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optimize keyword-get

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svn: r2305
This commit is contained in:
Eli Barzilay 2006-02-23 18:20:58 +00:00
parent e40e27435d
commit f41698de15
1 changed files with 13 additions and 8 deletions
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21
collects/mzlib/kw.ss
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@ -400,18 +400,23 @@
;; keyword searching utility (note: no errors for odd length)
(provide keyword-get)
(define (keyword-get args keyword . not-found)
(let loop ([args args])
(cond [(or (null? args) (null? (cdr args)) (not (keyword? (car args))))
(and (pair? not-found) ((car not-found)))]
[(eq? (car args) keyword) (cadr args)]
[else (loop (cddr args))])))
(define keyword-get
(case-lambda
[(args keyword not-found)
(let loop ([args args])
(cond [(or (null? args) (null? (cdr args)) (not (keyword? (car args))))
(not-found)]
[(eq? (car args) keyword) (cadr args)]
[else (loop (cddr args))]))]
;; the following makes another function call, but the code that is generated
;; by this module never gets here
[(args keyword) (keyword-get* args keyword #f)]))
;; a private version of keyword-get that is used with simple values
(define (keyword-get* args keyword . not-found)
(define (keyword-get* args keyword not-found)
(let loop ([args args])
(cond [(or (null? args) (null? (cdr args)) (not (keyword? (car args))))
(and (pair? not-found) (car not-found))]
not-found]
[(eq? (car args) keyword) (cadr args)]
[else (loop (cddr args))])))