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	/*
	* Copyright (c) 2003, 2013, Oracle and/or its affiliates. All rights reserved.
	* DO NOT ALTER OR REMOVE COPYRIGHT NOTICES OR THIS FILE HEADER.
	*
	* This code is free software; you can redistribute it and/or modify it
	* under the terms of the GNU General Public License version 2 only, as
	* published by the Free Software Foundation. Oracle designates this
	* particular file as subject to the "Classpath" exception as provided
	* by Oracle in the LICENSE file that accompanied this code.
	*
	* This code is distributed in the hope that it will be useful, but WITHOUT
	* ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
	* FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
	* version 2 for more details (a copy is included in the LICENSE file that
	* accompanied this code).
	*
	* You should have received a copy of the GNU General Public License version
	* 2 along with this work; if not, write to the Free Software Foundation,
	* Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA.
	*
	* Please contact Oracle, 500 Oracle Parkway, Redwood Shores, CA 94065 USA
	* or visit www.oracle.com if you need additional information or have any
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	*/

	package java.util.regex;

	/**
	* The result of a match operation.
	*
	* <p>This interface contains query methods used to determine the
	* results of a match against a regular expression. The match boundaries,
	* groups and group boundaries can be seen but not modified through
	* a <code>MatchResult</code>.
	*
	* @author Michael McCloskey
	* @see Matcher
	* @since 1.5
	*/
	public interface MatchResult {

	/**
	* Returns the start index of the match.
	*
	* @return The index of the first character matched
	*
	* @throws IllegalStateException
	* If no match has yet been attempted,
	* or if the previous match operation failed
	*/
	public int start();

	/**
	* Returns the start index of the subsequence captured by the given group
	* during this match.
	*
	* <p> <a href="Pattern.html#cg">Capturing groups</a> are indexed from left
	* to right, starting at one. Group zero denotes the entire pattern, so
	* the expression <i>m.</i><tt>start(0)</tt> is equivalent to
	* <i>m.</i><tt>start()</tt>. </p>
	*
	* @param group
	* The index of a capturing group in this matcher's pattern
	*
	* @return The index of the first character captured by the group,
	* or <tt>-1</tt> if the match was successful but the group
	* itself did not match anything
	*
	* @throws IllegalStateException
	* If no match has yet been attempted,
	* or if the previous match operation failed
	*
	* @throws IndexOutOfBoundsException
	* If there is no capturing group in the pattern
	* with the given index
	*/
	public int start(int group);

	/**
	* Returns the offset after the last character matched.
	*
	* @return The offset after the last character matched
	*
	* @throws IllegalStateException
	* If no match has yet been attempted,
	* or if the previous match operation failed
	*/
	public int end();

	/**
	* Returns the offset after the last character of the subsequence
	* captured by the given group during this match.
	*
	* <p> <a href="Pattern.html#cg">Capturing groups</a> are indexed from left
	* to right, starting at one. Group zero denotes the entire pattern, so
	* the expression <i>m.</i><tt>end(0)</tt> is equivalent to
	* <i>m.</i><tt>end()</tt>. </p>
	*
	* @param group
	* The index of a capturing group in this matcher's pattern
	*
	* @return The offset after the last character captured by the group,
	* or <tt>-1</tt> if the match was successful
	* but the group itself did not match anything
	*
	* @throws IllegalStateException
	* If no match has yet been attempted,
	* or if the previous match operation failed
	*
	* @throws IndexOutOfBoundsException
	* If there is no capturing group in the pattern
	* with the given index
	*/
	public int end(int group);

	/**
	* Returns the input subsequence matched by the previous match.
	*
	* <p> For a matcher <i>m</i> with input sequence <i>s</i>,
	* the expressions <i>m.</i><tt>group()</tt> and
	* <i>s.</i><tt>substring(</tt><i>m.</i><tt>start(),</tt> <i>m.</i><tt>end())</tt>
	* are equivalent. </p>
	*
	* <p> Note that some patterns, for example <tt>a*</tt>, match the empty
	* string. This method will return the empty string when the pattern
	* successfully matches the empty string in the input. </p>
	*
	* @return The (possibly empty) subsequence matched by the previous match,
	* in string form
	*
	* @throws IllegalStateException
	* If no match has yet been attempted,
	* or if the previous match operation failed
	*/
	public String group();

	/**
	* Returns the input subsequence captured by the given group during the
	* previous match operation.
	*
	* <p> For a matcher <i>m</i>, input sequence <i>s</i>, and group index
	* <i>g</i>, the expressions <i>m.</i><tt>group(</tt><i>g</i><tt>)</tt> and
	* <i>s.</i><tt>substring(</tt><i>m.</i><tt>start(</tt><i>g</i><tt>),</tt> <i>m.</i><tt>end(</tt><i>g</i><tt>))</tt>
	* are equivalent. </p>
	*
	* <p> <a href="Pattern.html#cg">Capturing groups</a> are indexed from left
	* to right, starting at one. Group zero denotes the entire pattern, so
	* the expression <tt>m.group(0)</tt> is equivalent to <tt>m.group()</tt>.
	* </p>
	*
	* <p> If the match was successful but the group specified failed to match
	* any part of the input sequence, then <tt>null</tt> is returned. Note
	* that some groups, for example <tt>(a*)</tt>, match the empty string.
	* This method will return the empty string when such a group successfully
	* matches the empty string in the input. </p>
	*
	* @param group
	* The index of a capturing group in this matcher's pattern
	*
	* @return The (possibly empty) subsequence captured by the group
	* during the previous match, or <tt>null</tt> if the group
	* failed to match part of the input
	*
	* @throws IllegalStateException
	* If no match has yet been attempted,
	* or if the previous match operation failed
	*
	* @throws IndexOutOfBoundsException
	* If there is no capturing group in the pattern
	* with the given index
	*/
	public String group(int group);

	/**
	* Returns the number of capturing groups in this match result's pattern.
	*
	* <p> Group zero denotes the entire pattern by convention. It is not
	* included in this count.
	*
	* <p> Any non-negative integer smaller than or equal to the value
	* returned by this method is guaranteed to be a valid group index for
	* this matcher. </p>
	*
	* @return The number of capturing groups in this matcher's pattern
	*/
	public int groupCount();

	}

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