SketchyLISP Reference |
Copyright (C) 2007 Nils M Holm |
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Conformance: R5RS Scheme
Purpose: Compute the length of a list.
Arguments:
X - list
Model:
(define (length x) (cond ((null? x) 0) (else (n+ (length (cdr x)) 1))))
Implementation:
(define (length x) (letrec ((_length (lambda (x r) (cond ((null? x) r) (else (_length (cdr x) (n+ r 1))))))) (_length x 0)))
Example:
(length '(a b c d e f)) => 6
See also:
digits,
append,
list-tail.
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