    001/*
    002 * Licensed to the Apache Software Foundation (ASF) under one or more
    003 * contributor license agreements.  See the NOTICE file distributed with
    004 * this work for additional information regarding copyright ownership.
    005 * The ASF licenses this file to You under the Apache License, Version 2.0
    006 * (the "License"); you may not use this file except in compliance with
    007 * the License.  You may obtain a copy of the License at
    008 *
    009 *      http://www.apache.org/licenses/LICENSE-2.0
    010 *
    011 * Unless required by applicable law or agreed to in writing, software
    012 * distributed under the License is distributed on an "AS IS" BASIS,
    013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    014 * See the License for the specific language governing permissions and
    015 * limitations under the License.
    016 */
    017
    018package org.apache.commons.text.matcher;
    019
    020/**
    021 * Determines if a character array portion matches.
    022 *
    023 * @since 1.3
    024 */
    025public interface StringMatcher {
    026
    027    /**
    028     * Returns the number of matching characters, zero for no match.
    029     * <p>
    030     * This method is called to check for a match. The parameter <code>pos</code> represents the current position to be
    031     * checked in the string <code>buffer</code> (a character array which must not be changed). The API guarantees that
    032     * <code>pos</code> is a valid index for <code>buffer</code>.
    033     * <p>
    034     * The character array may be larger than the active area to be matched. Only values in the buffer between the
    035     * specified indices may be accessed.
    036     * <p>
    037     * The matching code may check one character or many. It may check characters preceding <code>pos</code> as well as
    038     * those after, so long as no checks exceed the bounds specified.
    039     * <p>
    040     * It must return zero for no match, or a positive number if a match was found. The number indicates the number of
    041     * characters that matched.
    042     *
    043     * @param buffer
    044     *            the text content to match against, do not change
    045     * @param pos
    046     *            the starting position for the match, valid for buffer
    047     * @param bufferStart
    048     *            the first active index in the buffer, valid for buffer
    049     * @param bufferEnd
    050     *            the end index (exclusive) of the active buffer, valid for buffer
    051     * @return the number of matching characters, or zero if there is no match
    052     */
    053    int isMatch(char[] buffer, int pos, int bufferStart, int bufferEnd);
    054
    055}