55 lines
2.7 KiB
Scheme
55 lines
2.7 KiB
Scheme
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;;; dsm.ss
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;;;
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;;; Copyright (c) 1998-2016 R. Kent Dybvig and Oscar Waddell
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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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;;;
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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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;;;
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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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;;; authors: R. Kent Dybvig and Oscar Waddell
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(library (dsm) (export define-syntactic-monad) (import (chezscheme))
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(define-syntax define-syntactic-monad
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(syntax-rules ()
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[(_ name formal ...)
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(andmap identifier? #'(name formal ...))
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(define-syntax name
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(lambda (x)
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(syntax-case x (lambda case-lambda)
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[(key lambda more-formals . body)
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(with-implicit (key formal ...)
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#'(lambda (formal ... . more-formals) . body))]
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[(key case-lambda (more-formals . body) (... ...))
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(with-implicit (key formal ...)
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#'(case-lambda ((formal ... . more-formals) . body) (... ...)))]
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[(key proc ((x e) (... ...)) arg (... ...))
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(andmap identifier? #'(x (... ...)))
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(with-implicit (key formal ...)
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(for-each
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(lambda (x)
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(unless (let mem ((ls #'(formal ...)))
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(and (not (null? ls))
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(or (free-identifier=? x (car ls))
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(mem (cdr ls)))))
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(syntax-error x (format "in syntactic monad ~s, unrecognized identifier" 'name))))
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#'(x (... ...)))
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(with-syntax ([(t (... ...)) (generate-temporaries #'(arg (... ...)))])
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#'(let ((p proc) (x e) (... ...) (t arg) (... ...))
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(p formal ... t (... ...)))))]
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[(key proc) #'(key proc ())])))]))
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)
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