From: Kevin Ryde <user42@zip.com.au>
Subject: srfi-1 map!
Date: Tue, 11 Nov 2003 10:32:52 +1000 [thread overview]
Message-ID: <87ptfzpwwb.fsf@zip.com.au> (raw)
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I've been finding it a bit annoying that map can handle long lists but
map! can't.
* srfi-1.scm (map!): Define as an alias for map, previous definition
was not tail-recursive.
[-- Attachment #2: srfi-1.scm.mapx.diff --]
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--- srfi-1.scm.~1.29.~ 1970-01-01 10:00:01.000000000 +1000
+++ srfi-1.scm 2003-11-11 10:28:35.000000000 +1000
@@ -572,22 +572,8 @@
'()
(append! (apply f (map1 car l)) (lp (map1 cdr l)))))))
-(define (map! f list1 . rest)
- (if (null? rest)
- (let lp ((l list1))
- (if (null? l)
- '()
- (begin
- (set-car! l (f (car l)))
- (set-cdr! l (lp (cdr l)))
- l)))
- (let lp ((l (cons list1 rest)) (res list1))
- (if (any1 null? l)
- '()
- (begin
- (set-car! res (apply f (map1 car l)))
- (set-cdr! res (lp (map1 cdr l) (cdr res)))
- res)))))
+;; OPTIMIZE-ME: Re-use cons cells of given list(s)
+(define map! map)
(define (pair-for-each f clist1 . rest)
(if (null? rest)
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next reply other threads:[~2003-11-11 0:32 UTC|newest]
Thread overview: 5+ messages / expand[flat|nested] mbox.gz Atom feed top
2003-11-11 0:32 Kevin Ryde [this message]
2003-11-11 14:58 ` a circular dilemma . #0# (was Re: srfi-1 map!) Stephen Compall
2003-11-14 19:28 ` Kevin Ryde
2003-11-17 20:21 ` Stephen Compall
2003-11-18 22:57 ` Kevin Ryde
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