1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
|
;;; strings.scm -- Convenience functions to manipulate strings.
;;;
;;; Copyright 2003, 2004 Erick Gallesio - I3S-CNRS/ESSI <eg@unice.fr>
;;; Copyright 2005, 2006 Ludovic Court�s <ludovic.courtes@laas.fr>
;;;
;;; This program is free software; you can redistribute it and/or modify
;;; it under the terms of the GNU General Public License as published by
;;; the Free Software Foundation; either version 2 of the License, or
;;; (at your option) any later version.
;;;
;;; This program is distributed in the hope that it will be useful,
;;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
;;; GNU General Public License for more details.
;;;
;;; You should have received a copy of the GNU General Public License
;;; along with this program; if not, write to the Free Software
;;; Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307,
;;; USA.
(define-module (skribilo utils strings)
:export (strip-ref-base string-canonicalize
make-string-replace)
:autoload (skribilo parameters) (*ref-base*)
:use-module (skribilo lib)
:use-module (srfi srfi-13))
;;;
;;; Utilities.
;;;
(define (strip-ref-base file)
;; Given FILE, a file path (a string), remove `(*ref-base*)' from it.
;; This is useful, e.g., for hyperlinks.
(if (not (string? (*ref-base*)))
file
(let ((l (string-length (*ref-base*))))
(cond
((not (> (string-length file) (+ l 2)))
file)
((not (string-contains file (*ref-base*) 0 l))
file)
((not (char=? (string-ref file l) #\/))
file)
(else
(substring file (+ l 1) (string-length file)))))))
(define (string-canonicalize old)
;; Return a string that is a canonical summarized representation of string
;; OLD. This is a one-way function.
(let* ((l (string-length old))
(new (make-string l)))
(let loop ((r 0)
(w 0)
(s #f))
(cond
((= r l)
(cond
((= w 0)
"")
((char-whitespace? (string-ref new (- w 1)))
(substring new 0 (- w 1)))
((= w r)
new)
(else
(substring new 0 w))))
((char-whitespace? (string-ref old r))
(if s
(loop (+ r 1) w #t)
(begin
(string-set! new w #\-)
(loop (+ r 1) (+ w 1) #t))))
((or (char=? (string-ref old r) #\#)
(>= (char->integer (string-ref old r)) #x7f))
(string-set! new w #\-)
(loop (+ r 1) (+ w 1) #t))
(else
(string-set! new w (string-ref old r))
(loop (+ r 1) (+ w 1) #f))))))
;;;
;;; String writing.
;;;
;;
;; (define (%make-html-replace)
;; ;; Ad-hoc version for HTML, a little bit faster than the
;; ;; make-general-string-replace define later (particularily if there
;; ;; is nothing to replace since, it does not allocate a new string
;; (let ((specials (string->regexp "&|\"|<|>")))
;; (lambda (str)
;; (if (regexp-match specials str)
;; (begin
;; (let ((out (open-output-string)))
;; (dotimes (i (string-length str))
;; (let ((ch (string-ref str i)))
;; (case ch
;; ((#\") (display """ out))
;; ((#\&) (display "&" out))
;; ((#\<) (display "<" out))
;; ((#\>) (display ">" out))
;; (else (write-char ch out)))))
;; (get-output-string out)))
;; str))))
(define (%make-general-string-replace lst)
;; The general version
(let ((chars (make-hash-table)))
;; Setup a hash table equivalent to LST.
(for-each (lambda (chr)
(hashq-set! chars (car chr) (cadr chr)))
lst)
;; Help the GC.
(set! lst #f)
(lambda (str)
(let ((out (open-output-string)))
(string-for-each (lambda (ch)
(let ((res (hashq-ref chars ch #f)))
(display (if res res ch) out)))
str)
(get-output-string out)))))
(define %html-replacements
'((#\" """) (#\& "&") (#\< "<") (#\> ">")))
(define %string->html
(%make-general-string-replace %html-replacements))
(define (make-string-replace lst)
(let ((l (sort lst (lambda (r1 r2) (char<? (car r1) (car r2))))))
(cond
((equal? l %html-replacements)
%string->html)
(else
(%make-general-string-replace lst)))))
|
