22 lines
647 B
Scheme
22 lines
647 B
Scheme
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; -*- Mode: Scheme; Syntax: Scheme; Package: Scheme; -*-
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; Copyright (c) 1993-1999 by Richard Kelsey and Jonathan Rees. See file COPYING.
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; Templates implemented as vectors.
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(define *template-marker* (list '*template-marker*))
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(define (make-template len init)
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(let ((t (make-vector (+ len 1) init)))
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(vector-set! t 0 *template-marker*)
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t))
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(define (template? obj)
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(and (vector? obj)
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(> (vector-length obj) 0)
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(eq? (vector-ref obj 0) *template-marker*)))
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(define (template-length t) (- (vector-length t) 1))
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(define (template-ref t i) (vector-ref t (+ i 1)))
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(define (template-set! t i x) (vector-set! t (+ i 1) x))
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