regexp_replace

Started by Atsushi Ogawaabout 21 years ago10 messagespatches

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Atsushi Ogawa

a_ogawa@hi-ho.ne.jp

about 21 years ago

I made the patch that implements regexp_replace again.
The specification of this function is as follows.

regexp_replace(source text, pattern text, replacement text, [flags text])
returns text

Replace string that matches to regular expression in source text to
replacement text.

- pattern is regular expression pattern.
- replacement is replace string that can use '\1'-'\9', and '\&'.
'\1'-'\9': back reference to the n'th subexpression.
'\&' : entire matched string.
- flags can use the following values:
g: global (replace all)
i: ignore case
When the flags is not specified, case sensitive, replace the first
instance only.

regards,

--- Atsushi Ogawa

Andrew Dunstan

andrew@dunslane.net

about 21 years ago

In reply to: Atsushi Ogawa (#1)

Re: regexp_replace

I'm very glad to see this. But is a nicer name possible? To perl
programmers at least, "substitute" should make sense.

cheers

andrew

Atsushi Ogawa wrote:

Show quoted text

I made the patch that implements regexp_replace again.
The specification of this function is as follows.

regexp_replace(source text, pattern text, replacement text, [flags text])
returns text

Replace string that matches to regular expression in source text to
replacement text.

- pattern is regular expression pattern.
- replacement is replace string that can use '\1'-'\9', and '\&'.
'\1'-'\9': back reference to the n'th subexpression.
'\&' : entire matched string.
- flags can use the following values:
g: global (replace all)
i: ignore case
When the flags is not specified, case sensitive, replace the first
instance only.

regards,
--- Atsushi Ogawa
------------------------------------------------------------------------

---------------------------(end of broadcast)---------------------------
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Bruce Momjian

bruce@momjian.us

about 21 years ago

In reply to: Andrew Dunstan (#2)

Re: regexp_replace

Andrew Dunstan wrote:

I'm very glad to see this. But is a nicer name possible? To perl
programmers at least, "substitute" should make sense.

What is the matter with replace? We already have replace:

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Atsushi Ogawa

a_ogawa@hi-ho.ne.jp

about 21 years ago

In reply to: Bruce Momjian (#3)

Re: regexp_replace

Bruce Momjian wrote:

Andrew Dunstan wrote:

I'm very glad to see this. But is a nicer name possible? To perl
programmers at least, "substitute" should make sense.

What is the matter with replace? We already have replace:

test=> \df replace
List of functions
Schema | Name | Result data type | Argument data types
------------+---------+------------------+---------------------
pg_catalog | replace | text | text, text, text

I think that regexp_replace is a good name. It is easy to understand.

regards,

--- Atsushi Ogawa

Andrew Dunstan

andrew@dunslane.net

about 21 years ago

In reply to: Atsushi Ogawa (#4)

Re: regexp_replace

Atsushi Ogawa wrote:

I think that regexp_replace is a good name. It is easy to understand.

I'll go with the flow.

cheers

andrew

Pavel Stehule

pavel.stehule@gmail.com

about 21 years ago

In reply to: Atsushi Ogawa (#4)

Re: regexp_replace

pg_catalog | replace | text | text, text, text

I think that regexp_replace is a good name. It is easy to understand.

regards,

I prefere this name too

Regards
Pavel Stehule

Bruce Momjian

bruce@momjian.us

about 21 years ago

In reply to: Atsushi Ogawa (#1)

Re: regexp_replace

I have applied your patch, with slight adjustments in spacing and
documentation.

Patch applied. Thanks.

---------------------------------------------------------------------------

Atsushi Ogawa wrote:

I made the patch that implements regexp_replace again.
The specification of this function is as follows.

regexp_replace(source text, pattern text, replacement text, [flags text])
returns text

Replace string that matches to regular expression in source text to
replacement text.

- pattern is regular expression pattern.
- replacement is replace string that can use '\1'-'\9', and '\&'.
'\1'-'\9': back reference to the n'th subexpression.
'\&' : entire matched string.
- flags can use the following values:
g: global (replace all)
i: ignore case
When the flags is not specified, case sensitive, replace the first
instance only.

regards,
--- Atsushi Ogawa

[ Attachment, skipping... ]

---------------------------(end of broadcast)---------------------------
TIP 4: Don't 'kill -9' the postmaster

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

Andrew Dunstan

andrew@dunslane.net

about 21 years ago

In reply to: Bruce Momjian (#7)

Re: regexp_replace

The change below has broken tsearch2. See for example
http://www.pgbuildfarm.org/cgi-bin/show_log.pl?nm=shrew&dt=2005-07-10%2015:02:01

cheers

andrew

Bruce Momjian wrote:

I have applied your patch, with slight adjustments in spacing and
documentation.

Patch applied. Thanks.

[snip]

Show quoted text

Index: src/include/regex/regex.h
===================================================================
RCS file: /cvsroot/pgsql/src/include/regex/regex.h,v
retrieving revision 1.26
diff -c -c -r1.26 regex.h
*** src/include/regex/regex.h	29 Nov 2003 22:41:10 -0000	1.26
--- src/include/regex/regex.h	10 Jul 2005 04:52:51 -0000
***************
*** 163,169 ****
* the prototypes for exported functions
*/
extern int	pg_regcomp(regex_t *, const pg_wchar *, size_t, int);
! extern int	pg_regexec(regex_t *, const pg_wchar *, size_t, rm_detail_t *, size_t, regmatch_t[], int);
extern void pg_regfree(regex_t *);
extern size_t pg_regerror(int, const regex_t *, char *, size_t);

--- 163,169 ----
* the prototypes for exported functions
*/
extern int	pg_regcomp(regex_t *, const pg_wchar *, size_t, int);
! extern int	pg_regexec(regex_t *, const pg_wchar *, size_t, size_t, rm_detail_t *, size_t, regmatch_t[], int);
extern void pg_regfree(regex_t *);
extern size_t pg_regerror(int, const regex_t *, char *, size_t);

Atsushi Ogawa

a_ogawa@hi-ho.ne.jp

about 21 years ago

In reply to: Bruce Momjian (#7)

Re: regexp_replace

Bruce Momjian wrote:

I have applied your patch, with slight adjustments in spacing and
documentation.

Patch applied. Thanks.

Thank you for applying patch.
An attached patch is a small additional improvement.

This patch use appendStringInfoText instead of appendStringInfoString.
There is an overhead of PG_TEXT_GET_STR when appendStringInfoString is
executed by text type. This can be reduced by appendStringInfoText.

regards,

Atsushi Ogawa

#10

Bruce Momjian

bruce@momjian.us

almost 21 years ago

In reply to: Atsushi Ogawa (#9)

Re: regexp_replace

Patch applied. Thanks.

---------------------------------------------------------------------------

Atsushi Ogawa wrote:

Bruce Momjian wrote:

I have applied your patch, with slight adjustments in spacing and
documentation.

Patch applied. Thanks.

Thank you for applying patch.
An attached patch is a small additional improvement.

This patch use appendStringInfoText instead of appendStringInfoString.
There is an overhead of PG_TEXT_GET_STR when appendStringInfoString is
executed by text type. This can be reduced by appendStringInfoText.

regards,

Atsushi Ogawa

[ Attachment, skipping... ]

-- 
  Bruce Momjian                        |  http://candle.pha.pa.us
  pgman@candle.pha.pa.us               |  (610) 359-1001
  +  If your life is a hard drive,     |  13 Roberts Road
  +  Christ can be your backup.        |  Newtown Square, Pennsylvania 19073

regexp_replace

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