IfExpression.java

/*
Copyright (c) 2008 Arno Haase.
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
 */
package org.eclipse.xtend.backend.expr;

import org.eclipse.xtend.backend.common.ExecutionContext;
import org.eclipse.xtend.backend.common.ExpressionBase;
import org.eclipse.xtend.backend.common.SourcePos;


/**
 * 
 * @author Arno Haase (http://www.haase-consulting.com)
 */
public final class IfExpression extends ExpressionBase {
    private final ExpressionBase _cond, _if, _else;

    public IfExpression (ExpressionBase cond, ExpressionBase ifResult, ExpressionBase elseResult, SourcePos sourcePos) {
        super (sourcePos);
        
        _cond = cond;
        _if = ifResult;
        _else = elseResult;
    }

    public ExpressionBase getCondition() {
		return _cond;
	}

	public ExpressionBase getIfPart() {
		return _if;
	}

	public ExpressionBase getElsePart() {
		return _else;
	}

	@Override
    protected Object evaluateInternal (ExecutionContext ctx) {
        final Object cond = _cond.evaluate(ctx);
        
        if (cond == null) {
            ctx.logNullDeRef (getPos());
            return null;
        }
        
        if (Boolean.TRUE.equals (cond))
            return _if.evaluate(ctx);
        else
            return _else.evaluate(ctx);
    }
}