regularexpression.java

java1.6众多例子参考

                            ch = REUtil.composeFromSurrogates(ch,  target [  ++offset ] );
                        if (isEOLChar(ch))
                            return -1;
                    }
                    offset ++;
                } else {
                    int o1 = offset-1;
                    if (o1 >= con.limit || o1 < 0)
                        return -1;
                    int ch =  target [  o1 ] ;
                    if (isSet(opts, SINGLE_LINE)) {
                        if (REUtil.isLowSurrogate(ch) && o1-1 >= 0)
                            o1 --;
                    } else {
                        if (REUtil.isLowSurrogate(ch) && o1-1 >= 0)
                            ch = REUtil.composeFromSurrogates( target [  --o1 ] , ch);
                        if (!isEOLChar(ch))
                            return -1;
                    }
                    offset = o1;
                }
                op = op.next;
                break;

            case Op.RANGE:
            case Op.NRANGE:
                if (dx > 0) {
                    if (offset >= con.limit)
                        return -1;
                    int ch =  target [  offset ] ;
                    if (REUtil.isHighSurrogate(ch) && offset+1 < con.limit)
                        ch = REUtil.composeFromSurrogates(ch,  target [  ++offset ] );
                    RangeToken tok = op.getToken();
                    if (isSet(opts, IGNORE_CASE)) {
                        tok = tok.getCaseInsensitiveToken();
                        if (!tok.match(ch)) {
                            if (ch >= 0x10000)  return -1;
                            char uch;
                            if (!tok.match(uch = Character.toUpperCase((char)ch))
                                && !tok.match(Character.toLowerCase(uch)))
                                return -1;
                        }
                    } else {
                        if (!tok.match(ch))  return -1;
                    }
                    offset ++;
                } else {
                    int o1 = offset-1;
                    if (o1 >= con.limit || o1 < 0)
                        return -1;
                    int ch =  target [  o1 ] ;
                    if (REUtil.isLowSurrogate(ch) && o1-1 >= 0)
                        ch = REUtil.composeFromSurrogates( target [  --o1 ] , ch);
                    RangeToken tok = op.getToken();
                    if (isSet(opts, IGNORE_CASE)) {
                        tok = tok.getCaseInsensitiveToken();
                        if (!tok.match(ch)) {
                            if (ch >= 0x10000)  return -1;
                            char uch;
                            if (!tok.match(uch = Character.toUpperCase((char)ch))
                                && !tok.match(Character.toLowerCase(uch)))
                                return -1;
                        }
                    } else {
                        if (!tok.match(ch))  return -1;
                    }
                    offset = o1;
                }
                op = op.next;
                break;

            case Op.ANCHOR:
                boolean go = false;
                switch (op.getData()) {
                case '^':
                    if (isSet(opts, MULTIPLE_LINES)) {
                        if (!(offset == con.start
                              || offset > con.start && isEOLChar( target [  offset-1 ] )))
                            return -1;
                    } else {
                        if (offset != con.start)
                            return -1;
                    }
                    break;

                case '@':                         // Internal use only.
                    // The @ always matches line beginnings.
                    if (!(offset == con.start
                          || offset > con.start && isEOLChar( target [  offset-1 ] )))
                        return -1;
                    break;

                case '$':
                    if (isSet(opts, MULTIPLE_LINES)) {
                        if (!(offset == con.limit
                              || offset < con.limit && isEOLChar( target [  offset ] )))
                            return -1;
                    } else {
                        if (!(offset == con.limit
                              || offset+1 == con.limit && isEOLChar( target [  offset ] )
                              || offset+2 == con.limit &&  target [  offset ]  == CARRIAGE_RETURN
                              &&  target [  offset+1 ]  == LINE_FEED))
                            return -1;
                    }
                    break;

                case 'A':
                    if (offset != con.start)  return -1;
                    break;

                case 'Z':
                    if (!(offset == con.limit
                          || offset+1 == con.limit && isEOLChar( target [  offset ] )
                          || offset+2 == con.limit &&  target [  offset ]  == CARRIAGE_RETURN
                          &&  target [  offset+1 ]  == LINE_FEED))
                        return -1;
                    break;

                case 'z':
                    if (offset != con.limit)  return -1;
                    break;

                case 'b':
                    if (con.length == 0)  return -1;
                    {
                        int after = getWordType(target, con.start, con.limit, offset, opts);
                        if (after == WT_IGNORE)  return -1;
                        int before = getPreviousWordType(target, con.start, con.limit, offset, opts);
                        if (after == before)  return -1;
                    }
                    break;

                case 'B':
                    if (con.length == 0)
                        go = true;
                    else {
                        int after = getWordType(target, con.start, con.limit, offset, opts);
                        go = after == WT_IGNORE
                             || after == getPreviousWordType(target, con.start, con.limit, offset, opts);
                    }
                    if (!go)  return -1;
                    break;

                case '<':
                    if (con.length == 0 || offset == con.limit)  return -1;
                    if (getWordType(target, con.start, con.limit, offset, opts) != WT_LETTER
                        || getPreviousWordType(target, con.start, con.limit, offset, opts) != WT_OTHER)
                        return -1;
                    break;

                case '>':
                    if (con.length == 0 || offset == con.start)  return -1;
                    if (getWordType(target, con.start, con.limit, offset, opts) != WT_OTHER
                        || getPreviousWordType(target, con.start, con.limit, offset, opts) != WT_LETTER)
                        return -1;
                    break;
                } // switch anchor type
                op = op.next;
                break;

            case Op.BACKREFERENCE:
                {
                    int refno = op.getData();
                    if (refno <= 0 || refno >= this.nofparen)
                        throw new RuntimeException("Internal Error: Reference number must be more than zero: "+refno);
                    if (con.match.getBeginning(refno) < 0
                        || con.match.getEnd(refno) < 0)
                        return -1;                // ********
                    int o2 = con.match.getBeginning(refno);
                    int literallen = con.match.getEnd(refno)-o2;
                    if (!isSet(opts, IGNORE_CASE)) {
                        if (dx > 0) {
                            if (!regionMatches(target, offset, con.limit, o2, literallen))
                                return -1;
                            offset += literallen;
                        } else {
                            if (!regionMatches(target, offset-literallen, con.limit, o2, literallen))
                                return -1;
                            offset -= literallen;
                        }
                    } else {
                        if (dx > 0) {
                            if (!regionMatchesIgnoreCase(target, offset, con.limit, o2, literallen))
                                return -1;
                            offset += literallen;
                        } else {
                            if (!regionMatchesIgnoreCase(target, offset-literallen, con.limit,
                                                         o2, literallen))
                                return -1;
                            offset -= literallen;
                        }
                    }
                }
                op = op.next;
                break;
            case Op.STRING:
                {
                    String literal = op.getString();
                    int literallen = literal.length();
                    if (!isSet(opts, IGNORE_CASE)) {
                        if (dx > 0) {
                            if (!regionMatches(target, offset, con.limit, literal, literallen))
                                return -1;
                            offset += literallen;
                        } else {
                            if (!regionMatches(target, offset-literallen, con.limit, literal, literallen))
                                return -1;
                            offset -= literallen;
                        }
                    } else {
                        if (dx > 0) {
                            if (!regionMatchesIgnoreCase(target, offset, con.limit, literal, literallen))
                                return -1;
                            offset += literallen;
                        } else {
                            if (!regionMatchesIgnoreCase(target, offset-literallen, con.limit,
                                                         literal, literallen))
                                return -1;
                            offset -= literallen;
                        }
                    }
                }
                op = op.next;
                break;

            case Op.CLOSURE:
                {
                    /*
                     * Saves current position to avoid
                     * zero-width repeats.
                     */
                    int id = op.getData();
                    if (id >= 0) {
                        int previousOffset = con.offsets[id];
                        if (previousOffset < 0 || previousOffset != offset) {
                            con.offsets[id] = offset;
                        } else {
                            con.offsets[id] = -1;
                            op = op.next;
                            break;
                        }
                    }

                    int ret = this. matchCharArray (con, op.getChild(), offset, dx, opts);
                    if (id >= 0)  con.offsets[id] = -1;
                    if (ret >= 0)  return ret;
                    op = op.next;
                }
                break;

            case Op.QUESTION:
                {
                    int ret = this. matchCharArray (con, op.getChild(), offset, dx, opts);
                    if (ret >= 0)  return ret;
                    op = op.next;
                }
                break;

            case Op.NONGREEDYCLOSURE:
            case Op.NONGREEDYQUESTION:
                {
                    int ret = this. matchCharArray (con, op.next, offset, dx, opts);
                    if (ret >= 0)  return ret;
                    op = op.getChild();
                }
                break;

            case Op.UNION:
                for (int i = 0;  i < op.size();  i ++) {
                    int ret = this. matchCharArray (con, op.elementAt(i), offset, dx, opts);
                    if (DEBUG) {
                        System.err.println("UNION: "+i+", ret="+ret);
                    }
                    if (ret >= 0)  return ret;
                }
                return -1;

            case Op.CAPTURE:
                int refno = op.getData();
                if (con.match != null && refno > 0) {
                    int save = con.match.getBeginning(refno);
                    con.match.setBeginning(refno, offset);
                    int ret = this. matchCharArray (con, op.next, offset, dx, opts);
                    if (ret < 0)  con.match.setBeginning(refno, save);
                    return ret;
                } else if (con.match != null && refno < 0) {
                    int index = -refno;
                    int save = con.match.getEnd(index);
                    con.match.setEnd(index, offset);
                    int ret = this. matchCharArray (con, op.next, offset, dx, opts);
                    if (ret < 0)  con.match.setEnd(index, save);
                    return ret;
                }
                op = op.next;
                break;

            case Op.LOOKAHEAD:
                if (0 > this. matchCharArray (con, op.getChild(), offset, 1, opts))  return -1;
                op = op.next;
                break;
            case Op.NEGATIVELOOKAHEAD:
                if (0 <= this. matchCharArray (con, op.getChild(), offset, 1, opts))  return -1;
                op = op.next;
                break;
            case Op.LOOKBEHIND: