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; -*- Mode: Scheme; Syntax: Scheme; Package: Scheme; -*-
; Part of Scheme 48 1.9. See file COPYING for notices and license.
; Authors: Richard Kelsey, Jonathan Rees
; Templates implemented as vectors.
(define *template-marker* (list '*template-marker*))
(define (make-template len init)
(let ((t (make-vector (+ len 1) init)))
(vector-set! t 0 *template-marker*)
t))
(define (template? obj)
(and (vector? obj)
(> (vector-length obj) 0)
(eq? (vector-ref obj 0) *template-marker*)))
(define (template-length t) (- (vector-length t) 1))
(define (template-ref t i) (vector-ref t (+ i 1)))
(define (template-set! t i x) (vector-set! t (+ i 1) x))
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