X-Git-Url: https://git.saurik.com/cycript.git/blobdiff_plain/3b52fd1a20c639d7a716d3e0f3176a55f2fcba72..fb726fc55e2a79b03564be97d5057e28805d84f0:/Replace.cpp?ds=sidebyside

diff --git a/Replace.cpp b/Replace.cpp
index 7d861c9..e6b761f 100644
--- a/Replace.cpp
+++ b/Replace.cpp
@@ -1,95 +1,58 @@
+/* Cycript - Optimizing JavaScript Compiler/Runtime
+ * Copyright (C) 2009-2010  Jay Freeman (saurik)
+*/
+
+/* GNU Lesser General Public License, Version 3 {{{ */
+/*
+ * Cycript is free software: you can redistribute it and/or modify it under
+ * the terms of the GNU Lesser General Public License as published by the
+ * Free Software Foundation, either version 3 of the License, or (at your
+ * option) any later version.
+ *
+ * Cycript is distributed in the hope that it will be useful, but WITHOUT
+ * ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
+ * FITNESS FOR A PARTICULAR PURPOSE.  See the GNU Lesser General Public
+ * License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Cycript.  If not, see <http://www.gnu.org/licenses/>.
+**/
+/* }}} */
+
 #include "Parser.hpp"
+#include "Replace.hpp"
 
-#include <iostream>
 #include <iomanip>
 
-#include <objc/runtime.h>
-#include <sstream>
-
-#define $ \
-    new(context.pool_)
-
-#define $D(args...) \
-    ($ CYNumber(args))
-#define $E(args...) \
-    ($ CYExpress(args))
-#define $F(args...) \
-    ($ CYFunctionExpression(args))
-#define $I(args...) \
-    ($ CYIdentifier(args))
-#define $M(args...) \
-    ($ CYDirectMember(args))
-#define $P(args...) \
-    ($ CYFunctionParameter(args))
-#define $S(args...) \
-    ($ CYString(args))
-#define $V(name) \
-    ($ CYVariable($I(name)))
-
-#define $T(value) \
-    if (this == NULL) \
-        return value;
-#define $$ \
-    CYStatements()
-
-#define $P1(arg0, args...) \
-    $P($I(arg0), ##args)
-#define $P2(arg0, arg1, args...) \
-    $P($I(arg0), $P1(arg1, ##args))
-#define $P3(arg0, arg1, arg2, args...) \
-    $P($I(arg0), $P2(arg1, arg2, ##args))
-#define $P4(arg0, arg1, arg2, arg3, args...) \
-    $P($I(arg0), $P3(arg1, arg2, arg3, ##args))
-#define $P5(arg0, arg1, arg2, arg3, arg4, args...) \
-    $P($I(arg0), $P4(arg1, arg2, arg3, arg4, ##args))
-#define $P6(arg0, arg1, arg2, arg3, arg4, arg5, args...) \
-    $P($I(arg0), $P5(arg1, arg2, arg3, arg4, arg5, ##args))
-
-#define $C(args...) \
-    ($ CYCall(args))
-#define $C_(args...) \
-    ($ CYArgument(args))
-#define $N(args...) \
-    ($ CYNew(args))
-
-#define $C1_(arg0, args...) \
-    $C_(arg0, ##args)
-#define $C2_(arg0, arg1, args...) \
-    $C_(arg0, $C1_(arg1, ##args))
-#define $C3_(arg0, arg1, arg2, args...) \
-    $C_(arg0, $C2_(arg1, arg2, ##args))
-#define $C4_(arg0, arg1, arg2, arg3, args...) \
-    $C_(arg0, $C3_(arg1, arg2, arg3, ##args))
-#define $C5_(arg0, arg1, arg2, arg3, arg4, args...) \
-    $C_(arg0, $C4_(arg1, arg2, arg3, arg4, ##args))
-#define $C6_(arg0, arg1, arg2, arg3, arg4, arg5, args...) \
-    $C_(arg0, $C5_(arg1, arg2, arg3, arg4, arg5, ##args))
-
-#define $C0(func, args...) \
-    $C(func, ##args)
-#define $C1(func, args...) \
-    $C(func, $C1_(args))
-#define $C2(func, args...) \
-    $C(func, $C2_(args))
-#define $C3(func, args...) \
-    $C(func, $C3_(args))
-#define $C4(func, args...) \
-    $C(func, $C4_(args))
-#define $C5(func, args...) \
-    $C(func, $C5_(args))
-
-#define $N0(func, args...) \
-    $N(func, ##args)
-#define $N1(func, args...) \
-    $N(func, $C1_(args))
-#define $N2(func, args...) \
-    $N(func, $C2_(args))
-#define $N3(func, args...) \
-    $N(func, $C3_(args))
-#define $N4(func, args...) \
-    $N(func, $C4_(args))
-#define $N5(func, args...) \
-    $N(func, $C5_(args))
+CYExpression *CYAdd::Replace(CYContext &context) {
+    CYInfix::Replace(context);
+
+    CYExpression *lhp(lhs_->Primitive(context));
+    CYExpression *rhp(rhs_->Primitive(context));
+
+    CYString *lhs(dynamic_cast<CYString *>(lhp));
+    CYString *rhs(dynamic_cast<CYString *>(rhp));
+
+    if (lhs != NULL || rhs != NULL) {
+        if (lhs == NULL) {
+            lhs = lhp->String(context);
+            if (lhs == NULL)
+                return this;
+        } else if (rhs == NULL) {
+            rhs = rhp->String(context);
+            if (rhs == NULL)
+                return this;
+        }
+
+        return lhs->Concat(context, rhs);
+    }
+
+    if (CYNumber *lhn = lhp->Number(context))
+        if (CYNumber *rhn = rhp->Number(context))
+            return $D(lhn->Value() + rhn->Value());
+
+    return this;
+}
 
 CYExpression *CYAddressOf::Replace(CYContext &context) {
     CYPrefix::Replace(context);
@@ -103,7 +66,7 @@ void CYArgument::Replace(CYContext &context) { $T()
 
 CYExpression *CYArray::Replace(CYContext &context) {
     elements_->Replace(context);
-    return NULL;
+    return this;
 }
 
 CYExpression *CYArrayComprehension::Replace(CYContext &context) {
@@ -119,71 +82,62 @@ CYExpression *CYArrayComprehension::Replace(CYContext &context) {
 CYExpression *CYAssignment::Replace(CYContext &context) {
     context.Replace(lhs_);
     context.Replace(rhs_);
-    return NULL;
+    return this;
 }
 
 CYStatement *CYBlock::Replace(CYContext &context) {
-    statements_ = statements_->ReplaceAll(context);
-    return NULL;
+    context.ReplaceAll(statements_);
+    if (statements_ == NULL)
+        return $ CYEmpty();
+    return this;
 }
 
 CYStatement *CYBreak::Replace(CYContext &context) {
-    return NULL;
+    return this;
+}
+
+CYExpression *CYCall::AddArgument(CYContext &context, CYExpression *value) {
+    CYArgument **argument(&arguments_);
+    while (*argument != NULL)
+        argument = &(*argument)->next_;
+    *argument = $ CYArgument(value);
+    return this;
 }
 
 CYExpression *CYCall::Replace(CYContext &context) {
     context.Replace(function_);
     arguments_->Replace(context);
-    return NULL;
-}
-
-void CYCatch::Replace(CYContext &context) { $T()
-    code_.Replace(context);
-}
-
-CYStatement *CYCategory::Replace(CYContext &context) {
-    CYVariable *cyc($V("$cyc")), *cys($V("$cys"));
-
-    return $E($C1($F(NULL, $P5("$cys", "$cyp", "$cyc", "$cyn", "$cyt"), $$->*
-        $E($ CYAssign($V("$cyp"), $C1($V("object_getClass"), cys)))->*
-        $E($ CYAssign(cyc, cys))->*
-        messages_->Replace(context, true)
-    ), name_->ClassName(context, true)));
+    return this;
 }
 
-CYExpression *CYClass::Replace_(CYContext &context) {
-    CYVariable *cyc($V("$cyc")), *cys($V("$cys"));
+namespace cy {
+namespace Syntax {
 
-    CYExpression *name(name_ != NULL ? name_->ClassName(context, false) : $C1($V("$cyq"), $S("CY$")));
+void Catch::Replace(CYContext &context) { $T()
+    CYScope scope(CYScopeCatch, context, code_.statements_);
 
-    return $C1($F(NULL, $P6("$cys", "$cyp", "$cyc", "$cyn", "$cyt", "$cym"), $$->*
-        $E($ CYAssign($V("$cyp"), $C1($V("object_getClass"), cys)))->*
-        $E($ CYAssign(cyc, $C3($V("objc_allocateClassPair"), cys, name, $D(0))))->*
-        $E($ CYAssign($V("$cym"), $C1($V("object_getClass"), cyc)))->*
-        fields_->Replace(context)->*
-        messages_->Replace(context, false)->*
-        $E($C1($V("objc_registerClassPair"), cyc))->*
-        $ CYReturn(cyc)
-    ), super_ == NULL ? $ CYNull() : super_);
-}
+    context.Replace(name_);
+    context.scope_->Declare(context, name_, CYIdentifierCatch);
 
-CYExpression *CYClassExpression::Replace(CYContext &context) {
-    return Replace_(context);
+    code_.Replace(context);
+    scope.Close();
 }
 
-CYStatement *CYClassStatement::Replace(CYContext &context) {
-    return $E(Replace_(context));
-}
+} }
 
 void CYClause::Replace(CYContext &context) { $T()
     context.Replace(case_);
-    statements_ = statements_->ReplaceAll(context);
+    context.ReplaceAll(statements_);
     next_->Replace(context);
 }
 
+CYStatement *CYComment::Replace(CYContext &context) {
+    return this;
+}
+
 CYExpression *CYCompound::Replace(CYContext &context) {
-    expressions_ = expressions_->ReplaceAll(context);
-    return NULL;
+    context.ReplaceAll(expressions_);
+    return this;
 }
 
 CYFunctionParameter *CYComprehension::Parameters(CYContext &context) const { $T(NULL)
@@ -203,35 +157,77 @@ CYExpression *CYCondition::Replace(CYContext &context) {
     context.Replace(test_);
     context.Replace(true_);
     context.Replace(false_);
-    return NULL;
+    return this;
+}
+
+void CYContext::NonLocal(CYStatement *&statements) {
+    CYContext &context(*this);
+
+    if (nextlocal_ != NULL && nextlocal_->identifier_ != NULL) {
+        CYIdentifier *cye($I("$cye")->Replace(context));
+        CYIdentifier *unique(nextlocal_->identifier_->Replace(context));
+
+        CYStatement *declare(
+            $ CYVar($L1($L(unique, $ CYObject()))));
+
+        cy::Syntax::Catch *rescue(
+            $ cy::Syntax::Catch(cye, $$->*
+                $ CYIf($ CYIdentical($M($V(cye), $S("$cyk")), $V(unique)), $$->*
+                    $ CYReturn($M($V(cye), $S("$cyv"))))->*
+                $ cy::Syntax::Throw($V(cye))));
+
+        context.Replace(declare);
+        rescue->Replace(context);
+
+        statements = $$->*
+            declare->*
+            $ cy::Syntax::Try(statements, rescue, NULL);
+    }
+}
+
+CYIdentifier *CYContext::Unique() {
+    return $ CYIdentifier(apr_psprintf($pool, "$cy%u", unique_++));
 }
 
 CYStatement *CYContinue::Replace(CYContext &context) {
-    return NULL;
+    return this;
+}
+
+CYAssignment *CYDeclaration::Assignment(CYContext &context) {
+    CYExpression *variable(Replace(context));
+    return initialiser_ == NULL ? NULL : $ CYAssign(variable, initialiser_);
 }
 
 CYExpression *CYDeclaration::ForEachIn(CYContext &context) {
-    return $ CYVariable(identifier_);
+    return $V(identifier_);
 }
 
-void CYDeclaration::Replace(CYContext &context) {
-    context.Replace(initialiser_);
+CYExpression *CYDeclaration::Replace(CYContext &context) {
+    context.Replace(identifier_);
+    context.scope_->Declare(context, identifier_, CYIdentifierVariable);
+    return $V(identifier_);
 }
 
-void CYDeclarations::Replace(CYContext &context) { $T()
-    declaration_->Replace(context);
-    next_->Replace(context);
+CYProperty *CYDeclarations::Property(CYContext &context) { $T(NULL)
+    return $ CYProperty(declaration_->identifier_, declaration_->initialiser_ ?: $U, next_->Property(context));
+}
+
+CYCompound *CYDeclarations::Replace(CYContext &context) {
+    CYCompound *compound(next_ == NULL ? $ CYCompound() : next_->Replace(context));
+    if (CYAssignment *assignment = declaration_->Assignment(context))
+        compound->AddPrev(assignment);
+    return compound;
 }
 
 CYExpression *CYDirectMember::Replace(CYContext &context) {
     Replace_(context);
-    return NULL;
+    return this;
 }
 
 CYStatement *CYDoWhile::Replace(CYContext &context) {
     context.Replace(test_);
     context.Replace(code_);
-    return NULL;
+    return this;
 }
 
 void CYElement::Replace(CYContext &context) { $T()
@@ -239,13 +235,36 @@ void CYElement::Replace(CYContext &context) { $T()
     next_->Replace(context);
 }
 
+CYStatement *CYEmpty::Collapse(CYContext &context) {
+    return next_;
+}
+
 CYStatement *CYEmpty::Replace(CYContext &context) {
-    return NULL;
+    return this;
+}
+
+CYStatement *CYExpress::Collapse(CYContext &context) {
+    if (CYExpress *express = dynamic_cast<CYExpress *>(next_)) {
+        CYCompound *next(dynamic_cast<CYCompound *>(express->expression_));
+        if (next == NULL)
+            next = $ CYCompound(express->expression_);
+        next->AddPrev(expression_);
+        expression_ = next;
+        SetNext(express->next_);
+    }
+
+    return this;
 }
 
 CYStatement *CYExpress::Replace(CYContext &context) {
     context.Replace(expression_);
-    return NULL;
+    if (expression_ == NULL)
+        return $ CYEmpty();
+    return this;
+}
+
+CYExpression *CYExpression::AddArgument(CYContext &context, CYExpression *value) {
+    return $C1(this, value);
 }
 
 CYExpression *CYExpression::ClassName(CYContext &context, bool object) {
@@ -256,20 +275,12 @@ CYExpression *CYExpression::ForEachIn(CYContext &context) {
     return this;
 }
 
-CYExpression *CYExpression::ReplaceAll(CYContext &context) { $T(NULL)
-    CYExpression *replace(this);
-    context.Replace(replace);
-
-    if (CYExpression *next = next_->ReplaceAll(context))
-        replace->SetNext(next);
-    else
-        replace->SetNext(next_);
-
-    return replace;
+CYNumber *CYFalse::Number(CYContext &context) {
+    return $D(0);
 }
 
-CYStatement *CYField::Replace(CYContext &context) const {
-    return NULL;
+CYString *CYFalse::String(CYContext &context) {
+    return $S("false");
 }
 
 void CYFinally::Replace(CYContext &context) { $T()
@@ -277,18 +288,19 @@ void CYFinally::Replace(CYContext &context) { $T()
 }
 
 CYStatement *CYFor::Replace(CYContext &context) {
-    // XXX: initialiser_
+    context.Replace(initialiser_);
     context.Replace(test_);
     context.Replace(increment_);
     context.Replace(code_);
-    return NULL;
+    return this;
 }
 
 CYStatement *CYForIn::Replace(CYContext &context) {
-    // XXX: initialiser_
+    // XXX: this actually might need a prefix statement
+    context.Replace(initialiser_);
     context.Replace(set_);
     context.Replace(code_);
-    return NULL;
+    return this;
 }
 
 CYFunctionParameter *CYForInComprehension::Parameter(CYContext &context) const {
@@ -296,19 +308,18 @@ CYFunctionParameter *CYForInComprehension::Parameter(CYContext &context) const {
 }
 
 CYStatement *CYForInComprehension::Replace(CYContext &context, CYStatement *statement) const {
-    return $ CYForIn($ CYVariable(name_), set_, CYComprehension::Replace(context, statement));
+    return $ CYForIn($V(name_), set_, CYComprehension::Replace(context, statement));
 }
 
 CYStatement *CYForEachIn::Replace(CYContext &context) {
-    CYVariable *cys($V("$cys")), *cyt($V("$cyt"));
+    CYIdentifier *cys($I("$cys")), *cyt($I("$cyt"));
 
-    return $ CYWith($ CYObject($ CYProperty($S("$cys"), $D(0), $ CYProperty($S("$cyt"), $D(0)))), $ CYBlock($$->*
-        $E($ CYAssign(cys, set_))->*
-        $ CYForIn(cyt, cys, $ CYBlock($$->*
-            $E($ CYAssign(initialiser_->ForEachIn(context), $M(cys, cyt)))->*
+    return $ CYLet($L2($L(cys, set_), $L(cyt)), $$->*
+        $ CYForIn($V(cyt), $V(cys), $ CYBlock($$->*
+            $E($ CYAssign(initialiser_->ForEachIn(context), $M($V(cys), $V(cyt))))->*
             code_
         ))
-    ));
+    );
 }
 
 CYFunctionParameter *CYForEachInComprehension::Parameter(CYContext &context) const {
@@ -316,36 +327,88 @@ CYFunctionParameter *CYForEachInComprehension::Parameter(CYContext &context) con
 }
 
 CYStatement *CYForEachInComprehension::Replace(CYContext &context, CYStatement *statement) const {
-    CYVariable *cys($V("$cys")), *name($ CYVariable(name_));
+    CYIdentifier *cys($I("cys"));
 
     return $E($C0($F(NULL, $P1("$cys"), $$->*
-        $E($ CYAssign(cys, set_))->*
-        $ CYForIn(name, cys, $ CYBlock($$->*
-            $E($ CYAssign(name, $M(cys, name)))->*
+        $E($ CYAssign($V(cys), set_))->*
+        $ CYForIn($V(name_), $V(cys), $ CYBlock($$->*
+            $E($ CYAssign($V(name_), $M($V(cys), $V(name_))))->*
             CYComprehension::Replace(context, statement)
         ))
     )));
 }
 
-void CYFunction::Replace_(CYContext &context) {
+void CYFunction::Inject(CYContext &context) {
+    context.Replace(name_);
+    context.scope_->Declare(context, name_, CYIdentifierOther);
+}
+
+void CYFunction::Replace_(CYContext &context, bool outer) {
+    if (outer)
+        Inject(context);
+
+    CYScope scope(CYScopeFunction, context, code_.statements_);
+
+    CYNonLocal *nonlocal(context.nonlocal_);
+    CYNonLocal *nextlocal(context.nextlocal_);
+
+    bool localize;
+    if (nonlocal_ != NULL) {
+        localize = false;
+        context.nonlocal_ = nonlocal_;
+    } else {
+        localize = true;
+        nonlocal_ = $ CYNonLocal();
+        context.nextlocal_ = nonlocal_;
+    }
+
+    if (!outer && name_ != NULL)
+        Inject(context);
+
+    if (parameters_ != NULL)
+        parameters_ = parameters_->Replace(context, code_);
+
     code_.Replace(context);
+
+    if (localize)
+        context.NonLocal(code_.statements_);
+
+    context.nextlocal_ = nextlocal;
+    context.nonlocal_ = nonlocal;
+
+    scope.Close();
 }
 
 CYExpression *CYFunctionExpression::Replace(CYContext &context) {
-    Replace_(context);
-    return NULL;
+    Replace_(context, false);
+    return this;
+}
+
+CYFunctionParameter *CYFunctionParameter::Replace(CYContext &context, CYBlock &code) {
+    context.Replace(name_);
+    context.scope_->Declare(context, name_, CYIdentifierArgument);
+    if (next_ != NULL)
+        next_ = next_->Replace(context, code);
+    return this;
 }
 
 CYStatement *CYFunctionStatement::Replace(CYContext &context) {
-    Replace_(context);
-    return NULL;
+    Replace_(context, true);
+    return this;
+}
+
+CYIdentifier *CYIdentifier::Replace(CYContext &context) {
+    if (replace_ != NULL && replace_ != this)
+        return replace_->Replace(context);
+    replace_ = context.scope_->Lookup(context, this);
+    return replace_;
 }
 
 CYStatement *CYIf::Replace(CYContext &context) {
     context.Replace(test_);
     context.Replace(true_);
     context.Replace(false_);
-    return NULL;
+    return this;
 }
 
 CYFunctionParameter *CYIfComprehension::Parameter(CYContext &context) const {
@@ -369,12 +432,16 @@ CYExpression *CYIndirectMember::Replace(CYContext &context) {
 CYExpression *CYInfix::Replace(CYContext &context) {
     context.Replace(lhs_);
     context.Replace(rhs_);
-    return NULL;
+    return this;
 }
 
 CYStatement *CYLabel::Replace(CYContext &context) {
     context.Replace(statement_);
-    return NULL;
+    return this;
+}
+
+CYStatement *CYLet::Replace(CYContext &context) {
+    return $ CYWith($ CYObject(declarations_->Property(context)), &code_);
 }
 
 void CYMember::Replace_(CYContext &context) {
@@ -382,62 +449,139 @@ void CYMember::Replace_(CYContext &context) {
     context.Replace(property_);
 }
 
-CYStatement *CYMessage::Replace(CYContext &context, bool replace) const { $T(NULL)
-    CYVariable *cyn($V("$cyn"));
-    CYVariable *cyt($V("$cyt"));
-
-    return $ CYBlock($$->*
-        next_->Replace(context, replace)->*
-        $E($ CYAssign(cyn, parameters_->Selector(context)))->*
-        $E($ CYAssign(cyt, $C1($M(cyn, $S("type")), $V(instance_ ? "$cys" : "$cyp"))))->*
-        $E($C4($V(replace ? "class_replaceMethod" : "class_addMethod"),
-            $V(instance_ ? "$cyc" : "$cym"),
-            cyn,
-            $N2($V("Functor"), $F(NULL, $P2("self", "_cmd", parameters_->Parameters(context)), $$->*
-                $ CYReturn($C1($M($F(NULL, NULL, statements_), $S("call")), $V("self")))
-            ), cyt),
-            cyt
-        ))
-    );
+namespace cy {
+namespace Syntax {
+
+CYExpression *New::AddArgument(CYContext &context, CYExpression *value) {
+    CYSetLast(arguments_, $ CYArgument(value));
+    return this;
 }
 
-CYFunctionParameter *CYMessageParameter::Parameters(CYContext &context) const { $T(NULL)
-    CYFunctionParameter *next(next_->Parameters(context));
-    return name_ == NULL ? next : $ CYFunctionParameter(name_, next);
+CYExpression *New::Replace(CYContext &context) {
+    context.Replace(constructor_);
+    arguments_->Replace(context);
+    return this;
 }
 
-CYSelector *CYMessageParameter::Selector(CYContext &context) const {
-    return $ CYSelector(SelectorPart(context));
+} }
+
+CYNumber *CYNull::Number(CYContext &context) {
+    return $D(0);
 }
 
-CYSelectorPart *CYMessageParameter::SelectorPart(CYContext &context) const { $T(NULL)
-    CYSelectorPart *next(next_->SelectorPart(context));
-    return tag_ == NULL ? next : $ CYSelectorPart(tag_, name_ != NULL, next);
+CYString *CYNull::String(CYContext &context) {
+    return $S("null");
 }
 
-CYExpression *CYNew::Replace(CYContext &context) {
-    context.Replace(constructor_);
-    arguments_->Replace(context);
-    return NULL;
+CYNumber *CYNumber::Number(CYContext &context) {
+    return this;
+}
+
+CYString *CYNumber::String(CYContext &context) {
+    // XXX: there is a precise algorithm for this
+    return $S(apr_psprintf($pool, "%.17g", Value()));
 }
 
 CYExpression *CYObject::Replace(CYContext &context) {
     properties_->Replace(context);
-    return NULL;
+    return this;
+}
+
+CYFunctionParameter *CYOptionalFunctionParameter::Replace(CYContext &context, CYBlock &code) {
+    CYFunctionParameter *parameter($ CYFunctionParameter(name_, next_));
+    parameter = parameter->Replace(context, code);
+    context.Replace(initializer_);
+
+    CYVariable *name($V(name_));
+    code.AddPrev($ CYIf($ CYIdentical($ CYTypeOf(name), $S("undefined")), $$->*
+        $E($ CYAssign(name, initializer_))
+    ));
+
+    return parameter;
 }
 
 CYExpression *CYPostfix::Replace(CYContext &context) {
     context.Replace(lhs_);
-    return NULL;
+    return this;
 }
 
 CYExpression *CYPrefix::Replace(CYContext &context) {
     context.Replace(rhs_);
-    return NULL;
+    return this;
+}
+
+// XXX: this is evil evil black magic. don't ask, don't tell... don't believe!
+#define MappingSet "0etnirsoalfucdphmgyvbxTwSNECAFjDLkMOIBPqzRH$_WXUVGYKQJZ"
+//#define MappingSet "0abcdefghijklmnopqrstuvwxyzABCDEFGHIJKLMNOPQRSTUVWXYZ$_"
+
+namespace {
+    struct IdentifierUsageLess :
+        std::binary_function<CYIdentifier *, CYIdentifier *, bool>
+    {
+        _finline bool operator ()(CYIdentifier *lhs, CYIdentifier *rhs) const {
+            if (lhs->usage_ != rhs->usage_)
+                return lhs->usage_ > rhs->usage_;
+            return lhs < rhs;
+        }
+    };
+
+    typedef std::set<CYIdentifier *, IdentifierUsageLess> IdentifierUsages;
 }
 
 void CYProgram::Replace(CYContext &context) {
-    statements_ = statements_->ReplaceAll(context);
+    CYScope scope(CYScopeProgram, context, statements_);
+
+    context.nextlocal_ = $ CYNonLocal();
+    context.ReplaceAll(statements_);
+    context.NonLocal(statements_);
+
+    scope.Close();
+
+    size_t offset(0);
+
+    CYCStringSet external;
+    for (CYIdentifierValueSet::const_iterator i(scope.identifiers_.begin()); i != scope.identifiers_.end(); ++i)
+        external.insert((*i)->Word());
+
+    IdentifierUsages usages;
+
+    if (offset < context.rename_.size())
+        CYForEach (i, context.rename_[offset].identifier_)
+            usages.insert(i);
+
+    // XXX: totalling the probable occurrences and sorting by them would improve the result
+    for (CYIdentifierUsageVector::const_iterator i(context.rename_.begin()); i != context.rename_.end(); ++i, ++offset) {
+        //std::cout << *i << ":" << (*i)->offset_ << std::endl;
+
+        const char *name;
+
+        if (context.options_.verbose_)
+            name = apr_psprintf($pool, "$%"APR_SIZE_T_FMT"", offset);
+        else {
+            char id[8];
+            id[7] = '\0';
+
+          id:
+            unsigned position(7), local(offset + 1);
+
+            do {
+                unsigned index(local % (sizeof(MappingSet) - 1));
+                local /= sizeof(MappingSet) - 1;
+                id[--position] = MappingSet[index];
+            } while (local != 0);
+
+            if (external.find(id + position) != external.end()) {
+                ++offset;
+                goto id;
+            }
+
+            name = apr_pstrmemdup($pool, id + position, 7 - position);
+            // XXX: at some point, this could become a keyword
+        }
+
+        CYForEach (identifier, i->identifier_)
+            identifier->Set(name);
+    }
 }
 
 void CYProperty::Replace(CYContext &context) { $T()
@@ -446,106 +590,235 @@ void CYProperty::Replace(CYContext &context) { $T()
 }
 
 CYStatement *CYReturn::Replace(CYContext &context) {
+    if (context.nonlocal_ != NULL) {
+        CYProperty *value(value_ == NULL ? NULL : $ CYProperty($S("$cyv"), value_));
+        return $ cy::Syntax::Throw($ CYObject(
+            $ CYProperty($S("$cyk"), $V(context.nonlocal_->Target(context)), value)
+        ));
+    }
+
     context.Replace(value_);
-    return NULL;
+    return this;
 }
 
-CYExpression *CYSelector::Replace(CYContext &context) {
-    return $N1($V("Selector"), name_->Replace(context));
+CYExpression *CYRubyBlock::Replace(CYContext &context) {
+    // XXX: this needs to do something much more epic to handle return
+    return call_->AddArgument(context, proc_->Replace(context));
 }
 
-CYExpression *CYSend::Replace(CYContext &context) {
-    std::ostringstream name;
-    CYArgument **argument(&arguments_);
+CYExpression *CYRubyProc::Replace(CYContext &context) {
+    CYFunctionExpression *function($ CYFunctionExpression(NULL, parameters_, code_));
+    function->nonlocal_ = context.nextlocal_;
+    return function;
+}
 
-    while (*argument != NULL) {
-        if ((*argument)->name_ != NULL) {
-            name << *(*argument)->name_;
-            (*argument)->name_ = NULL;
-            if ((*argument)->value_ != NULL)
-                name << ':';
-        }
+CYScope::CYScope(CYScopeType type, CYContext &context, CYStatement *&statements) :
+    type_(type),
+    context_(context),
+    statements_(statements),
+    parent_(context.scope_)
+{
+    context_.scope_ = this;
+}
 
-        if ((*argument)->value_ == NULL)
-            *argument = (*argument)->next_;
-        else
-            argument = &(*argument)->next_;
+CYScope::~CYScope() {
+}
+
+void CYScope::Close() {
+    context_.scope_ = parent_;
+    Scope(context_, statements_);
+}
+
+void CYScope::Declare(CYContext &context, CYIdentifier *identifier, CYIdentifierFlags flags) {
+    if (type_ == CYScopeCatch && flags != CYIdentifierCatch)
+        parent_->Declare(context, identifier, flags);
+    else
+        internal_.insert(CYIdentifierAddressFlagsMap::value_type(identifier, flags));
+}
+
+CYIdentifier *CYScope::Lookup(CYContext &context, CYIdentifier *identifier) {
+    std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
+    return *insert.first;
+}
+
+void CYScope::Merge(CYContext &context, CYIdentifier *identifier) {
+    std::pair<CYIdentifierValueSet::iterator, bool> insert(identifiers_.insert(identifier));
+    if (!insert.second) {
+        if ((*insert.first)->offset_ < identifier->offset_)
+            (*insert.first)->offset_ = identifier->offset_;
+        identifier->replace_ = *insert.first;
+        (*insert.first)->usage_ += identifier->usage_ + 1;
     }
+}
 
-    SEL sel(sel_registerName(name.str().c_str()));
-    double address(static_cast<double>(reinterpret_cast<uintptr_t>(sel)));
+namespace {
+    struct IdentifierOffset {
+        size_t offset_;
+        CYIdentifierFlags flags_;
+        size_t usage_;
+        CYIdentifier *identifier_;
 
-    return $C2($V("objc_msgSend"), self_, $D(address), arguments_);
+        IdentifierOffset(CYIdentifier *identifier, CYIdentifierFlags flags) :
+            offset_(identifier->offset_),
+            flags_(flags),
+            usage_(identifier->usage_),
+            identifier_(identifier)
+        {
+        }
+    };
+
+    struct IdentifierOffsetLess :
+        std::binary_function<const IdentifierOffset &, const IdentifierOffset &, bool>
+    {
+        _finline bool operator ()(const IdentifierOffset &lhs, const IdentifierOffset &rhs) const {
+            if (lhs.offset_ != rhs.offset_)
+                return lhs.offset_ < rhs.offset_;
+            if (lhs.flags_ != rhs.flags_)
+                return lhs.flags_ < rhs.flags_;
+            /*if (lhs.usage_ != rhs.usage_)
+                return lhs.usage_ < rhs.usage_;*/
+            return lhs.identifier_ < rhs.identifier_;
+        }
+    };
+
+    typedef std::set<IdentifierOffset, IdentifierOffsetLess> IdentifierOffsets;
 }
 
-CYString *CYSelectorPart::Replace(CYContext &context) {
-    std::ostringstream str;
-    for (const CYSelectorPart *part(this); part != NULL; part = part->next_) {
-        if (part->name_ != NULL)
-            str << part->name_->Value();
-        if (part->value_)
-            str << ':';
+void CYScope::Scope(CYContext &context, CYStatement *&statements) {
+    if (parent_ == NULL)
+        return;
+
+    CYDeclarations *last(NULL), *curr(NULL);
+
+    IdentifierOffsets offsets;
+
+    for (CYIdentifierAddressFlagsMap::const_iterator i(internal_.begin()); i != internal_.end(); ++i)
+        if (i->second != CYIdentifierMagic)
+            offsets.insert(IdentifierOffset(i->first, i->second));
+
+    size_t offset(0);
+
+    for (IdentifierOffsets::const_iterator i(offsets.begin()); i != offsets.end(); ++i) {
+        if (i->flags_ == CYIdentifierVariable) {
+            CYDeclarations *next($ CYDeclarations($ CYDeclaration(i->identifier_)));
+            if (last == NULL)
+                last = next;
+            if (curr != NULL)
+                curr->SetNext(next);
+            curr = next;
+        }
+
+        if (offset < i->offset_)
+            offset = i->offset_;
+        if (context.rename_.size() <= offset)
+            context.rename_.resize(offset + 1);
+
+        CYIdentifierUsage &rename(context.rename_[offset++]);
+        i->identifier_->SetNext(rename.identifier_);
+        rename.identifier_ = i->identifier_;
+        rename.usage_ += i->identifier_->usage_ + 1;
+    }
+
+    if (last != NULL) {
+        CYVar *var($ CYVar(last));
+        var->SetNext(statements);
+        statements = var;
     }
-    return $S(apr_pstrdup(context.pool_, str.str().c_str()));
+
+    for (CYIdentifierValueSet::const_iterator i(identifiers_.begin()); i != identifiers_.end(); ++i)
+        if (internal_.find(*i) == internal_.end()) {
+            //std::cout << *i << '=' << offset << std::endl;
+            if ((*i)->offset_ < offset)
+                (*i)->offset_ = offset;
+            parent_->Merge(context, *i);
+        }
 }
 
-CYStatement *CYStatement::ReplaceAll(CYContext &context) { $T(NULL)
-    CYStatement *replace(this);
-    context.Replace(replace);
+CYStatement *CYStatement::Collapse(CYContext &context) {
+    return this;
+}
 
-    if (CYStatement *next = next_->ReplaceAll(context))
-        replace->SetNext(next);
-    else
-        replace->SetNext(next_);
+CYString *CYString::Concat(CYContext &context, CYString *rhs) const {
+    size_t size(size_ + rhs->size_);
+    char *value($ char[size + 1]);
+    memcpy(value, value_, size_);
+    memcpy(value + size_, rhs->value_, rhs->size_);
+    value[size] = '\0';
+    return $S(value, size);
+}
 
-    return replace;
+CYNumber *CYString::Number(CYContext &context) {
+    // XXX: there is a precise algorithm for this
+    return NULL;
+}
+
+CYString *CYString::String(CYContext &context) {
+    return this;
 }
 
 CYStatement *CYSwitch::Replace(CYContext &context) {
     context.Replace(value_);
     clauses_->Replace(context);
-    return NULL;
+    return this;
 }
 
 CYExpression *CYThis::Replace(CYContext &context) {
-    return NULL;
+    return this;
 }
 
-CYStatement *CYThrow::Replace(CYContext &context) {
+namespace cy {
+namespace Syntax {
+
+CYStatement *Throw::Replace(CYContext &context) {
     context.Replace(value_);
-    return NULL;
+    return this;
 }
 
+} }
+
 CYExpression *CYTrivial::Replace(CYContext &context) {
-    return NULL;
+    return this;
 }
 
-CYStatement *CYTry::Replace(CYContext &context) {
+CYNumber *CYTrue::Number(CYContext &context) {
+    return $D(1);
+}
+
+CYString *CYTrue::String(CYContext &context) {
+    return $S("true");
+}
+
+namespace cy {
+namespace Syntax {
+
+CYStatement *Try::Replace(CYContext &context) {
     code_.Replace(context);
     catch_->Replace(context);
     finally_->Replace(context);
-    return NULL;
+    return this;
 }
 
+} }
+
 CYStatement *CYVar::Replace(CYContext &context) {
-    declarations_->Replace(context);
-    return NULL;
+    return $E(declarations_->Replace(context));
 }
 
 CYExpression *CYVariable::Replace(CYContext &context) {
-    return NULL;
+    context.Replace(name_);
+    return this;
 }
 
 CYStatement *CYWhile::Replace(CYContext &context) {
     context.Replace(test_);
     context.Replace(code_);
-    return NULL;
+    return this;
 }
 
 CYStatement *CYWith::Replace(CYContext &context) {
     context.Replace(scope_);
     context.Replace(code_);
-    return NULL;
+    return this;
 }
 
 CYExpression *CYWord::ClassName(CYContext &context, bool object) {