row)
+
+SELECT to_json(ARRAY[[[null,null]],[[null,null]],[[null,null]]]);
+                   to_json                   
+---------------------------------------------
+ [[[null,null]],[[null,null]],[[null,null]]]
+(1 row)
+
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]);
+ERROR:  ARRAY could not convert type integer[] to text[]
+LINE 1: SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]]...
+                                          ^
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]::int[][][]);
+                            to_json                            
+---------------------------------------------------------------
+ [[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]
+(1 row)
+
+SELECT to_json(array[1,2,3,4,5]::int2vector);
+   to_json   
+-------------
+ [1,2,3,4,5]
+(1 row)
+
+SELECT to_json(array[1,2,3,4,5]::oidvector);
+   to_json   
+-------------
+ [1,2,3,4,5]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],5]::oidvector);
+ERROR:  syntax error at or near "5"
+LINE 1: SELECT to_json(array[[1,2],[3,4],5]::oidvector);
+                                         ^
+SELECT to_json(array[[1,2],[3,4],[5]]::oidvector);
+ERROR:  multidimensional arrays must have array expressions with matching dimensions
+SELECT to_json(array[[1,2],[3,4],[5,5]]::oidvector);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,5]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,6]]::oidvector);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,6]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,6]]::int2vector);
+       to_json       
+---------------------
+ [[1,2],[3,4],[5,6]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,6000]]::int2vector);
+        to_json         
+------------------------
+ [[1,2],[3,4],[5,6000]]
+(1 row)
+
+SELECT to_json(array[[1,2],[3,4],[5,60000]]::int2vector);
+ERROR:  smallint out of range
+SELECT to_json(array[[1,2],[3,4],[5,null]]::int2vector);
+        to_json         
+------------------------
+ [[1,2],[3,4],[5,null]]
+(1 row)
+
+SELECT to_json(array[[1,2],[null,4],[5,null]]::int2vector);
+          to_json          
+---------------------------
+ [[1,2],[null,4],[5,null]]
+(1 row)
+
+SELECT to_json(array[[1,2],[null,4],[5,null]]::oidvector);
+          to_json          
+---------------------------
+ [[1,2],[null,4],[5,null]]
+(1 row)
+
+SELECT to_json(array[[true,false],[false,true]]::bool[][]);
+           to_json           
+-----------------------------
+ [[true,false],[false,true]]
+(1 row)
+
+SELECT to_json(array[[true,false],[false,true],[null,null]]::bool[][]);
+                 to_json                 
+-----------------------------------------
+ [[true,false],[false,true],[null,null]]
+(1 row)
+
+SELECT to_json('{1,2,3}');
+ERROR:  could not determine polymorphic type because input has type "unknown"
+SELECT to_json('{1,2,3}'::text); -- should form "{1,2,3}", not build an array
+  to_json  
+-----------
+ "{1,2,3}"
+(1 row)
+
+SELECT to_json('{1,2,3}'::int[]);
+ to_json 
+---------
+ [1,2,3]
+(1 row)
+
+SELECT to_json('{one,two,three}'::text[]);
+        to_json        
+-----------------------
+ ["one","two","three"]
+(1 row)
+
+SELECT to_json('{one,two,three,null}'::text[]);
+          to_json           
+----------------------------
+ ["one","two","three",null]
+(1 row)
+
+SELECT to_json('{one,two,three,null,five}'::text[]);
+              to_json              
+-----------------------------------
+ ["one","two","three",null,"five"]
+(1 row)
+
+SELECT to_json('{null}'::text[]);
+ to_json 
+---------
+ [null]
+(1 row)
+
+SELECT to_json('{{null}}'::text[][]);
+ to_json  
+----------
+ [[null]]
+(1 row)
+
+-- to_json: invalid types
+SELECT to_json(row(1,2));
+ERROR:  to_json cannot convert record to JSON
+SELECT to_json('127.0.0.1'::INET);
+ERROR:  to_json cannot convert inet to JSON
+-- from_json: null
+SELECT from_json(null);
+ from_json 
+-----------
+ 
+(1 row)
+
+SELECT from_json(NULL::TEXT);
+ERROR:  function from_json(text) does not exist
+LINE 1: SELECT from_json(NULL::TEXT);
+               ^
+HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
+SELECT from_json(NULL::JSON);
+ from_json 
+-----------
+ 
+(1 row)
+
+-- from_json: string
+SELECT from_json('"valid string"');
+  from_json   
+--------------
+ valid string
+(1 row)
+
+SELECT from_json($$ "hello\nworld" $$);
+ from_json 
+-----------
+ hello    +
+ world
+(1 row)
+
+SELECT from_json($$ "hello\u0000world" $$);
+ERROR:  could not convert JSON-encoded string to TEXT: contains \u0000
+DETAIL:  the string was:  "hello\u0000world" 
+-- from_json: number
+SELECT from_json('123');
+ from_json 
+-----------
+ 123
+(1 row)
+
+SELECT from_json('123')::INT;
+ from_json 
+-----------
+       123
+(1 row)
+
+SELECT from_json('123.456')::INT;
+ERROR:  invalid input syntax for integer: "123.456"
+SELECT from_json('123.456')::FLOAT;
+ from_json 
+-----------
+   123.456
+(1 row)
+
+SELECT from_json('123e-38');
+ from_json 
+-----------
+ 123e-38
+(1 row)
+
+SELECT from_json('123e-38')::FLOAT;
+ from_json 
+-----------
+  1.23e-36
+(1 row)
+
+SELECT from_json('1.23e-38')::FLOAT;
+ from_json 
+-----------
+  1.23e-38
+(1 row)
+
+SELECT from_json('1.23e-38');
+ from_json 
+-----------
+ 1.23e-38
+(1 row)
+
+SELECT from_json('1.23e-38')::NUMERIC;
+                 from_json                  
+--------------------------------------------
+ 0.0000000000000000000000000000000000000123
+(1 row)
+
+-- from_json: bool
+SELECT from_json('true')::JSON;
+ from_json 
+-----------
+ true
+(1 row)
+
+SELECT from_json('true');
+ from_json 
+-----------
+ true
+(1 row)
+
+SELECT from_json('true')::BOOLEAN;
+ from_json 
+-----------
+ t
+(1 row)
+
+SELECT from_json('true')::BOOLEAN::JSON;
+ERROR:  could not parse JSON value
+SELECT from_json('true')::BOOLEAN::TEXT::JSON;
+ from_json 
+-----------
+ true
+(1 row)
+
+SELECT from_json('false')::BOOLEAN::TEXT::JSON;
+ from_json 
+-----------
+ false
+(1 row)
+
+SELECT from_json('false');
+ from_json 
+-----------
+ false
+(1 row)
+
+SELECT from_json('f');
+ERROR:  could not parse JSON value
+LINE 1: SELECT from_json('f');
+                         ^
+SELECT from_json('t');
+ERROR:  could not parse JSON value
+LINE 1: SELECT from_json('t');
+                         ^
+SELECT from_json('f'::BOOLEAN::TEXT);
+ERROR:  function from_json(text) does not exist
+LINE 1: SELECT from_json('f'::BOOLEAN::TEXT);
+               ^
+HINT:  No function matches the given name and argument types. You might need to add explicit type casts.
+SELECT from_json('f'::BOOLEAN::TEXT::JSON);
+ from_json 
+-----------
+ false
+(1 row)
+
+SELECT from_json('t'::BOOLEAN::TEXT::JSON);
+ from_json 
+-----------
+ true
+(1 row)
+
+-- from_json: object
+SELECT from_json('{"key": "value"}');
+ERROR:  from_json cannot be applied to JSON objects
+-- from_json: array
+SELECT from_json('[1,2,3]');
+ERROR:  from_json cannot be applied to JSON arrays
+-- from_json: invalid
+SELECT from_json('invalid');
+ERROR:  could not parse JSON value
+LINE 1: SELECT from_json('invalid');
+                         ^
+-- test from_json on a large string
+CREATE TABLE sample_query_text (json JSON);
+INSERT INTO sample_query_text VALUES ($$
+"SELECT pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c WHERE c.relkind IN ('i') AND substring(pg_catalog.quote_ident(c.relname),1,0)='' AND pg_catalog.pg_table_is_visible(c.oid) AND c.relnamespace <> (SELECT oid FROM pg_catalog.pg_namespace WHERE nspname = 'pg_catalog')\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' FROM pg_catalog.pg_namespace n WHERE substring(pg_catalog.quote_ident(n.nspname) || '.',1,0)='' AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) > 1\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n WHERE c.relnamespace = n.oid AND c.relkind IN ('i') AND substring(pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname),1,0)='' AND substring(pg_catalog.quote_ident(n.nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(n.nspname))+1) AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) = 1\n UNION SELECT 'ON' UNION SELECT 'CONCURRENTLY'\nLIMIT 1000"
+$$);
+SELECT md5(from_json(json)) FROM sample_query_text;
+               md5                
+----------------------------------
+ 1c0d28af72da21149acbdf305c197141
+(1 row)
+
+/* Make sure creating an array literal and subscripting
+ * preserves the original string exactly
+ * (except for trimming surrounding whitespace). */
+SELECT bool_and(btrim(before, E'\t\n\r ') = after) FROM (
+	SELECT
+		string AS before,
+		json_path(('  [ ' || string || '  ] ')::json, '$.[0]')::text AS after
+	FROM json_valid_test_strings
+) AS subquery;
+ bool_and 
+----------
+ t
+(1 row)
+
+-- Make sure json_validate works
+SELECT json_validate(string), string FROM json_test_strings;
+ json_validate |                          string                          
+---------------+----------------------------------------------------------
+ f             | 
+ f             |   
+ f             | "
+ f             | [,]
+ f             | [)
+ f             | []]
+ f             | [}
+ f             | {,}
+ f             | {]
+ f             | ["1":2]
+ f             | [1,2,]
+ f             | [1:2}
+ f             | {"1":2,}
+ f             | {1:2}
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7 ]}]}
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7]}]}
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]
+ f             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]]
+ f             | {"1":2, "3":4
+ f             | "1\u2"
+ f             | [,2]
+ f             | "3
+ f             | "3" "4"
+ f             | [3[4]
+ f             | [3[4]]
+ f             | [3, [4, [5], 6] 7, 8 9]
+ f             | [3, [4, [5], 6] 7, 8, 9]
+ f             | [3, [4, [5], 6], 7, 8 9]
+ f             | {"hello":true, "bye":false, null}
+ f             | {"hello":true, "bye":false, null:null}
+ f             | "hi
+ f             | "hi"""
+ f             | {"hi": "bye"]
+ f             | "\uD800\uD800"
+ f             | "\uD800\uDBFF"
+ f             | "\UD834\UDD1E"
+ f             | "\uDB00"
+ f             | "\uDB00\uDBFF"
+ t             | "\uFFFE"
+ t             | "\uFFFF"
+ f             | .
+ t             | ""
+ t             | []
+ t             | {}
+ f             | +.
+ t             | 0.5
+ f             | 0.e1
+ t             | {"1":{}}
+ t             | {"1":2}
+ t             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"]}]}
+ t             | {"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]}
+ t             | 1234
+ t             | -1234
+ t             | {"1":2, "3":4}
+ f             | +1234
+ f             | ++1234
+ t             | 123.456e14234
+ t             | 123.456e-14234
+ t             | 123.456e+14234
+ f             | 123.e-14234
+ t             | "1\u2000"
+ t             | "1\u20001"
+ t             | 2
+ f             | .246e-14234
+ f             | .2e-14234
+ t             | 3
+ f             | .3
+ t             | "3"
+ t             | [3]
+ f             | +3.
+ t             | 3.2e+1
+ t             | [3, [4]]
+ t             | [3, [4, [5]]]
+ t             | [3, [4, [5], 6]]
+ t             | [3, [4, [5], 6], 7]
+ t             | [3, [4, [5], 6], 7, 8]
+ t             | [3, [4, [5], 6], 7, 8, 9]
+ f             | +3.5
+ f             | .3e
+ f             | .3e1
+ f             | .3e-1
+ f             | .3e+1
+ f             | 3.e1
+ f             | 3.e+1
+ t             | 3e+1
+ f             | .5
+ f             | +.5
+ f             | .5e+1
+ t             | [ 7]
+ t             | [7 ]
+ t             | [7]
+ f             | .e-14234
+ t             | "hello"
+ t             | ["hello"]
+ t             | ["hello", "bye"]
+ t             | ["hello", "bye\n"]
+ t             | ["hello", "bye\n\r\t"]
+ t             | ["hello", "bye\n\r\t\b"]
+ t             | ["hello", "bye\n\r\t\b",true]
+ t             | ["hello", "bye\n\r\t\b",true , false]
+ t             | ["hello", "bye\n\r\t\b",true , false,    null]
+ f             | ["hello", "bye\n\r\t\v"]
+ t             | {"hello":true}
+ t             | {"hello":true, "bye":false}
+ t             | {"hello":true, "bye":false, "foo":["one","two","three"]}
+ t             | "hi"
+ t             | ["hi"]
+ t             | ["hi", "bye"]
+ t             | {"hi": "bye"}
+ t             | ["hi", "bye", 3]
+ t             | ["hi", "bye[", 3]
+ t             | "\u0007"
+ t             | "\u0008"
+ t             | "\u0009"
+ t             | "\u0010"
+ t             | "\u0020"
+ t             | "\u10000"
+ t             | "\u1234"
+ t             | "\u99999"
+ t             | "\ud800\udc00"
+ t             | "\uD800\uDC00"
+ t             | "\uD834\uDD1E"
+ t             | "\uDBFF\uDFFF"
+ t             | "\uFFFD"
+ t             | "\uFFFF"
+ f             | hello
+ t             | [32, 1]
+ f             | [32, 
+ t             | "\uD800\uDC00"
+ t             | "\n"
+ t             | "hello"
+ t             | "hello\u0009world"
+ t             | "hello"
+ t             | "hello\n"
+ t             | "hello"
+ t             | 3
+ f             | 3.
+ f             | .3
+ t             | 0.3
+ f             | 0.3e
+ f             | 0.3e+
+ t             | 0.3e+5
+ t             | 0.3e-5
+ t             | 0.3e5
+ t             | "hello"
+ f             | +3
+ t             | -3
+ f             | -3.
+ t             | -3.1
+ f             | .5
+ f             | 5.
+ f             | 5.e1
+ t             | 0.5
+ f             | .3e1
+ f             | .3e+1
+ f             | .3e-1
+ f             | .3e-1 .5
+ f             | .3e-1.5
+ f             | .3e+1.5
+ f             | .3e+.
+ f             | .3e+.5
+ f             | .3e+1.5
+ f             | 9.3e+1.5
+ f             | 9.e+1.5
+ f             | 9.e+
+ f             | 9.e+1
+ t             | "\""
+ t             | "\"3.5"
+ t             | "\"."
+ f             | "\".".
+ t             | "\"....."
+ f             | "\"\"\"\"""
+ f             | ["\"\"\"\"", .5]
+ f             | [.5]
+ t             | ["\"\"\"\"", 0.5]
+ f             | ["\"\"\"\"", .5]
+ f             | ["\"\"\"\"",.5]
+ f             | ["\"",.5]
+ f             | ["\".5",.5]
+ f             | ["\".5",".5\"".5]
+ f             | ["\".5",".5\"", .5]
+ f             | ["\".5",".5\"",.5]
+ t             | ["\".5",".5\"",0.5]
+ f             | {"key":/*comment*/"value"}
+ f             | {"key":/*comment"value"}
+ f             | {"key":"value"}/*
+ f             | {"key":"value"}/**/
+ f             | {"key":"value"}/***/
+ f             | {"key":"value"}/**//
+ f             | {"key":"value"}/**///
+ f             | {"key":"value"}/**///----
+ f             | {"key":"value"}#
+ f             | {"key":"value"}#{
+ f             | {"key":"value"}#{}
+ f             | {"key":"value"}#,
+ f             | {"key":"value"/**/, "k2":"v2"}
+ t             | "\u0027"
+ f             | "hello\'"
+ f             | 'hello\''
+ f             | 'hello'
+ f             | 'hell\'o'
+ f             | '\'hello'
+ f             | '\'hello\''
+ f             | \'hello\'
+ f             | 'hello\'
+ f             | ['hello\']
+ f             | ['hello\'']
+ f             | ['hello"']
+ f             | ['hello\"']
+ f             | ['hello"o']
+ f             | ['"']
+ f             | '"'
+ f             | '"hello"'
+ f             | '"hello'
+ f             | '"hi"'
+(215 rows)
+
+/*** json_get ***/
+SELECT json_get('{"key": "value", "key2": "value2"}', 'key');
+ json_get 
+----------
+ "value"
+(1 row)
+
+SELECT json_get('{"key": "value", "key": "value2"}', 'key');
+ERROR:  JSONPath expression matched multiple results
+/* These each return no result because 0 is a number
+   (indicating a numeric subscript),
+   not a string (indicating an object subscript). */
+SELECT json_get('{"0": "value", "key": "value"}', '0');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('{"0": "value", "0": "value"}', '[0]');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('{"0": "value", "0": "value"}', '.0');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('{"0": "value", "1": "value"}', '["0"]');
+ json_get 
+----------
+ "value"
+(1 row)
+
+SELECT json_get('{"0": "value", "0": "value"}', '["0"]');
+ERROR:  JSONPath expression matched multiple results
+SELECT json_get('[0,1,2,3]', '0');
+ json_get 
+----------
+ 0
+(1 row)
+
+SELECT json_get('[0,1,2,3]', '"0"');
+ json_get 
+----------
+ 
+(1 row)
+
+SELECT json_get('[0,1,2,3]', '*');
+ERROR:  JSONPath expression matched multiple results
+SELECT json_get('[0]', '*');
+ json_get 
+----------
+ 0
+(1 row)
+
+SELECT json_get('[[0]]', '..*');
+ERROR:  JSONPath expression matched multiple results
+/*** json_set ***/
+SELECT json_set('[1,2,3]', '[1]', 5::json);
+ json_set 
+----------
+ [1,5,3]
+(1 row)
+
+SELECT json_set('[1,2,3]', '[3]', 5::json);
+ json_set 
+----------
+ [1,2,3]
+(1 row)
+
+SELECT json_set('[1,2,3]', '[2]', 5::json);
+ json_set 
+----------
+ [1,2,5]
+(1 row)
+
+SELECT json_set('[1,2,3]', '[2]', '[0,1]'::json);
+  json_set   
+-------------
+ [1,2,[0,1]]
+(1 row)
+
+SELECT json_set('  [ 1 ,   2,3]', '1', '5');
+    json_set    
+----------------
+   [ 1 ,   5,3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [2,3],3]', '1', '5');
+    json_set    
+----------------
+   [ 1 ,   5,3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  5 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[5][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[4][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[3][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[2][0]', '5');
+           json_set            
+-------------------------------
+   [ 1 ,   [  2 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '   5  ');
+           json_set            
+-------------------------------
+   [ 1 ,   [  5 ,   3     ],3]
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1][0]', '   5  ');
+              json_set               
+-------------------------------------
+   [ 1 ,   [  5 ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '   5  ');
+              json_set               
+-------------------------------------
+   [ 1 ,   [  5 ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '     5  ');
+              json_set               
+-------------------------------------
+   [ 1 ,   [  5 ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\tworld"  $$);
+                     json_set                     
+--------------------------------------------------
+   [ 1 ,   [  "hello\tworld" ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\u0009world"  $$);
+                       json_set                       
+------------------------------------------------------
+   [ 1 ,   [  "hello\u0009world" ,   3     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][*]', $$     "hello\u0009world"  $$);
+                               json_set                                
+-----------------------------------------------------------------------
+   [ 1 ,   [  "hello\u0009world" ,   "hello\u0009world"     ]  , 3  ] 
+(1 row)
+
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+       json_set        
+-----------------------
+   "hello\u0009world" 
+(1 row)
+
+SELECT json_set('       [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+          json_set          
+----------------------------
+        "hello\u0009world" 
+(1 row)
+
+-- Since JavaScript doesn't do anything when you assign to a character subscript,
+-- neither will json_set.
+SELECT json_set('"hello"', '[0]', '"H"');
+ json_set 
+----------
+ "hello"
+(1 row)
+
+SELECT json_set('"hello"', '[0][0]', '"H"');
+ json_set 
+----------
+ "hello"
+(1 row)
+
+SELECT json_set('["hello"]', '[0][0]', '"H"');
+ json_set  
+-----------
+ ["hello"]
+(1 row)
+
+SELECT json_set('["hello"]', '[0][0][0]', '"H"');
+ json_set  
+-----------
+ ["hello"]
+(1 row)
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*]', '["set"]');
+                 json_set                  
+-------------------------------------------
+ [["set"],["set"],["set"],["set"],["set"]]
+(1 row)
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*][*]', '["set"]');
+              json_set               
+-------------------------------------
+ [0,1,2,[["set"],["set"],["set"]],4]
+(1 row)
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$..[*]', '["set"]');
+                 json_set                  
+-------------------------------------------
+ [["set"],["set"],["set"],["set"],["set"]]
+(1 row)
+
+/*** json_path ***/
+SELECT parse_json_path('..');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('..*');
+ parse_json_path 
+-----------------
+ $..[*]
+(1 row)
+
+SELECT parse_json_path('.*');
+ parse_json_path 
+-----------------
+ $[*]
+(1 row)
+
+SELECT parse_json_path('');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('$.*');
+ parse_json_path 
+-----------------
+ $[*]
+(1 row)
+
+SELECT parse_json_path('$');
+ parse_json_path 
+-----------------
+ $
+(1 row)
+
+SELECT parse_json_path('$*');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('*');
+ parse_json_path 
+-----------------
+ $[*]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 025  ] $$);
+ parse_json_path 
+-----------------
+ $..[25]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 $$);
+ parse_json_path 
+-----------------
+ $[0][3]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0_3 $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ . 0.3 $$);
+ parse_json_path 
+-----------------
+ $[0][3]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 031  ] $$);
+ parse_json_path 
+-----------------
+ $..[31]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello $$);
+ parse_json_path  
+------------------
+ $[0][3]["hello"]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . "back\\slash" $$);
+         parse_json_path         
+---------------------------------
+ $[0][3]["hello"]["back\\slash"]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . ["back\\slash"] $$);
+         parse_json_path         
+---------------------------------
+ $[0][3]["hello"]["back\\slash"]
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . back\slash $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ . 0 . 3 . hello . backslash $$);
+        parse_json_path        
+-------------------------------
+ $[0][3]["hello"]["backslash"]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 0x31  ] $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ [ 0x31  ] $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ _3 $$);
+ parse_json_path 
+-----------------
+ $["_3"]
+(1 row)
+
+SELECT parse_json_path($$ _3_ $$);
+ parse_json_path 
+-----------------
+ $["_3_"]
+(1 row)
+
+SELECT parse_json_path($$ [ _3 ] $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ _3 $$);
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$ $ . _3 $$);
+ parse_json_path 
+-----------------
+ $["_3"]
+(1 row)
+
+SELECT parse_json_path('..["5"]');
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path('..[5]');
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path('..5');
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path($$ .. [ -5  ] $$);
+ parse_json_path 
+-----------------
+ $..[-5]
+(1 row)
+
+SELECT parse_json_path($$ .. [ "5"  ] $$);
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path($$ .. [ +5  ] $$);
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path($$ .. [ 5  ] $$);
+ parse_json_path 
+-----------------
+ $..[5]
+(1 row)
+
+SELECT parse_json_path($$ .. ["5"] $$);
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path($$ ..["5"] $$);
+ parse_json_path 
+-----------------
+ $..["5"]
+(1 row)
+
+SELECT parse_json_path($$ [ "5" ] $$);
+ parse_json_path 
+-----------------
+ $["5"]
+(1 row)
+
+SELECT parse_json_path($$ [ 5 ] $$);
+ parse_json_path 
+-----------------
+ $[5]
+(1 row)
+
+SELECT parse_json_path('."hello"');
+ parse_json_path 
+-----------------
+ $["hello"]
+(1 row)
+
+SELECT parse_json_path('.hello');
+ parse_json_path 
+-----------------
+ $["hello"]
+(1 row)
+
+SELECT parse_json_path('...["hello world"]');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('..["hello world"]');
+  parse_json_path   
+--------------------
+ $..["hello world"]
+(1 row)
+
+SELECT parse_json_path('."hello world"');
+ parse_json_path  
+------------------
+ $["hello world"]
+(1 row)
+
+SELECT parse_json_path('.["hello world"]');
+ parse_json_path  
+------------------
+ $["hello world"]
+(1 row)
+
+SELECT parse_json_path('.hello world');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path('..["hello world"]["5"]');
+     parse_json_path     
+-------------------------
+ $..["hello world"]["5"]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]');
+    parse_json_path    
+-----------------------
+ $..["hello world"][5]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]..*.[*]');
+          parse_json_path           
+------------------------------------
+ $..["hello world"][5]..[3]..[*][*]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]..*');
+         parse_json_path         
+---------------------------------
+ $..["hello world"][5]..[3]..[*]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]');
+      parse_json_path       
+----------------------------
+ $..["hello world"][5]..[3]
+(1 row)
+
+SELECT parse_json_path('..["hello world"][5]..[3]*');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT parse_json_path($$
+	.. [ '"hello"\\"world"' ]
+	[ 5 ] .. [3] . * [ * ]
+$$);
+              parse_json_path              
+-------------------------------------------
+ $..["\"hello\"\\\"world\""][5]..[3][*][*]
+(1 row)
+
+select parse_json_path('$char');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('$.char');
+ parse_json_path 
+-----------------
+ $["char"]
+(1 row)
+
+select parse_json_path('$.char()');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('$.char(5)');
+ parse_json_path 
+-----------------
+ $.char(5)
+(1 row)
+
+select parse_json_path('$.char(  -1  )');
+ parse_json_path 
+-----------------
+ $.char(-1)
+(1 row)
+
+select parse_json_path('$.char(  -1  )  . char(0)');
+  parse_json_path   
+--------------------
+ $.char(-1).char(0)
+(1 row)
+
+select parse_json_path('$.char(  -1  )  . char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $.char(-1).char(0)
+(1 row)
+
+select parse_json_path('$.char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('$ . char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('$ .. char(  +1  )  . char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $..char(1).char(0)
+(1 row)
+
+select parse_json_path('$ .. char(  +1  )  .. char  ( 0 )  ');
+   parse_json_path   
+---------------------
+ $..char(1)..char(0)
+(1 row)
+
+select parse_json_path('$ . char(  +1  )  .. char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $.char(1)..char(0)
+(1 row)
+
+select parse_json_path('$ . char(  +1  )  char  ( 0 )  ');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('$ char(  +1  )  char  ( 0 )  ');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('.char(  +1  )  . char  ( 0 )  ');
+  parse_json_path  
+-------------------
+ $.char(1).char(0)
+(1 row)
+
+select parse_json_path('..char(  +1  )  . char  ( 0 )  ');
+  parse_json_path   
+--------------------
+ $..char(1).char(0)
+(1 row)
+
+select parse_json_path('...char(  +1  )  . char  ( 0 )  ');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+select parse_json_path('[char(5)]');
+ parse_json_path 
+-----------------
+ 
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(0)');
+ json_path 
+-----------
+ "⁰"
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(1)');
+ json_path 
+-----------
+ "¹"
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(2)');
+ json_path 
+-----------
+ "\u0000"
+(1 row)
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(3)');
+ json_path 
+-----------
+ "³"
+(1 row)
+
+SELECT json_path('"0123"', 'char(-1)');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('"0123"', 'char(0)');
+ json_path 
+-----------
+ "0"
+(1 row)
+
+SELECT json_path('"0123"', 'char(1)');
+ json_path 
+-----------
+ "1"
+(1 row)
+
+SELECT json_path('"0123"', 'char(2)');
+ json_path 
+-----------
+ "2"
+(1 row)
+
+SELECT json_path('"0123"', 'char(3)');
+ json_path 
+-----------
+ "3"
+(1 row)
+
+SELECT json_path('"0123"', 'char(4)');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('"⁰¹²³"', 'char(0)');
+ json_path 
+-----------
+ "⁰"
+(1 row)
+
+SELECT json_path('"⁰¹²³"', 'char(1)');
+ json_path 
+-----------
+ "¹"
+(1 row)
+
+SELECT json_path('"⁰¹²³"', 'char(2)');
+ json_path 
+-----------
+ "²"
+(1 row)
+
+SELECT json_path('"⁰¹²³"', 'char(3)');
+ json_path 
+-----------
+ "³"
+(1 row)
+
+SELECT json_path('[1,2,3]', '$');
+ json_path 
+-----------
+ [1,2,3]
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.+1');
+ json_path 
+-----------
+ 2
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.-1');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('[1,2,3]', '$.0');
+ json_path 
+-----------
+ 1
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.1');
+ json_path 
+-----------
+ 2
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.2');
+ json_path 
+-----------
+ 3
+(1 row)
+
+SELECT json_path('[1,2,3]', '$.3');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('[1,2,3]', '*');
+ json_path 
+-----------
+ 1
+ 2
+ 3
+(3 rows)
+
+SELECT json_path('[1,2,3]', '[0]');
+ json_path 
+-----------
+ 1
+(1 row)
+
+SELECT json_path('[1,2,3]', '[1]');
+ json_path 
+-----------
+ 2
+(1 row)
+
+SELECT json_path('[1,2,3]', '[2]');
+ json_path 
+-----------
+ 3
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', $$['2']$$);
+ json_path 
+-----------
+ "two"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["0"]');
+ json_path 
+-----------
+ "zero"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["1"]');
+ json_path 
+-----------
+ "one"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["2"]');
+ json_path 
+-----------
+ "two"
+(1 row)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[0]');
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[1]');
+ json_path 
+-----------
+(0 rows)
+
+-- Multiple JSONPath results are listed in BFS order
+-- (just because it's easier to implement efficiently than DFS)
+SELECT json_path('[0,1,[2, [3,4 , 5],6,[7,8],9],10]', '$..*');
+        json_path         
+--------------------------
+ 0
+ 1
+ [2, [3,4 , 5],6,[7,8],9]
+ 10
+ 2
+ [3,4 , 5]
+ 6
+ [7,8]
+ 9
+ 3
+ 4
+ 5
+ 7
+ 8
+(14 rows)
+
+CREATE TABLE sample (json JSON);
+INSERT INTO sample VALUES ($$
+{
+	"store": {
+		"books": [
+			{
+				"title": "book 0",
+				"author": "author 0",
+				"prices": [1,2,3]
+			}, {
+				"title": "book 1",
+				"author": "author 1",
+				"prices": [4,5,6]
+			}, {
+				"title": "book 2",
+				"author": "author 2",
+				"prices": [7,8,9]
+			}
+		],
+		"toys": [
+			"Yo-yo",
+			"Boomerang",
+			"Basketball"
+		]
+	}
+}
+$$);
+SELECT json_path(json, 'store.books[*]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].title') FROM sample;
+ json_path 
+-----------
+ "book 0"
+ "book 1"
+ "book 2"
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].author') FROM sample;
+ json_path  
+------------
+ "author 0"
+ "author 1"
+ "author 2"
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].prices') FROM sample;
+ json_path 
+-----------
+ [1,2,3]
+ [4,5,6]
+ [7,8,9]
+(3 rows)
+
+SELECT json_path(json, 'store.books[*].prices[*]') FROM sample;
+ json_path 
+-----------
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+(9 rows)
+
+SELECT json_path(json, 'store.toys[*]') FROM sample;
+  json_path   
+--------------
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(3 rows)
+
+SELECT json_path(json, 'store.toys[*][0]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, 'store.toys[*][1]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, 'store.toys[*][0][0]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, 'store.toys[*][0][1]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '..books') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ [                                                    +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ]
+(1 row)
+
+SELECT json_path(json, '..books[*]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+(3 rows)
+
+SELECT json_path(json, '..title') FROM sample;
+ json_path 
+-----------
+ "book 0"
+ "book 1"
+ "book 2"
+(3 rows)
+
+SELECT json_path(json, '..author') FROM sample;
+ json_path  
+------------
+ "author 0"
+ "author 1"
+ "author 2"
+(3 rows)
+
+SELECT json_path(json, '..prices[*]') FROM sample;
+ json_path 
+-----------
+ 1
+ 2
+ 3
+ 4
+ 5
+ 6
+ 7
+ 8
+ 9
+(9 rows)
+
+SELECT json_path(json, '..toys[*]') FROM sample;
+  json_path   
+--------------
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(3 rows)
+
+SELECT json_path(json, '..toys..[*]') FROM sample;
+  json_path   
+--------------
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(3 rows)
+
+SELECT json_path(json, '..[-1]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '..[0]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ 1
+ 4
+ 7
+ "Yo-yo"
+(5 rows)
+
+SELECT json_path(json, '..[1]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ 2
+ 5
+ 8
+ "Boomerang"
+(5 rows)
+
+SELECT json_path(json, '..[2]') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+ 3
+ 6
+ 9
+ "Basketball"
+(5 rows)
+
+SELECT json_path(json, '..[3]') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '$') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+         "store": {                                   +
+                 "books": [                           +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ],                                   +
+                 "toys": [                            +
+                         "Yo-yo",                     +
+                         "Boomerang",                 +
+                         "Basketball"                 +
+                 ]                                    +
+         }                                            +
+ }
+(1 row)
+
+SELECT json_path(json, '..*') FROM sample;
+                       json_path                       
+-------------------------------------------------------
+ {                                                    +
+                 "books": [                           +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ],                                   +
+                 "toys": [                            +
+                         "Yo-yo",                     +
+                         "Boomerang",                 +
+                         "Basketball"                 +
+                 ]                                    +
+         }
+ [                                                    +
+                         {                            +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }, {                         +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }, {                         +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }                            +
+                 ]
+ [                                                    +
+                         "Yo-yo",                     +
+                         "Boomerang",                 +
+                         "Basketball"                 +
+                 ]
+ {                                                    +
+                                 "title": "book 0",   +
+                                 "author": "author 0",+
+                                 "prices": [1,2,3]    +
+                         }
+ {                                                    +
+                                 "title": "book 1",   +
+                                 "author": "author 1",+
+                                 "prices": [4,5,6]    +
+                         }
+ {                                                    +
+                                 "title": "book 2",   +
+                                 "author": "author 2",+
+                                 "prices": [7,8,9]    +
+                         }
+ "book 0"
+ "author 0"
+ [1,2,3]
+ 1
+ 2
+ 3
+ "book 1"
+ "author 1"
+ [4,5,6]
+ 4
+ 5
+ 6
+ "book 2"
+ "author 2"
+ [7,8,9]
+ 7
+ 8
+ 9
+ "Yo-yo"
+ "Boomerang"
+ "Basketball"
+(27 rows)
+
+SELECT json_path(json, '..char(-1)') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+SELECT json_path(json, '..char(0)') FROM sample;
+ json_path 
+-----------
+ "b"
+ "a"
+ "b"
+ "a"
+ "b"
+ "a"
+ "Y"
+ "B"
+ "B"
+(9 rows)
+
+SELECT json_path(json, '..char(1)') FROM sample;
+ json_path 
+-----------
+ "o"
+ "u"
+ "o"
+ "u"
+ "o"
+ "u"
+ "o"
+ "o"
+ "a"
+(9 rows)
+
+SELECT json_path(json, '..char(2)') FROM sample;
+ json_path 
+-----------
+ "o"
+ "t"
+ "o"
+ "t"
+ "o"
+ "t"
+ "-"
+ "o"
+ "s"
+(9 rows)
+
+SELECT json_path(json, '..char(3)') FROM sample;
+ json_path 
+-----------
+ "k"
+ "h"
+ "k"
+ "h"
+ "k"
+ "h"
+ "y"
+ "m"
+ "k"
+(9 rows)
+
+SELECT json_path(json, '..char(100)') FROM sample;
+ json_path 
+-----------
+(0 rows)
+
+/*** json_condense ***/
+SELECT json_condense('"hello"');
+ json_condense 
+---------------
+ "hello"
+(1 row)
+
+SELECT json_condense($$"hello\u266Bworld"$$);
+  json_condense  
+-----------------
+ "hello♫world"
+(1 row)
+
+SELECT json_condense($$"hello\u266bworld"$$);
+  json_condense  
+-----------------
+ "hello♫world"
+(1 row)
+
+SELECT json_condense($$"hello♫world"$$);
+  json_condense  
+-----------------
+ "hello♫world"
+(1 row)
+
+SELECT json_condense($$      "hello world"    $$);
+ json_condense 
+---------------
+ "hello world"
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world"}    $$);
+   json_condense   
+-------------------
+ {"hello":"world"}
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world", "bye": 0.0001  }    $$);
+         json_condense          
+--------------------------------
+ {"hello":"world","bye":0.0001}
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world",
+								"bye": 0.0000001
+}    $$);
+           json_condense           
+-----------------------------------
+ {"hello":"world","bye":0.0000001}
+(1 row)
+
+SELECT json_condense($$    {  "hello" : "world"
+,
+"bye"
+: [-0.1234e1, 12345e0]		}    $$);
+                json_condense                
+---------------------------------------------
+ {"hello":"world","bye":[-0.1234e1,12345e0]}
+(1 row)
+
diff --git a/src/test/regress/parallel_schedule b/src/test/regress/parallel_schedule
index 191d1fe..4436be0 100644
--- a/src/test/regress/parallel_schedule
+++ b/src/test/regress/parallel_schedule
@@ -84,7 +84,7 @@ test: rules
 # ----------
 # Another group of parallel tests
 # ----------
-test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps
+test: select_views portals_p2 foreign_key cluster dependency guc bitmapops combocid tsearch tsdicts foreign_data window xmlmap functional_deps json
 
 # ----------
 # Another group of parallel tests
diff --git a/src/test/regress/serial_schedule b/src/test/regress/serial_schedule
index 80a9881..1210c7c 100644
--- a/src/test/regress/serial_schedule
+++ b/src/test/regress/serial_schedule
@@ -104,6 +104,7 @@ test: foreign_data
 test: window
 test: xmlmap
 test: functional_deps
+test: json
 test: plancache
 test: limit
 test: plpgsql
diff --git a/src/test/regress/sql/json.sql b/src/test/regress/sql/json.sql
new file mode 100644
index 0000000..c6b9e42
--- /dev/null
+++ b/src/test/regress/sql/json.sql
@@ -0,0 +1,484 @@
+SET client_min_messages = warning;
+\set ECHO none
+
+\i sql/json_test_strings.sql
+CREATE TABLE json_valid_test_strings AS
+	SELECT string FROM json_test_strings WHERE json_validate(string);
+
+\set ECHO all
+RESET client_min_messages;
+
+SELECT '[]'::JSON;
+SELECT '['::JSON;
+SELECT '[1,2,3]'::JSON;
+SELECT '[1,2,3]'::JSON::TEXT;
+SELECT '[1,2,3  ]'::JSON;
+SELECT '[1,2,3  ,4]'::JSON;
+SELECT '[1,2,3  ,4.0]'::JSON;
+SELECT '[1,2,3  ,4]'::JSON;
+SELECT 'true'::JSON;
+SELECT 'true'::TEXT::JSON;
+SELECT 'false'::JSON;
+SELECT 'null'::JSON;
+SELECT '1.1'::JSON;
+SELECT '"string"'::JSON;
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+SELECT '{"key1":"value1", "key2":"value2"}'::JSON;
+SELECT 15::JSON;
+
+SELECT json_type('[]');
+SELECT json_type('{}');
+SELECT json_type('true');
+SELECT json_type('false');
+SELECT json_type('null');
+
+CREATE TABLE testjson (j JSON);
+INSERT INTO testjson VALUES ('[1,2,3,4]');
+INSERT INTO testjson VALUES ('{"key":"value"}');
+INSERT INTO testjson VALUES ('{"key":"value"');
+INSERT INTO testjson VALUES ('');
+INSERT INTO testjson VALUES ('""');
+INSERT INTO testjson VALUES ('true');
+INSERT INTO testjson VALUES ('false');
+INSERT INTO testjson VALUES ('null');
+INSERT INTO testjson VALUES ('[]');
+INSERT INTO testjson VALUES ('{}');
+
+SELECT * FROM testjson;
+
+SELECT json_type(j) FROM testjson;
+
+
+-- to_json: null
+SELECT to_json(NULL);
+SELECT to_json(NULL::INT);
+SELECT to_json(NULL::INT[]);
+SELECT to_json(NULL::VOID);
+SELECT to_json(NULL::MONEY);
+SELECT to_json('null'::text); -- should yield '"null"', not 'null'
+SELECT json_type(to_json(NULL));
+SELECT json_type(to_json(NULL::INT));
+SELECT json_type(to_json(NULL::VOID));
+SELECT json_type(to_json(NULL::MONEY));
+
+-- to_json: string
+SELECT to_json('');
+SELECT json_type(to_json(''));
+SELECT to_json('string');
+SELECT json_type(to_json('string'));
+SELECT to_json('string'::VARCHAR);
+SELECT json_type(to_json('string'::VARCHAR));
+SELECT to_json('string'::VARCHAR(3));
+SELECT json_type(to_json('string'::VARCHAR(3)));
+SELECT to_json('{1,2,3}'::TEXT);
+SELECT json_type(to_json('{1,2,3}'::TEXT));
+SELECT to_json('"doubly-encoded"'::JSON);
+SELECT json_type(to_json('"doubly-encoded"'::JSON));
+SELECT to_json('"nested quotes"'::TEXT);
+SELECT json_type(to_json('"nested quotes"'::TEXT));
+SELECT to_json('"nested quotes"'::TEXT)::TEXT::JSON;
+SELECT json_type(to_json('"nested quotes"'::TEXT)::TEXT::JSON);
+SELECT to_json('h'::CHAR);
+SELECT json_type(to_json('h'::CHAR));
+SELECT to_json('hello world'::CHAR);
+SELECT json_type(to_json('hello world'::CHAR));
+SELECT to_json('hello world!'::CHAR(11));
+SELECT json_type(to_json('hello world!'::CHAR(11)));
+
+-- to_json: number
+SELECT to_json(12345);
+SELECT to_json(12345.678);
+SELECT json_type(to_json(12345));
+SELECT json_type(to_json(12345.678));
+SELECT to_json(+1.23e100::FLOAT);
+SELECT to_json('+1.23e100'::FLOAT);
+SELECT to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890);
+SELECT json_type(to_json(123456789012345678901234567890123456789012345678901234567890.123456789012345678901234567890123456789012345678901234567890));
+SELECT to_json('100'::MONEY);
+
+-- to_json: bool
+SELECT to_json(TRUE);
+SELECT to_json(FALSE);
+SELECT to_json(1=1);
+SELECT to_json(1=2);
+SELECT json_type(to_json(TRUE));
+SELECT json_type(to_json(FALSE));
+SELECT json_type(to_json(1=1));
+SELECT json_type(to_json(1=2));
+SELECT to_json(TRUE::TEXT)::TEXT = '"' || TRUE || '"';
+SELECT to_json(FALSE::TEXT)::TEXT = '"' || FALSE || '"';
+
+-- to_json: array
+SELECT to_json(ARRAY[1,2,3]);
+SELECT to_json(ARRAY[1,2,3]);
+SELECT to_json(ARRAY[[1],[2],[3]]);
+SELECT to_json(ARRAY[[1,2],[2],[3]]);
+SELECT to_json(ARRAY[[1,2],[3,4],[5,6]]);
+SELECT to_json(ARRAY[[],[],[]]);
+SELECT to_json(ARRAY[[],[],[]]::integer[][]);
+SELECT to_json(ARRAY['hello']);
+SELECT to_json(ARRAY['hello', 'world']);
+SELECT to_json(ARRAY['hello', 'world', 5]);
+SELECT to_json(ARRAY['hello', 'world', 5]::text[]);
+SELECT to_json(ARRAY[ARRAY['hello', 'world', 5]]::text[][]);
+SELECT to_json(ARRAY[]);
+SELECT to_json(ARRAY[]::text[]);
+SELECT to_json(ARRAY['hello', 'world', null]);
+SELECT to_json(ARRAY['hello', 'world', null, 5]);
+SELECT to_json(ARRAY['hello', 'world', null, '5']);
+SELECT to_json(ARRAY[null]);
+SELECT to_json(ARRAY[null, null]);
+SELECT to_json(ARRAY[[null],[null],[null]]);
+SELECT to_json(ARRAY[[null,null],[null,null],[null,null]]);
+SELECT to_json(ARRAY[[[null,null]],[[null,null]],[[null,null]]]);
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]);
+SELECT to_json(ARRAY[[[null,null],[0,1]],[[null,null],[2,3]],[[null,null],[4,5]]]::int[][][]);
+SELECT to_json(array[1,2,3,4,5]::int2vector);
+SELECT to_json(array[1,2,3,4,5]::oidvector);
+SELECT to_json(array[[1,2],[3,4],5]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5]]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5,5]]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5,6]]::oidvector);
+SELECT to_json(array[[1,2],[3,4],[5,6]]::int2vector);
+SELECT to_json(array[[1,2],[3,4],[5,6000]]::int2vector);
+SELECT to_json(array[[1,2],[3,4],[5,60000]]::int2vector);
+SELECT to_json(array[[1,2],[3,4],[5,null]]::int2vector);
+SELECT to_json(array[[1,2],[null,4],[5,null]]::int2vector);
+SELECT to_json(array[[1,2],[null,4],[5,null]]::oidvector);
+SELECT to_json(array[[true,false],[false,true]]::bool[][]);
+SELECT to_json(array[[true,false],[false,true],[null,null]]::bool[][]);
+SELECT to_json('{1,2,3}');
+SELECT to_json('{1,2,3}'::text); -- should form "{1,2,3}", not build an array
+SELECT to_json('{1,2,3}'::int[]);
+SELECT to_json('{one,two,three}'::text[]);
+SELECT to_json('{one,two,three,null}'::text[]);
+SELECT to_json('{one,two,three,null,five}'::text[]);
+SELECT to_json('{null}'::text[]);
+SELECT to_json('{{null}}'::text[][]);
+
+-- to_json: invalid types
+SELECT to_json(row(1,2));
+SELECT to_json('127.0.0.1'::INET);
+
+
+-- from_json: null
+SELECT from_json(null);
+SELECT from_json(NULL::TEXT);
+SELECT from_json(NULL::JSON);
+
+-- from_json: string
+SELECT from_json('"valid string"');
+SELECT from_json($$ "hello\nworld" $$);
+SELECT from_json($$ "hello\u0000world" $$);
+
+-- from_json: number
+SELECT from_json('123');
+SELECT from_json('123')::INT;
+SELECT from_json('123.456')::INT;
+SELECT from_json('123.456')::FLOAT;
+SELECT from_json('123e-38');
+SELECT from_json('123e-38')::FLOAT;
+SELECT from_json('1.23e-38')::FLOAT;
+SELECT from_json('1.23e-38');
+SELECT from_json('1.23e-38')::NUMERIC;
+
+-- from_json: bool
+SELECT from_json('true')::JSON;
+SELECT from_json('true');
+SELECT from_json('true')::BOOLEAN;
+SELECT from_json('true')::BOOLEAN::JSON;
+SELECT from_json('true')::BOOLEAN::TEXT::JSON;
+SELECT from_json('false')::BOOLEAN::TEXT::JSON;
+SELECT from_json('false');
+SELECT from_json('f');
+SELECT from_json('t');
+SELECT from_json('f'::BOOLEAN::TEXT);
+SELECT from_json('f'::BOOLEAN::TEXT::JSON);
+SELECT from_json('t'::BOOLEAN::TEXT::JSON);
+
+-- from_json: object
+SELECT from_json('{"key": "value"}');
+
+-- from_json: array
+SELECT from_json('[1,2,3]');
+
+-- from_json: invalid
+SELECT from_json('invalid');
+
+
+-- test from_json on a large string
+CREATE TABLE sample_query_text (json JSON);
+INSERT INTO sample_query_text VALUES ($$
+"SELECT pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c WHERE c.relkind IN ('i') AND substring(pg_catalog.quote_ident(c.relname),1,0)='' AND pg_catalog.pg_table_is_visible(c.oid) AND c.relnamespace <> (SELECT oid FROM pg_catalog.pg_namespace WHERE nspname = 'pg_catalog')\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' FROM pg_catalog.pg_namespace n WHERE substring(pg_catalog.quote_ident(n.nspname) || '.',1,0)='' AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) > 1\nUNION\nSELECT pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname) FROM pg_catalog.pg_class c, pg_catalog.pg_namespace n WHERE c.relnamespace = n.oid AND c.relkind IN ('i') AND substring(pg_catalog.quote_ident(n.nspname) || '.' || pg_catalog.quote_ident(c.relname),1,0)='' AND substring(pg_catalog.quote_ident(n.nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(n.nspname))+1) AND (SELECT pg_catalog.count(*) FROM pg_catalog.pg_namespace WHERE substring(pg_catalog.quote_ident(nspname) || '.',1,0) = substring('',1,pg_catalog.length(pg_catalog.quote_ident(nspname))+1)) = 1\n UNION SELECT 'ON' UNION SELECT 'CONCURRENTLY'\nLIMIT 1000"
+$$);
+SELECT md5(from_json(json)) FROM sample_query_text;
+
+
+/* Make sure creating an array literal and subscripting
+ * preserves the original string exactly
+ * (except for trimming surrounding whitespace). */
+SELECT bool_and(btrim(before, E'\t\n\r ') = after) FROM (
+	SELECT
+		string AS before,
+		json_path(('  [ ' || string || '  ] ')::json, '$.[0]')::text AS after
+	FROM json_valid_test_strings
+) AS subquery;
+
+
+-- Make sure json_validate works
+SELECT json_validate(string), string FROM json_test_strings;
+
+
+/*** json_get ***/
+
+SELECT json_get('{"key": "value", "key2": "value2"}', 'key');
+SELECT json_get('{"key": "value", "key": "value2"}', 'key');
+
+/* These each return no result because 0 is a number
+   (indicating a numeric subscript),
+   not a string (indicating an object subscript). */
+SELECT json_get('{"0": "value", "key": "value"}', '0');
+SELECT json_get('{"0": "value", "0": "value"}', '[0]');
+SELECT json_get('{"0": "value", "0": "value"}', '.0');
+
+SELECT json_get('{"0": "value", "1": "value"}', '["0"]');
+SELECT json_get('{"0": "value", "0": "value"}', '["0"]');
+
+SELECT json_get('[0,1,2,3]', '0');
+SELECT json_get('[0,1,2,3]', '"0"');
+SELECT json_get('[0,1,2,3]', '*');
+SELECT json_get('[0]', '*');
+SELECT json_get('[[0]]', '..*');
+
+
+/*** json_set ***/
+
+SELECT json_set('[1,2,3]', '[1]', 5::json);
+SELECT json_set('[1,2,3]', '[3]', 5::json);
+SELECT json_set('[1,2,3]', '[2]', 5::json);
+SELECT json_set('[1,2,3]', '[2]', '[0,1]'::json);
+SELECT json_set('  [ 1 ,   2,3]', '1', '5');
+SELECT json_set('  [ 1 ,   [2,3],3]', '1', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[5][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[4][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[3][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[2][0]', '5');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ],3]', '[1][0]', '   5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1][0]', '   5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '   5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', '     5  ');
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\tworld"  $$);
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][0]', $$     "hello\u0009world"  $$);
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '[1 ][*]', $$     "hello\u0009world"  $$);
+SELECT json_set('  [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+SELECT json_set('       [ 1 ,   [  2 ,   3     ]  , 3  ] ', '$', $$     "hello\u0009world"  $$);
+
+-- Since JavaScript doesn't do anything when you assign to a character subscript,
+-- neither will json_set.
+SELECT json_set('"hello"', '[0]', '"H"');
+SELECT json_set('"hello"', '[0][0]', '"H"');
+SELECT json_set('["hello"]', '[0][0]', '"H"');
+SELECT json_set('["hello"]', '[0][0][0]', '"H"');
+
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*]', '["set"]');
+SELECT json_set('[0,1,2,[3,4,5],4]', '$[*][*]', '["set"]');
+SELECT json_set('[0,1,2,[3,4,5],4]', '$..[*]', '["set"]');
+
+
+/*** json_path ***/
+
+SELECT parse_json_path('..');
+SELECT parse_json_path('..*');
+SELECT parse_json_path('.*');
+SELECT parse_json_path('');
+SELECT parse_json_path('$.*');
+SELECT parse_json_path('$');
+SELECT parse_json_path('$*');
+SELECT parse_json_path('*');
+SELECT parse_json_path($$ .. [ 025  ] $$);
+SELECT parse_json_path($$ $ . 0 . 3 $$);
+SELECT parse_json_path($$ $ . 0_3 $$);
+SELECT parse_json_path($$ $ . 0.3 $$);
+SELECT parse_json_path($$ .. [ 031  ] $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . "back\\slash" $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . ["back\\slash"] $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . back\slash $$);
+SELECT parse_json_path($$ $ . 0 . 3 . hello . backslash $$);
+SELECT parse_json_path($$ .. [ 0x31  ] $$);
+SELECT parse_json_path($$ [ 0x31  ] $$);
+SELECT parse_json_path($$ _3 $$);
+SELECT parse_json_path($$ _3_ $$);
+SELECT parse_json_path($$ [ _3 ] $$);
+SELECT parse_json_path($$ $ _3 $$);
+SELECT parse_json_path($$ $ . _3 $$);
+SELECT parse_json_path('..["5"]');
+SELECT parse_json_path('..[5]');
+SELECT parse_json_path('..5');
+SELECT parse_json_path($$ .. [ -5  ] $$);
+SELECT parse_json_path($$ .. [ "5"  ] $$);
+SELECT parse_json_path($$ .. [ +5  ] $$);
+SELECT parse_json_path($$ .. [ 5  ] $$);
+SELECT parse_json_path($$ .. ["5"] $$);
+SELECT parse_json_path($$ ..["5"] $$);
+SELECT parse_json_path($$ [ "5" ] $$);
+SELECT parse_json_path($$ [ 5 ] $$);
+SELECT parse_json_path('."hello"');
+SELECT parse_json_path('.hello');
+SELECT parse_json_path('...["hello world"]');
+SELECT parse_json_path('..["hello world"]');
+SELECT parse_json_path('."hello world"');
+SELECT parse_json_path('.["hello world"]');
+SELECT parse_json_path('.hello world');
+SELECT parse_json_path('..["hello world"]["5"]');
+SELECT parse_json_path('..["hello world"][5]');
+SELECT parse_json_path('..["hello world"][5]..[3]..*.[*]');
+SELECT parse_json_path('..["hello world"][5]..[3]..*');
+SELECT parse_json_path('..["hello world"][5]..[3]');
+SELECT parse_json_path('..["hello world"][5]..[3]*');
+SELECT parse_json_path($$
+	.. [ '"hello"\\"world"' ]
+	[ 5 ] .. [3] . * [ * ]
+$$);
+
+select parse_json_path('$char');
+select parse_json_path('$.char');
+select parse_json_path('$.char()');
+select parse_json_path('$.char(5)');
+select parse_json_path('$.char(  -1  )');
+select parse_json_path('$.char(  -1  )  . char(0)');
+select parse_json_path('$.char(  -1  )  . char  ( 0 )  ');
+select parse_json_path('$.char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('$ . char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('$ .. char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('$ .. char(  +1  )  .. char  ( 0 )  ');
+select parse_json_path('$ . char(  +1  )  .. char  ( 0 )  ');
+select parse_json_path('$ . char(  +1  )  char  ( 0 )  ');
+select parse_json_path('$ char(  +1  )  char  ( 0 )  ');
+select parse_json_path('char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('.char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('..char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('...char(  +1  )  . char  ( 0 )  ');
+select parse_json_path('[char(5)]');
+
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(0)');
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(1)');
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(2)');
+SELECT json_path($$"⁰¹\u0000³"$$, 'char(3)');
+SELECT json_path('"0123"', 'char(-1)');
+SELECT json_path('"0123"', 'char(0)');
+SELECT json_path('"0123"', 'char(1)');
+SELECT json_path('"0123"', 'char(2)');
+SELECT json_path('"0123"', 'char(3)');
+SELECT json_path('"0123"', 'char(4)');
+SELECT json_path('"⁰¹²³"', 'char(0)');
+SELECT json_path('"⁰¹²³"', 'char(1)');
+SELECT json_path('"⁰¹²³"', 'char(2)');
+SELECT json_path('"⁰¹²³"', 'char(3)');
+SELECT json_path('[1,2,3]', '$');
+SELECT json_path('[1,2,3]', '$.+1');
+SELECT json_path('[1,2,3]', '$.-1');
+SELECT json_path('[1,2,3]', '$.0');
+SELECT json_path('[1,2,3]', '$.1');
+SELECT json_path('[1,2,3]', '$.2');
+SELECT json_path('[1,2,3]', '$.3');
+SELECT json_path('[1,2,3]', '*');
+SELECT json_path('[1,2,3]', '[0]');
+SELECT json_path('[1,2,3]', '[1]');
+SELECT json_path('[1,2,3]', '[2]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', $$['2']$$);
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["0"]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["1"]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '["2"]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[0]');
+SELECT json_path('{"0": "zero", "1": "one", "2": "two"}', '[1]');
+
+-- Multiple JSONPath results are listed in BFS order
+-- (just because it's easier to implement efficiently than DFS)
+SELECT json_path('[0,1,[2, [3,4 , 5],6,[7,8],9],10]', '$..*');
+
+
+CREATE TABLE sample (json JSON);
+INSERT INTO sample VALUES ($$
+{
+	"store": {
+		"books": [
+			{
+				"title": "book 0",
+				"author": "author 0",
+				"prices": [1,2,3]
+			}, {
+				"title": "book 1",
+				"author": "author 1",
+				"prices": [4,5,6]
+			}, {
+				"title": "book 2",
+				"author": "author 2",
+				"prices": [7,8,9]
+			}
+		],
+		"toys": [
+			"Yo-yo",
+			"Boomerang",
+			"Basketball"
+		]
+	}
+}
+$$);
+
+SELECT json_path(json, 'store.books[*]') FROM sample;
+SELECT json_path(json, 'store.books[*].title') FROM sample;
+SELECT json_path(json, 'store.books[*].author') FROM sample;
+SELECT json_path(json, 'store.books[*].prices') FROM sample;
+SELECT json_path(json, 'store.books[*].prices[*]') FROM sample;
+SELECT json_path(json, 'store.toys[*]') FROM sample;
+SELECT json_path(json, 'store.toys[*][0]') FROM sample;
+SELECT json_path(json, 'store.toys[*][1]') FROM sample;
+SELECT json_path(json, 'store.toys[*][0][0]') FROM sample;
+SELECT json_path(json, 'store.toys[*][0][1]') FROM sample;
+
+SELECT json_path(json, '..books') FROM sample;
+SELECT json_path(json, '..books[*]') FROM sample;
+SELECT json_path(json, '..title') FROM sample;
+SELECT json_path(json, '..author') FROM sample;
+SELECT json_path(json, '..prices[*]') FROM sample;
+SELECT json_path(json, '..toys[*]') FROM sample;
+SELECT json_path(json, '..toys..[*]') FROM sample;
+
+SELECT json_path(json, '..[-1]') FROM sample;
+SELECT json_path(json, '..[0]') FROM sample;
+SELECT json_path(json, '..[1]') FROM sample;
+SELECT json_path(json, '..[2]') FROM sample;
+SELECT json_path(json, '..[3]') FROM sample;
+
+SELECT json_path(json, '$') FROM sample;
+SELECT json_path(json, '..*') FROM sample;
+
+SELECT json_path(json, '..char(-1)') FROM sample;
+SELECT json_path(json, '..char(0)') FROM sample;
+SELECT json_path(json, '..char(1)') FROM sample;
+SELECT json_path(json, '..char(2)') FROM sample;
+SELECT json_path(json, '..char(3)') FROM sample;
+SELECT json_path(json, '..char(100)') FROM sample;
+
+
+/*** json_condense ***/
+
+SELECT json_condense('"hello"');
+SELECT json_condense($$"hello\u266Bworld"$$);
+SELECT json_condense($$"hello\u266bworld"$$);
+SELECT json_condense($$"hello♫world"$$);
+SELECT json_condense($$      "hello world"    $$);
+SELECT json_condense($$    {  "hello" : "world"}    $$);
+SELECT json_condense($$    {  "hello" : "world", "bye": 0.0001  }    $$);
+SELECT json_condense($$    {  "hello" : "world",
+								"bye": 0.0000001
+}    $$);
+SELECT json_condense($$    {  "hello" : "world"
+,
+"bye"
+: [-0.1234e1, 12345e0]		}    $$);
+
+
+
diff --git a/src/test/regress/sql/json_test_strings.sql b/src/test/regress/sql/json_test_strings.sql
new file mode 100644
index 0000000..e64bdd1
--- /dev/null
+++ b/src/test/regress/sql/json_test_strings.sql
@@ -0,0 +1,221 @@
+/*
+ * This is not a test.  It is the set of
+ * test strings used by the json.sql test.
+ */
+
+CREATE TABLE json_test_strings (string TEXT);
+INSERT INTO json_test_strings VALUES ($$$$);
+INSERT INTO json_test_strings VALUES ($$  $$);
+INSERT INTO json_test_strings VALUES ($$"$$);
+INSERT INTO json_test_strings VALUES ($$[,]$$);
+INSERT INTO json_test_strings VALUES ($$[)$$);
+INSERT INTO json_test_strings VALUES ($$[]]$$);
+INSERT INTO json_test_strings VALUES ($$[}$$);
+INSERT INTO json_test_strings VALUES ($${,}$$);
+INSERT INTO json_test_strings VALUES ($${]$$);
+INSERT INTO json_test_strings VALUES ($$["1":2]$$);
+INSERT INTO json_test_strings VALUES ($$[1,2,]$$);
+INSERT INTO json_test_strings VALUES ($$[1:2}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2,}$$);
+INSERT INTO json_test_strings VALUES ($${1:2}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7 ]}]}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], [7]}]}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]]$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "3":4$$);
+INSERT INTO json_test_strings VALUES ($$"1\u2"$$);
+INSERT INTO json_test_strings VALUES ($$[,2]$$);
+INSERT INTO json_test_strings VALUES ($$"3$$);
+INSERT INTO json_test_strings VALUES ($$"3" "4"$$);
+INSERT INTO json_test_strings VALUES ($$[3[4]$$);
+INSERT INTO json_test_strings VALUES ($$[3[4]]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6] 7, 8 9]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6] 7, 8, 9]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6], 7, 8 9]$$);
+INSERT INTO json_test_strings VALUES ($${"hello":true, "bye":false, null}$$);
+INSERT INTO json_test_strings VALUES ($${"hello":true, "bye":false, null:null}$$);
+INSERT INTO json_test_strings VALUES ($$"hi$$);
+INSERT INTO json_test_strings VALUES ($$"hi"""$$);
+INSERT INTO json_test_strings VALUES ($${"hi": "bye"]$$);
+INSERT INTO json_test_strings VALUES ($$"\uD800\uD800"$$);
+INSERT INTO json_test_strings VALUES ($$"\uD800\uDBFF"$$);
+INSERT INTO json_test_strings VALUES ($$"\UD834\UDD1E"$$);
+INSERT INTO json_test_strings VALUES ($$"\uDB00"$$);
+INSERT INTO json_test_strings VALUES ($$"\uDB00\uDBFF"$$);
+INSERT INTO json_test_strings VALUES ($$"\uFFFE"$$);
+INSERT INTO json_test_strings VALUES ($$"\uFFFF"$$);
+INSERT INTO json_test_strings VALUES ($$.$$);
+INSERT INTO json_test_strings VALUES ($$""$$);
+INSERT INTO json_test_strings VALUES ($$[]$$);
+INSERT INTO json_test_strings VALUES ($${}$$);
+INSERT INTO json_test_strings VALUES ($$+.$$);
+INSERT INTO json_test_strings VALUES ($$0.5$$);
+INSERT INTO json_test_strings VALUES ($$0.e1$$);
+INSERT INTO json_test_strings VALUES ($${"1":{}}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"]}]}$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "2.5" : [3, 4, {}, {"5": ["6"], "7" :[8 ]}]}$$);
+INSERT INTO json_test_strings VALUES ($$1234$$);
+INSERT INTO json_test_strings VALUES ($$-1234$$);
+INSERT INTO json_test_strings VALUES ($${"1":2, "3":4}$$);
+INSERT INTO json_test_strings VALUES ($$+1234$$);
+INSERT INTO json_test_strings VALUES ($$++1234$$);
+INSERT INTO json_test_strings VALUES ($$123.456e14234$$);
+INSERT INTO json_test_strings VALUES ($$123.456e-14234$$);
+INSERT INTO json_test_strings VALUES ($$123.456e+14234$$);
+INSERT INTO json_test_strings VALUES ($$123.e-14234$$);
+INSERT INTO json_test_strings VALUES ($$"1\u2000"$$);
+INSERT INTO json_test_strings VALUES ($$"1\u20001"$$);
+INSERT INTO json_test_strings VALUES ($$2$$);
+INSERT INTO json_test_strings VALUES ($$.246e-14234$$);
+INSERT INTO json_test_strings VALUES ($$.2e-14234$$);
+INSERT INTO json_test_strings VALUES ($$3$$);
+INSERT INTO json_test_strings VALUES ($$.3$$);
+INSERT INTO json_test_strings VALUES ($$"3"$$);
+INSERT INTO json_test_strings VALUES ($$[3]$$);
+INSERT INTO json_test_strings VALUES ($$+3.$$);
+INSERT INTO json_test_strings VALUES ($$3.2e+1$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4]]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5]]]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6]]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6], 7]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6], 7, 8]$$);
+INSERT INTO json_test_strings VALUES ($$[3, [4, [5], 6], 7, 8, 9]$$);
+INSERT INTO json_test_strings VALUES ($$+3.5$$);
+INSERT INTO json_test_strings VALUES ($$.3e$$);
+INSERT INTO json_test_strings VALUES ($$.3e1$$);
+INSERT INTO json_test_strings VALUES ($$.3e-1$$);
+INSERT INTO json_test_strings VALUES ($$.3e+1$$);
+INSERT INTO json_test_strings VALUES ($$3.e1$$);
+INSERT INTO json_test_strings VALUES ($$3.e+1$$);
+INSERT INTO json_test_strings VALUES ($$3e+1$$);
+INSERT INTO json_test_strings VALUES ($$.5$$);
+INSERT INTO json_test_strings VALUES ($$+.5$$);
+INSERT INTO json_test_strings VALUES ($$.5e+1$$);
+INSERT INTO json_test_strings VALUES ($$[ 7]$$);
+INSERT INTO json_test_strings VALUES ($$[7 ]$$);
+INSERT INTO json_test_strings VALUES ($$[7]$$);
+INSERT INTO json_test_strings VALUES ($$.e-14234$$);
+INSERT INTO json_test_strings VALUES ($$"hello"$$);
+INSERT INTO json_test_strings VALUES ($$["hello"]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye"]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n"]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n\r\t"]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n\r\t\b"]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n\r\t\b",true]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n\r\t\b",true , false]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n\r\t\b",true , false,    null]$$);
+INSERT INTO json_test_strings VALUES ($$["hello", "bye\n\r\t\v"]$$);
+INSERT INTO json_test_strings VALUES ($${"hello":true}$$);
+INSERT INTO json_test_strings VALUES ($${"hello":true, "bye":false}$$);
+INSERT INTO json_test_strings VALUES ($${"hello":true, "bye":false, "foo":["one","two","three"]}$$);
+INSERT INTO json_test_strings VALUES ($$"hi"$$);
+INSERT INTO json_test_strings VALUES ($$["hi"]$$);
+INSERT INTO json_test_strings VALUES ($$["hi", "bye"]$$);
+INSERT INTO json_test_strings VALUES ($${"hi": "bye"}$$);
+INSERT INTO json_test_strings VALUES ($$["hi", "bye", 3]$$);
+INSERT INTO json_test_strings VALUES ($$["hi", "bye[", 3]$$);
+INSERT INTO json_test_strings VALUES ($$"\u0007"$$);
+INSERT INTO json_test_strings VALUES ($$"\u0008"$$);
+INSERT INTO json_test_strings VALUES ($$"\u0009"$$);
+INSERT INTO json_test_strings VALUES ($$"\u0010"$$);
+INSERT INTO json_test_strings VALUES ($$"\u0020"$$);
+INSERT INTO json_test_strings VALUES ($$"\u10000"$$);
+INSERT INTO json_test_strings VALUES ($$"\u1234"$$);
+INSERT INTO json_test_strings VALUES ($$"\u99999"$$);
+INSERT INTO json_test_strings VALUES ($$"\ud800\udc00"$$);
+INSERT INTO json_test_strings VALUES ($$"\uD800\uDC00"$$);
+INSERT INTO json_test_strings VALUES ($$"\uD834\uDD1E"$$);
+INSERT INTO json_test_strings VALUES ($$"\uDBFF\uDFFF"$$);
+INSERT INTO json_test_strings VALUES ($$"\uFFFD"$$);
+INSERT INTO json_test_strings VALUES ($$"\uFFFF"$$);
+INSERT INTO json_test_strings VALUES ($$hello$$);
+INSERT INTO json_test_strings VALUES ($$[32, 1]$$);
+INSERT INTO json_test_strings VALUES ($$[32, $$);
+INSERT INTO json_test_strings VALUES ($$"\uD800\uDC00"$$);
+INSERT INTO json_test_strings VALUES ($$"\n"$$);
+INSERT INTO json_test_strings VALUES ($$"hello"$$);
+INSERT INTO json_test_strings VALUES ($$"hello\u0009world"$$);
+INSERT INTO json_test_strings VALUES ($$"hello"$$);
+INSERT INTO json_test_strings VALUES ($$"hello\n"$$);
+INSERT INTO json_test_strings VALUES ($$"hello"$$);
+INSERT INTO json_test_strings VALUES ($$3$$);
+INSERT INTO json_test_strings VALUES ($$3.$$);
+INSERT INTO json_test_strings VALUES ($$.3$$);
+INSERT INTO json_test_strings VALUES ($$0.3$$);
+INSERT INTO json_test_strings VALUES ($$0.3e$$);
+INSERT INTO json_test_strings VALUES ($$0.3e+$$);
+INSERT INTO json_test_strings VALUES ($$0.3e+5$$);
+INSERT INTO json_test_strings VALUES ($$0.3e-5$$);
+INSERT INTO json_test_strings VALUES ($$0.3e5$$);
+INSERT INTO json_test_strings VALUES ($$"hello"$$);
+INSERT INTO json_test_strings VALUES ($$+3$$);
+INSERT INTO json_test_strings VALUES ($$-3$$);
+INSERT INTO json_test_strings VALUES ($$-3.$$);
+INSERT INTO json_test_strings VALUES ($$-3.1$$);
+INSERT INTO json_test_strings VALUES ($$.5$$);
+INSERT INTO json_test_strings VALUES ($$5.$$);
+INSERT INTO json_test_strings VALUES ($$5.e1$$);
+INSERT INTO json_test_strings VALUES ($$0.5$$);
+INSERT INTO json_test_strings VALUES ($$.3e1$$);
+INSERT INTO json_test_strings VALUES ($$.3e+1$$);
+INSERT INTO json_test_strings VALUES ($$.3e-1$$);
+INSERT INTO json_test_strings VALUES ($$.3e-1 .5$$);
+INSERT INTO json_test_strings VALUES ($$.3e-1.5$$);
+INSERT INTO json_test_strings VALUES ($$.3e+1.5$$);
+INSERT INTO json_test_strings VALUES ($$.3e+.$$);
+INSERT INTO json_test_strings VALUES ($$.3e+.5$$);
+INSERT INTO json_test_strings VALUES ($$.3e+1.5$$);
+INSERT INTO json_test_strings VALUES ($$9.3e+1.5$$);
+INSERT INTO json_test_strings VALUES ($$9.e+1.5$$);
+INSERT INTO json_test_strings VALUES ($$9.e+$$);
+INSERT INTO json_test_strings VALUES ($$9.e+1$$);
+INSERT INTO json_test_strings VALUES ($$"\""$$);
+INSERT INTO json_test_strings VALUES ($$"\"3.5"$$);
+INSERT INTO json_test_strings VALUES ($$"\"."$$);
+INSERT INTO json_test_strings VALUES ($$"\".".$$);
+INSERT INTO json_test_strings VALUES ($$"\"....."$$);
+INSERT INTO json_test_strings VALUES ($$"\"\"\"\"""$$);
+INSERT INTO json_test_strings VALUES ($$["\"\"\"\"", .5]$$);
+INSERT INTO json_test_strings VALUES ($$[.5]$$);
+INSERT INTO json_test_strings VALUES ($$["\"\"\"\"", 0.5]$$);
+INSERT INTO json_test_strings VALUES ($$["\"\"\"\"", .5]$$);
+INSERT INTO json_test_strings VALUES ($$["\"\"\"\"",.5]$$);
+INSERT INTO json_test_strings VALUES ($$["\"",.5]$$);
+INSERT INTO json_test_strings VALUES ($$["\".5",.5]$$);
+INSERT INTO json_test_strings VALUES ($$["\".5",".5\"".5]$$);
+INSERT INTO json_test_strings VALUES ($$["\".5",".5\"", .5]$$);
+INSERT INTO json_test_strings VALUES ($$["\".5",".5\"",.5]$$);
+INSERT INTO json_test_strings VALUES ($$["\".5",".5\"",0.5]$$);
+INSERT INTO json_test_strings VALUES ($${"key":/*comment*/"value"}$$);
+INSERT INTO json_test_strings VALUES ($${"key":/*comment"value"}$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}/*$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}/**/$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}/***/$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}/**//$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}/**///$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}/**///----$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}#$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}#{$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}#{}$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"}#,$$);
+INSERT INTO json_test_strings VALUES ($${"key":"value"/**/, "k2":"v2"}$$);
+INSERT INTO json_test_strings VALUES ($$"\u0027"$$);
+INSERT INTO json_test_strings VALUES ($$"hello\'"$$);
+INSERT INTO json_test_strings VALUES ($$'hello\''$$);
+INSERT INTO json_test_strings VALUES ($$'hello'$$);
+INSERT INTO json_test_strings VALUES ($$'hell\'o'$$);
+INSERT INTO json_test_strings VALUES ($$'\'hello'$$);
+INSERT INTO json_test_strings VALUES ($$'\'hello\''$$);
+INSERT INTO json_test_strings VALUES ($$\'hello\'$$);
+INSERT INTO json_test_strings VALUES ($$'hello\'$$);
+INSERT INTO json_test_strings VALUES ($$['hello\']$$);
+INSERT INTO json_test_strings VALUES ($$['hello\'']$$);
+INSERT INTO json_test_strings VALUES ($$['hello"']$$);
+INSERT INTO json_test_strings VALUES ($$['hello\"']$$);
+INSERT INTO json_test_strings VALUES ($$['hello"o']$$);
+INSERT INTO json_test_strings VALUES ($$['"']$$);
+INSERT INTO json_test_strings VALUES ($$'"'$$);
+INSERT INTO json_test_strings VALUES ($$'"hello"'$$);
+INSERT INTO json_test_strings VALUES ($$'"hello'$$);
+INSERT INTO json_test_strings VALUES ($$'"hi"'$$);