diff options
Diffstat (limited to 'src/backend/nodes/list.c')
| -rw-r--r-- | src/backend/nodes/list.c | 24 |
1 files changed, 23 insertions, 1 deletions
diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c index bf9e5c10d6f..1fbfd1efa88 100644 --- a/src/backend/nodes/list.c +++ b/src/backend/nodes/list.c @@ -8,7 +8,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.45 2003/01/24 03:58:34 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.46 2003/01/27 20:51:49 tgl Exp $ * * NOTES * XXX a few of the following functions are duplicated to handle @@ -640,6 +640,28 @@ set_differencei(List *l1, List *l2) } /* + * set_ptrDifference + * + * Same as set_difference, when pointer-equality comparison is sufficient + */ +List * +set_ptrDifference(List *l1, List *l2) +{ + List *result = NIL; + List *i; + + if (l2 == NIL) + return listCopy(l1); /* slightly faster path for empty l2 */ + + foreach(i, l1) + { + if (!ptrMember(lfirst(i), l2)) + result = lappend(result, lfirst(i)); + } + return result; +} + +/* * Reverse a list, non-destructively */ List * |