Replace.cpp

   1 /* Cycript - Optimizing JavaScript Compiler/Runtime
   2  * Copyright (C) 2009-2012  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 CYArgument *CYArgument::Replace(CYContext &context) { $T(NULL)
  67     context.Replace(value_);
  68     next_ = next_->Replace(context);
  69
  70     if (value_ == NULL) {
  71         if (next_ == NULL)
  72             return NULL;
  73         else
  74             value_ = $U;
  75     }
  76
  77     return this;
  78 }
  79
  80 CYExpression *CYArray::Replace(CYContext &context) {
  81     elements_->Replace(context);
  82     return this;
  83 }
  84
  85 CYExpression *CYArrayComprehension::Replace(CYContext &context) {
  86     CYVariable *cyv($V("$cyv"));
  87
  88     return $C0($F(NULL, $P1($L("$cyv"), comprehensions_->Parameters(context)), $$->*
  89         $E($ CYAssign(cyv, $ CYArray()))->*
  90         comprehensions_->Replace(context, $E($C1($M(cyv, $S("push")), expression_)))->*
  91         $ CYReturn(cyv)
  92     ));
  93 }
  94
  95 CYExpression *CYAssignment::Replace(CYContext &context) {
  96     context.Replace(lhs_);
  97     context.Replace(rhs_);
  98     return this;
  99 }
 100
 101 CYStatement *CYBlock::Replace(CYContext &context) {
 102     context.ReplaceAll(statements_);
 103     if (statements_ == NULL)
 104         return $ CYEmpty();
 105     return this;
 106 }
 107
 108 CYStatement *CYBreak::Replace(CYContext &context) {
 109     return this;
 110 }
 111
 112 CYExpression *CYCall::AddArgument(CYContext &context, CYExpression *value) {
 113     CYArgument **argument(&arguments_);
 114     while (*argument != NULL)
 115         argument = &(*argument)->next_;
 116     *argument = $ CYArgument(value);
 117     return this;
 118 }
 119
 120 CYExpression *CYCall::Replace(CYContext &context) {
 121     context.Replace(function_);
 122     arguments_->Replace(context);
 123     return this;
 124 }
 125
 126 namespace cy {
 127 namespace Syntax {
 128
 129 void Catch::Replace(CYContext &context) { $T()
 130     CYScope scope(true, context, code_.statements_);
 131
 132     context.Replace(name_);
 133     context.scope_->Declare(context, name_, CYIdentifierCatch);
 134
 135     code_.Replace(context);
 136     scope.Close();
 137 }
 138
 139 } }
 140
 141 void CYClause::Replace(CYContext &context) { $T()
 142     context.Replace(case_);
 143     context.ReplaceAll(statements_);
 144     next_->Replace(context);
 145 }
 146
 147 CYStatement *CYComment::Replace(CYContext &context) {
 148     return this;
 149 }
 150
 151 CYExpression *CYCompound::Replace(CYContext &context) {
 152     context.ReplaceAll(expressions_);
 153     if (expressions_ == NULL)
 154         return NULL;
 155     return this;
 156 }
 157
 158 CYExpression *CYCompound::Primitive(CYContext &context) {
 159     CYExpression *expression(expressions_);
 160     if (expression == NULL)
 161         return NULL;
 162     while (expression->next_ != NULL)
 163         expression = expression->next_;
 164     return expression->Primitive(context);
 165 }
 166
 167 CYFunctionParameter *CYComprehension::Parameters(CYContext &context) const { $T(NULL)
 168     CYFunctionParameter *next(next_->Parameters(context));
 169     if (CYFunctionParameter *parameter = Parameter(context)) {
 170         parameter->SetNext(next);
 171         return parameter;
 172     } else
 173         return next;
 174 }
 175
 176 CYStatement *CYComprehension::Replace(CYContext &context, CYStatement *statement) const {
 177     return next_ == NULL ? statement : next_->Replace(context, statement);
 178 }
 179
 180 CYExpression *CYCondition::Replace(CYContext &context) {
 181     context.Replace(test_);
 182     context.Replace(true_);
 183     context.Replace(false_);
 184     return this;
 185 }
 186
 187 void CYContext::NonLocal(CYStatement *&statements) {
 188     CYContext &context(*this);
 189
 190     if (nextlocal_ != NULL && nextlocal_->identifier_ != NULL) {
 191         CYIdentifier *cye($I("$cye")->Replace(context));
 192         CYIdentifier *unique(nextlocal_->identifier_->Replace(context));
 193
 194         CYStatement *declare(
 195             $ CYVar($L1($ CYDeclaration(unique, $ CYObject()))));
 196
 197         cy::Syntax::Catch *rescue(
 198             $ cy::Syntax::Catch(cye, $$->*
 199                 $ CYIf($ CYIdentical($M($V(cye), $S("$cyk")), $V(unique)), $$->*
 200                     $ CYReturn($M($V(cye), $S("$cyv"))))->*
 201                 $ cy::Syntax::Throw($V(cye))));
 202
 203         context.Replace(declare);
 204         rescue->Replace(context);
 205
 206         statements = $$->*
 207             declare->*
 208             $ cy::Syntax::Try(statements, rescue, NULL);
 209     }
 210 }
 211
 212 CYIdentifier *CYContext::Unique() {
 213     return $ CYIdentifier(apr_psprintf($pool, "$cy%u", unique_++));
 214 }
 215
 216 CYStatement *CYContinue::Replace(CYContext &context) {
 217     return this;
 218 }
 219
 220 CYStatement *CYDebugger::Replace(CYContext &context) {
 221     return this;
 222 }
 223
 224 CYAssignment *CYDeclaration::Assignment(CYContext &context) {
 225     if (initialiser_ == NULL)
 226         return NULL;
 227
 228     CYAssignment *value($ CYAssign(Variable(context), initialiser_));
 229     initialiser_ = NULL;
 230     return value;
 231 }
 232
 233 CYVariable *CYDeclaration::Variable(CYContext &context) {
 234     return $V(identifier_);
 235 }
 236
 237 CYStatement *CYDeclaration::ForEachIn(CYContext &context, CYExpression *value) {
 238     return $ CYVar($L1($ CYDeclaration(identifier_, value)));
 239 }
 240
 241 CYExpression *CYDeclaration::Replace(CYContext &context) {
 242     context.Replace(identifier_);
 243     context.scope_->Declare(context, identifier_, CYIdentifierVariable);
 244     return Variable(context);
 245 }
 246
 247 void CYDeclarations::Replace(CYContext &context) { $T()
 248     declaration_->Replace(context);
 249     next_->Replace(context);
 250 }
 251
 252 CYProperty *CYDeclarations::Property(CYContext &context) { $T(NULL)
 253     return $ CYProperty(declaration_->identifier_, declaration_->initialiser_, next_->Property(context));
 254 }
 255
 256 CYFunctionParameter *CYDeclarations::Parameter(CYContext &context) { $T(NULL)
 257     return $ CYFunctionParameter($ CYDeclaration(declaration_->identifier_), next_->Parameter(context));
 258 }
 259
 260 CYArgument *CYDeclarations::Argument(CYContext &context) { $T(NULL)
 261     return $ CYArgument(declaration_->initialiser_, next_->Argument(context));
 262 }
 263
 264 CYCompound *CYDeclarations::Compound(CYContext &context) { $T(NULL)
 265     CYCompound *compound(next_->Compound(context) ?: $ CYCompound());
 266     if (CYAssignment *assignment = declaration_->Assignment(context))
 267         compound->AddPrev(assignment);
 268     return compound;
 269 }
 270
 271 CYExpression *CYDirectMember::Replace(CYContext &context) {
 272     context.Replace(object_);
 273     context.Replace(property_);
 274     return this;
 275 }
 276
 277 CYStatement *CYDoWhile::Replace(CYContext &context) {
 278     context.Replace(test_);
 279     context.Replace(code_);
 280     return this;
 281 }
 282
 283 void CYElement::Replace(CYContext &context) { $T()
 284     context.Replace(value_);
 285     next_->Replace(context);
 286 }
 287
 288 CYStatement *CYEmpty::Replace(CYContext &context) {
 289     return NULL;
 290 }
 291
 292 CYStatement *CYExpress::Replace(CYContext &context) {
 293     while (CYExpress *express = dynamic_cast<CYExpress *>(next_)) {
 294         CYCompound *compound(dynamic_cast<CYCompound *>(express->expression_));
 295         if (compound == NULL)
 296             compound = $ CYCompound(express->expression_);
 297         compound->AddPrev(expression_);
 298         expression_ = compound;
 299         SetNext(express->next_);
 300     }
 301
 302     context.Replace(expression_);
 303     if (expression_ == NULL)
 304         return $ CYEmpty();
 305
 306     return this;
 307 }
 308
 309 CYExpression *CYExpression::AddArgument(CYContext &context, CYExpression *value) {
 310     return $C1(this, value);
 311 }
 312
 313 CYExpression *CYExpression::ClassName(CYContext &context, bool object) {
 314     return this;
 315 }
 316
 317 CYStatement *CYExpression::ForEachIn(CYContext &context, CYExpression *value) {
 318     return $E($ CYAssign(this, value));
 319 }
 320
 321 CYAssignment *CYExpression::Assignment(CYContext &context) {
 322     return NULL;
 323 }
 324
 325 CYNumber *CYFalse::Number(CYContext &context) {
 326     return $D(0);
 327 }
 328
 329 CYString *CYFalse::String(CYContext &context) {
 330     return $S("false");
 331 }
 332
 333 void CYFinally::Replace(CYContext &context) { $T()
 334     code_.Replace(context);
 335 }
 336
 337 CYStatement *CYFor::Replace(CYContext &context) {
 338     context.Replace(initialiser_);
 339     context.Replace(test_);
 340     context.Replace(increment_);
 341     context.Replace(code_);
 342     return this;
 343 }
 344
 345 CYCompound *CYForDeclarations::Replace(CYContext &context) {
 346     declarations_->Replace(context);
 347     return declarations_->Compound(context);
 348 }
 349
 350 // XXX: this still feels highly suboptimal
 351 CYStatement *CYForIn::Replace(CYContext &context) {
 352     if (CYAssignment *assignment = initialiser_->Assignment(context))
 353         return $ CYBlock($$->*
 354             $E(assignment)->*
 355             this
 356         );
 357
 358     context.Replace(initialiser_);
 359     context.Replace(set_);
 360     context.Replace(code_);
 361     return this;
 362 }
 363
 364 CYFunctionParameter *CYForInComprehension::Parameter(CYContext &context) const {
 365     return $ CYFunctionParameter($ CYDeclaration(name_));
 366 }
 367
 368 CYStatement *CYForInComprehension::Replace(CYContext &context, CYStatement *statement) const {
 369     return $ CYForIn($V(name_), set_, CYComprehension::Replace(context, statement));
 370 }
 371
 372 CYStatement *CYForOf::Replace(CYContext &context) {
 373     if (CYAssignment *assignment = initialiser_->Assignment(context))
 374         return $ CYBlock($$->*
 375             $E(assignment)->*
 376             this
 377         );
 378
 379     CYIdentifier *cys($I("$cys")), *cyt($I("$cyt"));
 380
 381     return $ CYLetStatement($L2($ CYDeclaration(cys, set_), $ CYDeclaration(cyt)), $$->*
 382         $ CYForIn($V(cyt), $V(cys), $ CYBlock($$->*
 383             initialiser_->ForEachIn(context, $M($V(cys), $V(cyt)))->*
 384             code_
 385         ))
 386     );
 387 }
 388
 389 CYFunctionParameter *CYForOfComprehension::Parameter(CYContext &context) const {
 390     return $ CYFunctionParameter($ CYDeclaration(name_));
 391 }
 392
 393 CYStatement *CYForOfComprehension::Replace(CYContext &context, CYStatement *statement) const {
 394     CYIdentifier *cys($I("cys"));
 395
 396     return $E($C0($F(NULL, $P1($L("$cys")), $$->*
 397         $E($ CYAssign($V(cys), set_))->*
 398         $ CYForIn($V(name_), $V(cys), $ CYBlock($$->*
 399             $E($ CYAssign($V(name_), $M($V(cys), $V(name_))))->*
 400             CYComprehension::Replace(context, statement)
 401         ))
 402     )));
 403 }
 404
 405 void CYFunction::Inject(CYContext &context) {
 406     context.Replace(name_);
 407     context.scope_->Declare(context, name_, CYIdentifierOther);
 408 }
 409
 410 void CYFunction::Replace_(CYContext &context, bool outer) {
 411     if (outer)
 412         Inject(context);
 413
 414     CYNonLocal *nonlocal(context.nonlocal_);
 415     CYNonLocal *nextlocal(context.nextlocal_);
 416
 417     bool localize;
 418     if (nonlocal_ != NULL) {
 419         localize = false;
 420         context.nonlocal_ = nonlocal_;
 421     } else {
 422         localize = true;
 423         nonlocal_ = $ CYNonLocal();
 424         context.nextlocal_ = nonlocal_;
 425     }
 426
 427     CYScope scope(!localize, context, code_.statements_);
 428
 429     if (!outer && name_ != NULL)
 430         Inject(context);
 431
 432     parameters_->Replace(context, code_);
 433     code_.Replace(context);
 434
 435     if (localize)
 436         context.NonLocal(code_.statements_);
 437
 438     context.nextlocal_ = nextlocal;
 439     context.nonlocal_ = nonlocal;
 440
 441     scope.Close();
 442 }
 443
 444 CYExpression *CYFunctionExpression::Replace(CYContext &context) {
 445     Replace_(context, false);
 446     return this;
 447 }
 448
 449 void CYFunctionParameter::Replace(CYContext &context, CYBlock &code) { $T()
 450     CYAssignment *assignment(initialiser_->Assignment(context));
 451     context.Replace(initialiser_);
 452
 453     next_->Replace(context, code);
 454
 455     if (assignment != NULL)
 456         // XXX: this cast is quite incorrect
 457         code.AddPrev($ CYIf($ CYIdentical($ CYTypeOf(dynamic_cast<CYExpression *>(initialiser_)), $S("undefined")), $$->*
 458             $E(assignment)
 459         ));
 460 }
 461
 462 CYStatement *CYFunctionStatement::Replace(CYContext &context) {
 463     Replace_(context, true);
 464     return this;
 465 }
 466
 467 CYIdentifier *CYIdentifier::Replace(CYContext &context) {
 468     if (replace_ != NULL && replace_ != this)
 469         return replace_->Replace(context);
 470     replace_ = context.scope_->Lookup(context, this);
 471     return replace_;
 472 }
 473
 474 CYStatement *CYIf::Replace(CYContext &context) {
 475     context.Replace(test_);
 476     context.Replace(true_);
 477     context.Replace(false_);
 478     return this;
 479 }
 480
 481 CYFunctionParameter *CYIfComprehension::Parameter(CYContext &context) const {
 482     return NULL;
 483 }
 484
 485 CYStatement *CYIfComprehension::Replace(CYContext &context, CYStatement *statement) const {
 486     return $ CYIf(test_, CYComprehension::Replace(context, statement));
 487 }
 488
 489 CYExpression *CYIndirect::Replace(CYContext &context) {
 490     return $M(rhs_, $S("$cyi"));
 491 }
 492
 493 CYExpression *CYIndirectMember::Replace(CYContext &context) {
 494     return $M($ CYIndirect(object_), property_);
 495 }
 496
 497 CYExpression *CYInfix::Replace(CYContext &context) {
 498     context.Replace(lhs_);
 499     context.Replace(rhs_);
 500     return this;
 501 }
 502
 503 CYStatement *CYLabel::Replace(CYContext &context) {
 504     context.Replace(statement_);
 505     return this;
 506 }
 507
 508 CYStatement *CYLetStatement::Replace(CYContext &context) {
 509     return $E($ CYCall(CYNonLocalize(context, $ CYFunctionExpression(NULL, declarations_->Parameter(context), code_)), declarations_->Argument(context)));
 510 }
 511
 512 namespace cy {
 513 namespace Syntax {
 514
 515 CYExpression *New::AddArgument(CYContext &context, CYExpression *value) {
 516     CYLast(arguments_) = $ CYArgument(value);
 517     return this;
 518 }
 519
 520 CYExpression *New::Replace(CYContext &context) {
 521     context.Replace(constructor_);
 522     arguments_->Replace(context);
 523     return this;
 524 }
 525
 526 } }
 527
 528 CYNumber *CYNull::Number(CYContext &context) {
 529     return $D(0);
 530 }
 531
 532 CYString *CYNull::String(CYContext &context) {
 533     return $S("null");
 534 }
 535
 536 CYNumber *CYNumber::Number(CYContext &context) {
 537     return this;
 538 }
 539
 540 CYString *CYNumber::String(CYContext &context) {
 541     // XXX: there is a precise algorithm for this
 542     return $S(apr_psprintf($pool, "%.17g", Value()));
 543 }
 544
 545 CYExpression *CYObject::Replace(CYContext &context) {
 546     properties_->Replace(context);
 547     return this;
 548 }
 549
 550 CYExpression *CYPostfix::Replace(CYContext &context) {
 551     context.Replace(lhs_);
 552     return this;
 553 }
 554
 555 CYExpression *CYPrefix::Replace(CYContext &context) {
 556     context.Replace(rhs_);
 557     return this;
 558 }
 559
 560 // XXX: this is evil evil black magic. don't ask, don't tell... don't believe!
 561 #define MappingSet "0etnirsoalfucdphmgyvbxTwSNECAFjDLkMOIBPqzRH$_WXUVGYKQJZ"
 562 //#define MappingSet "0abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_"
 563
 564 namespace {
 565     struct IdentifierUsageLess :
 566         std::binary_function<CYIdentifier *, CYIdentifier *, bool>
 567     {
 568         _finline bool operator ()(CYIdentifier *lhs, CYIdentifier *rhs) const {
 569             if (lhs->usage_ != rhs->usage_)
 570                 return lhs->usage_ > rhs->usage_;
 571             return lhs < rhs;
 572         }
 573     };
 574
 575     typedef std::set<CYIdentifier *, IdentifierUsageLess> IdentifierUsages;
 576 }
 577
 578 void CYProgram::Replace(CYContext &context) {
 579     CYScope scope(true, context, statements_);
 580
 581     context.nextlocal_ = $ CYNonLocal();
 582     context.ReplaceAll(statements_);
 583     context.NonLocal(statements_);
 584
 585     scope.Close();
 586
 587     size_t offset(0);
 588
 589     CYCStringSet external;
 590     for (CYIdentifierValueSet::const_iterator i(scope.identifiers_.begin()); i != scope.identifiers_.end(); ++i)
 591         external.insert((*i)->Word());
 592
 593     IdentifierUsages usages;
 594
 595     if (offset < context.rename_.size())
 596         CYForEach (i, context.rename_[offset].identifier_)
 597             usages.insert(i);
 598
 599     // XXX: totalling the probable occurrences and sorting by them would improve the result
 600     for (CYIdentifierUsageVector::const_iterator i(context.rename_.begin()); i != context.rename_.end(); ++i, ++offset) {
 601         //std::cout << *i << ":" << (*i)->offset_ << std::endl;
 602
 603         const char *name;
 604
 605         if (context.options_.verbose_)
 606             name = apr_psprintf($pool, "$%"APR_SIZE_T_FMT"", offset);
 607         else {
 608             char id[8];
 609             id[7] = '\0';
 610
 611           id:
 612             unsigned position(7), local(offset + 1);
 613
 614             do {
 615                 unsigned index(local % (sizeof(MappingSet) - 1));
 616                 local /= sizeof(MappingSet) - 1;
 617                 id[--position] = MappingSet[index];
 618             } while (local != 0);
 619
 620             if (external.find(id + position) != external.end()) {
 621                 ++offset;
 622                 goto id;
 623             }
 624
 625             name = apr_pstrmemdup($pool, id + position, 7 - position);
 626             // XXX: at some point, this could become a keyword
 627         }
 628
 629         CYForEach (identifier, i->identifier_)
 630             identifier->Set(name);
 631     }
 632 }
 633
 634 void CYProperty::Replace(CYContext &context) { $T()
 635     context.Replace(value_);
 636     next_->Replace(context);
 637     if (value_ == NULL)
 638         value_ = $U;
 639 }
 640
 641 CYStatement *CYReturn::Replace(CYContext &context) {
 642     if (context.nonlocal_ != NULL) {
 643         CYProperty *value(value_ == NULL ? NULL : $ CYProperty($S("$cyv"), value_));
 644         return $ cy::Syntax::Throw($ CYObject(
 645             $ CYProperty($S("$cyk"), $V(context.nonlocal_->Target(context)), value)
 646         ));
 647     }
 648
 649     context.Replace(value_);
 650     return this;
 651 }
 652
 653 CYExpression *CYRubyBlock::Replace(CYContext &context) {
 654     // XXX: this needs to do something much more epic to handle return
 655     return call_->AddArgument(context, proc_->Replace(context));
 656 }
 657
 658 CYExpression *CYRubyProc::Replace(CYContext &context) {
 659     return CYNonLocalize(context, $ CYFunctionExpression(NULL, parameters_, code_));
 660 }
 661
 662 CYScope::CYScope(bool transparent, CYContext &context, CYStatement *&statements) :
 663     transparent_(transparent),
 664     context_(context),
 665     statements_(statements),
 666     parent_(context.scope_)
 667 {
 668     context_.scope_ = this;
 669 }
 670
 671 CYScope::~CYScope() {
 672 }
 673
 674 void CYScope::Close() {
 675     context_.scope_ = parent_;
 676     Scope(context_, statements_);
 677 }
 678
 679 void CYScope::Declare(CYContext &context, CYIdentifier *identifier, CYIdentifierFlags flags) {
 680     if (!transparent_ || flags == CYIdentifierArgument || flags == CYIdentifierCatch)
 681         internal_.insert(CYIdentifierAddressFlagsMap::value_type(identifier, flags));
 682     else if (parent_ != NULL)
 683         parent_->Declare(context, identifier, flags);
 684 }
 685
 686 CYIdentifier *CYScope::Lookup(CYContext &context, CYIdentifier *identifier) {
 687     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 688     return *insert.first;
 689 }
 690
 691 void CYScope::Merge(CYContext &context, CYIdentifier *identifier) {
 692     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 693     if (!insert.second) {
 694         if ((*insert.first)->offset_ < identifier->offset_)
 695             (*insert.first)->offset_ = identifier->offset_;
 696         identifier->replace_ = *insert.first;
 697         (*insert.first)->usage_ += identifier->usage_ + 1;
 698     }
 699 }
 700
 701 namespace {
 702     struct IdentifierOffset {
 703         size_t offset_;
 704         CYIdentifierFlags flags_;
 705         size_t usage_;
 706         CYIdentifier *identifier_;
 707
 708         IdentifierOffset(CYIdentifier *identifier, CYIdentifierFlags flags) :
 709             offset_(identifier->offset_),
 710             flags_(flags),
 711             usage_(identifier->usage_),
 712             identifier_(identifier)
 713         {
 714         }
 715     };
 716
 717     struct IdentifierOffsetLess :
 718         std::binary_function<const IdentifierOffset &, const IdentifierOffset &, bool>
 719     {
 720         _finline bool operator ()(const IdentifierOffset &lhs, const IdentifierOffset &rhs) const {
 721             if (lhs.offset_ != rhs.offset_)
 722                 return lhs.offset_ < rhs.offset_;
 723             if (lhs.flags_ != rhs.flags_)
 724                 return lhs.flags_ < rhs.flags_;
 725             /*if (lhs.usage_ != rhs.usage_)
 726                 return lhs.usage_ < rhs.usage_;*/
 727             return lhs.identifier_ < rhs.identifier_;
 728         }
 729     };
 730
 731     typedef std::set<IdentifierOffset, IdentifierOffsetLess> IdentifierOffsets;
 732 }
 733
 734 void CYScope::Scope(CYContext &context, CYStatement *&statements) {
 735     if (parent_ == NULL)
 736         return;
 737
 738     CYDeclarations *last(NULL), *curr(NULL);
 739
 740     IdentifierOffsets offsets;
 741
 742     for (CYIdentifierAddressFlagsMap::const_iterator i(internal_.begin()); i != internal_.end(); ++i)
 743         if (i->second != CYIdentifierMagic)
 744             offsets.insert(IdentifierOffset(i->first, i->second));
 745
 746     size_t offset(0);
 747
 748     for (IdentifierOffsets::const_iterator i(offsets.begin()); i != offsets.end(); ++i) {
 749         if (i->flags_ == CYIdentifierVariable) {
 750             CYDeclarations *next($ CYDeclarations($ CYDeclaration(i->identifier_)));
 751             if (last == NULL)
 752                 last = next;
 753             if (curr != NULL)
 754                 curr->SetNext(next);
 755             curr = next;
 756         }
 757
 758         if (offset < i->offset_)
 759             offset = i->offset_;
 760         if (context.rename_.size() <= offset)
 761             context.rename_.resize(offset + 1);
 762
 763         CYIdentifierUsage &rename(context.rename_[offset++]);
 764         i->identifier_->SetNext(rename.identifier_);
 765         rename.identifier_ = i->identifier_;
 766         rename.usage_ += i->identifier_->usage_ + 1;
 767     }
 768
 769     if (last != NULL) {
 770         CYVar *var($ CYVar(last));
 771         var->SetNext(statements);
 772         statements = var;
 773     }
 774
 775     for (CYIdentifierValueSet::const_iterator i(identifiers_.begin()); i != identifiers_.end(); ++i)
 776         if (internal_.find(*i) == internal_.end()) {
 777             //std::cout << *i << '=' << offset << std::endl;
 778             if ((*i)->offset_ < offset)
 779                 (*i)->offset_ = offset;
 780             parent_->Merge(context, *i);
 781         }
 782 }
 783
 784 CYString *CYString::Concat(CYContext &context, CYString *rhs) const {
 785     size_t size(size_ + rhs->size_);
 786     char *value($ char[size + 1]);
 787     memcpy(value, value_, size_);
 788     memcpy(value + size_, rhs->value_, rhs->size_);
 789     value[size] = '\0';
 790     return $S(value, size);
 791 }
 792
 793 CYNumber *CYString::Number(CYContext &context) {
 794     // XXX: there is a precise algorithm for this
 795     return NULL;
 796 }
 797
 798 CYString *CYString::String(CYContext &context) {
 799     return this;
 800 }
 801
 802 CYStatement *CYSwitch::Replace(CYContext &context) {
 803     context.Replace(value_);
 804     clauses_->Replace(context);
 805     return this;
 806 }
 807
 808 CYExpression *CYThis::Replace(CYContext &context) {
 809     return this;
 810 }
 811
 812 namespace cy {
 813 namespace Syntax {
 814
 815 CYStatement *Throw::Replace(CYContext &context) {
 816     context.Replace(value_);
 817     return this;
 818 }
 819
 820 } }
 821
 822 CYExpression *CYTrivial::Replace(CYContext &context) {
 823     return this;
 824 }
 825
 826 CYNumber *CYTrue::Number(CYContext &context) {
 827     return $D(1);
 828 }
 829
 830 CYString *CYTrue::String(CYContext &context) {
 831     return $S("true");
 832 }
 833
 834 namespace cy {
 835 namespace Syntax {
 836
 837 CYStatement *Try::Replace(CYContext &context) {
 838     code_.Replace(context);
 839     catch_->Replace(context);
 840     finally_->Replace(context);
 841     return this;
 842 }
 843
 844 } }
 845
 846 CYStatement *CYVar::Replace(CYContext &context) {
 847     declarations_->Replace(context);
 848     return $E(declarations_->Compound(context));
 849 }
 850
 851 CYExpression *CYVariable::Replace(CYContext &context) {
 852     context.Replace(name_);
 853     return this;
 854 }
 855
 856 CYStatement *CYWhile::Replace(CYContext &context) {
 857     context.Replace(test_);
 858     context.Replace(code_);
 859     return this;
 860 }
 861
 862 CYStatement *CYWith::Replace(CYContext &context) {
 863     context.Replace(scope_);
 864     context.Replace(code_);
 865     return this;
 866 }
 867
 868 CYExpression *CYWord::ClassName(CYContext &context, bool object) {
 869     CYString *name($S(this));
 870     if (object)
 871         return $C1($V("objc_getClass"), name);
 872     else
 873         return name;
 874 }