From 6b8be199ae88979e508f98fb8a8b6fc17c2a7f2d Mon Sep 17 00:00:00 2001 From: Rose Hogenson Date: Sun, 9 Jan 2022 13:17:20 -0800 Subject: Define helper intercalate. --- list.csc | 14 ++++++++++++-- 1 file changed, 12 insertions(+), 2 deletions(-) (limited to 'list.csc') diff --git a/list.csc b/list.csc index c4bc013..799b070 100644 --- a/list.csc +++ b/list.csc @@ -1,9 +1,12 @@ (define-library (csc list) (export + intercalate revappend split-at take) - (import (scheme base)) + (import (scheme base) + (only (csc match) + match)) (begin @@ -30,4 +33,11 @@ (acc b)) (if (null? xs) acc - (loop (cdr xs) (cons (car xs) acc))))))) + (loop (cdr xs) (cons (car xs) acc))))) + + + (define (intercalate x l) + (match l + ('() '()) + ((_) l) + ((head . tail) (cons head (cons x (intercalate x tail)))))))) -- cgit v1.3.1