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 CYExpression *CYAdd::Replace(CYContext &context) {
  28     CYInfix::Replace(context);
  29
  30     CYExpression *lhp(lhs_->Primitive(context));
  31     CYExpression *rhp(rhs_->Primitive(context));
  32
  33     CYString *lhs(dynamic_cast<CYString *>(lhp));
  34     CYString *rhs(dynamic_cast<CYString *>(rhp));
  35
  36     if (lhs != NULL || rhs != NULL) {
  37         if (lhs == NULL) {
  38             lhs = lhp->String(context);
  39             if (lhs == NULL)
  40                 return this;
  41         } else if (rhs == NULL) {
  42             rhs = rhp->String(context);
  43             if (rhs == NULL)
  44                 return this;
  45         }
  46
  47         return lhs->Concat(context, rhs);
  48     }
  49
  50     if (CYNumber *lhn = lhp->Number(context))
  51         if (CYNumber *rhn = rhp->Number(context))
  52             return $D(lhn->Value() + rhn->Value());
  53
  54     return this;
  55 }
  56
  57 CYExpression *CYAddressOf::Replace(CYContext &context) {
  58     CYPrefix::Replace(context);
  59     return $C0($M(rhs_, $S("$cya")));
  60 }
  61
  62 void CYArgument::Replace(CYContext &context) { $T()
  63     context.Replace(value_);
  64     next_->Replace(context);
  65 }
  66
  67 CYExpression *CYArray::Replace(CYContext &context) {
  68     elements_->Replace(context);
  69     return this;
  70 }
  71
  72 CYExpression *CYArrayComprehension::Replace(CYContext &context) {
  73     CYVariable *cyv($V("$cyv"));
  74
  75     return $C0($F(NULL, $P1("$cyv", comprehensions_->Parameters(context)), $$->*
  76         $E($ CYAssign(cyv, $ CYArray()))->*
  77         comprehensions_->Replace(context, $E($C1($M(cyv, $S("push")), expression_)))->*
  78         $ CYReturn(cyv)
  79     ));
  80 }
  81
  82 CYExpression *CYAssignment::Replace(CYContext &context) {
  83     context.Replace(lhs_);
  84     context.Replace(rhs_);
  85     return this;
  86 }
  87
  88 CYStatement *CYBlock::Replace(CYContext &context) {
  89     context.ReplaceAll(statements_);
  90     if (statements_ == NULL)
  91         return $ CYEmpty();
  92     return this;
  93 }
  94
  95 CYStatement *CYBreak::Replace(CYContext &context) {
  96     return this;
  97 }
  98
  99 CYExpression *CYCall::AddArgument(CYContext &context, CYExpression *value) {
 100     CYArgument **argument(&arguments_);
 101     while (*argument != NULL)
 102         argument = &(*argument)->next_;
 103     *argument = $ CYArgument(value);
 104     return this;
 105 }
 106
 107 CYExpression *CYCall::Replace(CYContext &context) {
 108     context.Replace(function_);
 109     arguments_->Replace(context);
 110     return this;
 111 }
 112
 113 namespace cy {
 114 namespace Syntax {
 115
 116 void Catch::Replace(CYContext &context) { $T()
 117     CYScope scope(CYScopeCatch, context, code_.statements_);
 118
 119     context.Replace(name_);
 120     context.scope_->Declare(context, name_, CYIdentifierCatch);
 121
 122     code_.Replace(context);
 123     scope.Close();
 124 }
 125
 126 } }
 127
 128 void CYClause::Replace(CYContext &context) { $T()
 129     context.Replace(case_);
 130     context.ReplaceAll(statements_);
 131     next_->Replace(context);
 132 }
 133
 134 CYStatement *CYComment::Replace(CYContext &context) {
 135     return this;
 136 }
 137
 138 CYExpression *CYCompound::Replace(CYContext &context) {
 139     context.ReplaceAll(expressions_);
 140     if (expressions_ == NULL)
 141         return NULL;
 142     return this;
 143 }
 144
 145 CYFunctionParameter *CYComprehension::Parameters(CYContext &context) const { $T(NULL)
 146     CYFunctionParameter *next(next_->Parameters(context));
 147     if (CYFunctionParameter *parameter = Parameter(context)) {
 148         parameter->SetNext(next);
 149         return parameter;
 150     } else
 151         return next;
 152 }
 153
 154 CYStatement *CYComprehension::Replace(CYContext &context, CYStatement *statement) const {
 155     return next_ == NULL ? statement : next_->Replace(context, statement);
 156 }
 157
 158 CYExpression *CYCondition::Replace(CYContext &context) {
 159     context.Replace(test_);
 160     context.Replace(true_);
 161     context.Replace(false_);
 162     return this;
 163 }
 164
 165 void CYContext::NonLocal(CYStatement *&statements) {
 166     CYContext &context(*this);
 167
 168     if (nextlocal_ != NULL && nextlocal_->identifier_ != NULL) {
 169         CYIdentifier *cye($I("$cye")->Replace(context));
 170         CYIdentifier *unique(nextlocal_->identifier_->Replace(context));
 171
 172         CYStatement *declare(
 173             $ CYVar($L1($L(unique, $ CYObject()))));
 174
 175         cy::Syntax::Catch *rescue(
 176             $ cy::Syntax::Catch(cye, $$->*
 177                 $ CYIf($ CYIdentical($M($V(cye), $S("$cyk")), $V(unique)), $$->*
 178                     $ CYReturn($M($V(cye), $S("$cyv"))))->*
 179                 $ cy::Syntax::Throw($V(cye))));
 180
 181         context.Replace(declare);
 182         rescue->Replace(context);
 183
 184         statements = $$->*
 185             declare->*
 186             $ cy::Syntax::Try(statements, rescue, NULL);
 187     }
 188 }
 189
 190 CYIdentifier *CYContext::Unique() {
 191     return $ CYIdentifier(apr_psprintf($pool, "$cy%u", unique_++));
 192 }
 193
 194 CYStatement *CYContinue::Replace(CYContext &context) {
 195     return this;
 196 }
 197
 198 CYAssignment *CYDeclaration::Assignment(CYContext &context) {
 199     context.Replace(identifier_);
 200     CYExpression *variable(Replace(context));
 201     context.scope_->Declare(context, identifier_, CYIdentifierVariable);
 202     return initialiser_ == NULL ? NULL : $ CYAssign(variable, initialiser_);
 203 }
 204
 205 CYStatement *CYDeclaration::ForEachIn(CYContext &context, CYExpression *value) {
 206     return $ CYVar($L1($L(identifier_, value)));
 207 }
 208
 209 CYExpression *CYDeclaration::Replace(CYContext &context) {
 210     return $V(identifier_);
 211 }
 212
 213 CYProperty *CYDeclarations::Property(CYContext &context) { $T(NULL)
 214     return $ CYProperty(declaration_->identifier_, declaration_->initialiser_ ?: $U, next_->Property(context));
 215 }
 216
 217 CYCompound *CYDeclarations::Replace(CYContext &context) {
 218     CYCompound *compound(next_ == NULL ? $ CYCompound() : next_->Replace(context));
 219     if (CYAssignment *assignment = declaration_->Assignment(context))
 220         compound->AddPrev(assignment);
 221     return compound;
 222 }
 223
 224 CYExpression *CYDirectMember::Replace(CYContext &context) {
 225     Replace_(context);
 226     return this;
 227 }
 228
 229 CYStatement *CYDoWhile::Replace(CYContext &context) {
 230     context.Replace(test_);
 231     context.Replace(code_);
 232     return this;
 233 }
 234
 235 void CYElement::Replace(CYContext &context) { $T()
 236     context.Replace(value_);
 237     next_->Replace(context);
 238 }
 239
 240 CYStatement *CYEmpty::Replace(CYContext &context) {
 241     return NULL;
 242 }
 243
 244 CYStatement *CYExpress::Replace(CYContext &context) {
 245     while (CYExpress *express = dynamic_cast<CYExpress *>(next_)) {
 246         CYCompound *compound(dynamic_cast<CYCompound *>(express->expression_));
 247         if (compound == NULL)
 248             compound = $ CYCompound(express->expression_);
 249         compound->AddPrev(expression_);
 250         expression_ = compound;
 251         SetNext(express->next_);
 252     }
 253
 254     context.Replace(expression_);
 255     if (expression_ == NULL)
 256         return $ CYEmpty();
 257
 258     return this;
 259 }
 260
 261 CYExpression *CYExpression::AddArgument(CYContext &context, CYExpression *value) {
 262     return $C1(this, value);
 263 }
 264
 265 CYExpression *CYExpression::ClassName(CYContext &context, bool object) {
 266     return this;
 267 }
 268
 269 CYStatement *CYExpression::ForEachIn(CYContext &context, CYExpression *value) {
 270     return $E($ CYAssign(this, value));
 271 }
 272
 273 CYAssignment *CYExpression::Assignment(CYContext &context) {
 274     return NULL;
 275 }
 276
 277 CYNumber *CYFalse::Number(CYContext &context) {
 278     return $D(0);
 279 }
 280
 281 CYString *CYFalse::String(CYContext &context) {
 282     return $S("false");
 283 }
 284
 285 void CYFinally::Replace(CYContext &context) { $T()
 286     code_.Replace(context);
 287 }
 288
 289 CYStatement *CYFor::Replace(CYContext &context) {
 290     context.Replace(initialiser_);
 291     context.Replace(test_);
 292     context.Replace(increment_);
 293     context.Replace(code_);
 294     return this;
 295 }
 296
 297 CYStatement *CYForIn::Replace(CYContext &context) {
 298     CYAssignment *assignment(initialiser_->Assignment(context));
 299
 300     context.Replace(initialiser_);
 301     context.Replace(set_);
 302     context.Replace(code_);
 303
 304     if (assignment == NULL)
 305         return this;
 306
 307     return $ CYBlock($$->*
 308         $E(assignment)->*
 309         this
 310     );
 311 }
 312
 313 CYFunctionParameter *CYForInComprehension::Parameter(CYContext &context) const {
 314     return $ CYFunctionParameter(name_);
 315 }
 316
 317 CYStatement *CYForInComprehension::Replace(CYContext &context, CYStatement *statement) const {
 318     return $ CYForIn($V(name_), set_, CYComprehension::Replace(context, statement));
 319 }
 320
 321 CYStatement *CYForEachIn::Replace(CYContext &context) {
 322     CYIdentifier *cys($I("$cys")), *cyt($I("$cyt"));
 323
 324     return $ CYLet($L2($L(cys, set_), $L(cyt)), $$->*
 325         $ CYForIn($V(cyt), $V(cys), $ CYBlock($$->*
 326             initialiser_->ForEachIn(context, $M($V(cys), $V(cyt)))->*
 327             code_
 328         ))
 329     );
 330 }
 331
 332 CYFunctionParameter *CYForEachInComprehension::Parameter(CYContext &context) const {
 333     return $ CYFunctionParameter(name_);
 334 }
 335
 336 CYStatement *CYForEachInComprehension::Replace(CYContext &context, CYStatement *statement) const {
 337     CYIdentifier *cys($I("cys"));
 338
 339     return $E($C0($F(NULL, $P1("$cys"), $$->*
 340         $E($ CYAssign($V(cys), set_))->*
 341         $ CYForIn($V(name_), $V(cys), $ CYBlock($$->*
 342             $E($ CYAssign($V(name_), $M($V(cys), $V(name_))))->*
 343             CYComprehension::Replace(context, statement)
 344         ))
 345     )));
 346 }
 347
 348 void CYFunction::Inject(CYContext &context) {
 349     context.Replace(name_);
 350     context.scope_->Declare(context, name_, CYIdentifierOther);
 351 }
 352
 353 void CYFunction::Replace_(CYContext &context, bool outer) {
 354     if (outer)
 355         Inject(context);
 356
 357     CYScope scope(CYScopeFunction, context, code_.statements_);
 358
 359     CYNonLocal *nonlocal(context.nonlocal_);
 360     CYNonLocal *nextlocal(context.nextlocal_);
 361
 362     bool localize;
 363     if (nonlocal_ != NULL) {
 364         localize = false;
 365         context.nonlocal_ = nonlocal_;
 366     } else {
 367         localize = true;
 368         nonlocal_ = $ CYNonLocal();
 369         context.nextlocal_ = nonlocal_;
 370     }
 371
 372     if (!outer && name_ != NULL)
 373         Inject(context);
 374
 375     if (parameters_ != NULL)
 376         parameters_ = parameters_->Replace(context, code_);
 377
 378     code_.Replace(context);
 379
 380     if (localize)
 381         context.NonLocal(code_.statements_);
 382
 383     context.nextlocal_ = nextlocal;
 384     context.nonlocal_ = nonlocal;
 385
 386     scope.Close();
 387 }
 388
 389 CYExpression *CYFunctionExpression::Replace(CYContext &context) {
 390     Replace_(context, false);
 391     return this;
 392 }
 393
 394 CYFunctionParameter *CYFunctionParameter::Replace(CYContext &context, CYBlock &code) {
 395     context.Replace(name_);
 396     context.scope_->Declare(context, name_, CYIdentifierArgument);
 397     if (next_ != NULL)
 398         next_ = next_->Replace(context, code);
 399     return this;
 400 }
 401
 402 CYStatement *CYFunctionStatement::Replace(CYContext &context) {
 403     Replace_(context, true);
 404     return this;
 405 }
 406
 407 CYIdentifier *CYIdentifier::Replace(CYContext &context) {
 408     if (replace_ != NULL && replace_ != this)
 409         return replace_->Replace(context);
 410     replace_ = context.scope_->Lookup(context, this);
 411     return replace_;
 412 }
 413
 414 CYStatement *CYIf::Replace(CYContext &context) {
 415     context.Replace(test_);
 416     context.Replace(true_);
 417     context.Replace(false_);
 418     return this;
 419 }
 420
 421 CYFunctionParameter *CYIfComprehension::Parameter(CYContext &context) const {
 422     return NULL;
 423 }
 424
 425 CYStatement *CYIfComprehension::Replace(CYContext &context, CYStatement *statement) const {
 426     return $ CYIf(test_, CYComprehension::Replace(context, statement));
 427 }
 428
 429 CYExpression *CYIndirect::Replace(CYContext &context) {
 430     CYPrefix::Replace(context);
 431     return $M(rhs_, $S("$cyi"));
 432 }
 433
 434 CYExpression *CYIndirectMember::Replace(CYContext &context) {
 435     Replace_(context);
 436     return $M($ CYIndirect(object_), property_);
 437 }
 438
 439 CYExpression *CYInfix::Replace(CYContext &context) {
 440     context.Replace(lhs_);
 441     context.Replace(rhs_);
 442     return this;
 443 }
 444
 445 CYStatement *CYLabel::Replace(CYContext &context) {
 446     context.Replace(statement_);
 447     return this;
 448 }
 449
 450 CYStatement *CYLet::Replace(CYContext &context) {
 451     return $ CYWith($ CYObject(declarations_->Property(context)), &code_);
 452 }
 453
 454 void CYMember::Replace_(CYContext &context) {
 455     context.Replace(object_);
 456     context.Replace(property_);
 457 }
 458
 459 namespace cy {
 460 namespace Syntax {
 461
 462 CYExpression *New::AddArgument(CYContext &context, CYExpression *value) {
 463     CYSetLast(arguments_, $ CYArgument(value));
 464     return this;
 465 }
 466
 467 CYExpression *New::Replace(CYContext &context) {
 468     context.Replace(constructor_);
 469     arguments_->Replace(context);
 470     return this;
 471 }
 472
 473 } }
 474
 475 CYNumber *CYNull::Number(CYContext &context) {
 476     return $D(0);
 477 }
 478
 479 CYString *CYNull::String(CYContext &context) {
 480     return $S("null");
 481 }
 482
 483 CYNumber *CYNumber::Number(CYContext &context) {
 484     return this;
 485 }
 486
 487 CYString *CYNumber::String(CYContext &context) {
 488     // XXX: there is a precise algorithm for this
 489     return $S(apr_psprintf($pool, "%.17g", Value()));
 490 }
 491
 492 CYExpression *CYObject::Replace(CYContext &context) {
 493     properties_->Replace(context);
 494     return this;
 495 }
 496
 497 CYFunctionParameter *CYOptionalFunctionParameter::Replace(CYContext &context, CYBlock &code) {
 498     CYFunctionParameter *parameter($ CYFunctionParameter(name_, next_));
 499     parameter = parameter->Replace(context, code);
 500     context.Replace(initializer_);
 501
 502     CYVariable *name($V(name_));
 503     code.AddPrev($ CYIf($ CYIdentical($ CYTypeOf(name), $S("undefined")), $$->*
 504         $E($ CYAssign(name, initializer_))
 505     ));
 506
 507     return parameter;
 508 }
 509
 510 CYExpression *CYPostfix::Replace(CYContext &context) {
 511     context.Replace(lhs_);
 512     return this;
 513 }
 514
 515 CYExpression *CYPrefix::Replace(CYContext &context) {
 516     context.Replace(rhs_);
 517     return this;
 518 }
 519
 520 // XXX: this is evil evil black magic. don't ask, don't tell... don't believe!
 521 #define MappingSet "0etnirsoalfucdphmgyvbxTwSNECAFjDLkMOIBPqzRH$_WXUVGYKQJZ"
 522 //#define MappingSet "0abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_"
 523
 524 namespace {
 525     struct IdentifierUsageLess :
 526         std::binary_function<CYIdentifier *, CYIdentifier *, bool>
 527     {
 528         _finline bool operator ()(CYIdentifier *lhs, CYIdentifier *rhs) const {
 529             if (lhs->usage_ != rhs->usage_)
 530                 return lhs->usage_ > rhs->usage_;
 531             return lhs < rhs;
 532         }
 533     };
 534
 535     typedef std::set<CYIdentifier *, IdentifierUsageLess> IdentifierUsages;
 536 }
 537
 538 void CYProgram::Replace(CYContext &context) {
 539     CYScope scope(CYScopeProgram, context, statements_);
 540
 541     context.nextlocal_ = $ CYNonLocal();
 542     context.ReplaceAll(statements_);
 543     context.NonLocal(statements_);
 544
 545     scope.Close();
 546
 547     size_t offset(0);
 548
 549     CYCStringSet external;
 550     for (CYIdentifierValueSet::const_iterator i(scope.identifiers_.begin()); i != scope.identifiers_.end(); ++i)
 551         external.insert((*i)->Word());
 552
 553     IdentifierUsages usages;
 554
 555     if (offset < context.rename_.size())
 556         CYForEach (i, context.rename_[offset].identifier_)
 557             usages.insert(i);
 558
 559     // XXX: totalling the probable occurrences and sorting by them would improve the result
 560     for (CYIdentifierUsageVector::const_iterator i(context.rename_.begin()); i != context.rename_.end(); ++i, ++offset) {
 561         //std::cout << *i << ":" << (*i)->offset_ << std::endl;
 562
 563         const char *name;
 564
 565         if (context.options_.verbose_)
 566             name = apr_psprintf($pool, "$%"APR_SIZE_T_FMT"", offset);
 567         else {
 568             char id[8];
 569             id[7] = '\0';
 570
 571           id:
 572             unsigned position(7), local(offset + 1);
 573
 574             do {
 575                 unsigned index(local % (sizeof(MappingSet) - 1));
 576                 local /= sizeof(MappingSet) - 1;
 577                 id[--position] = MappingSet[index];
 578             } while (local != 0);
 579
 580             if (external.find(id + position) != external.end()) {
 581                 ++offset;
 582                 goto id;
 583             }
 584
 585             name = apr_pstrmemdup($pool, id + position, 7 - position);
 586             // XXX: at some point, this could become a keyword
 587         }
 588
 589         CYForEach (identifier, i->identifier_)
 590             identifier->Set(name);
 591     }
 592 }
 593
 594 void CYProperty::Replace(CYContext &context) { $T()
 595     context.Replace(value_);
 596     next_->Replace(context);
 597 }
 598
 599 CYStatement *CYReturn::Replace(CYContext &context) {
 600     if (context.nonlocal_ != NULL) {
 601         CYProperty *value(value_ == NULL ? NULL : $ CYProperty($S("$cyv"), value_));
 602         return $ cy::Syntax::Throw($ CYObject(
 603             $ CYProperty($S("$cyk"), $V(context.nonlocal_->Target(context)), value)
 604         ));
 605     }
 606
 607     context.Replace(value_);
 608     return this;
 609 }
 610
 611 CYExpression *CYRubyBlock::Replace(CYContext &context) {
 612     // XXX: this needs to do something much more epic to handle return
 613     return call_->AddArgument(context, proc_->Replace(context));
 614 }
 615
 616 CYExpression *CYRubyProc::Replace(CYContext &context) {
 617     CYFunctionExpression *function($ CYFunctionExpression(NULL, parameters_, code_));
 618     function->nonlocal_ = context.nextlocal_;
 619     return function;
 620 }
 621
 622 CYScope::CYScope(CYScopeType type, CYContext &context, CYStatement *&statements) :
 623     type_(type),
 624     context_(context),
 625     statements_(statements),
 626     parent_(context.scope_)
 627 {
 628     context_.scope_ = this;
 629 }
 630
 631 CYScope::~CYScope() {
 632 }
 633
 634 void CYScope::Close() {
 635     context_.scope_ = parent_;
 636     Scope(context_, statements_);
 637 }
 638
 639 void CYScope::Declare(CYContext &context, CYIdentifier *identifier, CYIdentifierFlags flags) {
 640     if (type_ == CYScopeCatch && flags != CYIdentifierCatch)
 641         parent_->Declare(context, identifier, flags);
 642     else
 643         internal_.insert(CYIdentifierAddressFlagsMap::value_type(identifier, flags));
 644 }
 645
 646 CYIdentifier *CYScope::Lookup(CYContext &context, CYIdentifier *identifier) {
 647     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 648     return *insert.first;
 649 }
 650
 651 void CYScope::Merge(CYContext &context, CYIdentifier *identifier) {
 652     std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
 653     if (!insert.second) {
 654         if ((*insert.first)->offset_ < identifier->offset_)
 655             (*insert.first)->offset_ = identifier->offset_;
 656         identifier->replace_ = *insert.first;
 657         (*insert.first)->usage_ += identifier->usage_ + 1;
 658     }
 659 }
 660
 661 namespace {
 662     struct IdentifierOffset {
 663         size_t offset_;
 664         CYIdentifierFlags flags_;
 665         size_t usage_;
 666         CYIdentifier *identifier_;
 667
 668         IdentifierOffset(CYIdentifier *identifier, CYIdentifierFlags flags) :
 669             offset_(identifier->offset_),
 670             flags_(flags),
 671             usage_(identifier->usage_),
 672             identifier_(identifier)
 673         {
 674         }
 675     };
 676
 677     struct IdentifierOffsetLess :
 678         std::binary_function<const IdentifierOffset &, const IdentifierOffset &, bool>
 679     {
 680         _finline bool operator ()(const IdentifierOffset &lhs, const IdentifierOffset &rhs) const {
 681             if (lhs.offset_ != rhs.offset_)
 682                 return lhs.offset_ < rhs.offset_;
 683             if (lhs.flags_ != rhs.flags_)
 684                 return lhs.flags_ < rhs.flags_;
 685             /*if (lhs.usage_ != rhs.usage_)
 686                 return lhs.usage_ < rhs.usage_;*/
 687             return lhs.identifier_ < rhs.identifier_;
 688         }
 689     };
 690
 691     typedef std::set<IdentifierOffset, IdentifierOffsetLess> IdentifierOffsets;
 692 }
 693
 694 void CYScope::Scope(CYContext &context, CYStatement *&statements) {
 695     if (parent_ == NULL)
 696         return;
 697
 698     CYDeclarations *last(NULL), *curr(NULL);
 699
 700     IdentifierOffsets offsets;
 701
 702     for (CYIdentifierAddressFlagsMap::const_iterator i(internal_.begin()); i != internal_.end(); ++i)
 703         if (i->second != CYIdentifierMagic)
 704             offsets.insert(IdentifierOffset(i->first, i->second));
 705
 706     size_t offset(0);
 707
 708     for (IdentifierOffsets::const_iterator i(offsets.begin()); i != offsets.end(); ++i) {
 709         if (i->flags_ == CYIdentifierVariable) {
 710             CYDeclarations *next($ CYDeclarations($ CYDeclaration(i->identifier_)));
 711             if (last == NULL)
 712                 last = next;
 713             if (curr != NULL)
 714                 curr->SetNext(next);
 715             curr = next;
 716         }
 717
 718         if (offset < i->offset_)
 719             offset = i->offset_;
 720         if (context.rename_.size() <= offset)
 721             context.rename_.resize(offset + 1);
 722
 723         CYIdentifierUsage &rename(context.rename_[offset++]);
 724         i->identifier_->SetNext(rename.identifier_);
 725         rename.identifier_ = i->identifier_;
 726         rename.usage_ += i->identifier_->usage_ + 1;
 727     }
 728
 729     if (last != NULL) {
 730         CYVar *var($ CYVar(last));
 731         var->SetNext(statements);
 732         statements = var;
 733     }
 734
 735     for (CYIdentifierValueSet::const_iterator i(identifiers_.begin()); i != identifiers_.end(); ++i)
 736         if (internal_.find(*i) == internal_.end()) {
 737             //std::cout << *i << '=' << offset << std::endl;
 738             if ((*i)->offset_ < offset)
 739                 (*i)->offset_ = offset;
 740             parent_->Merge(context, *i);
 741         }
 742 }
 743
 744 CYString *CYString::Concat(CYContext &context, CYString *rhs) const {
 745     size_t size(size_ + rhs->size_);
 746     char *value($ char[size + 1]);
 747     memcpy(value, value_, size_);
 748     memcpy(value + size_, rhs->value_, rhs->size_);
 749     value[size] = '\0';
 750     return $S(value, size);
 751 }
 752
 753 CYNumber *CYString::Number(CYContext &context) {
 754     // XXX: there is a precise algorithm for this
 755     return NULL;
 756 }
 757
 758 CYString *CYString::String(CYContext &context) {
 759     return this;
 760 }
 761
 762 CYStatement *CYSwitch::Replace(CYContext &context) {
 763     context.Replace(value_);
 764     clauses_->Replace(context);
 765     return this;
 766 }
 767
 768 CYExpression *CYThis::Replace(CYContext &context) {
 769     return this;
 770 }
 771
 772 namespace cy {
 773 namespace Syntax {
 774
 775 CYStatement *Throw::Replace(CYContext &context) {
 776     context.Replace(value_);
 777     return this;
 778 }
 779
 780 } }
 781
 782 CYExpression *CYTrivial::Replace(CYContext &context) {
 783     return this;
 784 }
 785
 786 CYNumber *CYTrue::Number(CYContext &context) {
 787     return $D(1);
 788 }
 789
 790 CYString *CYTrue::String(CYContext &context) {
 791     return $S("true");
 792 }
 793
 794 namespace cy {
 795 namespace Syntax {
 796
 797 CYStatement *Try::Replace(CYContext &context) {
 798     code_.Replace(context);
 799     catch_->Replace(context);
 800     finally_->Replace(context);
 801     return this;
 802 }
 803
 804 } }
 805
 806 CYStatement *CYVar::Replace(CYContext &context) {
 807     return $E(declarations_->Replace(context));
 808 }
 809
 810 CYExpression *CYVariable::Replace(CYContext &context) {
 811     context.Replace(name_);
 812     return this;
 813 }
 814
 815 CYStatement *CYWhile::Replace(CYContext &context) {
 816     context.Replace(test_);
 817     context.Replace(code_);
 818     return this;
 819 }
 820
 821 CYStatement *CYWith::Replace(CYContext &context) {
 822     context.Replace(scope_);
 823     context.Replace(code_);
 824     return this;
 825 }
 826
 827 CYExpression *CYWord::ClassName(CYContext &context, bool object) {
 828     CYString *name($S(this));
 829     if (object)
 830         return $C1($V("objc_getClass"), name);
 831     else
 832         return name;
 833 }