Replace.cpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2010  Jay Freeman (saurik)
   3 */
   4
   5 /* GNU Lesser General Public License, Version 3 {{{ */
   6 /*
   7  * Cycript is free software: you can redistribute it and/or modify it under
   8  * the terms of the GNU Lesser General Public License as published by the
   9  * Free Software Foundation, either version 3 of the License, or (at your
  10  * option) any later version.
  11  *
  12  * Cycript is distributed in the hope that it will be useful, but WITHOUT
  13  * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
  14  * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
  15  * License for more details.
  16  *
  17  * You should have received a copy of the GNU Lesser General Public License
  18  * along with Cycript.  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     CYExpression *lhp(lhs_->Primitive(context));
  36     CYExpression *rhp(rhs_->Primitive(context));
  37
  38     CYString *lhs(dynamic_cast<CYString *>(lhp));
  39     CYString *rhs(dynamic_cast<CYString *>(rhp));
  40
  41     if (lhs != NULL || rhs != NULL) {
  42         if (lhs == NULL) {
  43             lhs = lhp->String(context);
  44             if (lhs == NULL)
  45                 return this;
  46         } else if (rhs == NULL) {
  47             rhs = rhp->String(context);
  48             if (rhs == NULL)
  49                 return this;
  50         }
  51
  52         return lhs->Concat(context, rhs);
  53     }
  54
  55     if (CYNumber *lhn = lhp->Number(context))
  56         if (CYNumber *rhn = rhp->Number(context))
  57             return $D(lhn->Value() + rhn->Value());
  58
  59     return this;
  60 }
  61
  62 CYExpression *CYAddressOf::Replace(CYContext &context) {
  63     return $C0($M(rhs_, $S("$cya")));
  64 }
  65
  66 void CYArgument::Replace(CYContext &context) { $T()
  67     context.Replace(value_);
  68     next_->Replace(context);
  69 }
  70
  71 CYExpression *CYArray::Replace(CYContext &context) {
  72     elements_->Replace(context);
  73     return this;
  74 }
  75
  76 CYExpression *CYArrayComprehension::Replace(CYContext &context) {
  77     CYVariable *cyv($V("$cyv"));
  78
  79     return $C0($F(NULL, $P1("$cyv", comprehensions_->Parameters(context)), $$->*
  80         $E($ CYAssign(cyv, $ CYArray()))->*
  81         comprehensions_->Replace(context, $E($C1($M(cyv, $S("push")), expression_)))->*
  82         $ CYReturn(cyv)
  83     ));
  84 }
  85
  86 CYExpression *CYAssignment::Replace(CYContext &context) {
  87     context.Replace(lhs_);
  88     context.Replace(rhs_);
  89     return this;
  90 }
  91
  92 CYStatement *CYBlock::Replace(CYContext &context) {
  93     context.ReplaceAll(statements_);
  94     if (statements_ == NULL)
  95         return $ CYEmpty();
  96     return this;
  97 }
  98
  99 CYStatement *CYBreak::Replace(CYContext &context) {
 100     return this;
 101 }
 102
 103 CYExpression *CYCall::AddArgument(CYContext &context, CYExpression *value) {
 104     CYArgument **argument(&arguments_);
 105     while (*argument != NULL)
 106         argument = &(*argument)->next_;
 107     *argument = $ CYArgument(value);
 108     return this;
 109 }
 110
 111 CYExpression *CYCall::Replace(CYContext &context) {
 112     context.Replace(function_);
 113     arguments_->Replace(context);
 114     return this;
 115 }
 116
 117 namespace cy {
 118 namespace Syntax {
 119
 120 void Catch::Replace(CYContext &context) { $T()
 121     CYScope scope(true, context, code_.statements_);
 122
 123     context.Replace(name_);
 124     context.scope_->Declare(context, name_, CYIdentifierCatch);
 125
 126     code_.Replace(context);
 127     scope.Close();
 128 }
 129
 130 } }
 131
 132 void CYClause::Replace(CYContext &context) { $T()
 133     context.Replace(case_);
 134     context.ReplaceAll(statements_);
 135     next_->Replace(context);
 136 }
 137
 138 CYStatement *CYComment::Replace(CYContext &context) {
 139     return this;
 140 }
 141
 142 CYExpression *CYCompound::Replace(CYContext &context) {
 143     context.ReplaceAll(expressions_);
 144     if (expressions_ == NULL)
 145         return NULL;
 146     return this;
 147 }
 148
 149 CYFunctionParameter *CYComprehension::Parameters(CYContext &context) const { $T(NULL)
 150     CYFunctionParameter *next(next_->Parameters(context));
 151     if (CYFunctionParameter *parameter = Parameter(context)) {
 152         parameter->SetNext(next);
 153         return parameter;
 154     } else
 155         return next;
 156 }
 157
 158 CYStatement *CYComprehension::Replace(CYContext &context, CYStatement *statement) const {
 159     return next_ == NULL ? statement : next_->Replace(context, statement);
 160 }
 161
 162 CYExpression *CYCondition::Replace(CYContext &context) {
 163     context.Replace(test_);
 164     context.Replace(true_);
 165     context.Replace(false_);
 166     return this;
 167 }
 168
 169 void CYContext::NonLocal(CYStatement *&statements) {
 170     CYContext &context(*this);
 171
 172     if (nextlocal_ != NULL && nextlocal_->identifier_ != NULL) {
 173         CYIdentifier *cye($I("$cye")->Replace(context));
 174         CYIdentifier *unique(nextlocal_->identifier_->Replace(context));
 175
 176         CYStatement *declare(
 177             $ CYVar($L1($L(unique, $ CYObject()))));
 178
 179         cy::Syntax::Catch *rescue(
 180             $ cy::Syntax::Catch(cye, $$->*
 181                 $ CYIf($ CYIdentical($M($V(cye), $S("$cyk")), $V(unique)), $$->*
 182                     $ CYReturn($M($V(cye), $S("$cyv"))))->*
 183                 $ cy::Syntax::Throw($V(cye))));
 184
 185         context.Replace(declare);
 186         rescue->Replace(context);
 187
 188         statements = $$->*
 189             declare->*
 190             $ cy::Syntax::Try(statements, rescue, NULL);
 191     }
 192 }
 193
 194 CYIdentifier *CYContext::Unique() {
 195     return $ CYIdentifier(apr_psprintf($pool, "$cy%u", unique_++));
 196 }
 197
 198 CYStatement *CYContinue::Replace(CYContext &context) {
 199     return this;
 200 }
 201
 202 CYAssignment *CYDeclaration::Assignment(CYContext &context) {
 203     if (initialiser_ == NULL)
 204         return NULL;
 205
 206     CYAssignment *value($ CYAssign(Variable(context), initialiser_));
 207     initialiser_ = NULL;
 208     return value;
 209 }
 210
 211 CYVariable *CYDeclaration::Variable(CYContext &context) {
 212     return $V(identifier_);
 213 }
 214
 215 CYStatement *CYDeclaration::ForEachIn(CYContext &context, CYExpression *value) {
 216     return $ CYVar($L1($L(identifier_, value)));
 217 }
 218
 219 CYExpression *CYDeclaration::Replace(CYContext &context) {
 220     context.Replace(identifier_);
 221     context.scope_->Declare(context, identifier_, CYIdentifierVariable);
 222     return Variable(context);
 223 }
 224
 225 void CYDeclarations::Replace(CYContext &context) { $T()
 226     declaration_->Replace(context);
 227     next_->Replace(context);
 228 }
 229
 230 CYProperty *CYDeclarations::Property(CYContext &context) { $T(NULL)
 231     return $ CYProperty(declaration_->identifier_, declaration_->initialiser_ ?: $U, next_->Property(context));
 232 }
 233
 234 CYFunctionParameter *CYDeclarations::Parameter(CYContext &context) { $T(NULL)
 235     return $ CYFunctionParameter(declaration_->identifier_, next_->Parameter(context));
 236 }
 237
 238 CYArgument *CYDeclarations::Argument(CYContext &context) { $T(NULL)
 239     return $ CYArgument(declaration_->initialiser_ ?: $U, next_->Argument(context));
 240 }
 241
 242 CYCompound *CYDeclarations::Compound(CYContext &context) { $T(NULL)
 243     CYCompound *compound(next_->Compound(context) ?: $ CYCompound());
 244     if (CYAssignment *assignment = declaration_->Assignment(context))
 245         compound->AddPrev(assignment);
 246     return compound;
 247 }
 248
 249 CYExpression *CYDirectMember::Replace(CYContext &context) {
 250     context.Replace(object_);
 251     context.Replace(property_);
 252     return this;
 253 }
 254
 255 CYStatement *CYDoWhile::Replace(CYContext &context) {
 256     context.Replace(test_);
 257     context.Replace(code_);
 258     return this;
 259 }
 260
 261 void CYElement::Replace(CYContext &context) { $T()
 262     context.Replace(value_);
 263     next_->Replace(context);
 264 }
 265
 266 CYStatement *CYEmpty::Replace(CYContext &context) {
 267     return NULL;
 268 }
 269
 270 CYStatement *CYExpress::Replace(CYContext &context) {
 271     while (CYExpress *express = dynamic_cast<CYExpress *>(next_)) {
 272         CYCompound *compound(dynamic_cast<CYCompound *>(express->expression_));
 273         if (compound == NULL)
 274             compound = $ CYCompound(express->expression_);
 275         compound->AddPrev(expression_);
 276         expression_ = compound;
 277         SetNext(express->next_);
 278     }
 279
 280     context.Replace(expression_);
 281     if (expression_ == NULL)
 282         return $ CYEmpty();
 283
 284     return this;
 285 }
 286
 287 CYExpression *CYExpression::AddArgument(CYContext &context, CYExpression *value) {
 288     return $C1(this, value);
 289 }
 290
 291 CYExpression *CYExpression::ClassName(CYContext &context, bool object) {
 292     return this;
 293 }
 294
 295 CYStatement *CYExpression::ForEachIn(CYContext &context, CYExpression *value) {
 296     return $E($ CYAssign(this, value));
 297 }
 298
 299 CYAssignment *CYExpression::Assignment(CYContext &context) {
 300     return NULL;
 301 }
 302
 303 CYNumber *CYFalse::Number(CYContext &context) {
 304     return $D(0);
 305 }
 306
 307 CYString *CYFalse::String(CYContext &context) {
 308     return $S("false");
 309 }
 310
 311 void CYFinally::Replace(CYContext &context) { $T()
 312     code_.Replace(context);
 313 }
 314
 315 CYStatement *CYFor::Replace(CYContext &context) {
 316     context.Replace(initialiser_);
 317     context.Replace(test_);
 318     context.Replace(increment_);
 319     context.Replace(code_);
 320     return this;
 321 }
 322
 323 CYCompound *CYForDeclarations::Replace(CYContext &context) {
 324     declarations_->Replace(context);
 325     return declarations_->Compound(context);
 326 }
 327
 328 // XXX: this still feels highly suboptimal
 329 CYStatement *CYForIn::Replace(CYContext &context) {
 330     if (CYAssignment *assignment = initialiser_->Assignment(context))
 331         return $ CYBlock($$->*
 332             $E(assignment)->*
 333             this
 334         );
 335
 336     context.Replace(initialiser_);
 337     context.Replace(set_);
 338     context.Replace(code_);
 339     return this;
 340 }
 341
 342 CYFunctionParameter *CYForInComprehension::Parameter(CYContext &context) const {
 343     return $ CYFunctionParameter(name_);
 344 }
 345
 346 CYStatement *CYForInComprehension::Replace(CYContext &context, CYStatement *statement) const {
 347     return $ CYForIn($V(name_), set_, CYComprehension::Replace(context, statement));
 348 }
 349
 350 CYStatement *CYForEachIn::Replace(CYContext &context) {
 351     CYIdentifier *cys($I("$cys")), *cyt($I("$cyt"));
 352
 353     return $ CYLet($L2($L(cys, set_), $L(cyt)), $$->*
 354         $ CYForIn($V(cyt), $V(cys), $ CYBlock($$->*
 355             initialiser_->ForEachIn(context, $M($V(cys), $V(cyt)))->*
 356             code_
 357         ))
 358     );
 359 }
 360
 361 CYFunctionParameter *CYForEachInComprehension::Parameter(CYContext &context) const {
 362     return $ CYFunctionParameter(name_);
 363 }
 364
 365 CYStatement *CYForEachInComprehension::Replace(CYContext &context, CYStatement *statement) const {
 366     CYIdentifier *cys($I("cys"));
 367
 368     return $E($C0($F(NULL, $P1("$cys"), $$->*
 369         $E($ CYAssign($V(cys), set_))->*
 370         $ CYForIn($V(name_), $V(cys), $ CYBlock($$->*
 371             $E($ CYAssign($V(name_), $M($V(cys), $V(name_))))->*
 372             CYComprehension::Replace(context, statement)
 373         ))
 374     )));
 375 }
 376
 377 void CYFunction::Inject(CYContext &context) {
 378     context.Replace(name_);
 379     context.scope_->Declare(context, name_, CYIdentifierOther);
 380 }
 381
 382 void CYFunction::Replace_(CYContext &context, bool outer) {
 383     if (outer)
 384         Inject(context);
 385
 386     CYNonLocal *nonlocal(context.nonlocal_);
 387     CYNonLocal *nextlocal(context.nextlocal_);
 388
 389     bool localize;
 390     if (nonlocal_ != NULL) {
 391         localize = false;
 392         context.nonlocal_ = nonlocal_;
 393     } else {
 394         localize = true;
 395         nonlocal_ = $ CYNonLocal();
 396         context.nextlocal_ = nonlocal_;
 397     }
 398
 399     CYScope scope(!localize, context, code_.statements_);
 400
 401     if (!outer && name_ != NULL)
 402         Inject(context);
 403
 404     if (parameters_ != NULL)
 405         parameters_ = parameters_->Replace(context, code_);
 406
 407     code_.Replace(context);
 408
 409     if (localize)
 410         context.NonLocal(code_.statements_);
 411
 412     context.nextlocal_ = nextlocal;
 413     context.nonlocal_ = nonlocal;
 414
 415     scope.Close();
 416 }
 417
 418 CYExpression *CYFunctionExpression::Replace(CYContext &context) {
 419     Replace_(context, false);
 420     return this;
 421 }
 422
 423 CYFunctionParameter *CYFunctionParameter::Replace(CYContext &context, CYBlock &code) {
 424     context.Replace(name_);
 425     context.scope_->Declare(context, name_, CYIdentifierArgument);
 426     if (next_ != NULL)
 427         next_ = next_->Replace(context, code);
 428     return this;
 429 }
 430
 431 CYStatement *CYFunctionStatement::Replace(CYContext &context) {
 432     Replace_(context, true);
 433     return this;
 434 }
 435
 436 CYIdentifier *CYIdentifier::Replace(CYContext &context) {
 437     if (replace_ != NULL && replace_ != this)
 438         return replace_->Replace(context);
 439     replace_ = context.scope_->Lookup(context, this);
 440     return replace_;
 441 }
 442
 443 CYStatement *CYIf::Replace(CYContext &context) {
 444     context.Replace(test_);
 445     context.Replace(true_);
 446     context.Replace(false_);
 447     return this;
 448 }
 449
 450 CYFunctionParameter *CYIfComprehension::Parameter(CYContext &context) const {
 451     return NULL;
 452 }
 453
 454 CYStatement *CYIfComprehension::Replace(CYContext &context, CYStatement *statement) const {
 455     return $ CYIf(test_, CYComprehension::Replace(context, statement));
 456 }
 457
 458 CYExpression *CYIndirect::Replace(CYContext &context) {
 459     return $M(rhs_, $S("$cyi"));
 460 }
 461
 462 CYExpression *CYIndirectMember::Replace(CYContext &context) {
 463     return $M($ CYIndirect(object_), property_);
 464 }
 465
 466 CYExpression *CYInfix::Replace(CYContext &context) {
 467     context.Replace(lhs_);
 468     context.Replace(rhs_);
 469     return this;
 470 }
 471
 472 CYStatement *CYLabel::Replace(CYContext &context) {
 473     context.Replace(statement_);
 474     return this;
 475 }
 476
 477 CYStatement *CYLet::Replace(CYContext &context) {
 478     return $E($ CYCall(CYNonLocalize(context, $ CYFunctionExpression(NULL, declarations_->Parameter(context), code_)), declarations_->Argument(context)));
 479 }
 480
 481 namespace cy {
 482 namespace Syntax {
 483
 484 CYExpression *New::AddArgument(CYContext &context, CYExpression *value) {
 485     CYSetLast(arguments_, $ CYArgument(value));
 486     return this;
 487 }
 488
 489 CYExpression *New::Replace(CYContext &context) {
 490     context.Replace(constructor_);
 491     arguments_->Replace(context);
 492     return this;
 493 }
 494
 495 } }
 496
 497 CYNumber *CYNull::Number(CYContext &context) {
 498     return $D(0);
 499 }
 500
 501 CYString *CYNull::String(CYContext &context) {
 502     return $S("null");
 503 }
 504
 505 CYNumber *CYNumber::Number(CYContext &context) {
 506     return this;
 507 }
 508
 509 CYString *CYNumber::String(CYContext &context) {
 510     // XXX: there is a precise algorithm for this
 511     return $S(apr_psprintf($pool, "%.17g", Value()));
 512 }
 513
 514 CYExpression *CYObject::Replace(CYContext &context) {
 515     properties_->Replace(context);
 516     return this;
 517 }
 518
 519 CYFunctionParameter *CYOptionalFunctionParameter::Replace(CYContext &context, CYBlock &code) {
 520     CYFunctionParameter *parameter($ CYFunctionParameter(name_, next_));
 521     parameter = parameter->Replace(context, code);
 522     context.Replace(initializer_);
 523
 524     CYVariable *name($V(name_));
 525     code.AddPrev($ CYIf($ CYIdentical($ CYTypeOf(name), $S("undefined")), $$->*
 526         $E($ CYAssign(name, initializer_))
 527     ));
 528
 529     return parameter;
 530 }
 531
 532 CYExpression *CYPostfix::Replace(CYContext &context) {
 533     context.Replace(lhs_);
 534     return this;
 535 }
 536
 537 CYExpression *CYPrefix::Replace(CYContext &context) {
 538     context.Replace(rhs_);
 539     return this;
 540 }
 541
 542 // XXX: this is evil evil black magic. don't ask, don't tell... don't believe!
 543 #define MappingSet "0etnirsoalfucdphmgyvbxTwSNECAFjDLkMOIBPqzRH$_WXUVGYKQJZ"
 544 //#define MappingSet "0abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_"
 545
 546 namespace {
 547     struct IdentifierUsageLess :
 548         std::binary_function<CYIdentifier *, CYIdentifier *, bool>
 549     {
 550         _finline bool operator ()(CYIdentifier *lhs, CYIdentifier *rhs) const {
 551             if (lhs->usage_ != rhs->usage_)
 552                 return lhs->usage_ > rhs->usage_;
 553             return lhs < rhs;
 554         }
 555     };
 556
 557     typedef std::set<CYIdentifier *, IdentifierUsageLess> IdentifierUsages;
 558 }
 559
 560 void CYProgram::Replace(CYContext &context) {
 561     CYScope scope(true, context, statements_);
 562
 563     context.nextlocal_ = $ CYNonLocal();
 564     context.ReplaceAll(statements_);
 565     context.NonLocal(statements_);
 566
 567     scope.Close();
 568
 569     size_t offset(0);
 570
 571     CYCStringSet external;
 572     for (CYIdentifierValueSet::const_iterator i(scope.identifiers_.begin()); i != scope.identifiers_.end(); ++i)
 573         external.insert((*i)->Word());
 574
 575     IdentifierUsages usages;
 576
 577     if (offset < context.rename_.size())
 578         CYForEach (i, context.rename_[offset].identifier_)
 579             usages.insert(i);
 580
 581     // XXX: totalling the probable occurrences and sorting by them would improve the result
 582     for (CYIdentifierUsageVector::const_iterator i(context.rename_.begin()); i != context.rename_.end(); ++i, ++offset) {
 583         //std::cout << *i << ":" << (*i)->offset_ << std::endl;
 584
 585         const char *name;
 586
 587         if (context.options_.verbose_)
 588             name = apr_psprintf($pool, "$%"APR_SIZE_T_FMT"", offset);
 589         else {
 590             char id[8];
 591             id[7] = '\0';
 592
 593           id:
 594             unsigned position(7), local(offset + 1);
 595
 596             do {
 597                 unsigned index(local % (sizeof(MappingSet) - 1));
 598                 local /= sizeof(MappingSet) - 1;
 599                 id[--position] = MappingSet[index];
 600             } while (local != 0);
 601
 602             if (external.find(id + position) != external.end()) {
 603                 ++offset;
 604                 goto id;
 605             }
 606
 607             name = apr_pstrmemdup($pool, id + position, 7 - position);
 608             // XXX: at some point, this could become a keyword
 609         }
 610
 611         CYForEach (identifier, i->identifier_)
 612             identifier->Set(name);
 613     }
 614 }
 615
 616 void CYProperty::Replace(CYContext &context) { $T()
 617     context.Replace(value_);
 618     next_->Replace(context);
 619 }
 620
 621 CYStatement *CYReturn::Replace(CYContext &context) {
 622     if (context.nonlocal_ != NULL) {
 623         CYProperty *value(value_ == NULL ? NULL : $ CYProperty($S("$cyv"), value_));
 624         return $ cy::Syntax::Throw($ CYObject(
 625             $ CYProperty($S("$cyk"), $V(context.nonlocal_->Target(context)), value)
 626         ));
 627     }
 628
 629     context.Replace(value_);
 630     return this;
 631 }
 632
 633 CYExpression *CYRubyBlock::Replace(CYContext &context) {
 634     // XXX: this needs to do something much more epic to handle return
 635     return call_->AddArgument(context, proc_->Replace(context));
 636 }
 637
 638 CYExpression *CYRubyProc::Replace(CYContext &context) {
 639     return CYNonLocalize(context, $ CYFunctionExpression(NULL, parameters_, code_));
 640 }
 641
 642 CYScope::CYScope(bool transparent, CYContext &context, CYStatement *&statements) :
 643     transparent_(transparent),
 644     context_(context),
 645     statements_(statements),
 646     parent_(context.scope_)
 647 {
 648     context_.scope_ = this;
 649 }
 650
 651 CYScope::~CYScope() {
 652 }
 653
 654 void CYScope::Close() {
 655     context_.scope_ = parent_;
 656     Scope(context_, statements_);
 657 }
 658
 659 void CYScope::Declare(CYContext &context, CYIdentifier *identifier, CYIdentifierFlags flags) {
 660     if (!transparent_ || flags == CYIdentifierArgument || flags == CYIdentifierCatch)
 661         internal_.insert(CYIdentifierAddressFlagsMap::value_type(identifier, flags));
 662     else if (parent_ != NULL)
 663         parent_->Declare(context, identifier, flags);
 664 }
 665
 666 CYIdentifier *CYScope::Lookup(CYContext &context, CYIdentifier *identifier) {
 667     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 668     return *insert.first;
 669 }
 670
 671 void CYScope::Merge(CYContext &context, CYIdentifier *identifier) {
 672     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 673     if (!insert.second) {
 674         if ((*insert.first)->offset_ < identifier->offset_)
 675             (*insert.first)->offset_ = identifier->offset_;
 676         identifier->replace_ = *insert.first;
 677         (*insert.first)->usage_ += identifier->usage_ + 1;
 678     }
 679 }
 680
 681 namespace {
 682     struct IdentifierOffset {
 683         size_t offset_;
 684         CYIdentifierFlags flags_;
 685         size_t usage_;
 686         CYIdentifier *identifier_;
 687
 688         IdentifierOffset(CYIdentifier *identifier, CYIdentifierFlags flags) :
 689             offset_(identifier->offset_),
 690             flags_(flags),
 691             usage_(identifier->usage_),
 692             identifier_(identifier)
 693         {
 694         }
 695     };
 696
 697     struct IdentifierOffsetLess :
 698         std::binary_function<const IdentifierOffset &, const IdentifierOffset &, bool>
 699     {
 700         _finline bool operator ()(const IdentifierOffset &lhs, const IdentifierOffset &rhs) const {
 701             if (lhs.offset_ != rhs.offset_)
 702                 return lhs.offset_ < rhs.offset_;
 703             if (lhs.flags_ != rhs.flags_)
 704                 return lhs.flags_ < rhs.flags_;
 705             /*if (lhs.usage_ != rhs.usage_)
 706                 return lhs.usage_ < rhs.usage_;*/
 707             return lhs.identifier_ < rhs.identifier_;
 708         }
 709     };
 710
 711     typedef std::set<IdentifierOffset, IdentifierOffsetLess> IdentifierOffsets;
 712 }
 713
 714 void CYScope::Scope(CYContext &context, CYStatement *&statements) {
 715     if (parent_ == NULL)
 716         return;
 717
 718     CYDeclarations *last(NULL), *curr(NULL);
 719
 720     IdentifierOffsets offsets;
 721
 722     for (CYIdentifierAddressFlagsMap::const_iterator i(internal_.begin()); i != internal_.end(); ++i)
 723         if (i->second != CYIdentifierMagic)
 724             offsets.insert(IdentifierOffset(i->first, i->second));
 725
 726     size_t offset(0);
 727
 728     for (IdentifierOffsets::const_iterator i(offsets.begin()); i != offsets.end(); ++i) {
 729         if (i->flags_ == CYIdentifierVariable) {
 730             CYDeclarations *next($ CYDeclarations($ CYDeclaration(i->identifier_)));
 731             if (last == NULL)
 732                 last = next;
 733             if (curr != NULL)
 734                 curr->SetNext(next);
 735             curr = next;
 736         }
 737
 738         if (offset < i->offset_)
 739             offset = i->offset_;
 740         if (context.rename_.size() <= offset)
 741             context.rename_.resize(offset + 1);
 742
 743         CYIdentifierUsage &rename(context.rename_[offset++]);
 744         i->identifier_->SetNext(rename.identifier_);
 745         rename.identifier_ = i->identifier_;
 746         rename.usage_ += i->identifier_->usage_ + 1;
 747     }
 748
 749     if (last != NULL) {
 750         CYVar *var($ CYVar(last));
 751         var->SetNext(statements);
 752         statements = var;
 753     }
 754
 755     for (CYIdentifierValueSet::const_iterator i(identifiers_.begin()); i != identifiers_.end(); ++i)
 756         if (internal_.find(*i) == internal_.end()) {
 757             //std::cout << *i << '=' << offset << std::endl;
 758             if ((*i)->offset_ < offset)
 759                 (*i)->offset_ = offset;
 760             parent_->Merge(context, *i);
 761         }
 762 }
 763
 764 CYString *CYString::Concat(CYContext &context, CYString *rhs) const {
 765     size_t size(size_ + rhs->size_);
 766     char *value($ char[size + 1]);
 767     memcpy(value, value_, size_);
 768     memcpy(value + size_, rhs->value_, rhs->size_);
 769     value[size] = '\0';
 770     return $S(value, size);
 771 }
 772
 773 CYNumber *CYString::Number(CYContext &context) {
 774     // XXX: there is a precise algorithm for this
 775     return NULL;
 776 }
 777
 778 CYString *CYString::String(CYContext &context) {
 779     return this;
 780 }
 781
 782 CYStatement *CYSwitch::Replace(CYContext &context) {
 783     context.Replace(value_);
 784     clauses_->Replace(context);
 785     return this;
 786 }
 787
 788 CYExpression *CYThis::Replace(CYContext &context) {
 789     return this;
 790 }
 791
 792 namespace cy {
 793 namespace Syntax {
 794
 795 CYStatement *Throw::Replace(CYContext &context) {
 796     context.Replace(value_);
 797     return this;
 798 }
 799
 800 } }
 801
 802 CYExpression *CYTrivial::Replace(CYContext &context) {
 803     return this;
 804 }
 805
 806 CYNumber *CYTrue::Number(CYContext &context) {
 807     return $D(1);
 808 }
 809
 810 CYString *CYTrue::String(CYContext &context) {
 811     return $S("true");
 812 }
 813
 814 namespace cy {
 815 namespace Syntax {
 816
 817 CYStatement *Try::Replace(CYContext &context) {
 818     code_.Replace(context);
 819     catch_->Replace(context);
 820     finally_->Replace(context);
 821     return this;
 822 }
 823
 824 } }
 825
 826 CYStatement *CYVar::Replace(CYContext &context) {
 827     declarations_->Replace(context);
 828     return $E(declarations_->Compound(context));
 829 }
 830
 831 CYExpression *CYVariable::Replace(CYContext &context) {
 832     context.Replace(name_);
 833     return this;
 834 }
 835
 836 CYStatement *CYWhile::Replace(CYContext &context) {
 837     context.Replace(test_);
 838     context.Replace(code_);
 839     return this;
 840 }
 841
 842 CYStatement *CYWith::Replace(CYContext &context) {
 843     context.Replace(scope_);
 844     context.Replace(code_);
 845     return this;
 846 }
 847
 848 CYExpression *CYWord::ClassName(CYContext &context, bool object) {
 849     CYString *name($S(this));
 850     if (object)
 851         return $C1($V("objc_getClass"), name);
 852     else
 853         return name;
 854 }