com.simiacryptus.text.LanguageModel.java Source code

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Here is the source code for com.simiacryptus.text.LanguageModel.java

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/*
 * Copyright (c) 2018 by Andrew Charneski.
 *
 * The author licenses this file to you under the
 * Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance
 * with the License.  You may obtain a copy
 * of the License at
 *
 *   http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing,
 * software distributed under the License is distributed on an
 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
 * KIND, either express or implied.  See the License for the
 * specific language governing permissions and limitations
 * under the License.
 */

package com.simiacryptus.text;

import org.apache.commons.compress.utils.IOUtils;

import java.io.IOException;
import java.util.Arrays;
import java.util.Comparator;

/**
 * The enum Language model.
 */
public enum LanguageModel {
    /**
     * English language model.
     */
    English("English.trie"),
    /**
     * French language model.
     */
    French("French.trie"),
    /**
     * German language model.
     */
    German("German.trie");

    private final String resource;
    private volatile CharTrie trie;

    LanguageModel(String resource) {
        this.resource = resource;
    }

    /**
     * Match language model.
     *
     * @param text the text
     * @return the language model
     */
    public static LanguageModel match(String text) {
        return Arrays.stream(LanguageModel.values())
                .min(Comparator.comparing(model -> model.getTrie().getCodec().encodePPM(text, 2).bitLength)).get();
    }

    /**
     * Gets trie.
     *
     * @return the trie
     */
    public CharTrie getTrie() {
        if (null == trie) {
            synchronized (this) {
                if (null == trie) {
                    final byte[] bytes;
                    try {
                        bytes = IOUtils.toByteArray(getClass().getClassLoader().getResourceAsStream(resource));
                    } catch (IOException e) {
                        throw new RuntimeException(e);
                    }
                    trie = new ConvolutionalTrieSerializer().deserialize(CompressionUtil.decodeLZ(bytes));
                }
            }
        }
        return trie;
    }

}