/*
* $Id: Perl5MatchResult.java 124053 2005-01-04 01:24:35Z dfs $
*
* Copyright 2000-2005 The Apache Software Foundation
*
* Licensed 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.apache.oro.text.regex;
/**
* A class used to store and access the results of a Perl5Pattern match.
*
* @version @version@
* @since 1.0
* @see PatternMatcher
* @see Perl5Matcher
*/
public class Perl5MatchResult implements MatchResult {
/**
* The character offset into the line or stream where the match
* begins. Pattern matching methods that look for matches a line at
* a time should use this field as the offset into the line
* of the match. Methods that look for matches independent of line
* boundaries should use this field as the offset into the entire
* text stream.
*/
protected int _matchBeginOffset_;
/**
* Arrays containing the beginning and end offsets of the pattern
* groups matched within the actual matched pattern contained in the
* variable match
.
* Pattern matching methods that do not match subgroups, will only contain
* entries for group 0, which always refers to the entire pattern.
* beginGroupOffset
contains the start offset of the groups,
* indexed by group number, which will always be 0 for group 0.
* endGroupOffset
contains the ending offset + 1 of the groups.
* A group matching the null string will have beginGroupOffset
* and endGroupOffset
entries of equal value. Following a
* convention established by the GNU regular expression library for the
* C language, groups that are not part of a match contain -1 as their
* begin and end offsets.
*/
protected int[] _beginGroupOffset_, _endGroupOffset_;
/**
* The entire string that matched the pattern.
*/
protected String _match_;
/**
* Constructs a MatchResult able to store match information for
* a number of subpattern groups.
*
* @param groups The number of groups this MatchResult can store. * Only postitive values greater than or equal to 1 make any * sense. At minimum, a MatchResult stores one group which * represents the entire pattern matched including all subparts. */ protected Perl5MatchResult(int groups){ _beginGroupOffset_ = new int[groups]; _endGroupOffset_ = new int[groups]; } /** * @return The length of the match. */ public int length(){ int length; length = (_endGroupOffset_[0] - _beginGroupOffset_[0]); return (length > 0 ? length : 0); } /** * @return The number of groups contained in the result. This number * includes the 0th group. In other words, the result refers * to the number of parenthesized subgroups plus the entire match * itself. */ public int groups(){ return _beginGroupOffset_.length; } /** * @param group The pattern subgroup to return. * @return A string containing the indicated pattern subgroup. Group * 0 always refers to the entire match. If a group was never * matched, it returns null. This is not to be confused with * a group matching the null string, which will return a String * of length 0. */ public String group(int group){ int begin, end, length; if(group < _beginGroupOffset_.length){ begin = _beginGroupOffset_[group]; end = _endGroupOffset_[group]; length = _match_.length(); if(begin >= 0 && end >= 0) { if(begin < length && end <= length && end > begin) return _match_.substring(begin, end); else if(begin <= end) return ""; } } return null; } /** * @param group The pattern subgroup. * @return The offset into group 0 of the first token in the indicated * pattern subgroup. If a group was never matched or does * not exist, returns -1. */ public int begin(int group){ int begin, end;//, length; if(group < _beginGroupOffset_.length){ begin = _beginGroupOffset_[group]; end = _endGroupOffset_[group]; //length = _match_.length(); if(begin >= 0 && end >= 0)// && begin < length && end <= length) //return _beginGroupOffset_[group]; return begin; } return -1; } /** * @param group The pattern subgroup. * @return Returns one plus the offset into group 0 of the last token in * the indicated pattern subgroup. If a group was never matched * or does not exist, returns -1. A group matching the null * string will return its start offset. */ public int end(int group){ int begin, end; //, length; if(group < _beginGroupOffset_.length){ begin = _beginGroupOffset_[group]; end = _endGroupOffset_[group]; //length = _match_.length(); if(begin >= 0 && end >= 0)// && begin < length && end <= length) //return _endGroupOffset_[group]; return end; } return -1; } /** * Returns an offset marking the beginning of the pattern match * relative to the beginning of the input. *
* @param group The pattern subgroup. * @return The offset of the first token in the indicated * pattern subgroup. If a group was never matched or does * not exist, returns -1. */ public int beginOffset(int group){ int begin, end;//, length; if(group < _beginGroupOffset_.length){ begin = _beginGroupOffset_[group]; end = _endGroupOffset_[group]; //length = _match_.length(); if(begin >= 0 && end >= 0)// && begin < length && end <= length) //return _matchBeginOffset_ + _beginGroupOffset_[group]; return _matchBeginOffset_ + begin; } return -1; } /** * Returns an offset marking the end of the pattern match * relative to the beginning of the input. *
* @param group The pattern subgroup. * @return Returns one plus the offset of the last token in * the indicated pattern subgroup. If a group was never matched * or does not exist, returns -1. A group matching the null * string will return its start offset. */ public int endOffset(int group){ int begin, end;//, length; if(group < _endGroupOffset_.length){ begin = _beginGroupOffset_[group]; end = _endGroupOffset_[group]; //length = _match_.length(); if(begin >= 0 && end >= 0)// && begin < length && end <= length) //return _matchBeginOffset_ + _endGroupOffset_[group]; return _matchBeginOffset_ + end; } return -1; } /** * The same as group(0). * * @return A string containing the entire match. */ public String toString() { return group(0); } }