/*
* Copyright 2003-2012 JetBrains s.r.o.
*
* Licensed under the Apache License, Version 2.0 (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.apache.org/licenses/LICENSE-2.0
*
* 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 jetbrains.mps.languageScope;
import java.util.BitSet;
import java.util.Collections;
import java.util.LinkedList;
/**
* User: fyodor
* Date: 8/27/12
*/
public class LanguageScope {
private static final CurrentLanguageScope GLOBAL = new CurrentLanguageScope(new GlobalLanguageScope(), null);
private static ThreadLocal<LinkedList<CurrentLanguageScope>> CURRENT_STACK = new ThreadLocal<LinkedList<CurrentLanguageScope>>() {
@Override
protected LinkedList<CurrentLanguageScope> initialValue() {
return new LinkedList<CurrentLanguageScope>(Collections.singleton(GLOBAL));
}
};
private final LanguageScopeFactory myFactory;
private final BitSet myNsBitSet;
public static LanguageScope getGlobal () {
return GLOBAL.myLangScope;
}
public static LanguageScope getCurrent() {
CurrentLanguageScope cls = CURRENT_STACK.get().peek();
return cls.myLangScope;
}
public static void pushCurrent(LanguageScope langScope, Object owner) {
CURRENT_STACK.get().push(new CurrentLanguageScope(langScope, owner));
}
public static void popCurrent(LanguageScope languageScope, Object owner) {
if (CURRENT_STACK.get().size() == 1) throw new IllegalStateException("attempt to remove global LanguageScope");
CurrentLanguageScope cls = CURRENT_STACK.get().peek();
if (cls.myOwner != owner) throw new IllegalStateException("attempt to remove foreign LanguageScope");
if (cls.myLangScope!= languageScope) throw new IllegalStateException("attempt to remove another LanguageScope");
CURRENT_STACK.get().pop();
}
/*package*/ LanguageScope(LanguageScopeFactory factory, BitSet nsBitSet) {
myFactory = factory;
myNsBitSet = nsBitSet;
}
public boolean containsNamespace (String namespace) {
return myNsBitSet.get(myFactory.getIndexOf(namespace));
}
public LanguageScope disjunction(LanguageScope that) {
if (this.myFactory != that.myFactory) throw new IllegalArgumentException("incompatible language scope");
BitSet nsBitSet = this.myNsBitSet;
nsBitSet.or(that.myNsBitSet);
return new LanguageScope(this.myFactory, nsBitSet);
}
@Override
public boolean equals(Object that) {
if (that == this) return true;
if (that == null) return false;
if (that.getClass() != LanguageScope.class) return false;
if (this.myFactory != ((LanguageScope)that).myFactory) return false;
return this.myNsBitSet.equals(((LanguageScope)that).myNsBitSet);
}
@Override
public int hashCode() {
return myNsBitSet.hashCode()*37 + myFactory.hashCode()*43;
}
private static class GlobalLanguageScope extends LanguageScope {
private GlobalLanguageScope() {
super(null, null);
}
@Override
public boolean containsNamespace(String namespace) {
return true;
}
@Override
public boolean equals(Object that) {
return that == this;
}
@Override
public int hashCode() {
return System.identityHashCode(this);
}
}
private static class CurrentLanguageScope {
private Object myOwner;
private LanguageScope myLangScope;
public CurrentLanguageScope(LanguageScope langScope, Object owner) {
this.myOwner = owner;
this.myLangScope = langScope;
}
}
}