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;;;;"strport.scm" Portable string ports for Scheme
;;;Copyright 1993 Dorai Sitaram and Aubrey Jaffer.
;
;Permission to copy this software, to modify it, to redistribute it,
;to distribute modified versions, and to use it for any purpose is
;granted, subject to the following restrictions and understandings.
;
;1. Any copy made of this software must include this copyright notice
;in full.
;
;2. I have made no warranty or representation that the operation of
;this software will be error-free, and I am under no obligation to
;provide any services, by way of maintenance, update, or otherwise.
;
;3. In conjunction with products arising from the use of this
;material, there shall be no use of my name in any advertising,
;promotional, or sales literature without prior written consent in
;each case.
;N.B.: This implementation assumes you have tmpnam and
;delete-file defined in your .init file. tmpnam generates
;temp file names. delete-file may be defined to be a dummy
;procedure that does nothing.
;@
(define (call-with-output-string f)
(let ((tmpf (tmpnam)))
(call-with-output-file tmpf f)
(let ((s "") (buf (make-string 512)))
(call-with-input-file tmpf
(lambda (inp)
(let loop ((i 0))
(let ((c (read-char inp)))
(cond ((eof-object? c)
(set! s (string-append s (substring buf 0 i))))
((>= i 512)
(set! s (string-append s buf (string c)))
(loop 0))
(else
(string-set! buf i c)
(loop (+ i 1))))))))
(delete-file tmpf)
s)))
;@
(define (call-with-input-string s f)
(let ((tmpf (tmpnam)))
(call-with-output-file tmpf
(lambda (outp)
(display s outp)))
(let ((x (call-with-input-file tmpf f)))
(delete-file tmpf)
x)))
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