Deprecate the use of => as an operator name.

In HEAD, emit a warning when an operator named => is defined.
In both HEAD and the backbranches (except in 8.2, where contrib
modules do not have documentation), document that hstore's text =>
text operator may be removed in a future release, and encourage the
use of the hstore(text, text) function instead.  This function only
exists in HEAD (previously, it was called tconvert), so backpatch
it back to 8.2, when hstore was added.  Per discussion.

1 files changed, 11 insertions, 1 deletions

diff --git a/src/backend/commands/operatorcmds.c b/src/backend/commands/operatorcmds.c
index ff94aea42d4..2936c92a94e 100644
--- a/src/backend/commands/operatorcmds.c
+++ b/src/backend/commands/operatorcmds.c
@@ -9,7 +9,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/commands/operatorcmds.c,v 1.45 2010/02/14 18:42:14 rhaas Exp $
+ *	  $PostgreSQL: pgsql/src/backend/commands/operatorcmds.c,v 1.46 2010/06/22 11:36:16 rhaas Exp $
  *
  * DESCRIPTION
  *	  The "DefineFoo" routines take the parse tree and pick out the
@@ -88,6 +88,16 @@ DefineOperator(List *names, List *parameters)
 	/* Convert list of names to a name and namespace */
 	oprNamespace = QualifiedNameGetCreationNamespace(names, &oprName);
 
+	/*
+	 * The SQL standard committee has decided that => should be used for
+	 * named parameters; therefore, a future release of PostgreSQL may
+	 * disallow it as the name of a user-defined operator.
+	 */
+	if (strcmp(oprName, "=>") == 0)
+		ereport(WARNING,
+				(errmsg("=> is deprecated as an operator name"),
+				 errdetail("This name may be disallowed altogether in future versions of PostgreSQL.")));
+
 	/* Check we have creation rights in target namespace */
 	aclresult = pg_namespace_aclcheck(oprNamespace, GetUserId(), ACL_CREATE);
 	if (aclresult != ACLCHECK_OK)