From 64a60590ba5da8026abb65a7abe8fce9e573c476 Mon Sep 17 00:00:00 2001
From: Neil Conway <neilc@samurai.com>
Date: Mon, 27 Sep 2004 04:12:03 +0000
Subject: [PATCH] A few minor list-related cleanups:

(1) Replace while loop with the new forboth() construct in
parser/analyze.c

(2) Replace lcons() with lappend() in SearchCatCacheList(). Since these
now have the same performance, there is no reason to prefer lcons() in
this case, and using lappend() leads to cleaner code.

(3) Improve the name of the second parameter to for_each_cell()
---
 src/backend/parser/analyze.c       | 12 ++++--------
 src/backend/utils/cache/catcache.c | 11 ++++++-----
 src/include/nodes/pg_list.h        |  6 +++---
 3 files changed, 13 insertions(+), 16 deletions(-)

diff --git a/src/backend/parser/analyze.c b/src/backend/parser/analyze.c
index d05be5de5d..c3b547dd5b 100644
--- a/src/backend/parser/analyze.c
+++ b/src/backend/parser/analyze.c
@@ -6,7 +6,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.311 2004/08/29 05:06:44 momjian Exp $
+ *	$PostgreSQL: pgsql/src/backend/parser/analyze.c,v 1.312 2004/09/27 04:12:02 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -2273,25 +2273,21 @@ getSetColTypes(ParseState *pstate, Node *node)
 static void
 applyColumnNames(List *dst, List *src)
 {
-	ListCell   *dst_item = list_head(dst);
-	ListCell   *src_item = list_head(src);
+	ListCell   *dst_item;
+	ListCell   *src_item;
 
 	if (list_length(src) > list_length(dst))
 		ereport(ERROR,
 				(errcode(ERRCODE_SYNTAX_ERROR),
 			 errmsg("CREATE TABLE AS specifies too many column names")));
 
-	while (src_item != NULL && dst_item != NULL)
+	forboth(dst_item, dst, src_item, src)
 	{
 		TargetEntry *d = (TargetEntry *) lfirst(dst_item);
 		ColumnDef  *s = (ColumnDef *) lfirst(src_item);
 
 		Assert(d->resdom && !d->resdom->resjunk);
-
 		d->resdom->resname = pstrdup(s->colname);
-
-		dst_item = lnext(dst_item);
-		src_item = lnext(src_item);
 	}
 }
 
diff --git a/src/backend/utils/cache/catcache.c b/src/backend/utils/cache/catcache.c
index b66007c069..0a11411e9a 100644
--- a/src/backend/utils/cache/catcache.c
+++ b/src/backend/utils/cache/catcache.c
@@ -8,7 +8,7 @@
  *
  *
  * IDENTIFICATION
- *	  $PostgreSQL: pgsql/src/backend/utils/cache/catcache.c,v 1.116 2004/08/29 05:06:50 momjian Exp $
+ *	  $PostgreSQL: pgsql/src/backend/utils/cache/catcache.c,v 1.117 2004/09/27 04:12:02 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -1501,7 +1501,7 @@ SearchCatCacheList(CatCache *cache,
 		 * worth fixing.
 		 */
 		ct->refcount++;
-		ctlist = lcons(ct, ctlist);
+		ctlist = lappend(ctlist, ct);
 		nmembers++;
 	}
 
@@ -1522,16 +1522,17 @@ SearchCatCacheList(CatCache *cache,
 
 	cl->cl_magic = CL_MAGIC;
 	cl->my_cache = cache;
-	DLInitElem(&cl->cache_elem, (void *) cl);
+	DLInitElem(&cl->cache_elem, cl);
 	cl->refcount = 0;			/* for the moment */
 	cl->dead = false;
 	cl->ordered = ordered;
 	cl->nkeys = nkeys;
 	cl->hash_value = lHashValue;
 	cl->n_members = nmembers;
-	/* The list is backwards because we built it with lcons */
+
+	Assert(nmembers == list_length(ctlist));
 	ctlist_item = list_head(ctlist);
-	for (i = nmembers; --i >= 0;)
+	for (i = 0; i < nmembers; i++)
 	{
 		cl->members[i] = ct = (CatCTup *) lfirst(ctlist_item);
 		Assert(ct->c_list == NULL);
diff --git a/src/include/nodes/pg_list.h b/src/include/nodes/pg_list.h
index c35e7c64ba..d8957b3522 100644
--- a/src/include/nodes/pg_list.h
+++ b/src/include/nodes/pg_list.h
@@ -30,7 +30,7 @@
  * Portions Copyright (c) 1996-2004, PostgreSQL Global Development Group
  * Portions Copyright (c) 1994, Regents of the University of California
  *
- * $PostgreSQL: pgsql/src/include/nodes/pg_list.h,v 1.49 2004/08/29 05:06:57 momjian Exp $
+ * $PostgreSQL: pgsql/src/include/nodes/pg_list.h,v 1.50 2004/09/27 04:12:03 neilc Exp $
  *
  *-------------------------------------------------------------------------
  */
@@ -167,8 +167,8 @@ extern int	list_length(List *l);
  *	  a convenience macro which loops through a list starting from a
  *	  specified cell
  */
-#define for_each_cell(cell, l)	\
-	for ((cell) = (l); (cell) != NULL; (cell) = lnext(cell))
+#define for_each_cell(cell, initcell)	\
+	for ((cell) = (initcell); (cell) != NULL; (cell) = lnext(cell))
 
 /*
  * forboth -