Posted By

gleather on 01/14/08

Tagged

Versions (?)

Last Edited at 01/14/08 06:34pm

Statistics

Viewed 910 times

Favorited by 0 user(s)

Related snippets

list-index (Scheme)

/ Published in: Lisp

This one drove me crazy because of the requirement to return -1 if s not in los.

(list-index s los) returns the zero-based index of the first
occurence of s in los, or -1 if there is no occurences of s in los.

Expand | Embed | Plain Text

Copy this code and paste it in your HTML

(define list-index
        (lambda (s los)
                (if (null? los)
                        -1
                        (if (eq? (car los) s)
                                0
                                (if (= (list-index s (cdr los)) -1) 
                                        -1
                                        (+ 1 (list-index s (cdr los))))))))

Report this snippet Tweet

Comments

Subscribe to comments

Comment:

You need to login to post a comment.