Mercurial Hosting > luan
comparison src/luan/modules/parsers/LuanParser.java @ 1447:851b9a48cc44
Luan.parse
author | Franklin Schmidt <fschmidt@gmail.com> |
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date | Tue, 18 Feb 2020 14:54:35 -0700 |
parents | |
children | b89212fd04b5 |
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1446:f2082e9aeaa9 | 1447:851b9a48cc44 |
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1 package luan.modules.parsers; | |
2 | |
3 import goodjava.parser.Parser; | |
4 import goodjava.parser.ParseException; | |
5 import luan.Luan; | |
6 import luan.LuanTable; | |
7 import luan.LuanException; | |
8 | |
9 | |
10 public final class LuanParser { | |
11 | |
12 public static Object parse(Luan luan,String text) throws ParseException { | |
13 return new LuanParser(luan,text).parse(); | |
14 } | |
15 | |
16 private static final Object NULL = new Object(); | |
17 private final Luan luan; | |
18 private final Parser parser; | |
19 | |
20 private LuanParser(Luan luan,String text) { | |
21 this.luan = luan; | |
22 this.parser = new Parser(text); | |
23 } | |
24 | |
25 private ParseException exception(String msg) { | |
26 return new ParseException(parser,msg); | |
27 } | |
28 | |
29 private Object parse() throws ParseException { | |
30 do { spaces(); } while( endOfLine() ); | |
31 Object value = requiredValue(); | |
32 do { spaces(); } while( endOfLine() ); | |
33 if( !parser.endOfInput() ) | |
34 throw exception("unexpected text"); | |
35 return value; | |
36 } | |
37 | |
38 private Object requiredValue() throws ParseException { | |
39 Object value = value(); | |
40 if( value == null ) | |
41 throw exception("invalid value"); | |
42 if( value == NULL ) | |
43 return null; | |
44 return value; | |
45 } | |
46 | |
47 private Object value() throws ParseException { | |
48 if( parser.match("nil") ) | |
49 return NULL; | |
50 if( parser.match("true") ) | |
51 return Boolean.TRUE; | |
52 if( parser.match("false") ) | |
53 return Boolean.FALSE; | |
54 String s = string(); | |
55 if( s != null ) | |
56 return s; | |
57 Number n = number(); | |
58 if( n != null ) | |
59 return n; | |
60 LuanTable tbl = table(); | |
61 if( tbl != null ) | |
62 return tbl; | |
63 return null; | |
64 } | |
65 | |
66 private String string() throws ParseException { | |
67 parser.begin(); | |
68 if( !parser.match('"') ) | |
69 return parser.failure(null); | |
70 StringBuilder sb = new StringBuilder(); | |
71 while( parser.anyChar() ) { | |
72 char c = parser.lastChar(); | |
73 switch(c) { | |
74 case '"': | |
75 return parser.success(sb.toString()); | |
76 case '\\': | |
77 if( parser.anyChar() ) { | |
78 c = parser.lastChar(); | |
79 switch(c) { | |
80 case '"': | |
81 case '\'': | |
82 case '\\': | |
83 sb.append(c); | |
84 continue; | |
85 case 'b': | |
86 sb.append('\b'); | |
87 continue; | |
88 case 'f': | |
89 sb.append('\f'); | |
90 continue; | |
91 case 'n': | |
92 sb.append('\n'); | |
93 continue; | |
94 case 'r': | |
95 sb.append('\r'); | |
96 continue; | |
97 case 't': | |
98 sb.append('\t'); | |
99 continue; | |
100 case 'u': | |
101 int n = 0; | |
102 for( int i=0; i<4; i++ ) { | |
103 int d; | |
104 if( parser.inCharRange('0','9') ) { | |
105 d = parser.lastChar() - '0'; | |
106 } else if( parser.inCharRange('a','f') ) { | |
107 d = parser.lastChar() - 'a' + 10; | |
108 } else if( parser.inCharRange('A','F') ) { | |
109 d = parser.lastChar() - 'A' + 10; | |
110 } else { | |
111 throw exception("invalid hex digit"); | |
112 } | |
113 n = 16*n + d; | |
114 } | |
115 sb.append((char)n); | |
116 continue; | |
117 } | |
118 } | |
119 throw exception("invalid escape char"); | |
120 default: | |
121 sb.append(c); | |
122 } | |
123 } | |
124 parser.failure(); | |
125 throw exception("unclosed string"); | |
126 } | |
127 | |
128 private Number number() { | |
129 parser.begin(); | |
130 if( parser.match("double") ) { | |
131 Number n = inParens(); | |
132 if( n==null ) | |
133 return parser.failure(null); | |
134 n = Luan.asDouble(n); | |
135 if( n==null ) | |
136 return parser.failure(null); | |
137 return n; | |
138 } else if( parser.match("float") ) { | |
139 Number n = inParens(); | |
140 if( n==null ) | |
141 return parser.failure(null); | |
142 n = Luan.asFloat(n); | |
143 if( n==null ) | |
144 return parser.failure(null); | |
145 return n; | |
146 } else if( parser.match("integer") ) { | |
147 Number n = inParens(); | |
148 if( n==null ) | |
149 return parser.failure(null); | |
150 n = Luan.asInteger(n); | |
151 if( n==null ) | |
152 return parser.failure(null); | |
153 return n; | |
154 } else if( parser.match("long") ) { | |
155 Number n = inParens(); | |
156 if( n==null ) | |
157 return parser.failure(null); | |
158 n = Luan.asLong(n); | |
159 if( n==null ) | |
160 return parser.failure(null); | |
161 return n; | |
162 } else { | |
163 Number n = untypedNumber(); | |
164 if( n != null ) | |
165 return parser.success(n); | |
166 else | |
167 return parser.failure(null); | |
168 } | |
169 } | |
170 | |
171 private Number inParens() { | |
172 spaces(); | |
173 if( !parser.match('(') ) | |
174 return null; | |
175 spaces(); | |
176 Number n = untypedNumber(); | |
177 if( n==null ) | |
178 return null; | |
179 spaces(); | |
180 if( !parser.match(')') ) | |
181 return null; | |
182 return n; | |
183 } | |
184 | |
185 private Number untypedNumber() { | |
186 int start = parser.begin(); | |
187 boolean isFloat = false; | |
188 parser.match('-'); | |
189 if( !parser.match('0') ) { | |
190 if( !parser.inCharRange('1','9') ) | |
191 return parser.failure(null); | |
192 while( parser.inCharRange('0','9') ); | |
193 } | |
194 if( parser.match('.') ) { | |
195 if( !parser.inCharRange('0','9') ) | |
196 return parser.failure(null); | |
197 while( parser.inCharRange('0','9') ); | |
198 isFloat = true; | |
199 } | |
200 if( parser.anyOf("eE") ) { | |
201 parser.anyOf("+-"); | |
202 if( !parser.inCharRange('0','9') ) | |
203 return parser.failure(null); | |
204 while( parser.inCharRange('0','9') ); | |
205 isFloat = true; | |
206 } | |
207 String s = parser.textFrom(start); | |
208 Number n; | |
209 if(isFloat) | |
210 n = Double.valueOf(s); | |
211 else | |
212 n = Long.valueOf(s); | |
213 return parser.success(n); | |
214 } | |
215 | |
216 private LuanTable table() throws ParseException { | |
217 parser.begin(); | |
218 if( !parser.match('{') ) | |
219 return parser.failure(null); | |
220 LuanTable tbl = new LuanTable(luan); | |
221 do { | |
222 spaces(); | |
223 Object obj = value(); | |
224 if( obj != null ) { | |
225 if( obj != NULL ) | |
226 tbl.rawAdd(obj); | |
227 spaces(); | |
228 continue; | |
229 } | |
230 Object key = key(); | |
231 if( key != null ) { | |
232 spaces(); | |
233 requiredMatch('='); | |
234 spaces(); | |
235 Object value = requiredValue(); | |
236 spaces(); | |
237 try { | |
238 tbl.rawPut(key,value); | |
239 } catch(LuanException e) { | |
240 throw new RuntimeException(e); | |
241 } | |
242 } | |
243 } while( fieldSep() ); | |
244 requiredMatch('}'); | |
245 return parser.success(tbl); | |
246 } | |
247 | |
248 private Object key() throws ParseException { | |
249 if( parser.match('[') ) { | |
250 spaces(); | |
251 Object key = requiredValue(); | |
252 spaces(); | |
253 requiredMatch(']'); | |
254 return key; | |
255 } | |
256 int start = parser.currentIndex(); | |
257 if( nameFirstChar() ) { | |
258 while( nameChar() ); | |
259 return parser.textFrom(start); | |
260 } | |
261 return null; | |
262 } | |
263 | |
264 private boolean nameChar() { | |
265 return nameFirstChar() || parser.inCharRange('0','9'); | |
266 } | |
267 | |
268 private boolean nameFirstChar() { | |
269 return parser.inCharRange('a','z') || parser.inCharRange('A','Z') || parser.match('_'); | |
270 } | |
271 | |
272 private boolean fieldSep() throws ParseException { | |
273 return parser.anyOf(",;") || endOfLine(); | |
274 } | |
275 | |
276 private boolean endOfLine() { | |
277 return parser.match( "\r\n" ) || parser.match( '\r' ) || parser.match( '\n' ); | |
278 } | |
279 | |
280 private void requiredMatch(char c) throws ParseException { | |
281 if( !parser.match(c) ) | |
282 throw exception("'"+c+"' expected"); | |
283 } | |
284 | |
285 private void spaces() { | |
286 while( parser.anyOf(" \t") ); | |
287 } | |
288 | |
289 } |