From 3552f7f73bfbc8c57615608c0f3e49225f44f663 Mon Sep 17 00:00:00 2001 From: Sam Tobin-Hochstadt Date: Sat, 22 Mar 2008 01:37:55 +0000 Subject: [PATCH] handle empty structs svn: r9055 --- collects/scheme/match/parse.ss | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/collects/scheme/match/parse.ss b/collects/scheme/match/parse.ss index 3f6d48bc6d..499f7435c3 100644 --- a/collects/scheme/match/parse.ss +++ b/collects/scheme/match/parse.ss @@ -193,7 +193,7 @@ (let* (;; the accessors come in reverse order [acc (reverse acc)] ;; remove the first element, if it's #f - [acc (if (not (car acc)) (cdr acc) acc)]) + [acc (cond [(null? acc) acc] [(not (car acc)) (cdr acc)] [else acc])]) (make-Struct id pred (get-lineage #'s) acc (if (eq? '_ (syntax-e #'pats)) (map make-Dummy acc)