>From 3bc186efd1c735828b280b24b3acd7b3ed5a9c8a Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Tue, 15 Apr 2014 16:44:23 -0300
Subject: [PATCH 21/36] deparse/core: enable deparse of function defaults expr

---
 src/backend/utils/adt/ruleutils.c | 25 +++++++++++++++++++++++++
 src/include/utils/ruleutils.h     |  1 +
 2 files changed, 26 insertions(+)

diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 522ccf4..ac007ee 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -9580,3 +9580,28 @@ RelationGetColumnDefault(Relation rel, AttrNumber attno, List *dpcontext)
 
 	return defstr;
 }
+
+/*
+ * Return the defaults values of arguments to a function, as a list of
+ * deparsed expressions.
+ */
+List *
+FunctionGetDefaults(text *proargdefaults)
+{
+	List   *nodedefs;
+	List   *strdefs = NIL;
+	ListCell *cell;
+
+	nodedefs = (List *) stringToNode(TextDatumGetCString(proargdefaults));
+	if (!IsA(nodedefs, List))
+		elog(ERROR, "proargdefaults is not a list");
+
+	foreach(cell, nodedefs)
+	{
+		Node   *onedef = lfirst(cell);
+
+		strdefs = lappend(strdefs, deparse_expression_pretty(onedef, NIL, false, false, 0, 0));
+	}
+
+	return strdefs;
+}
diff --git a/src/include/utils/ruleutils.h b/src/include/utils/ruleutils.h
index 657069d..5648938 100644
--- a/src/include/utils/ruleutils.h
+++ b/src/include/utils/ruleutils.h
@@ -43,6 +43,7 @@ extern List *deparse_context_for_planstate(Node *planstate, List *ancestors,
 extern List *select_rtable_names_for_explain(List *rtable,
 								Bitmapset *rels_used);
 extern char *generate_collation_name(Oid collid);
+extern List *FunctionGetDefaults(text *proargdefaults);
 
 extern char *RelationGetColumnDefault(Relation rel, AttrNumber attno,
 						 List *dpcontext);
-- 
1.9.1