| /* gnu/regexp/RETokenOneOf.java |
| Copyright (C) 2006 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., 51 Franklin Street, Fifth Floor, Boston, MA |
| 02110-1301 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.java.util.regex; |
| import java.util.Vector; |
| import java.util.Stack; |
| |
| final class RETokenOneOf extends REToken { |
| private Vector options; |
| private boolean negative; |
| // True if this RETokenOneOf is supposed to match only one character, |
| // which is typically the case of a character class expression. |
| private boolean matchesOneChar; |
| |
| private Vector addition; |
| // This Vector addition is used to store nested character classes. |
| // For example, if the original expression is |
| // [2-7a-c[f-k][m-z]&&[^p-v][st]] |
| // the basic part /2-7a-c/ is stored in the Vector options, and |
| // the additional part /[f-k][m-z]&&[^p-v][st]/ is stored in the |
| // Vector addition in the following order (Reverse Polish Notation): |
| // -- The matching result of the basic part is assumed here. |
| // [f-k] -- REToken |
| // "|" -- or |
| // [m-z] -- REToken |
| // "|" -- or |
| // false |
| // [^p-v] -- REToken |
| // "|" -- or |
| // [st] -- REToken |
| // "|" -- or |
| // "&" -- and |
| // |
| // As it is clear from the explanation above, the Vector addition is |
| // effective only when this REToken originates from a character class |
| // expression. |
| |
| // This constructor is used for convenience when we know the set beforehand, |
| // e.g. \d --> new RETokenOneOf("0123456789",false, ..) |
| // \D --> new RETokenOneOf("0123456789",true, ..) |
| |
| RETokenOneOf(int subIndex, String optionsStr, boolean negative, boolean insens) { |
| super(subIndex); |
| options = new Vector(); |
| this.negative = negative; |
| for (int i = 0; i < optionsStr.length(); i++) |
| options.addElement(new RETokenChar(subIndex,optionsStr.charAt(i),insens)); |
| matchesOneChar = true; |
| } |
| |
| RETokenOneOf(int subIndex, Vector options, boolean negative) { |
| super(subIndex); |
| this.options = options; |
| this.negative = negative; |
| matchesOneChar = negative; |
| } |
| |
| RETokenOneOf(int subIndex, Vector options, Vector addition, boolean negative) { |
| super(subIndex); |
| this.options = options; |
| this.addition = addition; |
| this.negative = negative; |
| matchesOneChar = (negative || addition != null); |
| } |
| |
| int getMinimumLength() { |
| if (matchesOneChar) return 1; |
| int min = Integer.MAX_VALUE; |
| int x; |
| for (int i=0; i < options.size(); i++) { |
| if ((x = ((REToken) options.elementAt(i)).getMinimumLength()) < min) |
| min = x; |
| } |
| return min; |
| } |
| |
| int getMaximumLength() { |
| if (matchesOneChar) return 1; |
| int max = 0; |
| int x; |
| for (int i=0; i < options.size(); i++) { |
| if ((x = ((REToken) options.elementAt(i)).getMaximumLength()) > max) |
| max = x; |
| } |
| return max; |
| } |
| |
| boolean match(CharIndexed input, REMatch mymatch) { |
| if (matchesOneChar) return matchOneChar(input, mymatch); |
| else return matchOneRE(input, mymatch); |
| } |
| |
| boolean matchOneChar(CharIndexed input, REMatch mymatch) { |
| REMatch tryMatch; |
| boolean tryOnly; |
| if (addition == null) { |
| tryMatch = mymatch; |
| tryOnly = false; |
| } |
| else { |
| tryMatch = (REMatch) mymatch.clone(); |
| tryOnly = true; |
| } |
| boolean b = negative ? |
| matchN(input, tryMatch, tryOnly) : |
| matchP(input, tryMatch, tryOnly); |
| if (addition == null) return b; |
| |
| Stack stack = new Stack(); |
| stack.push(new Boolean(b)); |
| for (int i=0; i < addition.size(); i++) { |
| Object obj = addition.elementAt(i); |
| if (obj instanceof REToken) { |
| b = ((REToken)obj).match(input, (REMatch)mymatch.clone()); |
| stack.push(new Boolean(b)); |
| } |
| else if (obj instanceof Boolean) { |
| stack.push(obj); |
| } |
| else if (obj.equals("|")) { |
| b = ((Boolean)stack.pop()).booleanValue(); |
| b = ((Boolean)stack.pop()).booleanValue() || b; |
| stack.push(new Boolean(b)); |
| } |
| else if (obj.equals("&")) { |
| b = ((Boolean)stack.pop()).booleanValue(); |
| b = ((Boolean)stack.pop()).booleanValue() && b; |
| stack.push(new Boolean(b)); |
| } |
| else { |
| throw new RuntimeException("Invalid object found"); |
| } |
| } |
| b = ((Boolean)stack.pop()).booleanValue(); |
| if (b) { |
| ++mymatch.index; |
| return next(input, mymatch); |
| } |
| return false; |
| } |
| |
| private boolean matchN(CharIndexed input, REMatch mymatch, boolean tryOnly) { |
| if (input.charAt(mymatch.index) == CharIndexed.OUT_OF_BOUNDS) |
| return false; |
| |
| REMatch newMatch = null; |
| REMatch last = null; |
| REToken tk; |
| for (int i=0; i < options.size(); i++) { |
| tk = (REToken) options.elementAt(i); |
| REMatch tryMatch = (REMatch) mymatch.clone(); |
| if (tk.match(input, tryMatch)) { // match was successful |
| return false; |
| } // is a match |
| } // try next option |
| |
| if (tryOnly) return true; |
| ++mymatch.index; |
| return next(input, mymatch); |
| } |
| |
| private boolean matchP(CharIndexed input, REMatch mymatch, boolean tryOnly) { |
| REToken tk; |
| for (int i=0; i < options.size(); i++) { |
| tk = (REToken) options.elementAt(i); |
| REMatch tryMatch = (REMatch) mymatch.clone(); |
| if (tk.match(input, tryMatch)) { // match was successful |
| if (tryOnly) return true; |
| if (next(input, tryMatch)) { |
| mymatch.assignFrom(tryMatch); |
| return true; |
| } |
| } |
| } |
| return false; |
| } |
| |
| private boolean matchOneRE(CharIndexed input, REMatch mymatch) { |
| REMatch newMatch = findMatch(input, mymatch); |
| if (newMatch != null) { |
| mymatch.assignFrom(newMatch); |
| return true; |
| } |
| return false; |
| } |
| |
| REMatch findMatch(CharIndexed input, REMatch mymatch) { |
| if (matchesOneChar) return super.findMatch(input, mymatch); |
| return findMatch(input, mymatch, 0); |
| } |
| |
| REMatch backtrack(CharIndexed input, REMatch mymatch, Object param) { |
| return findMatch(input, mymatch, ((Integer)param).intValue()); |
| } |
| |
| private REMatch findMatch(CharIndexed input, REMatch mymatch, int optionIndex) { |
| for (int i = optionIndex; i < options.size(); i++) { |
| REToken tk = (REToken) options.elementAt(i); |
| tk = (REToken) tk.clone(); |
| tk.chain(getNext()); |
| REMatch tryMatch = (REMatch) mymatch.clone(); |
| if (tryMatch.backtrackStack == null) { |
| tryMatch.backtrackStack = new BacktrackStack(); |
| } |
| boolean stackPushed = false; |
| if (i + 1 < options.size()) { |
| tryMatch.backtrackStack.push(new BacktrackStack.Backtrack( |
| this, input, mymatch, new Integer(i + 1))); |
| stackPushed = true; |
| } |
| boolean b = tk.match(input, tryMatch); |
| if (b) { |
| return tryMatch; |
| } |
| if (stackPushed) tryMatch.backtrackStack.pop(); |
| } |
| return null; |
| } |
| |
| boolean returnsFixedLengthMatches() { return matchesOneChar; } |
| |
| int findFixedLengthMatches(CharIndexed input, REMatch mymatch, int max) { |
| if (!matchesOneChar) |
| return super.findFixedLengthMatches(input, mymatch, max); |
| int numRepeats = 0; |
| REMatch m = (REMatch) mymatch.clone(); |
| REToken tk = (REToken) this.clone(); |
| tk.chain(null); |
| while (true) { |
| if (numRepeats >= max) break; |
| m = tk.findMatch(input, m); |
| if (m == null) break; |
| numRepeats++; |
| } |
| return numRepeats; |
| } |
| |
| void dump(StringBuffer os) { |
| os.append(negative ? "[^" : "(?:"); |
| for (int i = 0; i < options.size(); i++) { |
| if (!negative && (i > 0)) os.append('|'); |
| ((REToken) options.elementAt(i)).dumpAll(os); |
| } |
| os.append(negative ? ']' : ')'); |
| } |
| } |