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1<!DOCTYPE html> 2 3<html> 4<head> 5 <title>grammar.coffee</title> 6 <meta http-equiv="content-type" content="text/html; charset=UTF-8"> 7 <meta name="viewport" content="width=device-width, target-densitydpi=160dpi, initial-scale=1.0; maximum-scale=1.0; user-scalable=0;"> 8 <link rel="stylesheet" media="all" href="docco.css" /> 9</head> 10<body> 11 <div id="container"> 12 <div id="background"></div> 13 14 <ul id="jump_to"> 15 <li> 16 <a class="large" href="javascript:void(0);">Jump To …</a> 17 <a class="small" href="javascript:void(0);">+</a> 18 <div id="jump_wrapper"> 19 <div id="jump_page_wrapper"> 20 <div id="jump_page"> 21 22 23 <a class="source" href="browser.html"> 24 browser.coffee 25 </a> 26 27 28 <a class="source" href="cake.html"> 29 cake.coffee 30 </a> 31 32 33 <a class="source" href="coffee-script.html"> 34 coffee-script.coffee 35 </a> 36 37 38 <a class="source" href="command.html"> 39 command.coffee 40 </a> 41 42 43 <a class="source" href="grammar.html"> 44 grammar.coffee 45 </a> 46 47 48 <a class="source" href="helpers.html"> 49 helpers.coffee 50 </a> 51 52 53 <a class="source" href="index.html"> 54 index.coffee 55 </a> 56 57 58 <a class="source" href="lexer.html"> 59 lexer.coffee 60 </a> 61 62 63 <a class="source" href="nodes.html"> 64 nodes.coffee 65 </a> 66 67 68 <a class="source" href="optparse.html"> 69 optparse.coffee 70 </a> 71 72 73 <a class="source" href="register.html"> 74 register.coffee 75 </a> 76 77 78 <a class="source" href="repl.html"> 79 repl.coffee 80 </a> 81 82 83 <a class="source" href="rewriter.html"> 84 rewriter.coffee 85 </a> 86 87 88 <a class="source" href="scope.html"> 89 scope.litcoffee 90 </a> 91 92 93 <a class="source" href="sourcemap.html"> 94 sourcemap.litcoffee 95 </a> 96 97 </div> 98 </div> 99 </li> 100 </ul> 101 102 <ul class="sections"> 103 104 <li id="title"> 105 <div class="annotation"> 106 <h1>grammar.coffee</h1> 107 </div> 108 </li> 109 110 111 112 <li id="section-1"> 113 <div class="annotation"> 114 115 <div class="pilwrap "> 116 <a class="pilcrow" href="#section-1">¶</a> 117 </div> 118 <p>The CoffeeScript parser is generated by <a href="http://github.com/zaach/jison">Jison</a> 119from this grammar file. Jison is a bottom-up parser generator, similar in 120style to <a href="http://www.gnu.org/software/bison">Bison</a>, implemented in JavaScript. 121It can recognize <a href="http://en.wikipedia.org/wiki/LR_grammar">LALR(1), LR(0), SLR(1), and LR(1)</a> 122type grammars. To create the Jison parser, we list the pattern to match 123on the left-hand side, and the action to take (usually the creation of syntax 124tree nodes) on the right. As the parser runs, it 125shifts tokens from our token stream, from left to right, and 126<a href="http://en.wikipedia.org/wiki/Bottom-up_parsing">attempts to match</a> 127the token sequence against the rules below. When a match can be made, it 128reduces into the <a href="http://en.wikipedia.org/wiki/Terminal_and_nonterminal_symbols">nonterminal</a> 129(the enclosing name at the top), and we proceed from there.</p> 130<p>If you run the <code>cake build:parser</code> command, Jison constructs a parse table 131from our rules and saves it into <code>lib/parser.js</code>.</p> 132 133 </div> 134 135 </li> 136 137 138 <li id="section-2"> 139 <div class="annotation"> 140 141 <div class="pilwrap "> 142 <a class="pilcrow" href="#section-2">¶</a> 143 </div> 144 <p>The only dependency is on the <strong>Jison.Parser</strong>.</p> 145 146 </div> 147 148 <div class="content"><div class='highlight'><pre>{Parser} = <span class="hljs-built_in">require</span> <span class="hljs-string">'jison'</span></pre></div></div> 149 150 </li> 151 152 153 <li id="section-3"> 154 <div class="annotation"> 155 156 <div class="pilwrap "> 157 <a class="pilcrow" href="#section-3">¶</a> 158 </div> 159 <h2 id="jison-dsl">Jison DSL</h2> 160 161 </div> 162 163 </li> 164 165 166 <li id="section-4"> 167 <div class="annotation"> 168 169 <div class="pilwrap "> 170 <a class="pilcrow" href="#section-4">¶</a> 171 </div> 172 173 </div> 174 175 </li> 176 177 178 <li id="section-5"> 179 <div class="annotation"> 180 181 <div class="pilwrap "> 182 <a class="pilcrow" href="#section-5">¶</a> 183 </div> 184 <p>Since we’re going to be wrapped in a function by Jison in any case, if our 185action immediately returns a value, we can optimize by removing the function 186wrapper and just returning the value directly.</p> 187 188 </div> 189 190 <div class="content"><div class='highlight'><pre>unwrap = <span class="hljs-regexp">/^function\s*\(\)\s*\{\s*return\s*([\s\S]*);\s*\}/</span></pre></div></div> 191 192 </li> 193 194 195 <li id="section-6"> 196 <div class="annotation"> 197 198 <div class="pilwrap "> 199 <a class="pilcrow" href="#section-6">¶</a> 200 </div> 201 <p>Our handy DSL for Jison grammar generation, thanks to 202<a href="http://github.com/creationix">Tim Caswell</a>. For every rule in the grammar, 203we pass the pattern-defining string, the action to run, and extra options, 204optionally. If no action is specified, we simply pass the value of the 205previous nonterminal.</p> 206 207 </div> 208 209 <div class="content"><div class='highlight'><pre><span class="hljs-function"><span class="hljs-title">o</span> = <span class="hljs-params">(patternString, action, options)</span> -></span> 210 patternString = patternString.replace <span class="hljs-regexp">/\s{2,}/g</span>, <span class="hljs-string">' '</span> 211 patternCount = patternString.split(<span class="hljs-string">' '</span>).length 212 <span class="hljs-keyword">return</span> [patternString, <span class="hljs-string">'$$ = $1;'</span>, options] <span class="hljs-keyword">unless</span> action 213 action = <span class="hljs-keyword">if</span> match = unwrap.exec action <span class="hljs-keyword">then</span> match[<span class="hljs-number">1</span>] <span class="hljs-keyword">else</span> <span class="hljs-string">"(<span class="hljs-subst">#{action}</span>())"</span></pre></div></div> 214 215 </li> 216 217 218 <li id="section-7"> 219 <div class="annotation"> 220 221 <div class="pilwrap "> 222 <a class="pilcrow" href="#section-7">¶</a> 223 </div> 224 <p>All runtime functions we need are defined on “yy”</p> 225 226 </div> 227 228 <div class="content"><div class='highlight'><pre> action = action.replace <span class="hljs-regexp">/\bnew /g</span>, <span class="hljs-string">'$&yy.'</span> 229 action = action.replace <span class="hljs-regexp">/\b(?:Block\.wrap|extend)\b/g</span>, <span class="hljs-string">'yy.$&'</span></pre></div></div> 230 231 </li> 232 233 234 <li id="section-8"> 235 <div class="annotation"> 236 237 <div class="pilwrap "> 238 <a class="pilcrow" href="#section-8">¶</a> 239 </div> 240 <p>Returns a function which adds location data to the first parameter passed 241in, and returns the parameter. If the parameter is not a node, it will 242just be passed through unaffected.</p> 243 244 </div> 245 246 <div class="content"><div class='highlight'><pre> <span class="hljs-function"><span class="hljs-title">addLocationDataFn</span> = <span class="hljs-params">(first, last)</span> -></span> 247 <span class="hljs-keyword">if</span> <span class="hljs-keyword">not</span> last 248 <span class="hljs-string">"yy.addLocationDataFn(@<span class="hljs-subst">#{first}</span>)"</span> 249 <span class="hljs-keyword">else</span> 250 <span class="hljs-string">"yy.addLocationDataFn(@<span class="hljs-subst">#{first}</span>, @<span class="hljs-subst">#{last}</span>)"</span> 251 252 action = action.replace <span class="hljs-regexp">/LOC\(([0-9]*)\)/g</span>, addLocationDataFn(<span class="hljs-string">'$1'</span>) 253 action = action.replace <span class="hljs-regexp">/LOC\(([0-9]*),\s*([0-9]*)\)/g</span>, addLocationDataFn(<span class="hljs-string">'$1'</span>, <span class="hljs-string">'$2'</span>) 254 255 [patternString, <span class="hljs-string">"$$ = <span class="hljs-subst">#{addLocationDataFn(<span class="hljs-number">1</span>, patternCount)}</span>(<span class="hljs-subst">#{action}</span>);"</span>, options]</pre></div></div> 256 257 </li> 258 259 260 <li id="section-9"> 261 <div class="annotation"> 262 263 <div class="pilwrap "> 264 <a class="pilcrow" href="#section-9">¶</a> 265 </div> 266 <h2 id="grammatical-rules">Grammatical Rules</h2> 267 268 </div> 269 270 </li> 271 272 273 <li id="section-10"> 274 <div class="annotation"> 275 276 <div class="pilwrap "> 277 <a class="pilcrow" href="#section-10">¶</a> 278 </div> 279 280 </div> 281 282 </li> 283 284 285 <li id="section-11"> 286 <div class="annotation"> 287 288 <div class="pilwrap "> 289 <a class="pilcrow" href="#section-11">¶</a> 290 </div> 291 <p>In all of the rules that follow, you’ll see the name of the nonterminal as 292the key to a list of alternative matches. With each match’s action, the 293dollar-sign variables are provided by Jison as references to the value of 294their numeric position, so in this rule:</p> 295<pre><code><span class="hljs-string">"Expression UNLESS Expression"</span> 296</code></pre><p><code>$1</code> would be the value of the first <code>Expression</code>, <code>$2</code> would be the token 297for the <code>UNLESS</code> terminal, and <code>$3</code> would be the value of the second 298<code>Expression</code>.</p> 299 300 </div> 301 302 <div class="content"><div class='highlight'><pre>grammar =</pre></div></div> 303 304 </li> 305 306 307 <li id="section-12"> 308 <div class="annotation"> 309 310 <div class="pilwrap "> 311 <a class="pilcrow" href="#section-12">¶</a> 312 </div> 313 <p>The <strong>Root</strong> is the top-level node in the syntax tree. Since we parse bottom-up, 314all parsing must end here.</p> 315 316 </div> 317 318 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Root</span>: [ 319 o <span class="hljs-string">''</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Block 320 o <span class="hljs-string">'Body'</span> 321 ]</pre></div></div> 322 323 </li> 324 325 326 <li id="section-13"> 327 <div class="annotation"> 328 329 <div class="pilwrap "> 330 <a class="pilcrow" href="#section-13">¶</a> 331 </div> 332 <p>Any list of statements and expressions, separated by line breaks or semicolons.</p> 333 334 </div> 335 336 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Body</span>: [ 337 o <span class="hljs-string">'Line'</span>,<span class="hljs-function"> -></span> Block.wrap [$<span class="hljs-number">1</span>] 338 o <span class="hljs-string">'Body TERMINATOR Line'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>push $<span class="hljs-number">3</span> 339 o <span class="hljs-string">'Body TERMINATOR'</span> 340 ]</pre></div></div> 341 342 </li> 343 344 345 <li id="section-14"> 346 <div class="annotation"> 347 348 <div class="pilwrap "> 349 <a class="pilcrow" href="#section-14">¶</a> 350 </div> 351 <p>Block and statements, which make up a line in a body.</p> 352 353 </div> 354 355 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Line</span>: [ 356 o <span class="hljs-string">'Expression'</span> 357 o <span class="hljs-string">'Statement'</span> 358 ]</pre></div></div> 359 360 </li> 361 362 363 <li id="section-15"> 364 <div class="annotation"> 365 366 <div class="pilwrap "> 367 <a class="pilcrow" href="#section-15">¶</a> 368 </div> 369 <p>Pure statements which cannot be expressions.</p> 370 371 </div> 372 373 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Statement</span>: [ 374 o <span class="hljs-string">'Return'</span> 375 o <span class="hljs-string">'Comment'</span> 376 o <span class="hljs-string">'STATEMENT'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 377 ]</pre></div></div> 378 379 </li> 380 381 382 <li id="section-16"> 383 <div class="annotation"> 384 385 <div class="pilwrap "> 386 <a class="pilcrow" href="#section-16">¶</a> 387 </div> 388 <p>All the different types of expressions in our language. The basic unit of 389CoffeeScript is the <strong>Expression</strong> — everything that can be an expression 390is one. Blocks serve as the building blocks of many other rules, making 391them somewhat circular.</p> 392 393 </div> 394 395 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Expression</span>: [ 396 o <span class="hljs-string">'Value'</span> 397 o <span class="hljs-string">'Invocation'</span> 398 o <span class="hljs-string">'Code'</span> 399 o <span class="hljs-string">'Operation'</span> 400 o <span class="hljs-string">'Assign'</span> 401 o <span class="hljs-string">'If'</span> 402 o <span class="hljs-string">'Try'</span> 403 o <span class="hljs-string">'While'</span> 404 o <span class="hljs-string">'For'</span> 405 o <span class="hljs-string">'Switch'</span> 406 o <span class="hljs-string">'Class'</span> 407 o <span class="hljs-string">'Throw'</span> 408 ]</pre></div></div> 409 410 </li> 411 412 413 <li id="section-17"> 414 <div class="annotation"> 415 416 <div class="pilwrap "> 417 <a class="pilcrow" href="#section-17">¶</a> 418 </div> 419 <p>An indented block of expressions. Note that the <a href="rewriter.html">Rewriter</a> 420will convert some postfix forms into blocks for us, by adjusting the 421token stream.</p> 422 423 </div> 424 425 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Block</span>: [ 426 o <span class="hljs-string">'INDENT OUTDENT'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Block 427 o <span class="hljs-string">'INDENT Body OUTDENT'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">2</span> 428 ]</pre></div></div> 429 430 </li> 431 432 433 <li id="section-18"> 434 <div class="annotation"> 435 436 <div class="pilwrap "> 437 <a class="pilcrow" href="#section-18">¶</a> 438 </div> 439 <p>A literal identifier, a variable name or property.</p> 440 441 </div> 442 443 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Identifier</span>: [ 444 o <span class="hljs-string">'IDENTIFIER'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 445 ]</pre></div></div> 446 447 </li> 448 449 450 <li id="section-19"> 451 <div class="annotation"> 452 453 <div class="pilwrap "> 454 <a class="pilcrow" href="#section-19">¶</a> 455 </div> 456 <p>Alphanumerics are separated from the other <strong>Literal</strong> matchers because 457they can also serve as keys in object literals.</p> 458 459 </div> 460 461 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">AlphaNumeric</span>: [ 462 o <span class="hljs-string">'NUMBER'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 463 o <span class="hljs-string">'String'</span> 464 ] 465 466 <span class="hljs-attribute">String</span>: [ 467 o <span class="hljs-string">'STRING'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 468 o <span class="hljs-string">'STRING_START Body STRING_END'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Parens $<span class="hljs-number">2</span> 469 ] 470 471 <span class="hljs-attribute">Regex</span>: [ 472 o <span class="hljs-string">'REGEX'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 473 o <span class="hljs-string">'REGEX_START Invocation REGEX_END'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">2</span> 474 ]</pre></div></div> 475 476 </li> 477 478 479 <li id="section-20"> 480 <div class="annotation"> 481 482 <div class="pilwrap "> 483 <a class="pilcrow" href="#section-20">¶</a> 484 </div> 485 <p>All of our immediate values. Generally these can be passed straight 486through and printed to JavaScript.</p> 487 488 </div> 489 490 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Literal</span>: [ 491 o <span class="hljs-string">'AlphaNumeric'</span> 492 o <span class="hljs-string">'JS'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 493 o <span class="hljs-string">'Regex'</span> 494 o <span class="hljs-string">'DEBUGGER'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Literal $<span class="hljs-number">1</span> 495 o <span class="hljs-string">'UNDEFINED'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Undefined 496 o <span class="hljs-string">'NULL'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Null 497 o <span class="hljs-string">'BOOL'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Bool $<span class="hljs-number">1</span> 498 ]</pre></div></div> 499 500 </li> 501 502 503 <li id="section-21"> 504 <div class="annotation"> 505 506 <div class="pilwrap "> 507 <a class="pilcrow" href="#section-21">¶</a> 508 </div> 509 <p>Assignment of a variable, property, or index to a value.</p> 510 511 </div> 512 513 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Assign</span>: [ 514 o <span class="hljs-string">'Assignable = Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign $<span class="hljs-number">1</span>, $<span class="hljs-number">3</span> 515 o <span class="hljs-string">'Assignable = TERMINATOR Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign $<span class="hljs-number">1</span>, $<span class="hljs-number">4</span> 516 o <span class="hljs-string">'Assignable = INDENT Expression OUTDENT'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign $<span class="hljs-number">1</span>, $<span class="hljs-number">4</span> 517 ]</pre></div></div> 518 519 </li> 520 521 522 <li id="section-22"> 523 <div class="annotation"> 524 525 <div class="pilwrap "> 526 <a class="pilcrow" href="#section-22">¶</a> 527 </div> 528 <p>Assignment when it happens within an object literal. The difference from 529the ordinary <strong>Assign</strong> is that these allow numbers and strings as keys.</p> 530 531 </div> 532 533 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">AssignObj</span>: [ 534 o <span class="hljs-string">'ObjAssignable'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 535 o <span class="hljs-string">'ObjAssignable : Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign LOC(<span class="hljs-number">1</span>)(<span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span>), $<span class="hljs-number">3</span>, <span class="hljs-string">'object'</span>, 536 <span class="hljs-attribute">operatorToken</span>: LOC(<span class="hljs-number">2</span>)(<span class="hljs-keyword">new</span> Literal $<span class="hljs-number">2</span>) 537 o <span class="hljs-string">'ObjAssignable : 538 INDENT Expression OUTDENT'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign LOC(<span class="hljs-number">1</span>)(<span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span>), $<span class="hljs-number">4</span>, <span class="hljs-string">'object'</span>, 539 <span class="hljs-attribute">operatorToken</span>: LOC(<span class="hljs-number">2</span>)(<span class="hljs-keyword">new</span> Literal $<span class="hljs-number">2</span>) 540 o <span class="hljs-string">'SimpleObjAssignable = Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign LOC(<span class="hljs-number">1</span>)(<span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span>), $<span class="hljs-number">3</span>, <span class="hljs-literal">null</span>, 541 <span class="hljs-attribute">operatorToken</span>: LOC(<span class="hljs-number">2</span>)(<span class="hljs-keyword">new</span> Literal $<span class="hljs-number">2</span>) 542 o <span class="hljs-string">'SimpleObjAssignable = 543 INDENT Expression OUTDENT'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Assign LOC(<span class="hljs-number">1</span>)(<span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span>), $<span class="hljs-number">4</span>, <span class="hljs-literal">null</span>, 544 <span class="hljs-attribute">operatorToken</span>: LOC(<span class="hljs-number">2</span>)(<span class="hljs-keyword">new</span> Literal $<span class="hljs-number">2</span>) 545 o <span class="hljs-string">'Comment'</span> 546 ] 547 548 <span class="hljs-attribute">SimpleObjAssignable</span>: [ 549 o <span class="hljs-string">'Identifier'</span> 550 o <span class="hljs-string">'ThisProperty'</span> 551 ] 552 553 <span class="hljs-attribute">ObjAssignable</span>: [ 554 o <span class="hljs-string">'SimpleObjAssignable'</span> 555 o <span class="hljs-string">'AlphaNumeric'</span> 556 ]</pre></div></div> 557 558 </li> 559 560 561 <li id="section-23"> 562 <div class="annotation"> 563 564 <div class="pilwrap "> 565 <a class="pilcrow" href="#section-23">¶</a> 566 </div> 567 <p>A return statement from a function body.</p> 568 569 </div> 570 571 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Return</span>: [ 572 o <span class="hljs-string">'RETURN Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Return $<span class="hljs-number">2</span> 573 o <span class="hljs-string">'RETURN'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Return 574 ]</pre></div></div> 575 576 </li> 577 578 579 <li id="section-24"> 580 <div class="annotation"> 581 582 <div class="pilwrap "> 583 <a class="pilcrow" href="#section-24">¶</a> 584 </div> 585 <p>A block comment.</p> 586 587 </div> 588 589 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Comment</span>: [ 590 o <span class="hljs-string">'HERECOMMENT'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Comment $<span class="hljs-number">1</span> 591 ]</pre></div></div> 592 593 </li> 594 595 596 <li id="section-25"> 597 <div class="annotation"> 598 599 <div class="pilwrap "> 600 <a class="pilcrow" href="#section-25">¶</a> 601 </div> 602 <p>The <strong>Code</strong> node is the function literal. It’s defined by an indented block 603of <strong>Block</strong> preceded by a function arrow, with an optional parameter 604list.</p> 605 606 </div> 607 608 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Code</span>: [ 609 o <span class="hljs-string">'PARAM_START ParamList PARAM_END FuncGlyph Block'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Code $<span class="hljs-number">2</span>, $<span class="hljs-number">5</span>, $<span class="hljs-number">4</span> 610 o <span class="hljs-string">'FuncGlyph Block'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Code [], $<span class="hljs-number">2</span>, $<span class="hljs-number">1</span> 611 ]</pre></div></div> 612 613 </li> 614 615 616 <li id="section-26"> 617 <div class="annotation"> 618 619 <div class="pilwrap "> 620 <a class="pilcrow" href="#section-26">¶</a> 621 </div> 622 <p>CoffeeScript has two different symbols for functions. <code>-></code> is for ordinary 623functions, and <code>=></code> is for functions bound to the current value of <em>this</em>.</p> 624 625 </div> 626 627 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">FuncGlyph</span>: [ 628 o <span class="hljs-string">'->'</span>,<span class="hljs-function"> -></span> <span class="hljs-string">'func'</span> 629 o <span class="hljs-string">'=>'</span>,<span class="hljs-function"> -></span> <span class="hljs-string">'boundfunc'</span> 630 ]</pre></div></div> 631 632 </li> 633 634 635 <li id="section-27"> 636 <div class="annotation"> 637 638 <div class="pilwrap "> 639 <a class="pilcrow" href="#section-27">¶</a> 640 </div> 641 <p>An optional, trailing comma.</p> 642 643 </div> 644 645 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">OptComma</span>: [ 646 o <span class="hljs-string">''</span> 647 o <span class="hljs-string">','</span> 648 ]</pre></div></div> 649 650 </li> 651 652 653 <li id="section-28"> 654 <div class="annotation"> 655 656 <div class="pilwrap "> 657 <a class="pilcrow" href="#section-28">¶</a> 658 </div> 659 <p>The list of parameters that a function accepts can be of any length.</p> 660 661 </div> 662 663 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">ParamList</span>: [ 664 o <span class="hljs-string">''</span>,<span class="hljs-function"> -></span> [] 665 o <span class="hljs-string">'Param'</span>,<span class="hljs-function"> -></span> [$<span class="hljs-number">1</span>] 666 o <span class="hljs-string">'ParamList , Param'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>concat $<span class="hljs-number">3</span> 667 o <span class="hljs-string">'ParamList OptComma TERMINATOR Param'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>concat $<span class="hljs-number">4</span> 668 o <span class="hljs-string">'ParamList OptComma INDENT ParamList OptComma OUTDENT'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>concat $<span class="hljs-number">4</span> 669 ]</pre></div></div> 670 671 </li> 672 673 674 <li id="section-29"> 675 <div class="annotation"> 676 677 <div class="pilwrap "> 678 <a class="pilcrow" href="#section-29">¶</a> 679 </div> 680 <p>A single parameter in a function definition can be ordinary, or a splat 681that hoovers up the remaining arguments.</p> 682 683 </div> 684 685 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Param</span>: [ 686 o <span class="hljs-string">'ParamVar'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Param $<span class="hljs-number">1</span> 687 o <span class="hljs-string">'ParamVar ...'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Param $<span class="hljs-number">1</span>, <span class="hljs-literal">null</span>, <span class="hljs-literal">on</span> 688 o <span class="hljs-string">'ParamVar = Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Param $<span class="hljs-number">1</span>, $<span class="hljs-number">3</span> 689 o <span class="hljs-string">'...'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Expansion 690 ]</pre></div></div> 691 692 </li> 693 694 695 <li id="section-30"> 696 <div class="annotation"> 697 698 <div class="pilwrap "> 699 <a class="pilcrow" href="#section-30">¶</a> 700 </div> 701 <p>Function Parameters</p> 702 703 </div> 704 705 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">ParamVar</span>: [ 706 o <span class="hljs-string">'Identifier'</span> 707 o <span class="hljs-string">'ThisProperty'</span> 708 o <span class="hljs-string">'Array'</span> 709 o <span class="hljs-string">'Object'</span> 710 ]</pre></div></div> 711 712 </li> 713 714 715 <li id="section-31"> 716 <div class="annotation"> 717 718 <div class="pilwrap "> 719 <a class="pilcrow" href="#section-31">¶</a> 720 </div> 721 <p>A splat that occurs outside of a parameter list.</p> 722 723 </div> 724 725 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Splat</span>: [ 726 o <span class="hljs-string">'Expression ...'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Splat $<span class="hljs-number">1</span> 727 ]</pre></div></div> 728 729 </li> 730 731 732 <li id="section-32"> 733 <div class="annotation"> 734 735 <div class="pilwrap "> 736 <a class="pilcrow" href="#section-32">¶</a> 737 </div> 738 <p>Variables and properties that can be assigned to.</p> 739 740 </div> 741 742 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">SimpleAssignable</span>: [ 743 o <span class="hljs-string">'Identifier'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 744 o <span class="hljs-string">'Value Accessor'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>add $<span class="hljs-number">2</span> 745 o <span class="hljs-string">'Invocation Accessor'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span>, [].concat $<span class="hljs-number">2</span> 746 o <span class="hljs-string">'ThisProperty'</span> 747 ]</pre></div></div> 748 749 </li> 750 751 752 <li id="section-33"> 753 <div class="annotation"> 754 755 <div class="pilwrap "> 756 <a class="pilcrow" href="#section-33">¶</a> 757 </div> 758 <p>Everything that can be assigned to.</p> 759 760 </div> 761 762 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Assignable</span>: [ 763 o <span class="hljs-string">'SimpleAssignable'</span> 764 o <span class="hljs-string">'Array'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 765 o <span class="hljs-string">'Object'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 766 ]</pre></div></div> 767 768 </li> 769 770 771 <li id="section-34"> 772 <div class="annotation"> 773 774 <div class="pilwrap "> 775 <a class="pilcrow" href="#section-34">¶</a> 776 </div> 777 <p>The types of things that can be treated as values — assigned to, invoked 778as functions, indexed into, named as a class, etc.</p> 779 780 </div> 781 782 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Value</span>: [ 783 o <span class="hljs-string">'Assignable'</span> 784 o <span class="hljs-string">'Literal'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 785 o <span class="hljs-string">'Parenthetical'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 786 o <span class="hljs-string">'Range'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value $<span class="hljs-number">1</span> 787 o <span class="hljs-string">'This'</span> 788 ]</pre></div></div> 789 790 </li> 791 792 793 <li id="section-35"> 794 <div class="annotation"> 795 796 <div class="pilwrap "> 797 <a class="pilcrow" href="#section-35">¶</a> 798 </div> 799 <p>The general group of accessors into an object, by property, by prototype 800or by array index or slice.</p> 801 802 </div> 803 804 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Accessor</span>: [ 805 o <span class="hljs-string">'. Identifier'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Access $<span class="hljs-number">2</span> 806 o <span class="hljs-string">'?. Identifier'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Access $<span class="hljs-number">2</span>, <span class="hljs-string">'soak'</span> 807 o <span class="hljs-string">':: Identifier'</span>,<span class="hljs-function"> -></span> [LOC(<span class="hljs-number">1</span>)(<span class="hljs-keyword">new</span> Access <span class="hljs-keyword">new</span> Literal(<span class="hljs-string">'prototype'</span>)), LOC(<span class="hljs-number">2</span>)(<span class="hljs-keyword">new</span> Access $<span class="hljs-number">2</span>)] 808 o <span class="hljs-string">'?:: Identifier'</span>,<span class="hljs-function"> -></span> [LOC(<span class="hljs-number">1</span>)(<span class="hljs-keyword">new</span> Access <span class="hljs-keyword">new</span> Literal(<span class="hljs-string">'prototype'</span>), <span class="hljs-string">'soak'</span>), LOC(<span class="hljs-number">2</span>)(<span class="hljs-keyword">new</span> Access $<span class="hljs-number">2</span>)] 809 o <span class="hljs-string">'::'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Access <span class="hljs-keyword">new</span> Literal <span class="hljs-string">'prototype'</span> 810 o <span class="hljs-string">'Index'</span> 811 ]</pre></div></div> 812 813 </li> 814 815 816 <li id="section-36"> 817 <div class="annotation"> 818 819 <div class="pilwrap "> 820 <a class="pilcrow" href="#section-36">¶</a> 821 </div> 822 <p>Indexing into an object or array using bracket notation.</p> 823 824 </div> 825 826 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Index</span>: [ 827 o <span class="hljs-string">'INDEX_START IndexValue INDEX_END'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">2</span> 828 o <span class="hljs-string">'INDEX_SOAK Index'</span>,<span class="hljs-function"> -></span> extend $<span class="hljs-number">2</span>, soak : <span class="hljs-literal">yes</span> 829 ] 830 831 <span class="hljs-attribute">IndexValue</span>: [ 832 o <span class="hljs-string">'Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Index $<span class="hljs-number">1</span> 833 o <span class="hljs-string">'Slice'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Slice $<span class="hljs-number">1</span> 834 ]</pre></div></div> 835 836 </li> 837 838 839 <li id="section-37"> 840 <div class="annotation"> 841 842 <div class="pilwrap "> 843 <a class="pilcrow" href="#section-37">¶</a> 844 </div> 845 <p>In CoffeeScript, an object literal is simply a list of assignments.</p> 846 847 </div> 848 849 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Object</span>: [ 850 o <span class="hljs-string">'{ AssignList OptComma }'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Obj $<span class="hljs-number">2</span>, $<span class="hljs-number">1.</span>generated 851 ]</pre></div></div> 852 853 </li> 854 855 856 <li id="section-38"> 857 <div class="annotation"> 858 859 <div class="pilwrap "> 860 <a class="pilcrow" href="#section-38">¶</a> 861 </div> 862 <p>Assignment of properties within an object literal can be separated by 863comma, as in JavaScript, or simply by newline.</p> 864 865 </div> 866 867 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">AssignList</span>: [ 868 o <span class="hljs-string">''</span>,<span class="hljs-function"> -></span> [] 869 o <span class="hljs-string">'AssignObj'</span>,<span class="hljs-function"> -></span> [$<span class="hljs-number">1</span>] 870 o <span class="hljs-string">'AssignList , AssignObj'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>concat $<span class="hljs-number">3</span> 871 o <span class="hljs-string">'AssignList OptComma TERMINATOR AssignObj'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>concat $<span class="hljs-number">4</span> 872 o <span class="hljs-string">'AssignList OptComma INDENT AssignList OptComma OUTDENT'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">1.</span>concat $<span class="hljs-number">4</span> 873 ]</pre></div></div> 874 875 </li> 876 877 878 <li id="section-39"> 879 <div class="annotation"> 880 881 <div class="pilwrap "> 882 <a class="pilcrow" href="#section-39">¶</a> 883 </div> 884 <p>Class definitions have optional bodies of prototype property assignments, 885and optional references to the superclass.</p> 886 887 </div> 888 889 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Class</span>: [ 890 o <span class="hljs-string">'CLASS'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class 891 o <span class="hljs-string">'CLASS Block'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class <span class="hljs-literal">null</span>, <span class="hljs-literal">null</span>, $<span class="hljs-number">2</span> 892 o <span class="hljs-string">'CLASS EXTENDS Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class <span class="hljs-literal">null</span>, $<span class="hljs-number">3</span> 893 o <span class="hljs-string">'CLASS EXTENDS Expression Block'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class <span class="hljs-literal">null</span>, $<span class="hljs-number">3</span>, $<span class="hljs-number">4</span> 894 o <span class="hljs-string">'CLASS SimpleAssignable'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class $<span class="hljs-number">2</span> 895 o <span class="hljs-string">'CLASS SimpleAssignable Block'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class $<span class="hljs-number">2</span>, <span class="hljs-literal">null</span>, $<span class="hljs-number">3</span> 896 o <span class="hljs-string">'CLASS SimpleAssignable EXTENDS Expression'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class $<span class="hljs-number">2</span>, $<span class="hljs-number">4</span> 897 o <span class="hljs-string">'CLASS SimpleAssignable EXTENDS Expression Block'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Class $<span class="hljs-number">2</span>, $<span class="hljs-number">4</span>, $<span class="hljs-number">5</span> 898 ]</pre></div></div> 899 900 </li> 901 902 903 <li id="section-40"> 904 <div class="annotation"> 905 906 <div class="pilwrap "> 907 <a class="pilcrow" href="#section-40">¶</a> 908 </div> 909 <p>Ordinary function invocation, or a chained series of calls.</p> 910 911 </div> 912 913 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Invocation</span>: [ 914 o <span class="hljs-string">'Value OptFuncExist Arguments'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Call $<span class="hljs-number">1</span>, $<span class="hljs-number">3</span>, $<span class="hljs-number">2</span> 915 o <span class="hljs-string">'Invocation OptFuncExist Arguments'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Call $<span class="hljs-number">1</span>, $<span class="hljs-number">3</span>, $<span class="hljs-number">2</span> 916 o <span class="hljs-string">'SUPER'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Call <span class="hljs-string">'super'</span>, [<span class="hljs-keyword">new</span> Splat <span class="hljs-keyword">new</span> Literal <span class="hljs-string">'arguments'</span>] 917 o <span class="hljs-string">'SUPER Arguments'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Call <span class="hljs-string">'super'</span>, $<span class="hljs-number">2</span> 918 ]</pre></div></div> 919 920 </li> 921 922 923 <li id="section-41"> 924 <div class="annotation"> 925 926 <div class="pilwrap "> 927 <a class="pilcrow" href="#section-41">¶</a> 928 </div> 929 <p>An optional existence check on a function.</p> 930 931 </div> 932 933 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">OptFuncExist</span>: [ 934 o <span class="hljs-string">''</span>,<span class="hljs-function"> -></span> <span class="hljs-literal">no</span> 935 o <span class="hljs-string">'FUNC_EXIST'</span>,<span class="hljs-function"> -></span> <span class="hljs-literal">yes</span> 936 ]</pre></div></div> 937 938 </li> 939 940 941 <li id="section-42"> 942 <div class="annotation"> 943 944 <div class="pilwrap "> 945 <a class="pilcrow" href="#section-42">¶</a> 946 </div> 947 <p>The list of arguments to a function call.</p> 948 949 </div> 950 951 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">Arguments</span>: [ 952 o <span class="hljs-string">'CALL_START CALL_END'</span>,<span class="hljs-function"> -></span> [] 953 o <span class="hljs-string">'CALL_START ArgList OptComma CALL_END'</span>,<span class="hljs-function"> -></span> $<span class="hljs-number">2</span> 954 ]</pre></div></div> 955 956 </li> 957 958 959 <li id="section-43"> 960 <div class="annotation"> 961 962 <div class="pilwrap "> 963 <a class="pilcrow" href="#section-43">¶</a> 964 </div> 965 <p>A reference to the <em>this</em> current object.</p> 966 967 </div> 968 969 <div class="content"><div class='highlight'><pre> <span class="hljs-attribute">This</span>: [ 970 o <span class="hljs-string">'THIS'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value <span class="hljs-keyword">new</span> Literal <span class="hljs-string">'this'</span> 971 o <span class="hljs-string">'@'</span>,<span class="hljs-function"> -></span> <span class="hljs-keyword">new</span> Value <span class="hljs-keyword">new</span> Literal <span class="hljs-string">'this'</span> 972 ]</pre></div></div> 973 974 </li>…
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