InvocationOnCollectionExpression.java

/*
Copyright (c) 2008 Arno Haase, Andr� Arnold.
All rights reserved. This program and the accompanying materials
are made available under the terms of the Eclipse Public License v1.0
which accompanies this distribution, and is available at
http://www.eclipse.org/legal/epl-v10.html

Contributors:
    Arno Haase - initial API and implementation
    Andr� Arnold
 */
package org.eclipse.xtend.backend.expr;

import java.util.ArrayList;
import java.util.Collection;
import java.util.List;

import org.eclipse.xtend.backend.common.ExecutionContext;
import org.eclipse.xtend.backend.common.ExpressionBase;
import org.eclipse.xtend.backend.common.QualifiedName;
import org.eclipse.xtend.backend.common.SourcePos;
import org.eclipse.xtend.backend.common.SyntaxConstants;
import org.eclipse.xtend.backend.syslib.CollectionOperations;


/**
 * 
 * @author Arno Haase (http://www.haase-consulting.com)
 * @author Andr� Arnold
 */
public final class InvocationOnCollectionExpression extends ExpressionBase {
    private final ExpressionBase _coll;
    private final QualifiedName _functionName;
    private final List<ExpressionBase> _params;
    
    public InvocationOnCollectionExpression (ExpressionBase coll, QualifiedName functionName, List<ExpressionBase> params, SourcePos sourcePos) {
        super (sourcePos);
        
        _coll = coll;
        _functionName = functionName;
        _params = params;
    }

    public ExpressionBase getCollection() {
		return _coll;
	}

	public QualifiedName getFunctionName() {
		return _functionName;
	}

	public List<ExpressionBase> getParams() {
		return _params;
	}

	@Override
    protected Object evaluateInternal(ExecutionContext ctx) {
        final Collection<?> coll = (Collection<?>) _coll.evaluate(ctx);
        boolean firstParamIsThis = false;
        if (_params.size() > 0 && _params.get(0) instanceof LocalVarEvalExpression)
        	if (((LocalVarEvalExpression)_params.get(0)).getLocalVarName().equals(SyntaxConstants.THIS))
        		firstParamIsThis = true;
        if (coll == null) {
            ctx.logNullDeRef (getPos());
            return null;
        }
        
        final List<Object> params = new ArrayList<Object>();
        params.add (null); //placeholder
        for (ExpressionBase expr: _params)
        	params.add (expr.evaluate (ctx));
        
        final Collection<Object> result = CollectionOperations.createMatchingCollection (coll);
        
        for (Object o: coll) {
        	params.set (0, o);

        	CollectionOperations.addFlattened (result, ctx.getFunctionDefContext().invoke (ctx, _functionName, params, firstParamIsThis));
        }
        
        return result;
    }
}