QueryLabelFilter.java

/*
 * Carrot2 project.
 *
 * Copyright (C) 2002-2016, Dawid Weiss, Stanisław Osiński.
 * All rights reserved.
 *
 * Refer to the full license file "carrot2.LICENSE"
 * in the root folder of the repository checkout or at:
 * http://www.carrot2.org/carrot2.LICENSE
 */

package org.carrot2.text.preprocessing.filter;

import org.carrot2.core.attribute.Processing;
import org.carrot2.text.analysis.ITokenizer;
import org.carrot2.text.preprocessing.PreprocessingContext;
import org.carrot2.util.attribute.Attribute;
import org.carrot2.util.attribute.AttributeLevel;
import org.carrot2.util.attribute.Bindable;
import org.carrot2.util.attribute.DefaultGroups;
import org.carrot2.util.attribute.Group;
import org.carrot2.util.attribute.Input;
import org.carrot2.util.attribute.Label;
import org.carrot2.util.attribute.Level;

/**
 * Accepts labels that do not consist only of query words.
 */
@Bindable(prefix = "QueryLabelFilter")
public class QueryLabelFilter extends SingleLabelFilterBase
{
    /**
     * Remove query words. Removes labels that consist only of words contained in the
     * query.
     */
    @Input
    @Processing
    @Attribute
    @Label("Remove query words")
    @Level(AttributeLevel.BASIC)
    @Group(DefaultGroups.LABELS)    
    public boolean enabled = true;

    @Override
    public boolean acceptPhrase(PreprocessingContext context, int phraseIndex)
    {
        final int [] wordIndices = context.allPhrases.wordIndices[phraseIndex];
        final short [] flag = context.allWords.type;

        for (int i = 0; i < wordIndices.length; i++)
        {
            if (!isQueryWord(flag[wordIndices[i]]))
            {
                return true;
            }
        }

        return false;
    }

    @Override
    public boolean acceptWord(PreprocessingContext context, int wordIndex)
    {
        return !isQueryWord(context.allWords.type[wordIndex]);
    }

    private final boolean isQueryWord(short flag)
    {
        return (flag & ITokenizer.TF_QUERY_WORD) != 0;
    }

    public boolean isEnabled()
    {
        return enabled;
    }
}