| /* gnu/regexp/RETokenWordBoundary.java |
| Copyright (C) 2001, 2004 Free Software Foundation, Inc. |
| |
| This file is part of GNU Classpath. |
| |
| GNU Classpath is free software; you can redistribute it and/or modify |
| it under the terms of the GNU General Public License as published by |
| the Free Software Foundation; either version 2, or (at your option) |
| any later version. |
| |
| GNU Classpath 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 for more details. |
| |
| You should have received a copy of the GNU General Public License |
| along with GNU Classpath; see the file COPYING. If not, write to the |
| Free Software Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA |
| 02111-1307 USA. |
| |
| Linking this library statically or dynamically with other modules is |
| making a combined work based on this library. Thus, the terms and |
| conditions of the GNU General Public License cover the whole |
| combination. |
| |
| As a special exception, the copyright holders of this library give you |
| permission to link this library with independent modules to produce an |
| executable, regardless of the license terms of these independent |
| modules, and to copy and distribute the resulting executable under |
| terms of your choice, provided that you also meet, for each linked |
| independent module, the terms and conditions of the license of that |
| module. An independent module is a module which is not derived from |
| or based on this library. If you modify this library, you may extend |
| this exception to your version of the library, but you are not |
| obligated to do so. If you do not wish to do so, delete this |
| exception statement from your version. */ |
| |
| |
| package gnu.regexp; |
| |
| /** |
| * Represents a combination lookahead/lookbehind for POSIX [:alnum:]. |
| */ |
| final class RETokenWordBoundary extends REToken { |
| private boolean negated; |
| private int where; |
| static final int BEGIN = 1; |
| static final int END = 2; |
| |
| RETokenWordBoundary(int subIndex, int where, boolean negated) { |
| super(subIndex); |
| this.where = where; |
| this.negated = negated; |
| } |
| |
| boolean match(CharIndexed input, REMatch mymatch) { |
| // Word boundary means input[index-1] was a word character |
| // and input[index] is not, or input[index] is a word character |
| // and input[index-1] was not |
| // In the string "one two three", these positions match: |
| // |o|n|e| |t|w|o| |t|h|r|e|e| |
| // ^ ^ ^ ^ ^ ^ |
| boolean after = false; // is current character a letter or digit? |
| boolean before = false; // is previous character a letter or digit? |
| char ch; |
| |
| // TODO: Also check REG_ANCHORINDEX vs. anchor |
| if (((mymatch.eflags & RE.REG_ANCHORINDEX) != RE.REG_ANCHORINDEX) |
| || (mymatch.offset + mymatch.index > mymatch.anchor)) { |
| if ((ch = input.charAt(mymatch.index - 1)) != CharIndexed.OUT_OF_BOUNDS) { |
| before = Character.isLetterOrDigit(ch) || (ch == '_'); |
| } |
| } |
| |
| if ((ch = input.charAt(mymatch.index)) != CharIndexed.OUT_OF_BOUNDS) { |
| after = Character.isLetterOrDigit(ch) || (ch == '_'); |
| } |
| |
| // if (before) and (!after), we're at end (\>) |
| // if (after) and (!before), we're at beginning (\<) |
| boolean doNext = false; |
| |
| if ((where & BEGIN) == BEGIN) { |
| doNext = after && !before; |
| } |
| if ((where & END) == END) { |
| doNext ^= before && !after; |
| } |
| |
| if (negated) doNext = !doNext; |
| |
| return (doNext ? next(input, mymatch) : false); |
| } |
| |
| void dump(StringBuffer os) { |
| if (where == (BEGIN | END)) { |
| os.append( negated ? "\\B" : "\\b" ); |
| } else if (where == BEGIN) { |
| os.append("\\<"); |
| } else { |
| os.append("\\>"); |
| } |
| } |
| } |