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better name-age

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svn: r15815
This commit is contained in:
Eli Barzilay 2009-08-27 16:08:27 +00:00
parent 8eb158b863
commit 78471a5b86
1 changed files with 9 additions and 7 deletions
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16
collects/scheme/generator.ss
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@ -22,16 +22,18 @@
(define-syntax-rule (generator body0 body ...)
(let ([tag (make-continuation-prompt-tag)])
(define y
(let ([yield (lambda (r) (shift-at tag k (set! cont k) r))]) yield))
(splicing-syntax-parameterize ([yield (make-rename-transformer #'y)])
(define yielder
(let ([yield (lambda (val) (shift-at tag k (set! cont k) val))])
yield))
(splicing-syntax-parameterize ([yield (make-rename-transformer #'yielder)])
(define (cont)
(reset-at tag
(let ([r (begin body0 body ...)])
(let ([retval (begin body0 body ...)])
;; normal return:
(set! cont (lambda () r))
r))))
(lambda () (cont))))
(set! cont (lambda () retval))
retval))))
(define (generator) (cont))
generator))
(define stop-value (gensym))