blob: 870209503c3b4152f4da02faae9808fb1610ce3b (
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
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
|
(ns lang.lexer
(:require [clojure.template :refer [do-template]]
[clojure.core.match :refer [match]]
[lang.util :as &util :refer [exec return* return fail fail*
repeat-m try-m try-all-m]]))
(declare lex-forms lex-list lex-tuple lex-record lex-tag)
;; [Utils]
(defn ^:private lex-regex [regex]
(fn [text]
(if-let [[match] (re-find regex text)]
(return* (.substring text (.length match)) match)
(fail* (str "Pattern failed: " regex " -- " text)))))
(defn ^:private lex-regex2 [regex]
(fn [text]
(if-let [[match tok1 tok2] (re-find regex text)]
(return* (.substring text (.length match)) [tok1 tok2])
(fail* (str "Pattern failed: " regex " -- " text)))))
(defn ^:private lex-str [prefix]
(fn [text]
(if (.startsWith text prefix)
(return* (.substring text (.length prefix)) prefix)
(fail* (str "String failed: " prefix " -- " text)))))
(defn ^:private escape-char [escaped]
(condp = escaped
"\\t" (return "\t")
"\\b" (return "\b")
"\\n" (return "\n")
"\\r" (return "\r")
"\\f" (return "\f")
"\\\"" (return "\"")
"\\\\" (return "\\")
;; else
(fail (str "Unknown escape character: " escaped))))
(def ^:private lex-string-body
(try-all-m [(exec [[prefix escaped] (lex-regex2 #"(?s)^([^\"\\]*)(\\.)")
;; :let [_ (prn '[prefix escaped] [prefix escaped])]
unescaped (escape-char escaped)
;; :let [_ (prn 'unescaped unescaped)]
postfix lex-string-body
;; :let [_ (prn 'postfix postfix)]
;; :let [_ (prn 'FULL (str prefix unescaped postfix))]
]
(return (str prefix unescaped postfix)))
(lex-regex #"(?s)^([^\"\\]*)")]))
;; [Lexers]
(def ^:private lex-white-space (lex-regex #"^(\s+)"))
(def +ident-re+ #"^([a-zA-Z\-\+\_\=!@$%^&*<>\.,/\\\|':][0-9a-zA-Z\-\+\_\=!@$%^&*<>\.,/\\\|':]*)")
(do-template [<name> <tag> <regex>]
(def <name>
(exec [token (lex-regex <regex>)]
(return [<tag> token])))
^:private lex-boolean ::boolean #"^(true|false)"
^:private lex-float ::float #"^(0|[1-9][0-9]*)\.[0-9]+"
^:private lex-int ::int #"^(0|[1-9][0-9]*)"
^:private lex-ident ::ident +ident-re+)
(def ^:private lex-char
(exec [_ (lex-str "#\"")
token (try-all-m [(exec [escaped (lex-regex #"^(\\.)")]
(escape-char escaped))
(lex-regex #"^(.)")])
_ (lex-str "\"")]
(return [::char token])))
(def ^:private lex-string
(exec [_ (lex-str "\"")
;; state &util/get-state
;; :let [_ (prn 'PRE state)]
token lex-string-body
_ (lex-str "\"")
;; state &util/get-state
;; :let [_ (prn 'POST state)]
]
(return [::string token])))
(def ^:private lex-single-line-comment
(exec [_ (lex-str "##")
comment (lex-regex #"^([^\n]*)")
_ (lex-regex #"^(\n?)")
;; :let [_ (prn 'comment comment)]
]
(return [::comment comment])))
(def ^:private lex-multi-line-comment
(exec [_ (lex-str "#(")
;; :let [_ (prn 'OPEN)]
;; comment (lex-regex #"^(#\(.*\)#)")
comment (try-all-m [(lex-regex #"(?is)^((?!#\().)*?(?=\)#)")
(exec [pre (lex-regex #"(?is)^(.+?(?=#\())")
;; :let [_ (prn 'PRE pre)]
[_ inner] lex-multi-line-comment
;; :let [_ (prn 'INNER inner)]
post (lex-regex #"(?is)^(.+?(?=\)#))")
;:let [_ (prn 'POST post)]
]
(return (str pre "#(" inner ")#" post)))])
;; :let [_ (prn 'COMMENT comment)]
_ (lex-str ")#")
;; :let [_ (prn 'CLOSE)]
;; :let [_ (prn 'multi-comment comment)]
]
(return [::comment comment])))
(def ^:private lex-tag
(exec [_ (lex-str "#")
token (lex-regex +ident-re+)]
(return [::tag token])))
(def ^:private lex-form
(exec [_ (try-m lex-white-space)
form (try-all-m [lex-boolean
lex-float
lex-int
lex-char
lex-string
lex-ident
lex-tag
lex-list
lex-tuple
lex-record
lex-single-line-comment
lex-multi-line-comment])
_ (try-m lex-white-space)]
(return form)))
(def lex-forms
(exec [forms (repeat-m lex-form)]
(return (filter #(match %
[::comment _]
false
_
true)
forms))))
(def ^:private lex-list
(exec [_ (lex-str "(")
members lex-forms
_ (lex-str ")")]
(return [::list members])))
(def ^:private lex-tuple
(exec [_ (lex-str "[")
members lex-forms
_ (lex-str "]")]
(return [::tuple members])))
(def ^:private lex-record
(exec [_ (lex-str "{")
members lex-forms
_ (lex-str "}")]
(return [::record members])))
;; [Interface]
(defn lex [text]
(match (lex-forms text)
[::&util/ok [?state ?forms]]
(if (empty? ?state)
?forms
(assert false (str "Unconsumed input: " ?state)))
[::&util/failure ?message]
(assert false ?message)))
|
