62 lines
2.5 KiB
Racket
62 lines
2.5 KiB
Racket
;; Copyright (c) 2009 Derick Eddington.
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;;
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;; Permission is hereby granted, free of charge, to any person obtaining a
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;; copy of this software and associated documentation files (the "Software"),
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;; to deal in the Software without restriction, including without limitation
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;; the rights to use, copy, modify, merge, publish, distribute, sublicense,
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;; and/or sell copies of the Software, and to permit persons to whom the
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;; Software is furnished to do so, subject to the following conditions:
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;; The above copyright notice and this permission notice shall be included in
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;; all copies or substantial portions of the Software.
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;; Except as contained in this notice, the name(s) of the above copyright
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;; holders shall not be used in advertising or otherwise to promote the sale,
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;; use or other dealings in this Software without prior written authorization.
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;; THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
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;; IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
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;; FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL
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;; THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
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;; LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING
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;; FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
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;; DEALINGS IN THE SOFTWARE.
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#!r6rs
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(library (srfi :6)
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(export
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(rename (open-string-input-port open-input-string))
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open-output-string
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get-output-string)
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(import
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(rnrs)
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(only (scheme base) make-weak-hasheq hash-ref hash-set!))
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(define accumed-ht (make-weak-hasheq))
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(define (open-output-string)
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(letrec ([sop
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(make-custom-textual-output-port
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"string-output-port"
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(lambda (string start count) ; write!
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(when (positive? count)
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(let ([al (hash-ref accumed-ht sop)])
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(hash-set! accumed-ht sop
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(cons (substring string start (+ start count)) al))))
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count)
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#f ; get-position TODO?
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#f ; set-position! TODO?
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#f #| closed TODO? |# )])
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(hash-set! accumed-ht sop '())
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sop))
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(define (get-output-string sop)
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(if (output-port? sop)
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(cond [(hash-ref accumed-ht sop #f)
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=> (lambda (al) (apply string-append (reverse al)))]
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[else
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(assertion-violation 'get-output-string "not a string-output-port" sop)])
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(assertion-violation 'get-output-string "not an output-port" sop)))
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)
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