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| 1 // Copyright (c) 2011, the Dart project authors. Please see the AUTHORS file | |
| 2 // for details. All rights reserved. Use of this source code is governed by a | |
| 3 // BSD-style license that can be found in the LICENSE file. | |
| 4 | |
| 5 /** | |
| 6 * Base class for simple recursive descent parsers. | |
| 7 * Handles the lower level stuff, i.e. what a scanner/tokenizer would do. | |
| 8 */ | |
| 9 class _Parser { | |
| 10 static final WHITESPACE = ' \r\n\t'; | |
| 11 | |
| 12 // TODO(jmesserly): shouldn't need this optimization, but dart_json parser | |
| 13 // found that they needed this. | |
| 14 static final A_BIG = 65; // 'A'.charCodeAt(0) | |
| 15 static final Z_BIG = 90; // 'Z'.charCodeAt(0) | |
| 16 static final A_SMALL = 97; // 'a'.charCodeAt(0) | |
| 17 static final Z_SMALL = 122; // 'z'.charCodeAt(0) | |
| 18 static final TAB = 9; // '\t'.charCodeAt(0) | |
| 19 static final NEW_LINE = 10; // '\n'.charCodeAt(0) | |
| 20 static final LINE_FEED = 13; // '\r'.charCodeAt(0) | |
| 21 static final SPACE = 32; // ' '.charCodeAt(0) | |
| 22 static final ZERO = 48; // '0'.charCodeAt(0) | |
| 23 static final NINE = 57; // '9'.charCodeAt(0) | |
| 24 static final DOT = 46; // '.'.charCodeAt(0) | |
| 25 static final R_PAREN = 41; // ')'.charCodeAt(0) | |
| 26 | |
| 27 final String _src; | |
| 28 int _offset; | |
| 29 | |
| 30 // TODO(jmesserly): should be this._offset = 0, see bug 5332175. | |
| 31 _Parser(this._src) : _offset = 0; | |
| 32 | |
| 33 // TODO(jmesserly): these should exist in the standard lib. | |
| 34 // I took this from dart_json.dart | |
| 35 static bool _isWhitespace(int c) { | |
| 36 switch (c) { | |
| 37 case SPACE: | |
| 38 case TAB: | |
| 39 case NEW_LINE: | |
| 40 case LINE_FEED: | |
| 41 return true; | |
| 42 } | |
| 43 return false; | |
| 44 } | |
| 45 | |
| 46 static bool _isDigit(int c) { | |
| 47 return (ZERO <= c) && (c <= NINE); | |
| 48 } | |
| 49 | |
| 50 static bool _isLetter(int c) { | |
| 51 return (A_SMALL <= c) && (c <= Z_SMALL) || (A_BIG <= c) && (c <= Z_BIG); | |
| 52 } | |
| 53 | |
| 54 void _error(String msg) { | |
| 55 throw new SyntaxErrorException(msg, _src, _offset); | |
| 56 } | |
| 57 | |
| 58 int get length() => _src.length; | |
| 59 | |
| 60 int get remaining() => _src.length - _offset; | |
| 61 | |
| 62 int _peekChar() => _src.charCodeAt(_offset); | |
| 63 | |
| 64 bool get endOfInput() => _offset >= _src.length; | |
| 65 | |
| 66 bool _maybeEatWhitespace() { | |
| 67 int start = _offset; | |
| 68 while (_offset < length && _isWhitespace(_peekChar())) { | |
| 69 _offset++; | |
| 70 } | |
| 71 return _offset != start; | |
| 72 } | |
| 73 | |
| 74 bool _maybeEatMultiLineComment() { | |
| 75 if (_maybeEat('/*', /*eatWhitespace:*/false)) { | |
| 76 while (!_maybeEat('*/', /*eatWhitespace:*/false)) { | |
| 77 if (_offset >= length) { | |
| 78 _error('expected */'); | |
| 79 } | |
| 80 _offset++; | |
| 81 } | |
| 82 return true; | |
| 83 } | |
| 84 return false; | |
| 85 } | |
| 86 | |
| 87 void _maybeEatWhitespaceOrComments() { | |
| 88 while (_maybeEatWhitespace() || _maybeEatMultiLineComment()) {} | |
| 89 } | |
| 90 | |
| 91 void _eatEnd() { | |
| 92 _maybeEatWhitespaceOrComments(); | |
| 93 if (!endOfInput) { | |
| 94 _error('expected end of input'); | |
| 95 } | |
| 96 } | |
| 97 | |
| 98 bool _maybeEat(String value, [bool eatWhitespace = true]) { | |
| 99 if (eatWhitespace) { | |
| 100 _maybeEatWhitespaceOrComments(); | |
| 101 } | |
| 102 if (remaining < value.length) { | |
| 103 return false; | |
| 104 } | |
| 105 for (int i = 0; i < value.length; i++) { | |
| 106 if (_src[_offset + i] != value[i]) { | |
| 107 return false; | |
| 108 } | |
| 109 } | |
| 110 | |
| 111 // If we're eating something that's like a word, make sure | |
| 112 // it's not followed by more characters. | |
| 113 // This is ugly. Proper tokenization would make this cleaner. | |
| 114 if (_isLetter(value.charCodeAt(value.length - 1))) { | |
| 115 int i = _offset + value.length; | |
| 116 if (i < _src.length && _isLetter(_src.charCodeAt(i))) { | |
| 117 return false; | |
| 118 } | |
| 119 } | |
| 120 | |
| 121 _offset += value.length; | |
| 122 return true; | |
| 123 } | |
| 124 | |
| 125 void _eat(String value, [bool eatWhitespace = true]) { | |
| 126 if (!_maybeEat(value)) { | |
| 127 _error('expected "$value"'); | |
| 128 } | |
| 129 } | |
| 130 | |
| 131 String _maybeEatString() { | |
| 132 // TODO(jmesserly): make this match CSS string parsing | |
| 133 String quote = "'"; | |
| 134 if (!_maybeEat(quote)) { | |
| 135 quote = '"'; | |
| 136 if (!_maybeEat(quote)) { | |
| 137 return null; | |
| 138 } | |
| 139 } | |
| 140 | |
| 141 bool hasEscape = false; | |
| 142 int start = _offset; | |
| 143 while (!_maybeEat(quote)) { | |
| 144 if (endOfInput) { | |
| 145 _error('expected "$quote"'); | |
| 146 } | |
| 147 if (_maybeEat('\\')) { | |
| 148 hasEscape = true; | |
| 149 } | |
| 150 _offset++; | |
| 151 } | |
| 152 String result = _src.substring(start, _offset - 1); | |
| 153 if (hasEscape) { | |
| 154 // TODO(jmesserly): more escape sequences | |
| 155 result = result.replaceFirst('\\', ''); | |
| 156 } | |
| 157 return result; | |
| 158 } | |
| 159 | |
| 160 /** Eats something like a keyword. */ | |
| 161 String _eatWord() { | |
| 162 int start = _offset; | |
| 163 while (_offset < length && _isLetter(_peekChar())) { | |
| 164 _offset++; | |
| 165 } | |
| 166 return _src.substring(start, _offset); | |
| 167 } | |
| 168 | |
| 169 /** Eats an integer. */ | |
| 170 int _maybeEatInt() { | |
| 171 int start = _offset; | |
| 172 bool dot = false; | |
| 173 while (_offset < length && _isDigit(_peekChar())) { | |
| 174 _offset++; | |
| 175 } | |
| 176 | |
| 177 if (start == _offset) { | |
| 178 return null; | |
| 179 } | |
| 180 | |
| 181 return Math.parseInt(_src.substring(start, _offset)); | |
| 182 } | |
| 183 | |
| 184 /** Eats an integer. */ | |
| 185 int _eatInt() { | |
| 186 int result = _maybeEatInt(); | |
| 187 if (result == null) { | |
| 188 _error('expected positive integer'); | |
| 189 } | |
| 190 return result; | |
| 191 } | |
| 192 | |
| 193 /** Eats something like a positive decimal: 12.345. */ | |
| 194 num _eatDouble() { | |
| 195 int start = _offset; | |
| 196 bool dot = false; | |
| 197 while (_offset < length) { | |
| 198 int c = _peekChar(); | |
| 199 if (!_isDigit(c)) { | |
| 200 if (c == DOT && !dot) { | |
| 201 dot = true; | |
| 202 } else { | |
| 203 // Not a digit or decimal seperator | |
| 204 break; | |
| 205 } | |
| 206 } | |
| 207 _offset++; | |
| 208 } | |
| 209 | |
| 210 if (start == _offset) { | |
| 211 _error('expected positive decimal number'); | |
| 212 } | |
| 213 | |
| 214 return Math.parseDouble(_src.substring(start, _offset)); | |
| 215 } | |
| 216 } | |
| 217 | |
| 218 /** Parses a grid template. */ | |
| 219 class _GridTemplateParser extends _Parser { | |
| 220 _GridTemplateParser._internal(String src) : super(src); | |
| 221 | |
| 222 /** Parses the grid-rows and grid-columns CSS properties into object form. */ | |
| 223 static GridTemplate parse(String str) { | |
| 224 if (str == null) return null; | |
| 225 final p = new _GridTemplateParser._internal(str); | |
| 226 final result = p._parseTemplate(); | |
| 227 p._eatEnd(); | |
| 228 return result; | |
| 229 } | |
| 230 | |
| 231 /** Parses a grid-cell value. */ | |
| 232 static String parseCell(String str) { | |
| 233 if (str == null) return null; | |
| 234 final p = new _GridTemplateParser._internal(str); | |
| 235 final result = p._maybeEatString(); | |
| 236 p._eatEnd(); | |
| 237 return result; | |
| 238 } | |
| 239 | |
| 240 // => <string>+ | 'none' | |
| 241 GridTemplate _parseTemplate() { | |
| 242 if (_maybeEat('none')) { | |
| 243 return null; | |
| 244 } | |
| 245 final rows = new List<String>(); | |
| 246 String row; | |
| 247 while ((row = _maybeEatString()) != null) { | |
| 248 rows.add(row); | |
| 249 } | |
| 250 if (rows.length == 0) { | |
| 251 _error('expected at least one cell, or "none"'); | |
| 252 } | |
| 253 return new GridTemplate(rows); | |
| 254 } | |
| 255 } | |
| 256 | |
| 257 /** Parses a grid-row or grid-column */ | |
| 258 class _GridItemParser extends _Parser { | |
| 259 _GridItemParser._internal(String src) : super(src); | |
| 260 | |
| 261 /** Parses the grid-rows and grid-columns CSS properties into object form. */ | |
| 262 static _GridLocation parse(String cell, GridTrackList list) { | |
| 263 if (cell == null) return null; | |
| 264 final p = new _GridItemParser._internal(cell); | |
| 265 final result = p._parseTrack(list); | |
| 266 p._eatEnd(); | |
| 267 return result; | |
| 268 } | |
| 269 | |
| 270 // [ [ <integer> | <string> | 'start' | 'end' ] | |
| 271 // [ <integer> | <string> | 'start' | 'end' ]? ] | |
| 272 // | 'auto' | |
| 273 _GridLocation _parseTrack(GridTrackList list) { | |
| 274 if (_maybeEat('auto')) { | |
| 275 return null; | |
| 276 } | |
| 277 int start = _maybeParseLine(list); | |
| 278 if (start == null) { | |
| 279 _error('expected row/column number or name'); | |
| 280 } | |
| 281 int end = _maybeParseLine(list); | |
| 282 int span = null; | |
| 283 if (end != null) { | |
| 284 span = end - start; | |
| 285 if (span <= 0) { | |
| 286 _error('expected row/column span to be a positive integer'); | |
| 287 } | |
| 288 } | |
| 289 return new _GridLocation(start, span); | |
| 290 } | |
| 291 | |
| 292 // [ <integer> | <string> | 'start' | 'end' ] | |
| 293 int _maybeParseLine(GridTrackList list) { | |
| 294 if (_maybeEat('start')) { | |
| 295 return 1; | |
| 296 } else if (_maybeEat('end')) { | |
| 297 // The end is exclusive and 1-based, so return one past the size of the | |
| 298 // track list. | |
| 299 // TODO(jmesserly): this won't interact properly with implicit | |
| 300 // rows/columns. Instead it will snap to the number of tracks at the point | |
| 301 // where it is evaluated. | |
| 302 return list.tracks.length + 1; | |
| 303 } | |
| 304 | |
| 305 String name = _maybeEatString(); | |
| 306 if (name == null) { | |
| 307 return _maybeEatInt(); | |
| 308 } else { | |
| 309 int edge = list.lineNames[name]; | |
| 310 if (edge == null) { | |
| 311 _error('row/column name "$name" not found in the parent\'s ' | |
| 312 + ' grid-row/grid-columns properties'); | |
| 313 } | |
| 314 return edge; | |
| 315 } | |
| 316 } | |
| 317 } | |
| 318 | |
| 319 /** | |
| 320 * Parses grid-rows and grid-column properties, see: | |
| 321 * [http://dev.w3.org/csswg/css3-grid-align/#grid-columns-and-rows-properties] | |
| 322 * This is kept as a recursive descent parser for simplicity. | |
| 323 */ | |
| 324 // TODO(jmesserly): implement missing features from the spec. Mainly around | |
| 325 // CSS units, support for all escape sequences, etc. | |
| 326 class _GridTrackParser extends _Parser { | |
| 327 final List<GridTrack> _tracks; | |
| 328 final Map<String, int> _lineNames; | |
| 329 | |
| 330 _GridTrackParser._internal(String src) | |
| 331 : super(src), | |
| 332 _tracks = new List<GridTrack>(), | |
| 333 _lineNames = new Map<String, int>(); | |
| 334 | |
| 335 /** Parses the grid-rows and grid-columns CSS properties into object form. */ | |
| 336 static GridTrackList parse(String str) { | |
| 337 if (str == null) return null; | |
| 338 final p = new _GridTrackParser._internal(str); | |
| 339 final result = p._parseTrackList(); | |
| 340 p._eatEnd(); | |
| 341 return result; | |
| 342 } | |
| 343 | |
| 344 /** | |
| 345 * Parses the grid-row-sizing and grid-column-sizing CSS properties into | |
| 346 * object form. | |
| 347 */ | |
| 348 static TrackSizing parseTrackSizing(String str) { | |
| 349 if (str == null) str = 'auto'; | |
| 350 final p = new _GridTrackParser._internal(str); | |
| 351 final result = p._parseTrackMinmax(); | |
| 352 p._eatEnd(); | |
| 353 return result; | |
| 354 } | |
| 355 | |
| 356 // <track-list> => [ [ <string> ]* <track-group> [ <string> ]* ]+ | 'none' | |
| 357 GridTrackList _parseTrackList() { | |
| 358 if (_maybeEat('none')) { | |
| 359 return null; | |
| 360 } | |
| 361 _parseTrackListHelper(); | |
| 362 return new GridTrackList(_tracks, _lineNames); | |
| 363 } | |
| 364 | |
| 365 /** Code shared by _parseTrackList and _parseTrackGroup */ | |
| 366 void _parseTrackListHelper([List<GridTrack> resultTracks = null]) { | |
| 367 _maybeEatWhitespace(); | |
| 368 while (!endOfInput) { | |
| 369 String name; | |
| 370 while ((name = _maybeEatString()) != null) { | |
| 371 _lineNames[name] = _tracks.length + 1; // should be 1-based | |
| 372 } | |
| 373 | |
| 374 _maybeEatWhitespace(); | |
| 375 if (endOfInput) { | |
| 376 return; | |
| 377 } | |
| 378 | |
| 379 if (resultTracks != null) { | |
| 380 if (_peekChar() == R_PAREN) { | |
| 381 return; | |
| 382 } | |
| 383 resultTracks.add(new GridTrack(_parseTrackMinmax())); | |
| 384 } else { | |
| 385 _parseTrackGroup(); | |
| 386 } | |
| 387 | |
| 388 _maybeEatWhitespace(); | |
| 389 } | |
| 390 } | |
| 391 | |
| 392 // <track-group> => [ '(' [ [ <string> ]* <track-minmax> [ <string> ]* ]+ ')' | |
| 393 // [ '[' <positive-number> ']' ]? ] | |
| 394 // | <track-minmax> | |
| 395 void _parseTrackGroup() { | |
| 396 if (_maybeEat('(')) { | |
| 397 final tracks = new List<GridTrack>(); | |
| 398 _parseTrackListHelper(tracks); | |
| 399 _eat(')'); | |
| 400 if (_maybeEat('[')) { | |
| 401 num expand = _eatInt(); | |
| 402 _eat(']'); | |
| 403 | |
| 404 if (expand <= 0) { | |
| 405 _error('expected positive number'); | |
| 406 } | |
| 407 | |
| 408 // Repeat the track definition (but not the names) the specified number | |
| 409 // of times. See: | |
| 410 // http://dev.w3.org/csswg/css3-grid-align/#grid-repeating-columns-and-r
ows | |
| 411 for (int i = 0; i < expand; i++) { | |
| 412 for (GridTrack t in tracks) { | |
| 413 _tracks.add(t.clone()); | |
| 414 } | |
| 415 } | |
| 416 } | |
| 417 } else { | |
| 418 _tracks.add(new GridTrack(_parseTrackMinmax())); | |
| 419 } | |
| 420 } | |
| 421 | |
| 422 // <track-minmax> => 'minmax(' <track-breadth> ',' <track-breadth> ')' | |
| 423 // | 'auto' | <track-breadth> | |
| 424 TrackSizing _parseTrackMinmax() { | |
| 425 if (_maybeEat('auto') || _maybeEat('fit-content')) { | |
| 426 return const TrackSizing.auto(); | |
| 427 } | |
| 428 if (_maybeEat('minmax(')) { | |
| 429 final min = _parseTrackBreadth(); | |
| 430 _eat(','); | |
| 431 final max = _parseTrackBreadth(); | |
| 432 _eat(')'); | |
| 433 return new TrackSizing(min, max); | |
| 434 } else { | |
| 435 final breadth = _parseTrackBreadth(); | |
| 436 return new TrackSizing(breadth, breadth); | |
| 437 } | |
| 438 } | |
| 439 | |
| 440 // <track-breadth> => <length> | <percentage> | <fraction> | |
| 441 // | 'min-content' | 'max-content' | |
| 442 SizingFunction _parseTrackBreadth() { | |
| 443 if (_maybeEat('min-content')) { | |
| 444 return const MinContentSizing(); | |
| 445 } else if (_maybeEat('max-content')) { | |
| 446 return const MaxContentSizing(); | |
| 447 } | |
| 448 | |
| 449 num value = _eatDouble(); | |
| 450 | |
| 451 String units; | |
| 452 if (_maybeEat('%')) { | |
| 453 units = '%'; | |
| 454 } else { | |
| 455 units = _eatWord(); | |
| 456 } | |
| 457 | |
| 458 if (units == 'fr') { | |
| 459 return new FractionSizing(value); | |
| 460 } else { | |
| 461 return new FixedSizing(value, units); | |
| 462 } | |
| 463 } | |
| 464 } | |
| 465 | |
| 466 | |
| 467 /** | |
| 468 * Exception thrown because the grid style properties had incorrect values. | |
| 469 */ | |
| 470 class SyntaxErrorException implements Exception { | |
| 471 final String _message; | |
| 472 final int _offset; | |
| 473 final String _source; | |
| 474 | |
| 475 const SyntaxErrorException(this._message, this._source, this._offset); | |
| 476 | |
| 477 String toString() { | |
| 478 String location; | |
| 479 if (_offset < _source.length) { | |
| 480 location = 'location: ' + _source.substring(_offset); | |
| 481 } else { | |
| 482 location = 'end of input'; | |
| 483 } | |
| 484 return 'SyntaxErrorException: $_message at $location'; | |
| 485 } | |
| 486 } | |
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Chromium Code Reviews
Issue 9382027:
Move client/{base, observable, layout, touch, util, view} to samples/ui_lib . (Closed)
Base URL: http://dart.googlecode.com/svn/branches/bleeding_edge/dart/