java/i18n/src/org/netbeans/modules/i18n/regexp/Translator.java

/*
 * Licensed to the Apache Software Foundation (ASF) under one
 * or more contributor license agreements.  See the NOTICE file
 * distributed with this work for additional information
 * regarding copyright ownership.  The ASF 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 org.netbeans.modules.i18n.regexp;

import java.util.Map;

/**
 * Translator of Apache's Regexp regular expressions to JDK's regular
 * expressions.
 *
 * @author  Marian Petras
 */
public final class Translator {

    /**
     * Translates the given Apache Regexp regular expression
     * into a JDK's regular expression.
     *
     * @param  regexp  regular expression according to Apache's Regexp library
     *                 syntax rules
     * @return  regular expression according to syntax rules of JDK's class
     *          {@link java.util.regex.Pattern Pattern}.
     * @exception  java.lang.IllegalArgumentException
     *             if the argument was <code>null</code>
     * @exception  ParseException
     *             if the given expression contained a syntax error
     */
    public static String translateRegexp(String regexp)
            throws IllegalArgumentException, ParseException {
        TreeNodeRoot tree = Parser.parse(regexp);
        return Generator.generateRegexp(tree);
    }

    /**
     * Translates the given Apache Regexp regular expression
     * into a JDK's regular expression.
     *
     * @param  regexp  regular expression according to Apache's Regexp library
     *                 syntax rules
     * @param  tokenReplacements  maps token names to strings to be put in place
     *                            of them, or <code>null</code> to ignore tokens
     *                            (leave them unchanged)
     * @return  regular expression according to syntax rules of JDK's class
     *          {@link java.util.regex.Pattern Pattern}.
     * @exception  java.lang.IllegalArgumentException
     *             if the regular expression is <code>null</code>
     * @exception  java.lang.ClassCastException
     *             if not all keys in the map were strings
     * @exception  ParseException
     *             if the given expression contained a syntax error
     */
    public static String translateRegexp(String regexp,
                                         Map<String,String> tokenReplacements)
            throws IllegalArgumentException, ParseException {

        if ((tokenReplacements == null) || (tokenReplacements.isEmpty())) {
            return translateRegexp(regexp);
        }

        String[] tokenNames = new String[tokenReplacements.size()];
        try {
            tokenReplacements.keySet().toArray(tokenNames);
        } catch (ArrayStoreException ex) {
            throw new ClassCastException();
        }
        TreeNodeRoot tree = Parser.parse(regexp, tokenNames);
        return Generator.generateRegexp(tree, tokenReplacements);
    }

}