1;;;
2;;; srfi-185 - Linear adjustable-length strings
3;;;
4;;;   Copyright (c) 2020  Shiro Kawai  <shiro@acm.org>
5;;;
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7;;;   modification, are permitted provided that the following conditions
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9;;;
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11;;;      notice, this list of conditions and the following disclaimer.
12;;;
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16;;;
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32;;;
33
34;; In Gauche, string bodies are immutable and we just use an extra
35;; indirection to realize mutable strings.  Lenght-changing mutation
36;; doesn't give any performance advantage at all.  So we chose not to
37;; reuse the argument of linear-update procedures.
38
39(define-module srfi-185
40  (use srfi-13)
41  (export string-append-linear!
42          string-replace-linear!
43          string-append!
44          string-replace!))
45(select-module srfi-185)
46
47(define (string-append-linear! dst . args)
48  (string-concatenate (cons dst (map (^s (if (char? s) (string s) s)) args))))
49
50(define (string-replace-linear! dst dst-start dst-end src
51                                :optional src-start src-end)
52  (string-replace dst src dst-start dst-end src-start src-end))
53
54(define-syntax string-append!
55  (syntax-rules ()
56    [(_ dst . args) (set! dst (string-append-linear! dst . args))]))
57
58(define-syntax string-replace!
59  (syntax-rules ()
60    [(_ dst dstart dend src . opts)
61     (set! dst (string-replace dst src dstart dend . opts))]))
62