/*
* Copyright (c) 2012, the Dart project authors.
*
* Licensed under the Eclipse Public License v1.0 (the "License"); you may not use this file except
* in compliance with the License. You may obtain a copy of the License at
*
* http://www.eclipse.org/legal/epl-v10.html
*
* Unless required by applicable law or agreed to in writing, software distributed under the License
* is distributed on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express
* or implied. See the License for the specific language governing permissions and limitations under
* the License.
*/
package com.google.dart.engine.internal.scope;
import com.google.dart.engine.ast.Identifier;
import com.google.dart.engine.element.Element;
import com.google.dart.engine.element.LibraryElement;
import com.google.dart.engine.error.AnalysisError;
import com.google.dart.engine.error.AnalysisErrorListener;
import com.google.dart.engine.error.CompileTimeErrorCode;
import java.util.HashMap;
/**
* Instances of the class {@code EnclosedScope} implement a scope that is lexically enclosed in
* another scope.
*
* @coverage dart.engine.resolver
*/
public class EnclosedScope extends Scope {
/**
* The scope in which this scope is lexically enclosed.
*/
private Scope enclosingScope;
/**
* A table mapping names that will be defined in this scope, but right now are not initialized.
* According to the scoping rules these names are hidden, even if they were defined in an outer
* scope.
*/
private HashMap<String, Element> hiddenElements = new HashMap<String, Element>();
/**
* A flag indicating whether there are any names defined in this scope.
*/
private boolean hasHiddenName = false;
/**
* Initialize a newly created scope enclosed within another scope.
*
* @param enclosingScope the scope in which this scope is lexically enclosed
*/
public EnclosedScope(Scope enclosingScope) {
this.enclosingScope = enclosingScope;
}
@Override
public Scope getEnclosingScope() {
return enclosingScope;
}
@Override
public AnalysisErrorListener getErrorListener() {
return enclosingScope.getErrorListener();
}
/**
* Record that given element is declared in this scope, but hasn't been initialized yet, so it is
* error to use. If there is already an element with the given name defined in an outer scope,
* then it will become unavailable.
*
* @param element the element declared, but not initialized in this scope
*/
public void hide(Element element) {
if (element != null) {
String name = element.getName();
if (name != null && !name.isEmpty()) {
hiddenElements.put(name, element);
hasHiddenName = true;
}
}
}
@Override
protected Element internalLookup(Identifier identifier, String name, LibraryElement referencingLibrary) {
Element element = localLookup(name, referencingLibrary);
if (element != null) {
return element;
}
// May be there is a hidden Element.
if (hasHiddenName) {
Element hiddenElement = hiddenElements.get(name);
if (hiddenElement != null) {
getErrorListener().onError(
new AnalysisError(
getSource(identifier),
identifier.getOffset(),
identifier.getLength(),
CompileTimeErrorCode.REFERENCED_BEFORE_DECLARATION));
return hiddenElement;
}
}
// Check enclosing scope.
return enclosingScope.internalLookup(identifier, name, referencingLibrary);
}
}