org.eclipse.xtext.xbase.lib.internal.BooleanFunctionDelegate.java Source code

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Here is the source code for org.eclipse.xtext.xbase.lib.internal.BooleanFunctionDelegate.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.xbase.lib.internal;

import org.eclipse.xtext.xbase.lib.Functions.Function1;

import com.google.common.annotations.GwtCompatible;
import com.google.common.base.Predicate;

/**
 * Internal wrapper to look like a google.collect predicate
 * 
 * @param <T>
 *            the type of the objects that can be used by this predicate.
 */
@GwtCompatible
public class BooleanFunctionDelegate<T> implements Predicate<T> {

    private final Function1<? super T, Boolean> delegate;

    /**
     * Creates a new {@link BooleanFunctionDelegate} that wraps the given delegate function. This implementation will
     * throw a {@link NullPointerException} if the delegate's {@link Function1#apply(Object) implementation} returns
     * <code>null</code> for a given object.
     * 
     * @param delegate
     *            the delegate function. May not be <code>null</code>.
     */
    public BooleanFunctionDelegate(Function1<? super T, Boolean> delegate) {
        if (delegate == null)
            throw new NullPointerException("delegate");
        this.delegate = delegate;
    }

    @Override
    public boolean apply(T input) {
        Boolean result = delegate.apply(input);
        return result.booleanValue();
    }

}