From c93d192c32c376705d3b0a740c81156a44e63ecb Mon Sep 17 00:00:00 2001 From: Akshay Date: Wed, 4 Nov 2020 08:53:43 +0530 Subject: add basic evaluator, environment --- util/alist.scm | 12 ++++++++++++ 1 file changed, 12 insertions(+) create mode 100644 util/alist.scm (limited to 'util/alist.scm') diff --git a/util/alist.scm b/util/alist.scm new file mode 100644 index 0000000..4e19440 --- /dev/null +++ b/util/alist.scm @@ -0,0 +1,12 @@ +(define (is-elem-assoc-list key assoc-list) + (cond + [(null? assoc-list) #f] + [(eq? key (caar assoc-list)) #t] + [else (lookup-assoc-list key (cdr assoc-list))])) + +(define (lookup-assoc-list key assoc-list) + (cond + [(null? assoc-list) #f] + [(eq? key (caar assoc-list)) (cdar assoc-list)] + [else (lookup-assoc-list key (cdr assoc-list))])) + -- cgit v1.2.3