org.eclipse.xtext.util.formallang.CfgUtil.java Source code

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Here is the source code for org.eclipse.xtext.util.formallang.CfgUtil.java

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/*******************************************************************************
 * Copyright (c) 2011 itemis AG (http://www.itemis.eu) and others.
 * 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
 *******************************************************************************/
package org.eclipse.xtext.util.formallang;

import com.google.common.base.Predicate;
import com.google.common.collect.ArrayListMultimap;
import com.google.common.collect.Multimap;

/**
 * @author Moritz Eysholdt - Initial contribution and API
 */
public class CfgUtil {

    protected static class IsCall<E> implements Predicate<E> {

        protected Cfg<E, ?> cfg;

        public IsCall(Cfg<E, ?> cfg) {
            super();
            this.cfg = cfg;
        }

        @Override
        public boolean apply(E input) {
            return cfg.getCall(input) != null;
        }

    }

    public <E, T> Multimap<E, E> getCallers(Cfg<E, T> cfg) {
        Multimap<E, E> result = ArrayListMultimap.create();
        getCallers(cfg, cfg.getRoot(), result);
        return result;
    }

    protected <E, T> void getCallers(Cfg<E, T> cfg, E root, Multimap<E, E> callers) {
        for (E call : new ProductionUtil().getAllChildren(cfg, root)) {
            E called = cfg.getCall(call);
            if (called != null) {
                boolean contained = callers.containsKey(called) || called == cfg.getRoot();
                callers.put(called, call);
                if (!contained)
                    getCallers(cfg, called, callers);
            }
        }
    }
}