001: /*
002: * The Apache Software License, Version 1.1
003: *
004: *
005: * Copyright (c) 1999 The Apache Software Foundation. All rights
006: * reserved.
007: *
008: * Redistribution and use in source and binary forms, with or without
009: * modification, are permitted provided that the following conditions
010: * are met:
011: *
012: * 1. Redistributions of source code must retain the above copyright
013: * notice, this list of conditions and the following disclaimer.
014: *
015: * 2. Redistributions in binary form must reproduce the above copyright
016: * notice, this list of conditions and the following disclaimer in
017: * the documentation and/or other materials provided with the
018: * distribution.
019: *
020: * 3. The end-user documentation included with the redistribution,
021: * if any, must include the following acknowledgment:
022: * "This product includes software developed by the
023: * Apache Software Foundation (http://www.apache.org/)."
024: * Alternately, this acknowledgment may appear in the software itself,
025: * if and wherever such third-party acknowledgments normally appear.
026: *
027: * 4. The names "Xerces" and "Apache Software Foundation" must
028: * not be used to endorse or promote products derived from this
029: * software without prior written permission. For written
030: * permission, please contact apache@apache.org.
031: *
032: * 5. Products derived from this software may not be called "Apache",
033: * nor may "Apache" appear in their name, without prior written
034: * permission of the Apache Software Foundation.
035: *
036: * THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
037: * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
038: * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
039: * DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
040: * ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
041: * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
042: * LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
043: * USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
044: * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
045: * OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
046: * OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
047: * SUCH DAMAGE.
048: * ====================================================================
049: *
050: * This software consists of voluntary contributions made by many
051: * individuals on behalf of the Apache Software Foundation and was
052: * originally based on software copyright (c) 1999, International
053: * Business Machines, Inc., http://www.apache.org. For more
054: * information on the Apache Software Foundation, please see
055: * <http://www.apache.org/>.
056: */
057:
058: package org.apache.xerces.validators.common;
059:
060: import org.apache.xerces.framework.XMLContentSpec;
061: import org.apache.xerces.utils.ImplementationMessages;
062:
063: /**
064: *
065: * @version
066: */
067: public class CMBinOp extends CMNode {
068: // -------------------------------------------------------------------
069: // Constructors
070: // -------------------------------------------------------------------
071: public CMBinOp(int type, CMNode leftNode, CMNode rightNode)
072: throws CMException {
073: super (type);
074:
075: // Insure that its one of the types we require
076: if ((type() != XMLContentSpec.CONTENTSPECNODE_CHOICE)
077: && (type() != XMLContentSpec.CONTENTSPECNODE_SEQ)) {
078: throw new CMException(ImplementationMessages.VAL_BST);
079: }
080:
081: // Store the nodes and init any data that needs it
082: fLeftChild = leftNode;
083: fRightChild = rightNode;
084: }
085:
086: // -------------------------------------------------------------------
087: // Package, final methods
088: // -------------------------------------------------------------------
089: final CMNode getLeft() {
090: return fLeftChild;
091: }
092:
093: final CMNode getRight() {
094: return fRightChild;
095: }
096:
097: // -------------------------------------------------------------------
098: // Package, inherited methods
099: // -------------------------------------------------------------------
100: boolean isNullable() throws CMException {
101: //
102: // If its an alternation, then if either child is nullable then
103: // this node is nullable. If its a concatenation, then both of
104: // them have to be nullable.
105: //
106: if (type() == XMLContentSpec.CONTENTSPECNODE_CHOICE)
107: return (fLeftChild.isNullable() || fRightChild.isNullable());
108: else if (type() == XMLContentSpec.CONTENTSPECNODE_SEQ)
109: return (fLeftChild.isNullable() && fRightChild.isNullable());
110: else
111: throw new CMException(ImplementationMessages.VAL_BST);
112: }
113:
114: // -------------------------------------------------------------------
115: // Protected, inherited methods
116: // -------------------------------------------------------------------
117: protected void calcFirstPos(CMStateSet toSet) throws CMException {
118: if (type() == XMLContentSpec.CONTENTSPECNODE_CHOICE) {
119: // Its the the union of the first positions of our children.
120: toSet.setTo(fLeftChild.firstPos());
121: toSet.union(fRightChild.firstPos());
122: } else if (type() == XMLContentSpec.CONTENTSPECNODE_SEQ) {
123: //
124: // If our left child is nullable, then its the union of our
125: // children's first positions. Else is our left child's first
126: // positions.
127: //
128: toSet.setTo(fLeftChild.firstPos());
129: if (fLeftChild.isNullable())
130: toSet.union(fRightChild.firstPos());
131: } else {
132: throw new CMException(ImplementationMessages.VAL_BST);
133: }
134: }
135:
136: protected void calcLastPos(CMStateSet toSet) throws CMException {
137: if (type() == XMLContentSpec.CONTENTSPECNODE_CHOICE) {
138: // Its the the union of the first positions of our children.
139: toSet.setTo(fLeftChild.lastPos());
140: toSet.union(fRightChild.lastPos());
141: } else if (type() == XMLContentSpec.CONTENTSPECNODE_SEQ) {
142: //
143: // If our right child is nullable, then its the union of our
144: // children's last positions. Else is our right child's last
145: // positions.
146: //
147: toSet.setTo(fRightChild.lastPos());
148: if (fRightChild.isNullable())
149: toSet.union(fLeftChild.lastPos());
150: } else {
151: throw new CMException(ImplementationMessages.VAL_BST);
152: }
153: }
154:
155: // -------------------------------------------------------------------
156: // Private data members
157: //
158: // fLeftChild
159: // fRightChild
160: // These are the references to the two nodes that are on either
161: // side of this binary operation.
162: // -------------------------------------------------------------------
163: private CMNode fLeftChild;
164: private CMNode fRightChild;
165: };
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