001: /*
002: * Copyright (c) 1998-2008 Caucho Technology -- all rights reserved
003: *
004: * This file is part of Resin(R) Open Source
005: *
006: * Each copy or derived work must preserve the copyright notice and this
007: * notice unmodified.
008: *
009: * Resin Open Source is free software; you can redistribute it and/or modify
010: * it under the terms of the GNU General Public License as published by
011: * the Free Software Foundation; either version 2 of the License, or
012: * (at your option) any later version.
013: *
014: * Resin Open Source is distributed in the hope that it will be useful,
015: * but WITHOUT ANY WARRANTY; without even the implied warranty of
016: * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE, or any warranty
017: * of NON-INFRINGEMENT. See the GNU General Public License for more
018: * details.
019: *
020: * You should have received a copy of the GNU General Public License
021: * along with Resin Open Source; if not, write to the
022: * Free SoftwareFoundation, Inc.
023: * 59 Temple Place, Suite 330
024: * Boston, MA 02111-1307 USA
025: *
026: * @author Scott Ferguson
027: */
028:
029: package com.caucho.xpath.pattern;
030:
031: import com.caucho.xpath.Env;
032: import com.caucho.xpath.ExprEnvironment;
033: import com.caucho.xpath.XPathException;
034:
035: import org.w3c.dom.Node;
036:
037: /**
038: * Implementation of the 'a|b' pattern. It's made public
039: * so XSLT can separate the left and right sides.
040: */
041: public class UnionPattern extends AbstractPattern {
042: private AbstractPattern _left;
043: private AbstractPattern _right;
044:
045: public UnionPattern(AbstractPattern left, AbstractPattern right) {
046: super (null);
047:
048: if (right.getParent() instanceof FromAttributes
049: && left.getParent() instanceof FromChildren) {
050: _left = right;
051: _right = left;
052: } else {
053: _left = left;
054: _right = right;
055: }
056: }
057:
058: /**
059: * Match if either pattern matches.
060: *
061: * @param node the node to test
062: * @param env the variable environment
063: *
064: * @return true if the pattern matches.
065: */
066: public boolean match(Node node, ExprEnvironment env)
067: throws XPathException {
068: return (_left.match(node, env) || _right.match(node, env));
069: }
070:
071: /**
072: * Returns true if the nodes are ascending.
073: */
074: public boolean isStrictlyAscending() {
075: // @*|node()
076: if (_left.getParent() instanceof FromAttributes
077: && _right.getParent() instanceof FromChildren)
078: return true;
079: else
080: return false;
081: }
082:
083: /**
084: * Creates a new node iterator.
085: *
086: * @param node the starting node
087: * @param env the xpath environment
088: * @param match the axis match pattern
089: *
090: * @return the node iterator
091: */
092: public NodeIterator createNodeIterator(Node node,
093: ExprEnvironment env, AbstractPattern match)
094: throws XPathException {
095: NodeIterator leftIter = _left.createNodeIterator(node, env,
096: _left.copyPosition());
097: NodeIterator rightIter = _right.createNodeIterator(node, env,
098: _right.copyPosition());
099:
100: return new UnionIterator(env, leftIter, rightIter);
101: }
102:
103: public int position(Node node, Env env, AbstractPattern pattern)
104: throws XPathException {
105: NodeIterator iter = select(node, env);
106:
107: int i = 1;
108: while (iter.hasNext()) {
109: if (iter.next() == node)
110: return i;
111: i++;
112: }
113:
114: return 0;
115: }
116:
117: public int count(Node node, Env env, AbstractPattern pattern)
118: throws XPathException {
119: NodeIterator iter = select(node, env);
120: int count = 0;
121:
122: while (iter.hasNext()) {
123: iter.next();
124: count++;
125: }
126:
127: return count;
128: }
129:
130: /**
131: * Return left node of the union.
132: */
133: public AbstractPattern getLeft() {
134: return _left;
135: }
136:
137: /**
138: * Return right node of the union.
139: */
140: public AbstractPattern getRight() {
141: return _right;
142: }
143:
144: public String toString() {
145: // XXX: '(' ?? ')'
146: return _left.toString() + "|" + _right.toString();
147: }
148: }
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