/**
* Copyright 2004-2016 Riccardo Solmi. All rights reserved.
* This file is part of the Whole Platform.
*
* The Whole Platform 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.
*
* The Whole Platform 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 the Whole Platform. If not, see <http://www.gnu.org/licenses/>.
*/
package org.whole.lang.iterators;
import java.util.NoSuchElementException;
import org.whole.lang.bindings.BindingManagerFactory;
import org.whole.lang.bindings.IBindingScope;
import org.whole.lang.model.IEntity;
import org.whole.lang.operations.ICloneContext;
import org.whole.lang.operations.InterpreterOperation;
/**
* @author Riccardo Solmi
*/
public class TemplateInterpreterIterator<E extends IEntity> extends AbstractCloneableIterator<E> {
protected IEntity resetEntity;
protected IEntity pattern;
protected IEntityIterator<E> nextEntityIterator;
protected TemplateInterpreterIterator(IEntity pattern) {
this.pattern = pattern;
}
public IEntityIterator<E> clone(ICloneContext cc) {
TemplateInterpreterIterator<E> iterator = (TemplateInterpreterIterator<E>) super.clone(cc);
iterator.nextEntityIterator = cc.clone(nextEntityIterator);
return iterator;
}
public void reset(IEntity entity) {
resetEntity = entity;
clearLookaheadScope();
nextEntityIterator = null;
}
private IBindingScope lookaheadScope;
public IBindingScope lookaheadScope() {
if (lookaheadScope != null)
return lookaheadScope;
if (nextEntityIterator != null)
return nextEntityIterator.lookaheadScope();
else
return lookaheadScope = BindingManagerFactory.instance.createSimpleScope();
}
protected void clearLookaheadScope() {
if (lookaheadScope != null) {
for (String name : lookaheadScope.wLocalNames())
getBindings().wUnset(name);
lookaheadScope.wClear();
}
}
public boolean hasNext() {
return lookahead() != null;
}
public E lookahead() {
if (nextEntityIterator != null)
return nextEntityIterator.lookahead();
clearLookaheadScope();
getBindings().wEnterScope(lookaheadScope(), true);
IEntity selfEntity = getBindings().wGet("self");
if (selfEntity != resetEntity)
getBindings().wDef("self", resetEntity);
IBindingScope results = InterpreterOperation.interpret(pattern, getBindings(), true);
getBindings().wExitScope();
nextEntityIterator = results.getResultIterator();
if (results.hasResultIterator()) {
results.setResultIterator(null);
selfEntity = getBindings().wGet("self");
if (selfEntity != resetEntity)
getBindings().wDef("self", resetEntity);
nextEntityIterator.reset(resetEntity);
lookaheadScope = null;
}
return nextEntityIterator.lookahead();
}
public E next() {
E result = lookahead();
if (result == null)
throw new NoSuchElementException();
if (lookaheadScope != null)
getBindings().wAddAll(lookaheadScope());
nextEntityIterator.next();
return result;
}
public void prune() {
if (nextEntityIterator != null)
nextEntityIterator.prune();
}
public void set(E entity) {
if (nextEntityIterator != null)
nextEntityIterator.set(entity);
}
public void add(E entity) {
if (nextEntityIterator != null)
nextEntityIterator.add(entity);
}
public void remove() {
if (nextEntityIterator != null)
nextEntityIterator.remove();
}
@Override
public void toString(StringBuilder sb) {
sb.append("eval(");
sb.append(pattern.toString());
sb.append(")");
}
}