diff options
Diffstat (limited to 'src/backend/nodes/list.c')
| -rw-r--r-- | src/backend/nodes/list.c | 27 |
1 files changed, 26 insertions, 1 deletions
diff --git a/src/backend/nodes/list.c b/src/backend/nodes/list.c index 87dd3b6562b..f814047af43 100644 --- a/src/backend/nodes/list.c +++ b/src/backend/nodes/list.c @@ -7,7 +7,7 @@ * * * IDENTIFICATION - * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.26 1999/08/14 19:29:35 tgl Exp $ + * $Header: /cvsroot/pgsql/src/backend/nodes/list.c,v 1.27 1999/08/16 02:17:42 tgl Exp $ * * NOTES * XXX a few of the following functions are duplicated to handle @@ -448,6 +448,31 @@ intLispRemove(int elem, List *list) #endif /* + * ltruncate + * Truncate a list to n elements. + * Does nothing if n >= length(list). + * NB: the list is modified in-place! + */ +List * +ltruncate(int n, List *list) +{ + List *ptr; + + if (n <= 0) + return NIL; /* truncate to zero length */ + + foreach(ptr, list) + { + if (--n == 0) + { + lnext(ptr) = NIL; + break; + } + } + return list; +} + +/* * set_difference * * Return l1 without the elements in l2. |