blob: 6fe95b83ae4b0977f020a37e47409ad754f4ea18 (
plain)
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
146
147
|
(in-package #:json)
(defun the-char (c)
(unit (lambda (x) (char= c x))))
(defun some-char (&rest char-list)
(unit (lambda (x) (find x char-list))))
(defun not-these-chars (&rest char-list)
(unit (lambda (x) (not (find x char-list)))))
(defparameter number-literal
(let ((signed-digits
(comp ((sign (zero-or-one (some-char #\- #\+)))
(natural (one-or-more (unit #'digit-char-p))))
(cons sign natural))))
(comp ((base signed-digits)
(dot (zero-or-one (the-char #\.)))
(fraction (if dot
(either (one-or-more (unit #'digit-char-p))
(fail "Malformed fractional part."))
nothing))
(e (zero-or-one (some-char #\e #\E)))
(exponent (if e
(either signed-digits
(fail "Malformed exponent part."))
nothing)))
(read-from-string
(str:from-list
(remove nil (append base (cons dot fraction) (cons e exponent))))))))
(defparameter string-literal
(comp ((_ (the-char #\"))
(chars (zero-or-more (either (comp ((slash (the-char #\\))
(escaped (unit))
(codepoints (if (char= escaped #\u)
(comp ((cp0 (unit #'digit-char-p))
(cp1 (unit #'digit-char-p))
(cp2 (unit #'digit-char-p))
(cp3 (unit #'digit-char-p)))
(let ((str (make-string 7)))
(setf (char str 0) #\#)
(setf (char str 1) #\\)
(setf (char str 2) #\u)
(setf (char str 3) cp0)
(setf (char str 4) cp1)
(setf (char str 5) cp2)
(setf (char str 6) cp3)
str))
nothing)))
(case escaped
(#\n
#\Newline)
(#\t
#\Tab)
(#\u
(read-from-string codepoints))
(t escaped)))
(not-these-chars #\" #\\))))
(_ (either (the-char #\")
(fail "String is not properly closed."))))
(str:from-list chars)))
(defparameter whitespace
(comp ((_ (zero-or-more (some-char #\Space #\Newline #\Tab))))
nil))
(defparameter true-symbol
(comp ((_ (the-char #\t))
(_ (either (comp ((_ (the-char #\r))
(_ (the-char #\u))
(_ (the-char #\e)))
nil)
(fail "Expected 'true'."))))
'true))
(defparameter false-symbol
(comp ((_ (the-char #\f))
(_ (either (comp ((_ (the-char #\a))
(_ (the-char #\l))
(_ (the-char #\s))
(_ (the-char #\e)))
nil)
(fail "Expected 'false'."))))
'false))
(defparameter null-symbol
(comp ((_ (the-char #\n))
(_ (either (comp ((_ (the-char #\u))
(_ (the-char #\l))
(_ (the-char #\l)))
nil)
(fail "Expected 'null'."))))
'null))
(defvar json-value)
(defun separated-list (value-type separator)
(comp ((v value-type)
(sep (zero-or-one (the-char separator)))
(vn (if sep
(either (separated-list value-type separator)
(fail "Expected another value."))
nothing)))
(cons v vn)))
(defparameter json-array
(comp ((_ (the-char #\[))
(vn (zero-or-one (separated-list json-value #\,)))
(_ (the-char #\])))
(apply #'vector vn)))
(defparameter json-object
(let ((json-pair
(comp ((_ whitespace)
(k (either string-literal
(fail "Expected a string.")))
(_ whitespace)
(_ (either (the-char #\:)
(fail "Expected a \":\"")))
(v json-value))
(cons k v))))
(comp ((_ (the-char #\{))
(vn (zero-or-one (separated-list json-pair #\,)))
(_ (the-char #\})))
(let* ((obj (make-hash-table :test #'equal :size (length vn))))
(dolist (v vn)
(setf (gethash (car v) obj) (cdr v)))
obj))))
(setf json-value
(comp ((_ whitespace)
(v (either number-literal
string-literal
json-object
json-array
true-symbol
false-symbol
null-symbol))
(_ whitespace))
v))
(defun parse-string (str)
(run json-value (input:from-string str)))
(defun parse-file (file)
(run json-value (input:from-file file)))
|