Replace.cpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2015  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU Affero General Public License, Version 3 {{{ */
   6 /*
   7  * This program is free software: you can redistribute it and/or modify
   8  * it under the terms of the GNU Affero General Public License as published by
   9  * the Free Software Foundation, either version 3 of the License, or
  10  * (at your option) any later version.
  11
  12  * This program is distributed in the hope that it will be useful,
  13  * but WITHOUT ANY WARRANTY; without even the implied warranty of
  14  * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15  * GNU Affero General Public License for more details.
  16
  17  * You should have received a copy of the GNU Affero General Public License
  18  * along with this program.  If not, see <http://www.gnu.org/licenses/>.
  19 **/
  20 /* }}} */
  21
  22 #include "Parser.hpp"
  23 #include "Replace.hpp"
  24
  25 #include <iomanip>
  26
  27 CYFunctionExpression *CYNonLocalize(CYContext &context, CYFunctionExpression *function) {
  28     function->nonlocal_ = context.nextlocal_;
  29     return function;
  30 }
  31
  32 static void CYImplicitReturn(CYStatement *&code) {
  33     if (CYStatement *&last = CYGetLast(code))
  34         last = last->Return();
  35 }
  36
  37 CYExpression *CYAdd::Replace(CYContext &context) {
  38     CYInfix::Replace(context);
  39
  40     CYString *lhs(dynamic_cast<CYString *>(lhs_));
  41     CYString *rhs(dynamic_cast<CYString *>(rhs_));
  42
  43     if (lhs != NULL || rhs != NULL) {
  44         if (lhs == NULL) {
  45             lhs = lhs_->String(context);
  46             if (lhs == NULL)
  47                 return this;
  48         } else if (rhs == NULL) {
  49             rhs = rhs_->String(context);
  50             if (rhs == NULL)
  51                 return this;
  52         }
  53
  54         return lhs->Concat(context, rhs);
  55     }
  56
  57     if (CYNumber *lhn = lhs_->Number(context))
  58         if (CYNumber *rhn = rhs_->Number(context))
  59             return $D(lhn->Value() + rhn->Value());
  60
  61     return this;
  62 }
  63
  64 CYExpression *CYAddressOf::Replace(CYContext &context) {
  65     return $C0($M(rhs_, $S("$cya")));
  66 }
  67
  68 CYArgument *CYArgument::Replace(CYContext &context) { $T(NULL)
  69     context.Replace(value_);
  70     next_ = next_->Replace(context);
  71
  72     if (value_ == NULL) {
  73         if (next_ == NULL)
  74             return NULL;
  75         else
  76             value_ = $U;
  77     }
  78
  79     return this;
  80 }
  81
  82 CYExpression *CYArray::Replace(CYContext &context) {
  83     elements_->Replace(context);
  84     return this;
  85 }
  86
  87 CYExpression *CYArrayComprehension::Replace(CYContext &context) {
  88     CYVariable *cyv($V("$cyv"));
  89
  90     return $C0($F(NULL, $P1($L("$cyv"), comprehensions_->Parameters(context)), $$->*
  91         $E($ CYAssign(cyv, $ CYArray()))->*
  92         comprehensions_->Replace(context, $E($C1($M(cyv, $S("push")), expression_)))->*
  93         $ CYReturn(cyv)
  94     ));
  95 }
  96
  97 CYExpression *CYAssignment::Replace(CYContext &context) {
  98     context.Replace(lhs_);
  99     context.Replace(rhs_);
 100     return this;
 101 }
 102
 103 CYStatement *CYBlock::Return() {
 104     CYImplicitReturn(code_);
 105     return this;
 106 }
 107
 108 CYStatement *CYBlock::Replace(CYContext &context) {
 109     context.ReplaceAll(code_);
 110     if (code_ == NULL)
 111         return $ CYEmpty();
 112     return this;
 113 }
 114
 115 CYStatement *CYBreak::Replace(CYContext &context) {
 116     return this;
 117 }
 118
 119 CYExpression *CYCall::AddArgument(CYContext &context, CYExpression *value) {
 120     CYArgument **argument(&arguments_);
 121     while (*argument != NULL)
 122         argument = &(*argument)->next_;
 123     *argument = $ CYArgument(value);
 124     return this;
 125 }
 126
 127 CYExpression *CYCall::Replace(CYContext &context) {
 128     context.Replace(function_);
 129     arguments_->Replace(context);
 130     return this;
 131 }
 132
 133 namespace cy {
 134 namespace Syntax {
 135
 136 void Catch::Replace(CYContext &context) { $T()
 137     CYScope scope(true, context);
 138
 139     context.Replace(name_);
 140     context.scope_->Declare(context, name_, CYIdentifierCatch);
 141
 142     context.ReplaceAll(code_);
 143     scope.Close(context, code_);
 144 }
 145
 146 } }
 147
 148 void CYClause::Replace(CYContext &context) { $T()
 149     context.Replace(case_);
 150     context.ReplaceAll(code_);
 151     next_->Replace(context);
 152 }
 153
 154 CYStatement *CYComment::Replace(CYContext &context) {
 155     return this;
 156 }
 157
 158 CYExpression *CYCompound::Replace(CYContext &context) {
 159     context.Replace(expression_);
 160     context.Replace(next_);
 161
 162     if (CYCompound *compound = dynamic_cast<CYCompound *>(expression_)) {
 163         expression_ = compound->expression_;
 164         compound->expression_ = compound->next_;
 165         compound->next_ = next_;
 166         next_ = compound;
 167     }
 168
 169     return this;
 170 }
 171
 172 CYFunctionParameter *CYCompound::Parameter() const {
 173     CYFunctionParameter *next(next_->Parameter());
 174     if (next == NULL)
 175         return NULL;
 176
 177     CYFunctionParameter *parameter(expression_->Parameter());
 178     if (parameter == NULL)
 179         return NULL;
 180
 181     parameter->SetNext(next);
 182     return parameter;
 183 }
 184
 185 CYFunctionParameter *CYComprehension::Parameters(CYContext &context) const { $T(NULL)
 186     CYFunctionParameter *next(next_->Parameters(context));
 187     if (CYFunctionParameter *parameter = Parameter(context)) {
 188         parameter->SetNext(next);
 189         return parameter;
 190     } else
 191         return next;
 192 }
 193
 194 CYStatement *CYComprehension::Replace(CYContext &context, CYStatement *statement) const {
 195     return next_ == NULL ? statement : next_->Replace(context, statement);
 196 }
 197
 198 CYExpression *CYCondition::Replace(CYContext &context) {
 199     context.Replace(test_);
 200     context.Replace(true_);
 201     context.Replace(false_);
 202     return this;
 203 }
 204
 205 void CYContext::NonLocal(CYStatement *&statements) {
 206     CYContext &context(*this);
 207
 208     if (nextlocal_ != NULL && nextlocal_->identifier_ != NULL) {
 209         CYIdentifier *cye($I("$cye")->Replace(context));
 210         CYIdentifier *unique(nextlocal_->identifier_->Replace(context));
 211
 212         CYStatement *declare(
 213             $ CYVar($L1($ CYDeclaration(unique, $ CYObject()))));
 214
 215         cy::Syntax::Catch *rescue(
 216             $ cy::Syntax::Catch(cye, $$->*
 217                 $ CYIf($ CYIdentical($M($V(cye), $S("$cyk")), $V(unique)), $$->*
 218                     $ CYReturn($M($V(cye), $S("$cyv"))))->*
 219                 $ cy::Syntax::Throw($V(cye))));
 220
 221         // XXX: I don't understand any of this
 222         context.Replace(declare);
 223         rescue->Replace(context);
 224
 225         statements = $$->*
 226             declare->*
 227             $ cy::Syntax::Try(statements, rescue, NULL);
 228     }
 229 }
 230
 231 CYIdentifier *CYContext::Unique() {
 232     return $ CYIdentifier($pool.strcat("$cy", $pool.itoa(unique_++), NULL));
 233 }
 234
 235 CYStatement *CYContinue::Replace(CYContext &context) {
 236     return this;
 237 }
 238
 239 CYStatement *CYDebugger::Replace(CYContext &context) {
 240     return this;
 241 }
 242
 243 CYAssignment *CYDeclaration::Assignment(CYContext &context) {
 244     if (initialiser_ == NULL)
 245         return NULL;
 246
 247     CYAssignment *value($ CYAssign(Variable(context), initialiser_));
 248     initialiser_ = NULL;
 249     return value;
 250 }
 251
 252 CYVariable *CYDeclaration::Variable(CYContext &context) {
 253     return $V(identifier_);
 254 }
 255
 256 CYStatement *CYDeclaration::ForEachIn(CYContext &context, CYExpression *value) {
 257     return $ CYVar($L1($ CYDeclaration(identifier_, value)));
 258 }
 259
 260 CYExpression *CYDeclaration::Replace(CYContext &context) {
 261     context.Replace(identifier_);
 262     context.scope_->Declare(context, identifier_, CYIdentifierVariable);
 263     return Variable(context);
 264 }
 265
 266 void CYDeclarations::Replace(CYContext &context) { $T()
 267     declaration_->Replace(context);
 268     next_->Replace(context);
 269 }
 270
 271 CYProperty *CYDeclarations::Property(CYContext &context) { $T(NULL)
 272     return $ CYProperty(declaration_->identifier_, declaration_->initialiser_, next_->Property(context));
 273 }
 274
 275 CYFunctionParameter *CYDeclarations::Parameter(CYContext &context) { $T(NULL)
 276     return $ CYFunctionParameter($ CYDeclaration(declaration_->identifier_), next_->Parameter(context));
 277 }
 278
 279 CYArgument *CYDeclarations::Argument(CYContext &context) { $T(NULL)
 280     return $ CYArgument(declaration_->initialiser_, next_->Argument(context));
 281 }
 282
 283 CYExpression *CYDeclarations::Expression(CYContext &context) { $T(NULL)
 284     CYExpression *compound(next_->Expression(context));
 285     if (CYAssignment *assignment = declaration_->Assignment(context))
 286         if (compound == NULL)
 287             compound = assignment;
 288         else
 289             compound = $ CYCompound(assignment, compound);
 290     return compound;
 291 }
 292
 293 CYExpression *CYDirectMember::Replace(CYContext &context) {
 294     context.Replace(object_);
 295     context.Replace(property_);
 296     return this;
 297 }
 298
 299 CYStatement *CYDoWhile::Replace(CYContext &context) {
 300     context.Replace(test_);
 301     context.ReplaceAll(code_);
 302     return this;
 303 }
 304
 305 void CYElement::Replace(CYContext &context) { $T()
 306     context.Replace(value_);
 307     next_->Replace(context);
 308 }
 309
 310 CYStatement *CYEmpty::Replace(CYContext &context) {
 311     return NULL;
 312 }
 313
 314 CYExpression *CYEncodedType::Replace(CYContext &context) {
 315     return typed_->Replace(context);
 316 }
 317
 318 CYStatement *CYExpress::Return() {
 319     return $ CYReturn(expression_);
 320 }
 321
 322 CYStatement *CYExpress::Replace(CYContext &context) {
 323     context.Replace(expression_);
 324     return this;
 325 }
 326
 327 CYExpression *CYExpression::AddArgument(CYContext &context, CYExpression *value) {
 328     return $C1(this, value);
 329 }
 330
 331 CYExpression *CYExpression::ClassName(CYContext &context, bool object) {
 332     return this;
 333 }
 334
 335 CYStatement *CYExpression::ForEachIn(CYContext &context, CYExpression *value) {
 336     return $E($ CYAssign(this, value));
 337 }
 338
 339 CYAssignment *CYExpression::Assignment(CYContext &context) {
 340     return NULL;
 341 }
 342
 343 CYFunctionParameter *CYExpression::Parameter() const {
 344     return NULL;
 345 }
 346
 347 CYStatement *CYExternal::Replace(CYContext &context) {
 348     return $E($ CYAssign($V(typed_->identifier_), $C1(typed_->Replace(context), $C2($V("dlsym"), $V("RTLD_DEFAULT"), $S(typed_->identifier_->Word())))));
 349 }
 350
 351 CYNumber *CYFalse::Number(CYContext &context) {
 352     return $D(0);
 353 }
 354
 355 CYString *CYFalse::String(CYContext &context) {
 356     return $S("false");
 357 }
 358
 359 CYExpression *CYFatArrow::Replace(CYContext &context) {
 360     CYFunctionExpression *function($ CYFunctionExpression(NULL, parameters_, code_));
 361     function->this_.SetNext(context.this_);
 362     return function;
 363 }
 364
 365 void CYFinally::Replace(CYContext &context) { $T()
 366     context.ReplaceAll(code_);
 367 }
 368
 369 CYStatement *CYFor::Replace(CYContext &context) {
 370     context.Replace(initialiser_);
 371     context.Replace(test_);
 372     context.Replace(increment_);
 373     context.ReplaceAll(code_);
 374     return this;
 375 }
 376
 377 CYExpression *CYForDeclarations::Replace(CYContext &context) {
 378     declarations_->Replace(context);
 379     return declarations_->Expression(context);
 380 }
 381
 382 // XXX: this still feels highly suboptimal
 383 CYStatement *CYForIn::Replace(CYContext &context) {
 384     if (CYAssignment *assignment = initialiser_->Assignment(context))
 385         return $ CYBlock($$->*
 386             $E(assignment)->*
 387             this
 388         );
 389
 390     context.Replace(initialiser_);
 391     context.Replace(set_);
 392     context.ReplaceAll(code_);
 393     return this;
 394 }
 395
 396 CYFunctionParameter *CYForInComprehension::Parameter(CYContext &context) const {
 397     return $ CYFunctionParameter($ CYDeclaration(name_));
 398 }
 399
 400 CYStatement *CYForInComprehension::Replace(CYContext &context, CYStatement *statement) const {
 401     return $ CYForIn($V(name_), set_, CYComprehension::Replace(context, statement));
 402 }
 403
 404 CYStatement *CYForOf::Replace(CYContext &context) {
 405     if (CYAssignment *assignment = initialiser_->Assignment(context))
 406         return $ CYBlock($$->*
 407             $E(assignment)->*
 408             this
 409         );
 410
 411     CYIdentifier *cys($I("$cys")), *cyt($I("$cyt"));
 412
 413     return $ CYLetStatement($L2($ CYDeclaration(cys, set_), $ CYDeclaration(cyt)), $$->*
 414         $ CYForIn($V(cyt), $V(cys), $ CYBlock($$->*
 415             initialiser_->ForEachIn(context, $M($V(cys), $V(cyt)))->*
 416             code_
 417         ))
 418     );
 419 }
 420
 421 CYFunctionParameter *CYForOfComprehension::Parameter(CYContext &context) const {
 422     return $ CYFunctionParameter($ CYDeclaration(name_));
 423 }
 424
 425 CYStatement *CYForOfComprehension::Replace(CYContext &context, CYStatement *statement) const {
 426     CYIdentifier *cys($I("$cys"));
 427
 428     return $E($C0($F(NULL, $P1($L("$cys")), $$->*
 429         $E($ CYAssign($V(cys), set_))->*
 430         $ CYForIn($V(name_), $V(cys), $ CYBlock($$->*
 431             $E($ CYAssign($V(name_), $M($V(cys), $V(name_))))->*
 432             CYComprehension::Replace(context, statement)
 433         ))
 434     )));
 435 }
 436
 437 void CYFunction::Inject(CYContext &context) {
 438     context.Replace(name_);
 439     context.scope_->Declare(context, name_, CYIdentifierOther);
 440 }
 441
 442 void CYFunction::Replace_(CYContext &context, bool outer) {
 443     if (outer)
 444         Inject(context);
 445
 446     CYThisScope *_this(context.this_);
 447     context.this_ = &this_;
 448     context.this_ = CYGetLast(context.this_);
 449
 450     CYNonLocal *nonlocal(context.nonlocal_);
 451     CYNonLocal *nextlocal(context.nextlocal_);
 452
 453     bool localize;
 454     if (nonlocal_ != NULL) {
 455         localize = false;
 456         context.nonlocal_ = nonlocal_;
 457     } else {
 458         localize = true;
 459         nonlocal_ = $ CYNonLocal();
 460         context.nextlocal_ = nonlocal_;
 461     }
 462
 463     CYScope scope(!localize, context);
 464
 465     if (!outer && name_ != NULL)
 466         Inject(context);
 467
 468     parameters_->Replace(context, code_);
 469     context.ReplaceAll(code_);
 470
 471     if (implicit_)
 472         CYImplicitReturn(code_);
 473
 474     if (CYIdentifier *identifier = this_.identifier_)
 475         code_ = $$->*
 476             $ CYVar($L1($ CYDeclaration(identifier, $ CYThis())))->*
 477             code_;
 478
 479     if (localize)
 480         context.NonLocal(code_);
 481
 482     context.nextlocal_ = nextlocal;
 483     context.nonlocal_ = nonlocal;
 484
 485     context.this_ = _this;
 486
 487     scope.Close(context, code_);
 488 }
 489
 490 CYExpression *CYFunctionExpression::Replace(CYContext &context) {
 491     Replace_(context, false);
 492     return this;
 493 }
 494
 495 void CYFunctionParameter::Replace(CYContext &context, CYStatement *&statements) { $T()
 496     CYAssignment *assignment(initialiser_->Assignment(context));
 497     context.Replace(initialiser_);
 498
 499     next_->Replace(context, statements);
 500
 501     if (assignment != NULL)
 502         statements = $$->*
 503             // XXX: this cast is quite incorrect
 504             $ CYIf($ CYIdentical($ CYTypeOf(dynamic_cast<CYExpression *>(initialiser_)), $S("undefined")), $$->*
 505                 $E(assignment)
 506             )->*
 507             statements;
 508 }
 509
 510 CYStatement *CYFunctionStatement::Replace(CYContext &context) {
 511     Replace_(context, true);
 512     return this;
 513 }
 514
 515 CYIdentifier *CYIdentifier::Replace(CYContext &context) {
 516     if (replace_ != NULL && replace_ != this)
 517         return replace_->Replace(context);
 518     replace_ = context.scope_->Lookup(context, this);
 519     return replace_;
 520 }
 521
 522 CYStatement *CYIf::Return() {
 523     CYImplicitReturn(true_);
 524     CYImplicitReturn(false_);
 525     return this;
 526 }
 527
 528 CYStatement *CYIf::Replace(CYContext &context) {
 529     context.Replace(test_);
 530     context.ReplaceAll(true_);
 531     context.ReplaceAll(false_);
 532     return this;
 533 }
 534
 535 CYFunctionParameter *CYIfComprehension::Parameter(CYContext &context) const {
 536     return NULL;
 537 }
 538
 539 CYStatement *CYIfComprehension::Replace(CYContext &context, CYStatement *statement) const {
 540     return $ CYIf(test_, CYComprehension::Replace(context, statement));
 541 }
 542
 543 CYStatement *CYImport::Replace(CYContext &context) {
 544     return $ CYVar($L1($L(module_->part_->Word(), $C1($V("require"), module_->Replace(context, "/")))));
 545 }
 546
 547 CYExpression *CYIndirect::Replace(CYContext &context) {
 548     return $M(rhs_, $S("$cyi"));
 549 }
 550
 551 CYExpression *CYIndirectMember::Replace(CYContext &context) {
 552     return $M($ CYIndirect(object_), property_);
 553 }
 554
 555 CYExpression *CYInfix::Replace(CYContext &context) {
 556     context.Replace(lhs_);
 557     context.Replace(rhs_);
 558     return this;
 559 }
 560
 561 CYStatement *CYLabel::Replace(CYContext &context) {
 562     context.Replace(statement_);
 563     return this;
 564 }
 565
 566 CYExpression *CYLambda::Replace(CYContext &context) {
 567     return $N2($V("Functor"), $ CYFunctionExpression(NULL, parameters_->Parameters(context), code_), parameters_->TypeSignature(context, typed_->Replace(context)));
 568 }
 569
 570 CYStatement *CYLetStatement::Replace(CYContext &context) {
 571     return $E($ CYCall(CYNonLocalize(context, $ CYFunctionExpression(NULL, declarations_->Parameter(context), code_)), declarations_->Argument(context)));
 572 }
 573
 574 CYString *CYModule::Replace(CYContext &context, const char *separator) const {
 575     if (next_ == NULL)
 576         return $ CYString(part_);
 577     return $ CYString($pool.strcat(next_->Replace(context, separator)->Value(), separator, part_->Word(), NULL));
 578 }
 579
 580 CYExpression *CYMultiply::Replace(CYContext &context) {
 581     CYInfix::Replace(context);
 582
 583     if (CYNumber *lhn = lhs_->Number(context))
 584         if (CYNumber *rhn = rhs_->Number(context))
 585             return $D(lhn->Value() * rhn->Value());
 586
 587     return this;
 588 }
 589
 590 namespace cy {
 591 namespace Syntax {
 592
 593 CYExpression *New::AddArgument(CYContext &context, CYExpression *value) {
 594     CYSetLast(arguments_) = $ CYArgument(value);
 595     return this;
 596 }
 597
 598 CYExpression *New::Replace(CYContext &context) {
 599     context.Replace(constructor_);
 600     arguments_->Replace(context);
 601     return this;
 602 }
 603
 604 } }
 605
 606 CYNumber *CYNull::Number(CYContext &context) {
 607     return $D(0);
 608 }
 609
 610 CYString *CYNull::String(CYContext &context) {
 611     return $S("null");
 612 }
 613
 614 CYNumber *CYNumber::Number(CYContext &context) {
 615     return this;
 616 }
 617
 618 CYString *CYNumber::String(CYContext &context) {
 619     // XXX: there is a precise algorithm for this
 620     return $S($pool.sprintf(24, "%.17g", Value()));
 621 }
 622
 623 CYExpression *CYObject::Replace(CYContext &context) {
 624     properties_->Replace(context);
 625     return this;
 626 }
 627
 628 CYExpression *CYParenthetical::Replace(CYContext &context) {
 629     return expression_;
 630 }
 631
 632 CYExpression *CYPostfix::Replace(CYContext &context) {
 633     context.Replace(lhs_);
 634     return this;
 635 }
 636
 637 CYExpression *CYPrefix::Replace(CYContext &context) {
 638     context.Replace(rhs_);
 639     return this;
 640 }
 641
 642 // XXX: this is evil evil black magic. don't ask, don't tell... don't believe!
 643 #define MappingSet "0etnirsoalfucdphmgyvbxTwSNECAFjDLkMOIBPqzRH$_WXUVGYKQJZ"
 644 //#define MappingSet "0abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_"
 645
 646 namespace {
 647     struct IdentifierUsageLess :
 648         std::binary_function<CYIdentifier *, CYIdentifier *, bool>
 649     {
 650         _finline bool operator ()(CYIdentifier *lhs, CYIdentifier *rhs) const {
 651             if (lhs->usage_ != rhs->usage_)
 652                 return lhs->usage_ > rhs->usage_;
 653             return lhs < rhs;
 654         }
 655     };
 656
 657     typedef std::set<CYIdentifier *, IdentifierUsageLess> IdentifierUsages;
 658 }
 659
 660 void CYProgram::Replace(CYContext &context) {
 661     CYScope scope(true, context);
 662
 663     context.nextlocal_ = $ CYNonLocal();
 664     context.ReplaceAll(code_);
 665     context.NonLocal(code_);
 666
 667     scope.Close(context, code_);
 668
 669     size_t offset(0);
 670
 671     CYCStringSet external;
 672     for (CYIdentifierValueSet::const_iterator i(scope.identifiers_.begin()); i != scope.identifiers_.end(); ++i)
 673         external.insert((*i)->Word());
 674
 675     IdentifierUsages usages;
 676
 677     if (offset < context.rename_.size())
 678         CYForEach (i, context.rename_[offset].identifier_)
 679             usages.insert(i);
 680
 681     // XXX: totalling the probable occurrences and sorting by them would improve the result
 682     for (CYIdentifierUsageVector::const_iterator i(context.rename_.begin()); i != context.rename_.end(); ++i, ++offset) {
 683         //std::cout << *i << ":" << (*i)->offset_ << std::endl;
 684
 685         const char *name;
 686
 687         if (context.options_.verbose_)
 688             name = $pool.strcat("$", $pool.itoa(offset), NULL);
 689         else {
 690             char id[8];
 691             id[7] = '\0';
 692
 693           id:
 694             unsigned position(7), local(offset + 1);
 695
 696             do {
 697                 unsigned index(local % (sizeof(MappingSet) - 1));
 698                 local /= sizeof(MappingSet) - 1;
 699                 id[--position] = MappingSet[index];
 700             } while (local != 0);
 701
 702             if (external.find(id + position) != external.end()) {
 703                 ++offset;
 704                 goto id;
 705             }
 706
 707             name = $pool.strmemdup(id + position, 7 - position);
 708             // XXX: at some point, this could become a keyword
 709         }
 710
 711         CYForEach (identifier, i->identifier_)
 712             identifier->Set(name);
 713     }
 714 }
 715
 716 void CYProperty::Replace(CYContext &context) { $T()
 717     context.Replace(value_);
 718     next_->Replace(context);
 719     if (value_ == NULL)
 720         value_ = $U;
 721 }
 722
 723 CYStatement *CYReturn::Replace(CYContext &context) {
 724     if (context.nonlocal_ != NULL) {
 725         CYProperty *value(value_ == NULL ? NULL : $ CYProperty($S("$cyv"), value_));
 726         return $ cy::Syntax::Throw($ CYObject(
 727             $ CYProperty($S("$cyk"), $V(context.nonlocal_->Target(context)), value)
 728         ));
 729     }
 730
 731     context.Replace(value_);
 732     return this;
 733 }
 734
 735 CYExpression *CYRubyBlock::Replace(CYContext &context) {
 736     return call_->AddArgument(context, proc_->Replace(context));
 737 }
 738
 739 CYExpression *CYRubyProc::Replace(CYContext &context) {
 740     CYFunctionExpression *function($ CYFunctionExpression(NULL, parameters_, code_));
 741     function = CYNonLocalize(context, function);
 742     function->implicit_ = true;
 743     return function;
 744 }
 745
 746 CYScope::CYScope(bool transparent, CYContext &context) :
 747     transparent_(transparent),
 748     parent_(context.scope_)
 749 {
 750     context.scope_ = this;
 751 }
 752
 753 void CYScope::Declare(CYContext &context, CYIdentifier *identifier, CYIdentifierFlags flags) {
 754     if (!transparent_ || flags == CYIdentifierArgument || flags == CYIdentifierCatch)
 755         internal_.insert(CYIdentifierAddressFlagsMap::value_type(identifier, flags));
 756     else if (parent_ != NULL)
 757         parent_->Declare(context, identifier, flags);
 758 }
 759
 760 CYIdentifier *CYScope::Lookup(CYContext &context, CYIdentifier *identifier) {
 761     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 762     return *insert.first;
 763 }
 764
 765 void CYScope::Merge(CYContext &context, CYIdentifier *identifier) {
 766     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 767     if (!insert.second) {
 768         if ((*insert.first)->offset_ < identifier->offset_)
 769             (*insert.first)->offset_ = identifier->offset_;
 770         identifier->replace_ = *insert.first;
 771         (*insert.first)->usage_ += identifier->usage_ + 1;
 772     }
 773 }
 774
 775 namespace {
 776     struct IdentifierOffset {
 777         size_t offset_;
 778         CYIdentifierFlags flags_;
 779         size_t usage_;
 780         CYIdentifier *identifier_;
 781
 782         IdentifierOffset(CYIdentifier *identifier, CYIdentifierFlags flags) :
 783             offset_(identifier->offset_),
 784             flags_(flags),
 785             usage_(identifier->usage_),
 786             identifier_(identifier)
 787         {
 788         }
 789     };
 790
 791     struct IdentifierOffsetLess :
 792         std::binary_function<const IdentifierOffset &, const IdentifierOffset &, bool>
 793     {
 794         _finline bool operator ()(const IdentifierOffset &lhs, const IdentifierOffset &rhs) const {
 795             if (lhs.offset_ != rhs.offset_)
 796                 return lhs.offset_ < rhs.offset_;
 797             if (lhs.flags_ != rhs.flags_)
 798                 return lhs.flags_ < rhs.flags_;
 799             /*if (lhs.usage_ != rhs.usage_)
 800                 return lhs.usage_ < rhs.usage_;*/
 801             return lhs.identifier_ < rhs.identifier_;
 802         }
 803     };
 804
 805     typedef std::set<IdentifierOffset, IdentifierOffsetLess> IdentifierOffsets;
 806 }
 807
 808 void CYScope::Close(CYContext &context, CYStatement *&statements) {
 809     context.scope_ = parent_;
 810
 811     if (parent_ == NULL)
 812         return;
 813
 814     CYDeclarations *last(NULL), *curr(NULL);
 815
 816     IdentifierOffsets offsets;
 817
 818     for (CYIdentifierAddressFlagsMap::const_iterator i(internal_.begin()); i != internal_.end(); ++i)
 819         if (i->second != CYIdentifierMagic)
 820             offsets.insert(IdentifierOffset(i->first, i->second));
 821
 822     size_t offset(0);
 823
 824     for (IdentifierOffsets::const_iterator i(offsets.begin()); i != offsets.end(); ++i) {
 825         if (i->flags_ == CYIdentifierVariable) {
 826             CYDeclarations *next($ CYDeclarations($ CYDeclaration(i->identifier_)));
 827             if (last == NULL)
 828                 last = next;
 829             if (curr != NULL)
 830                 curr->SetNext(next);
 831             curr = next;
 832         }
 833
 834         if (offset < i->offset_)
 835             offset = i->offset_;
 836         if (context.rename_.size() <= offset)
 837             context.rename_.resize(offset + 1);
 838
 839         CYIdentifierUsage &rename(context.rename_[offset++]);
 840         i->identifier_->SetNext(rename.identifier_);
 841         rename.identifier_ = i->identifier_;
 842         rename.usage_ += i->identifier_->usage_ + 1;
 843     }
 844
 845     if (last != NULL) {
 846         CYVar *var($ CYVar(last));
 847         var->SetNext(statements);
 848         statements = var;
 849     }
 850
 851     for (CYIdentifierValueSet::const_iterator i(identifiers_.begin()); i != identifiers_.end(); ++i)
 852         if (internal_.find(*i) == internal_.end()) {
 853             //std::cout << *i << '=' << offset << std::endl;
 854             if ((*i)->offset_ < offset)
 855                 (*i)->offset_ = offset;
 856             parent_->Merge(context, *i);
 857         }
 858 }
 859
 860 CYStatement *CYStatement::Return() {
 861     return this;
 862 }
 863
 864 CYString *CYString::Concat(CYContext &context, CYString *rhs) const {
 865     size_t size(size_ + rhs->size_);
 866     char *value($ char[size + 1]);
 867     memcpy(value, value_, size_);
 868     memcpy(value + size_, rhs->value_, rhs->size_);
 869     value[size] = '\0';
 870     return $S(value, size);
 871 }
 872
 873 CYNumber *CYString::Number(CYContext &context) {
 874     // XXX: there is a precise algorithm for this
 875     return NULL;
 876 }
 877
 878 CYString *CYString::String(CYContext &context) {
 879     return this;
 880 }
 881
 882 CYStatement *CYSwitch::Replace(CYContext &context) {
 883     context.Replace(value_);
 884     clauses_->Replace(context);
 885     return this;
 886 }
 887
 888 CYExpression *CYThis::Replace(CYContext &context) {
 889     if (context.this_ != NULL)
 890         return $V(context.this_->Identifier(context));
 891     return this;
 892 }
 893
 894 namespace cy {
 895 namespace Syntax {
 896
 897 CYStatement *Throw::Replace(CYContext &context) {
 898     context.Replace(value_);
 899     return this;
 900 }
 901
 902 } }
 903
 904 CYExpression *CYTrivial::Replace(CYContext &context) {
 905     return this;
 906 }
 907
 908 CYNumber *CYTrue::Number(CYContext &context) {
 909     return $D(1);
 910 }
 911
 912 CYString *CYTrue::String(CYContext &context) {
 913     return $S("true");
 914 }
 915
 916 namespace cy {
 917 namespace Syntax {
 918
 919 CYStatement *Try::Replace(CYContext &context) {
 920     context.ReplaceAll(code_);
 921     catch_->Replace(context);
 922     finally_->Replace(context);
 923     return this;
 924 }
 925
 926 } }
 927
 928 CYExpression *CYTypeArrayOf::Replace_(CYContext &context, CYExpression *type) {
 929     return next_->Replace(context, $ CYCall($ CYDirectMember(type, $ CYString("arrayOf")), $ CYArgument(size_)));
 930 }
 931
 932 CYExpression *CYTypeBlockWith::Replace_(CYContext &context, CYExpression *type) {
 933     return next_->Replace(context, $ CYCall($ CYDirectMember(type, $ CYString("blockWith")), parameters_->Argument(context)));
 934 }
 935
 936 CYExpression *CYTypeConstant::Replace_(CYContext &context, CYExpression *type) {
 937     return next_->Replace(context, $ CYCall($ CYDirectMember(type, $ CYString("constant"))));
 938 }
 939
 940 CYStatement *CYTypeDefinition::Replace(CYContext &context) {
 941     return $E($ CYAssign($V(typed_->identifier_), typed_->Replace(context)));
 942 }
 943
 944 CYExpression *CYTypeError::Replace(CYContext &context) {
 945     _assert(false);
 946     return NULL;
 947 }
 948
 949 CYExpression *CYTypeModifier::Replace(CYContext &context, CYExpression *type) { $T(type)
 950     return Replace_(context, type);
 951 }
 952
 953 CYExpression *CYTypeFunctionWith::Replace_(CYContext &context, CYExpression *type) {
 954     return next_->Replace(context, $ CYCall($ CYDirectMember(type, $ CYString("functionWith")), parameters_->Argument(context)));
 955 }
 956
 957 CYExpression *CYTypeLong::Replace(CYContext &context) {
 958     return $ CYCall($ CYDirectMember(specifier_->Replace(context), $ CYString("long")));
 959 }
 960
 961 CYExpression *CYTypePointerTo::Replace_(CYContext &context, CYExpression *type) {
 962     return next_->Replace(context, $ CYCall($ CYDirectMember(type, $ CYString("pointerTo"))));
 963 }
 964
 965 CYExpression *CYTypeShort::Replace(CYContext &context) {
 966     return $ CYCall($ CYDirectMember(specifier_->Replace(context), $ CYString("short")));
 967 }
 968
 969 CYExpression *CYTypeSigned::Replace(CYContext &context) {
 970     return $ CYCall($ CYDirectMember(specifier_->Replace(context), $ CYString("signed")));
 971 }
 972
 973 CYExpression *CYTypeUnsigned::Replace(CYContext &context) {
 974     return $ CYCall($ CYDirectMember(specifier_->Replace(context), $ CYString("unsigned")));
 975 }
 976
 977 CYExpression *CYTypeVariable::Replace(CYContext &context) {
 978     return $V(name_);
 979 }
 980
 981 CYExpression *CYTypeVoid::Replace(CYContext &context) {
 982     return $N1($V("Type"), $ CYString("v"));
 983 }
 984
 985 CYExpression *CYTypeVolatile::Replace_(CYContext &context, CYExpression *type) {
 986     return next_->Replace(context, $ CYCall($ CYDirectMember(type, $ CYString("volatile"))));
 987 }
 988
 989 CYExpression *CYTypedIdentifier::Replace(CYContext &context) {
 990     return modifier_->Replace(context, specifier_->Replace(context));
 991 }
 992
 993 CYTypeFunctionWith *CYTypedIdentifier::Function() {
 994     CYTypeModifier **modifier(&modifier_);
 995     if (*modifier == NULL)
 996         return NULL;
 997     while ((*modifier)->next_ != NULL)
 998         modifier = &(*modifier)->next_;
 999     CYTypeFunctionWith *function((*modifier)->Function());
1000     if (function == NULL)
1001         return NULL;
1002     *modifier = NULL;
1003     return function;
1004 }
1005
1006 CYArgument *CYTypedParameter::Argument(CYContext &context) { $T(NULL)
1007     return $ CYArgument(typed_->Replace(context), next_->Argument(context));
1008 }
1009
1010 CYFunctionParameter *CYTypedParameter::Parameters(CYContext &context) { $T(NULL)
1011     return $ CYFunctionParameter($ CYDeclaration(typed_->identifier_ ?: context.Unique()), next_->Parameters(context));
1012 }
1013
1014 CYExpression *CYTypedParameter::TypeSignature(CYContext &context, CYExpression *prefix) { $T(prefix)
1015     return next_->TypeSignature(context, $ CYAdd(prefix, typed_->Replace(context)));
1016 }
1017
1018 CYStatement *CYVar::Replace(CYContext &context) {
1019     declarations_->Replace(context);
1020     if (CYExpression *expression = declarations_->Expression(context))
1021         return $E(expression);
1022     return $ CYEmpty();
1023 }
1024
1025 CYExpression *CYVariable::Replace(CYContext &context) {
1026     context.Replace(name_);
1027     return this;
1028 }
1029
1030 CYFunctionParameter *CYVariable::Parameter() const {
1031     return $ CYFunctionParameter($ CYDeclaration(name_));
1032 }
1033
1034 CYStatement *CYWhile::Replace(CYContext &context) {
1035     context.Replace(test_);
1036     context.ReplaceAll(code_);
1037     return this;
1038 }
1039
1040 CYStatement *CYWith::Replace(CYContext &context) {
1041     context.Replace(scope_);
1042     context.ReplaceAll(code_);
1043     return this;
1044 }
1045
1046 CYExpression *CYWord::ClassName(CYContext &context, bool object) {
1047     CYString *name($S(this));
1048     if (object)
1049         return $C1($V("objc_getClass"), name);
1050     else
1051         return name;
1052 }