BEGIN LICENSE BLOCK *****
Version: EPL 2.0/GPL 2.0/LGPL 2.1
The contents of this file are subject to the Eclipse Public
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.eclipse.org/legal/epl-v20.html
Software distributed under the License is distributed on an "AS
IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
implied. See the License for the specific language governing
rights and limitations under the License.
Copyright (C) 2001 Alan Moore 
Copyright (C) 2001-2004 Jan Arne Petersen 
Copyright (C) 2002 Benoit Cerrina 
Copyright (C) 2002-2004 Anders Bengtsson 
Copyright (C) 2004 Thomas E Enebo 
Copyright (C) 2004 Charles O Nutter 
Copyright (C) 2004 Stefan Matthias Aust 
Alternatively, the contents of this file may be used under the terms of
either of the GNU General Public License Version 2 or later (the "GPL"),
or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
in which case the provisions of the GPL or the LGPL are applicable instead
of those above. If you wish to allow use of your version of this file only
under the terms of either the GPL or the LGPL, and not to allow others to
use your version of this file under the terms of the EPL, indicate your
decision by deleting the provisions above and replace them with the notice
and other provisions required by the GPL or the LGPL. If you do not delete
the provisions above, a recipient may use your version of this file under
the terms of any one of the EPL, the GPL or the LGPL.
END LICENSE BLOCK /***** BEGIN LICENSE BLOCK *****
 * Version: EPL 2.0/GPL 2.0/LGPL 2.1
 *
 * The contents of this file are subject to the Eclipse Public
 * 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.eclipse.org/legal/epl-v20.html
 *
 * Software distributed under the License is distributed on an "AS
 * IS" basis, WITHOUT WARRANTY OF ANY KIND, either express or
 * implied. See the License for the specific language governing
 * rights and limitations under the License.
 *
 * Copyright (C) 2001 Alan Moore <alan_moore@gmx.net>
 * Copyright (C) 2001-2004 Jan Arne Petersen <jpetersen@uni-bonn.de>
 * Copyright (C) 2002 Benoit Cerrina <b.cerrina@wanadoo.fr>
 * Copyright (C) 2002-2004 Anders Bengtsson <ndrsbngtssn@yahoo.se>
 * Copyright (C) 2004 Thomas E Enebo <enebo@acm.org>
 * Copyright (C) 2004 Charles O Nutter <headius@headius.com>
 * Copyright (C) 2004 Stefan Matthias Aust <sma@3plus4.de>
 *
 * Alternatively, the contents of this file may be used under the terms of
 * either of the GNU General Public License Version 2 or later (the "GPL"),
 * or the GNU Lesser General Public License Version 2.1 or later (the "LGPL"),
 * in which case the provisions of the GPL or the LGPL are applicable instead
 * of those above. If you wish to allow use of your version of this file only
 * under the terms of either the GPL or the LGPL, and not to allow others to
 * use your version of this file under the terms of the EPL, indicate your
 * decision by deleting the provisions above and replace them with the notice
 * and other provisions required by the GPL or the LGPL. If you do not delete
 * the provisions above, a recipient may use your version of this file under
 * the terms of any one of the EPL, the GPL or the LGPL.
 ***** END LICENSE BLOCK *****/

package org.jruby;

import java.util.Arrays;
import java.util.Iterator;

import org.jcodings.Encoding;
import org.joni.Matcher;
import org.joni.NameEntry;
import org.joni.Regex;
import org.joni.Region;
import org.joni.exception.JOniException;
import org.jruby.anno.JRubyMethod;
import org.jruby.anno.JRubyClass;
import org.jruby.runtime.Block;
import org.jruby.runtime.ClassIndex;
import org.jruby.runtime.ObjectAllocator;
import org.jruby.runtime.ThreadContext;
import org.jruby.runtime.Visibility;
import org.jruby.runtime.builtin.IRubyObject;
import org.jruby.util.ByteList;
import org.jruby.util.ByteListHolder;
import org.jruby.util.RegexpOptions;
import org.jruby.util.StringSupport;

Author:
olabini/**
 * @author olabini
 */
@JRubyClass(name="MatchData")
public class RubyMatchData extends RubyObject {
    Region regs;        // captures
    int begin, end;     // begin and end are used when not groups defined
    RubyString str;     // source string
    private Object pattern; // Regex or (un-quoted) RubyString
    transient RubyRegexp regexp;
    private boolean charOffsetUpdated;
    private Region charOffsets;

    public static RubyClass createMatchDataClass(Ruby runtime) {
        RubyClass matchDataClass = runtime.defineClass("MatchData", runtime.getObject(), MATCH_DATA_ALLOCATOR);
        runtime.setMatchData(matchDataClass);

        matchDataClass.setClassIndex(ClassIndex.MATCHDATA);
        matchDataClass.setReifiedClass(RubyMatchData.class);

        runtime.defineGlobalConstant("MatchingData", matchDataClass);
        matchDataClass.kindOf = new RubyModule.JavaClassKindOf(RubyMatchData.class);

        matchDataClass.getMetaClass().undefineMethod("new");
        matchDataClass.defineAnnotatedMethods(RubyMatchData.class);
        return matchDataClass;
    }

    private static ObjectAllocator MATCH_DATA_ALLOCATOR = new ObjectAllocator() {
        @Override
        public IRubyObject allocate(Ruby runtime, RubyClass klass) {
            return new RubyMatchData(runtime, klass);
        }
    };

    public RubyMatchData(Ruby runtime) {
        super(runtime, runtime.getMatchData());
    }

    public RubyMatchData(Ruby runtime, RubyClass metaClass) {
        super(runtime, metaClass);
    }

    final void initMatchData(final ThreadContext context,
        RubyString str, Matcher matcher, Regex pattern) {

        // FIXME: This is pretty gross; we should have a cleaner initialization
        // that doesn't depend on package-visible fields and ideally is atomic,
        // probably using an immutable structure we replace all at once.

        // The region must be cloned because a subsequent match will update the
        // region, resulting in the MatchData created here pointing at the
        // incorrect region (capture/group).
        Region region = matcher.getRegion(); // lazy, null when no groups defined
        this.regs = region == null ? null : region.clone();
        this.begin = matcher.getBegin();
        this.end = matcher.getEnd();
        this.pattern = pattern;
        this.regexp = null;

        this.charOffsets = null;
        this.charOffsetUpdated = false;

        this.str = str.newFrozen();
        this.infectBy(str);
    }

    final void initMatchData(final ThreadContext context,
        RubyString str, int beg, RubyString pattern) {

        this.regs = null;
        this.begin = beg;
        this.end = beg + pattern.size();
        this.pattern = pattern.newFrozen();
        this.regexp = null;

        this.charOffsets = null;
        this.charOffsetUpdated = false;

        this.str = str.newFrozen();
        this.infectBy(str);
    }

    @Override
    public void copySpecialInstanceVariables(IRubyObject clone) {
        RubyMatchData match = (RubyMatchData) clone;
        match.regs = this.regs;
        match.begin = this.begin;
        match.end = this.end;
        match.pattern = this.pattern;
        match.regexp = this.regexp;
        match.charOffsetUpdated = this.charOffsetUpdated;
        match.charOffsets = this.charOffsets;
        // match.str = this.str; // uninitialized MatchData?!?
    }

    @Override
    public ClassIndex getNativeClassIndex() {
        return ClassIndex.MATCHDATA;
    }

    private static final class Pair implements Comparable<Pair> {
        int bytePos, charPos;
        @Override
        public int compareTo(Pair pair) {
            return bytePos - pair.bytePos;
        }
    }

    private static void updatePairs(ByteList value, Encoding encoding, Pair[] pairs) {
        Arrays.sort(pairs);

        int length = pairs.length;
        byte[] bytes = value.getUnsafeBytes();
        int p = value.getBegin();
        int s = p;
        int c = 0;

        for (int i = 0; i < length; i++) {
            int q = s + pairs[i].bytePos;
            c += StringSupport.strLength(encoding, bytes, p, q);
            pairs[i].charPos = c;
            p = q;
        }
    }

    private void updateCharOffsetOnlyOneReg(ByteList value, Encoding encoding) {
        if (charOffsetUpdated) return;

        if (charOffsets == null || charOffsets.numRegs < 1) charOffsets = new Region(1);

        if (encoding.maxLength() == 1) {
            charOffsets.beg[0] = begin;
            charOffsets.end[0] = end;
            charOffsetUpdated = true;
            return;
        }

        Pair[] pairs = new Pair[2];
        if (begin >= 0) {
            pairs[0] = new Pair();
            pairs[0].bytePos = begin;
            pairs[1] = new Pair();
            pairs[1].bytePos = end;
        }

        updatePairs(value, encoding, pairs);

        if (begin < 0) {
            charOffsets.beg[0] = charOffsets.end[0] = -1;
            return;
        }
        Pair key = new Pair();
        key.bytePos = begin;
        charOffsets.beg[0] = pairs[Arrays.binarySearch(pairs, key)].charPos;
        key.bytePos = end;
        charOffsets.end[0] = pairs[Arrays.binarySearch(pairs, key)].charPos;

        charOffsetUpdated = true;
    }

    private void updateCharOffsetManyRegs(ByteList value, Encoding encoding) {
        if (charOffsetUpdated) return;

        final Region regs = this.regs;
        int numRegs = regs.numRegs;

        if (charOffsets == null || charOffsets.numRegs < numRegs) charOffsets = new Region(numRegs);

        if (encoding.maxLength() == 1) {
            for (int i = 0; i < numRegs; i++) {
                charOffsets.beg[i] = regs.beg[i];
                charOffsets.end[i] = regs.end[i];
            }
            charOffsetUpdated = true;
            return;
        }

        Pair[] pairs = new Pair[numRegs * 2];
        for (int i = 0; i < pairs.length; i++) pairs[i] = new Pair();

        int numPos = 0;
        for (int i = 0; i < numRegs; i++) {
            if (regs.beg[i] < 0) continue;
            pairs[numPos++].bytePos = regs.beg[i];
            pairs[numPos++].bytePos = regs.end[i];
        }

        updatePairs(value, encoding, pairs);

        Pair key = new Pair();
        for (int i = 0; i < regs.numRegs; i++) {
            if (regs.beg[i] < 0) {
                charOffsets.beg[i] = charOffsets.end[i] = -1;
                continue;
            }
            key.bytePos = regs.beg[i];
            charOffsets.beg[i] = pairs[Arrays.binarySearch(pairs, key)].charPos;
            key.bytePos = regs.end[i];
            charOffsets.end[i] = pairs[Arrays.binarySearch(pairs, key)].charPos;
        }

        charOffsetUpdated = true;
    }

    private void updateCharOffset() {
        if (charOffsetUpdated) return;

        ByteList value = str.getByteList();
        Encoding enc = value.getEncoding();

        if (regs == null) {
            updateCharOffsetOnlyOneReg(value, enc);
        } else {
            updateCharOffsetManyRegs(value, enc);
        }

        charOffsetUpdated = true;
    }

    private static final int MATCH_BUSY = ObjectFlags.MATCH_BUSY;

    // rb_match_busy
    public final void use() {
        flags |= MATCH_BUSY;
    }

    public final boolean used() {
        return (flags & MATCH_BUSY) != 0;
    }

    final void check() {
        if (str == null) throw metaClass.runtime.newTypeError("uninitialized Match");
    }

    final Regex getPattern() {
        final Object pattern = this.pattern;
        if (pattern instanceof Regex) return (Regex) pattern;
        if (pattern == null) throw metaClass.runtime.newTypeError("uninitialized Match (missing pattern)");
        // when a regexp is avoided for matching we lazily instantiate one from the unquoted string :
        Regex regexPattern = RubyRegexp.getQuotedRegexpFromCache(metaClass.runtime, (RubyString) pattern, RegexpOptions.NULL_OPTIONS);
        this.pattern = regexPattern;
        return regexPattern;
    }

    private RubyRegexp getRegexp() {
        RubyRegexp regexp = this.regexp;
        if (regexp != null) return regexp;
        final Regex pattern = getPattern();
        return this.regexp = RubyRegexp.newRegexp(metaClass.runtime, (ByteList) pattern.getUserObject(), pattern);
    }

    private static RubyString makeShared(Ruby runtime, RubyString str, int index, int length) {
        return str.makeShared(runtime, index, length);
    }

    private RubyArray match_array(Ruby runtime, int start) {
        check();
        IRubyObject nil = runtime.getNil();
        if (regs == null) {
            if (start != 0) return runtime.newEmptyArray();
            if (begin == -1) {
                return runtime.newArray(nil);
            } else {
                RubyString ss = makeShared(runtime, str, begin, end - begin);
                return runtime.newArray( ss.infectBy(this) );
            }
        } else {
            RubyArray arr = RubyArray.newBlankArray(runtime, regs.numRegs - start);
            int index = 0;
            for (int i=start; i < regs.numRegs; i++) {
                if (regs.beg[i] == -1) {
                    arr.storeInternal(index++, nil);
                } else {
                    RubyString ss = makeShared(runtime, str, regs.beg[i], regs.end[i] - regs.beg[i]);
                    arr.storeInternal(index++, ss.infectBy(this));
                }
            }
            return arr;
        }

    }

    public IRubyObject group(long n) {
        return RubyRegexp.nth_match((int)n, this);
    }

    public IRubyObject group(int n) {
        return RubyRegexp.nth_match(n, this);
    }

    public int getNameToBackrefNumber(String name) {
        try {
            byte[] bytes = name.getBytes();
            return getPattern().nameToBackrefNumber(bytes, 0, bytes.length, regs);
        } catch (JOniException je) {
            throw metaClass.runtime.newIndexError(je.getMessage());
        }
    }

    // This returns a list of values in the order the names are defined (named capture local var
    // feature uses this).
    public IRubyObject[] getNamedBackrefValues(Ruby runtime) {
        final Regex pattern = getPattern();
        if (pattern.numberOfNames() == 0) return NULL_ARRAY;

        IRubyObject[] values = new IRubyObject[pattern.numberOfNames()];

        int j = 0;
        for (Iterator<NameEntry> i = pattern.namedBackrefIterator(); i.hasNext();) {
            NameEntry e = i.next();

            int nth = pattern.nameToBackrefNumber(e.name, e.nameP, e.nameEnd, regs);
            values[j++] = RubyRegexp.nth_match(nth, this);
        }

        return values;
    }

    @JRubyMethod
    @Override
    public RubyString inspect() {
        if (str == null) return (RubyString) anyToString();

        Ruby runtime = metaClass.runtime;
        RubyString result = runtime.newString();
        result.cat((byte)'#').cat((byte)'<');
        result.append(getMetaClass().getRealClass().to_s());

        NameEntry[] names = new NameEntry[regs == null ? 1 : regs.numRegs];

        final Regex pattern = getPattern();
        for (Iterator<NameEntry> i = pattern.namedBackrefIterator(); i.hasNext();) {
            NameEntry e = i.next();
            for (int num : e.getBackRefs()) names[num] = e;
        }

        for (int i = 0; i < names.length; i++) {
            result.cat((byte)' ');
            if (i > 0) {
                NameEntry e = names[i];
                if (e != null) {
                    result.cat(e.name, e.nameP, e.nameEnd - e.nameP);
                } else {
                    result.cat((byte)('0' + i));
                }
                result.cat((byte)':');
            }
            IRubyObject v = RubyRegexp.nth_match(i, this);
            if (v.isNil()) {
                result.cat(RubyNil.nilBytes); // "nil"
            } else {
                result.append(((RubyString)v).inspect(runtime));
            }
        }

        return result.cat((byte)'>');
    }

    @JRubyMethod
    public RubyRegexp regexp(ThreadContext context, Block block) {
        check();
        return getRegexp();
    }

    @JRubyMethod
    public IRubyObject names(ThreadContext context, Block block) {
        check();
        return getRegexp().names(context);
    }

    
match_to_a
/** match_to_a
     *
     */
    @JRubyMethod
    @Override
    public RubyArray to_a() {
        return match_array(metaClass.runtime, 0);
    }

    @JRubyMethod(rest = true)
    public IRubyObject values_at(ThreadContext context, IRubyObject[] args) {
        check();
        Ruby runtime = context.runtime;

        RubyArray result = RubyArray.newArray(runtime, args.length);

        for (IRubyObject arg : args) {
            if (arg instanceof RubyFixnum) {
                result.append(RubyRegexp.nth_match(arg.convertToInteger().getIntValue(), this));
            } else {
                int num = namevToBacktraceNumber(context, arg);
                if (num >= 0) {
                    result.append(RubyRegexp.nth_match(num, this));
                } else {
                    matchAryAref(context, arg, result);
                }
            }
        }

        return result;
    }

    public IRubyObject values_at(IRubyObject[] args) {
        return values_at(metaClass.runtime.getCurrentContext(), args);
    }

    
match_captures
/** match_captures
     *
     */
    @JRubyMethod
    public IRubyObject captures(ThreadContext context) {
        return match_array(context.runtime, 1);
    }

    private int nameToBackrefNumber(RubyString str) {
        check();
        return nameToBackrefNumber(metaClass.runtime, getPattern(), regs, str);
    }

    private static int nameToBackrefNumber(Ruby runtime, Regex pattern, Region regs, ByteListHolder str) {
        if (pattern == null) {
            throw runtime.newIndexError("undefined group name reference: " + str);
        }
        ByteList value = str.getByteList();
        try {
            return pattern.nameToBackrefNumber(value.getUnsafeBytes(), value.getBegin(), value.getBegin() + value.getRealSize(), regs);
        } catch (JOniException je) {
            throw runtime.newIndexError(je.getMessage());
        }
    }

    public final int backrefNumber(Ruby runtime, IRubyObject obj) {
        check();
        return backrefNumber(runtime, getPattern(), regs, obj);
    }

    public static int backrefNumber(Ruby runtime, Regex pattern, Region regs, IRubyObject obj) {
        if (obj instanceof RubySymbol) {
            return nameToBackrefNumber(runtime, pattern, regs, (RubyString)((RubySymbol)obj).id2name());
        } else if (obj instanceof RubyString) {
            return nameToBackrefNumber(runtime, pattern, regs, (RubyString)obj);
        } else {
            return RubyNumeric.num2int(obj);
        }
    }

    // MRI: namev_to_backref_number
    private int namevToBacktraceNumber(ThreadContext context, IRubyObject name) {
        int num = -1;

        switch (name.getType().getClassIndex()) {
            case SYMBOL:
                name = name.asString();
	            /* fall through */
            case STRING:
                Ruby runtime = context.runtime;
                if (regexp.isNil() || RubyEncoding.areCompatible(regexp, name) == null ||
                        (num = nameToBackrefNumber(runtime, regexp.getPattern(), regs, name.convertToString())) < 1) {
                    nameToBackrefError(runtime, name.toString());
                }
                return num;

            default:
                return -1;
        }
    }

    private int nameToBackrefError(Ruby runtime, String name) {
        throw runtime.newIndexError("undefined group name reference " + name);
    }

    // MRI: match_ary_subseq
    private IRubyObject matchArySubseq(ThreadContext context, int beg, int len, RubyArray result) {
        assert result != null;

        int olen = regs.numRegs;
        int wantedEnd = beg + len;
        int j, end = olen < wantedEnd ? olen : wantedEnd;

        if (len == 0) return result;

        for (j = beg; j < end; j++) {
            result.append(RubyRegexp.nth_match(j, this));
        }

        // if not enough groups, force length to be as wide as desired by setting last value to nil
        if (wantedEnd > j) {
            int newLength = result.size() + wantedEnd - j;
            result.storeInternal(newLength - 1, context.nil);
        }

        return result;
    }

    // MRI: match_ary_aref
    private IRubyObject matchAryAref(ThreadContext context, IRubyObject index, RubyArray result) {
        int[] begLen = new int[2];
        int numRegs = regs.numRegs;

        /* check if idx is Range */
        IRubyObject isRange = RubyRange.rangeBeginLength(context, index, numRegs, begLen, 1);

        if (isRange.isNil()) return context.nil;

        if (!isRange.isTrue()) {
            IRubyObject nthMatch = RubyRegexp.nth_match(index.convertToInteger().getIntValue(), this);

            // this should never happen here, but MRI allows any VALUE for result
            // if (result.isNil()) return nthMatch;

            return result.push(nthMatch);
        }

        return matchArySubseq(context, begLen[0], begLen[1], result);
    }


    @Deprecated
    public IRubyObject op_aref19(IRubyObject idx, IRubyObject rest) {
        return op_aref(idx, rest);
    }

    
match_aref
/** match_aref
     *
     */
    @JRubyMethod(name = "[]")
    public IRubyObject op_aref(IRubyObject idx) {
        check();
        IRubyObject result = op_arefCommon(idx);
        return result == null ? to_a().aref(idx) : result;
    }

    
match_aref
/** match_aref
    *
    */
    @JRubyMethod(name = "[]")
    public IRubyObject op_aref(IRubyObject idx, IRubyObject rest) {
        IRubyObject result;
        return !rest.isNil() || (result = op_arefCommon(idx)) == null ? to_a().aref(idx, rest) : result;
    }

    private IRubyObject op_arefCommon(IRubyObject idx) {
        if (idx instanceof RubyFixnum) {
            int num = RubyNumeric.fix2int(idx);
            if (num >= 0) return RubyRegexp.nth_match(num, this);
        } else {
            if (idx instanceof RubySymbol) {
                return RubyRegexp.nth_match(nameToBackrefNumber((RubyString)((RubySymbol)idx).id2name()), this);
            } else if (idx instanceof RubyString) {
                return RubyRegexp.nth_match(nameToBackrefNumber((RubyString)idx), this);
            }
        }
        return null;
    }

    public final IRubyObject at(final int nth) {
        return RubyRegexp.nth_match(nth, this);
    }

    
match_size
/** match_size
     *
     */
    @JRubyMethod(name = {"size", "length"})
    public IRubyObject size(ThreadContext context) {
        check();
        Ruby runtime = context.runtime;
        return regs == null ? RubyFixnum.one(runtime) : RubyFixnum.newFixnum(runtime, regs.numRegs);
    }

    
MRI: match_begin
/**
     * MRI: match_begin
     */
    @JRubyMethod
    public IRubyObject begin(ThreadContext context, IRubyObject index) {
        check();
        final Ruby runtime = context.runtime;
        final int i = backrefNumber(runtime, index);

        if (i < 0 || (regs == null ? 1 : regs.numRegs) <= i) {
            throw runtime.newIndexError("index " + i + " out of matches");
        }

        int b = regs == null ? begin : regs.beg[i];

        if (b < 0) return context.nil;

        updateCharOffset();

        return RubyFixnum.newFixnum(runtime, charOffsets.beg[i]);
    }

    
match_end
/** match_end
     *
     */
    @JRubyMethod
    public IRubyObject end(ThreadContext context, IRubyObject index) {
        check();

        final Ruby runtime = context.runtime;
        final int i = backrefNumber(runtime, index);

        if (i < 0 || (regs == null ? 1 : regs.numRegs) <= i) {
            throw runtime.newIndexError("index " + i + " out of matches");
        }

        int e = regs == null ? end : regs.end[i];

        if (e < 0) return context.nil;

        if ( ! str.singleByteOptimizable() ) {
            updateCharOffset();
            e = charOffsets.end[i];
        }

        return RubyFixnum.newFixnum(runtime, e);
    }

    
match_offset
/** match_offset
     *
     */
    public IRubyObject offset(ThreadContext context, IRubyObject index) {
        return offset19(context, index);
    }

    @JRubyMethod(name = "offset")
    public IRubyObject offset19(ThreadContext context, IRubyObject index) {
        check();

        final Ruby runtime = context.runtime;
        final int i = backrefNumber(runtime, index);

        if (i < 0 || (regs == null ? 1 : regs.numRegs) <= i) {
            throw runtime.newIndexError("index " + i + " out of matches");
        }

        int b, e;
        if (regs == null) {
            b = begin;
            e = end;
        } else {
            b = regs.beg[i];
            e = regs.end[i];
        }

        if (b < 0) return runtime.newArray(context.nil, context.nil);

        if ( ! str.singleByteOptimizable() ) {
            updateCharOffset();
            b = charOffsets.beg[i];
            e = charOffsets.end[i];
        }

        return runtime.newArray(RubyFixnum.newFixnum(runtime, b), RubyFixnum.newFixnum(runtime, e));
    }

    
match_pre_match
/** match_pre_match
     *
     */
    @JRubyMethod
    public IRubyObject pre_match(ThreadContext context) {
        check();
        if (begin == -1) return context.nil;

        return makeShared(context.runtime, str, 0, begin).infectBy(this);
    }

    
match_post_match
/** match_post_match
     *
     */
    @JRubyMethod
    public IRubyObject post_match(ThreadContext context) {
        check();
        if (begin == -1) return context.nil;

        final int strLen = str.getByteList().length();
        return makeShared(context.runtime, str, end, strLen - end).infectBy(this);
    }

    
match_to_s
/** match_to_s
     *
     */
    @JRubyMethod
    @Override
    public IRubyObject to_s() {
        check();
        IRubyObject ss = RubyRegexp.last_match(this);
        if (ss.isNil()) ss = RubyString.newEmptyString(metaClass.runtime);
        if (isTaint()) ss.setTaint(true);
        return ss;
    }

    
match_string
/** match_string
     *
     */
    @JRubyMethod
    public IRubyObject string() {
        check();
        return str; //str is frozen
    }

    @JRubyMethod(required = 1, visibility = Visibility.PRIVATE)
    @Override
    public IRubyObject initialize_copy(IRubyObject original) {
        if (this == original) return this;

        checkFrozen();

        if (!(original instanceof RubyMatchData)) {
            throw getRuntime().newTypeError("wrong argument class");
        }

        RubyMatchData origMatchData = (RubyMatchData)original;
        str = origMatchData.str;
        regs = origMatchData.regs;

        return this;
    }

    @Override
    public boolean equals(Object other) {
        if (this == other) return true;
        if (!(other instanceof RubyMatchData)) return false;

        final RubyMatchData that = (RubyMatchData) other;

        return (this.str == that.str || (this.str != null && this.str.equals(that.str))) &&
               (this.regexp == that.regexp || (this.getRegexp().equals(that.getRegexp()))) &&
               (this.charOffsets == that.charOffsets || (this.charOffsets != null && this.charOffsets.equals(that.charOffsets))) &&
               this.charOffsetUpdated == that.charOffsetUpdated &&
               this.begin == that.begin && this.end == that.end;
    }

    @JRubyMethod(name = {"eql?", "=="}, required = 1)
    @Override
    public IRubyObject eql_p(IRubyObject obj) {
        return metaClass.runtime.newBoolean( equals(obj) );
    }

    @Override
    public int hashCode() {
        check();
        return getPattern().hashCode() ^ str.hashCode();
    }

    @JRubyMethod
    @Override
    public RubyFixnum hash() {
        return metaClass.runtime.newFixnum( hashCode() );
    }

    @JRubyMethod
    public RubyHash named_captures(ThreadContext context) {
        check();
        Ruby runtime = context.runtime;
        RubyHash hash = RubyHash.newHash(runtime);
        if (regexp == context.nil) return hash;

        for (Iterator<NameEntry> i = getPattern().namedBackrefIterator(); i.hasNext();) {
            NameEntry entry = i.next();
            RubyString key = RubyString.newStringShared(runtime, new ByteList(entry.name, entry.nameP, entry.nameEnd - entry.nameP, regexp.getEncoding(), false));
            boolean found = false;

            for (int b : entry.getBackRefs()) {
                IRubyObject value = RubyRegexp.nth_match(b, this);
                if (value.isTrue()) {
                    hash.op_asetForString(runtime, key, value);
                    found = true;
                }
            }

            if (!found) hash.op_asetForString(runtime, key, context.nil);
        }

        return hash;
    }

    
Get the begin offset of the given region, or -1 if the region does not exist.
Params:
i – the region for which to fetch the begin offset
Returns:
the begin offset for the region/**
     * Get the begin offset of the given region, or -1 if the region does not exist.
     *
     * @param i the region for which to fetch the begin offset
     * @return the begin offset for the region
     */
    public int begin(int i) {
        if (regs == null) {
            if (i > 1) return -1;
            return begin;
        }
        if (i > regs.numRegs) return -1;
        return regs.beg[i];
    }

    
Get the end offset of the given region, or -1 if the region does not exist.
Params:
i – the region for which to fetch the end offset
Returns:
the end offset for the region/**
     * Get the end offset of the given region, or -1 if the region does not exist.
     *
     * @param i the region for which to fetch the end offset
     * @return the end offset for the region
     */
    public int end(int i) {
        if (regs == null) {
            if (i > 1) return -1;
            return end;
        }
        if (i > regs.numRegs) return -1;
        return regs.end[i];
    }

    
Fetch the number of regions in this match.
Returns:
the number of regions in this match/**
     * Fetch the number of regions in this match.
     *
     * @return the number of regions in this match
     */
    public int numRegs() {
        return regs == null ? 1 : regs.numRegs;
    }

}