forked from gambit/gambit
/
url.scm
139 lines (119 loc) · 4.86 KB
/
url.scm
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
;;;============================================================================
;;; File: "url.scm"
;;; Copyright (c) 2011 by Marc Feeley, All Rights Reserved.
;;;============================================================================
(##namespace ("url#"))
(##include "~~lib/gambit#.scm")
(##include "url#.scm")
(declare
(standard-bindings)
(extended-bindings)
(block)
(fixnum)
(not safe)
)
;;;============================================================================
;; Encoding and decoding of x-www-form-urlencoded data.
(define (url-encode str #!optional (start 0) (end (string-length str)) (space-to-plus? #f))
(define chunk-length 1024)
(define (hex n)
(string-ref "0123456789ABCDEF" (bitwise-and n 15)))
(define (encode-chunk len i end)
(if (< i end)
(let ((c (string-ref str i)))
(if (or (and (char>=? c #\a) (char<=? c #\z))
(and (char>=? c #\A) (char<=? c #\Z))
(and (char>=? c #\0) (char<=? c #\9))
(char=? c #\-)
(char=? c #\_)
(char=? c #\.)
(char=? c #\!)
(char=? c #\~)
(char=? c #\*)
(char=? c #\')
(char=? c #\()
(char=? c #\))
(and (char=? c #\space) space-to-plus?))
(let ((result (encode-chunk (+ len 1) (+ i 1) end)))
(string-set!
result
len
(if (and (char=? c #\space) space-to-plus?) #\+ c))
result)
(let ((result (encode-chunk (+ len 3) (+ i 1) end)))
(let ((n (char->integer c)))
(string-set! result (+ len 0) #\%)
(string-set! result (+ len 1) (hex (arithmetic-shift n -4)))
(string-set! result (+ len 2) (hex n))
result))))
(make-string len)))
(let loop ((i start) (chunks '()))
(let ((span (min (- end i) chunk-length)))
(if (= span 0)
(##append-strings ;; apply string-append
(reverse chunks))
(let* ((next-i (+ i span))
(chunk (encode-chunk 0 i next-i)))
(loop next-i (cons chunk chunks)))))))
(define (url-decode str #!optional (start 0) (end (string-length str)) (plus-to-space? #f))
(define chunk-length 1024)
(define (hex? c)
(cond ((and (char>=? c #\0) (char<=? c #\9))
(- (char->integer c) (char->integer #\0)))
((and (char>=? c #\a) (char<=? c #\f))
(+ 10 (- (char->integer c) (char->integer #\a))))
((and (char>=? c #\A) (char<=? c #\F))
(+ 10 (- (char->integer c) (char->integer #\A))))
(else
#f)))
(define (decode len i end)
(if (and (< i end)
(< len chunk-length))
(let ((c (string-ref str i)))
(cond ((or (and (char>=? c #\a) (char<=? c #\z))
(and (char>=? c #\A) (char<=? c #\Z))
(and (char>=? c #\0) (char<=? c #\9))
(char=? c #\-)
(char=? c #\_)
(char=? c #\.)
(char=? c #\!)
(char=? c #\~)
(char=? c #\*)
(char=? c #\')
(char=? c #\()
(char=? c #\))
(and (char=? c #\+) plus-to-space?))
(let ((result (decode (+ len 1) (+ i 1) end)))
(and result
(begin
(string-set!
(cdr result)
len
(if (and (char=? c #\+) plus-to-space?) #\space c))
result))))
((char=? c #\%)
(if (< (+ i 2) end)
(let* ((a (hex? (string-ref str (+ i 1))))
(b (hex? (string-ref str (+ i 2)))))
(and a
b
(let ((result (decode (+ len 1) (+ i 3) end)))
(and result
(begin
(string-set! (cdr result)
len
(integer->char
(+ (arithmetic-shift a 4) b)))
result)))))
#f))
(else
#f)))
(cons i (make-string len))))
(let loop ((i start) (chunks '()))
(if (< i end)
(let ((x (decode 0 i end)))
(and x
(loop (car x) (cons (cdr x) chunks))))
(##append-strings ;; apply string-append
(reverse chunks)))))
;;;============================================================================