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/* ____ ____ ____ ____ ______ *\
** / __// __ \/ __// __ \/ ____/ SOcos COmpiles Scala **
** __\_ \/ /_/ / /__/ /_/ /\_ \ (c) 2002, LAMP/EPFL **
** /_____/\____/\___/\____/____/ **
\* */
// $Id$
package scalac.symtab;
import java.util.Map;
import java.util.HashMap;
import scalac.util.FreshNameCreator;
import scalac.util.Debug;
/**
* This class implements a symbol cloner. It automatically determines
* the new owner of cloned symbols, clones their type and keeps track
* of all cloned symbols. Clone a type means clone all symbol declared
* in that type (for example parameters of a MethodType).
*/
public class SymbolCloner {
//########################################################################
// Public Fields
/** The fresh name generator used to rename cloned symbols */
public final FreshNameCreator renamer;
/** A table that maps owners of symbols to owners of cloned symbols */
public final Map/*<Symbol,Symbol*/ owners;
/** A map<cloned,clone> into which cloned symbols are stored */
public final Map/*<Symbol,Symbol*/ clones;
//########################################################################
// Public Constructor
/** Initializes a new instance. */
public SymbolCloner(FreshNameCreator renamer) {
this(renamer, new HashMap());
}
/** Initializes a new instance. */
public SymbolCloner(FreshNameCreator renamer, Map owners) {
this(renamer, owners, new HashMap());
}
/** Initializes a new instance. */
public SymbolCloner(FreshNameCreator renamer, Map owners, Map clones) {
this.renamer = renamer;
this.owners = owners;
this.clones = clones;
}
//########################################################################
// Public Methods - Cloning symbols
/**
* Returns the owner for the clone of the given symbol. The
* default implementation returns the clone of the symbol's owner
* if that owner has been cloned or else returns the owner
* associated to the symbol's owner in the owner table.
*/
public Symbol getOwnerFor(Symbol symbol) {
Symbol oldowner = symbol.owner();
Object newowner = clones.get(oldowner);
if (newowner == null) newowner = owners.get(oldowner);
assert newowner != null : Debug.show(symbol);
return (Symbol)newowner;
}
/** Clones the given symbol. */
public Symbol cloneSymbol(Symbol symbol) {
return cloneSymbol(symbol, false);
}
/** Clones the given symbol and renames it if rename is true. */
public Symbol cloneSymbol(Symbol symbol, boolean rename) {
assert !symbol.isPrimaryConstructor() : Debug.show(symbol);
assert !symbol.isModuleClass() : Debug.show(symbol);
assert !symbol.isClass() : Debug.show(symbol);
assert !symbol.isModule() : Debug.show(symbol);
assert !owners.containsKey(symbol) : Debug.show(symbol);
assert !clones.containsKey(symbol) :
Debug.show(symbol) + " -> " + Debug.show(clones.get(symbol));
Symbol clone = symbol.cloneSymbol(getOwnerFor(symbol));
if (rename) {
assert !symbol.isConstructor() : Debug.show(symbol);
clone.name = renamer.newName(symbol.name);
}
clones.put(symbol, clone);
clone.setType(cloneType(symbol.info()));
return clone;
}
/** Clones the given symbols. */
public Symbol[] cloneSymbols(Symbol[] symbols) {
return cloneSymbols(symbols, false);
}
/** Clones the given symbols and renames them if rename is true. */
public Symbol[] cloneSymbols(Symbol[] symbols, boolean rename) {
if (symbols.length == 0) return Symbol.EMPTY_ARRAY;
Symbol[] clones = new Symbol[symbols.length];
for (int i = 0; i < clones.length; i++)
clones[i] = cloneSymbol(symbols[i], rename);
return clones;
}
/** Clones the given type. */
public Type cloneType(Type type) {
switch (type) {
case PolyType(Symbol[] tparams, Type result):
Symbol[] clones = cloneSymbols(tparams);
Type clone = Type.PolyType(clones, cloneType(result));
return Type.getSubst(tparams, clones).applyParams(clone);
case MethodType(Symbol[] vparams, Type result):
return Type.MethodType(cloneSymbols(vparams), cloneType(result));
default:
return type;
}
}
//########################################################################
}
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