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