From 84247a1882862df39f66c4eb944e994839d3f15b Mon Sep 17 00:00:00 2001 From: Sam Tobin-Hochstadt Date: Mon, 21 Jun 2010 17:37:47 -0400 Subject: [PATCH] allow optional specifcation of var pattern original commit: b8777d20b26837d8ecfa78eeeda25fdccdb4a783 --- collects/typed-scheme/types/abbrev.rkt | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/collects/typed-scheme/types/abbrev.rkt b/collects/typed-scheme/types/abbrev.rkt index c2608c17..0ab61f3d 100644 --- a/collects/typed-scheme/types/abbrev.rkt +++ b/collects/typed-scheme/types/abbrev.rkt @@ -58,8 +58,8 @@ (define-match-expander Listof: (lambda (stx) (syntax-parse stx - [(_ elem-pat) - #'(Mu: var (Union: (list (Value: '()) (Pair: elem-pat (F: var)))))]))) + [(_ elem-pat (~optional var-pat #:defaults ([var-pat #'var]))) + (syntax/loc stx (Mu: var-pat (Union: (list (Value: '()) (Pair: elem-pat (F: var-pat))))))]))) (define-match-expander List: (lambda (stx)