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	/*
	* Copyright (c) 2017, Oracle and/or its affiliates. All rights reserved.
	*/
	/*
	* Licensed to the Apache Software Foundation (ASF) under one or more
	* contributor license agreements. See the NOTICE file distributed with
	* this work for additional information regarding copyright ownership.
	* The ASF licenses this file to You under the Apache License, Version 2.0
	* (the "License"); you may not use this file except in compliance with
	* the License. You may obtain a copy of the License at
	*
	* http://www.apache.org/licenses/LICENSE-2.0
	*
	* Unless required by applicable law or agreed to in writing, software
	* distributed under the License is distributed on an "AS IS" BASIS,
	* WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
	* See the License for the specific language governing permissions and
	* limitations under the License.
	*/

	package com.sun.org.apache.xpath.internal;

	import com.sun.org.apache.xalan.internal.res.XSLMessages;
	import com.sun.org.apache.xml.internal.dtm.DTM;
	import com.sun.org.apache.xml.internal.utils.PrefixResolver;
	import com.sun.org.apache.xml.internal.utils.QName;
	import com.sun.org.apache.xml.internal.utils.SAXSourceLocator;
	import com.sun.org.apache.xpath.internal.compiler.Compiler;
	import com.sun.org.apache.xpath.internal.compiler.FunctionTable;
	import com.sun.org.apache.xpath.internal.compiler.XPathParser;
	import com.sun.org.apache.xpath.internal.objects.XObject;
	import com.sun.org.apache.xpath.internal.res.XPATHErrorResources;
	import java.io.Serializable;
	import java.util.List;
	import javax.xml.transform.ErrorListener;
	import javax.xml.transform.SourceLocator;
	import javax.xml.transform.TransformerException;

	/**
	* The XPath class wraps an expression object and provides general services
	* for execution of that expression.
	* @xsl.usage advanced
	* @LastModified: Oct 2017
	*/
	public class XPath implements Serializable, ExpressionOwner
	{
	static final long serialVersionUID = 3976493477939110553L;

	/** The top of the expression tree.
	* @serial */
	private Expression m_mainExp;

	/**
	* The function table for xpath build-in functions
	*/
	private transient FunctionTable m_funcTable = null;

	/**
	* initial the function table
	*/
	private void initFunctionTable(){
	m_funcTable = new FunctionTable();
	}

	/**
	* Get the raw Expression object that this class wraps.
	*
	*
	* @return the raw Expression object, which should not normally be null.
	*/
	public Expression getExpression()
	{
	return m_mainExp;
	}

	/**
	* This function is used to fixup variables from QNames to stack frame
	* indexes at stylesheet build time.
	* @param vars List of QNames that correspond to variables. This list
	* should be searched backwards for the first qualified name that
	* corresponds to the variable reference qname. The position of the
	* QName in the vector from the start of the vector will be its position
	* in the stack frame (but variables above the globalsTop value will need
	* to be offset to the current stack frame).
	*/
	public void fixupVariables(List<QName> vars, int globalsSize)
	{
	m_mainExp.fixupVariables(vars, globalsSize);
	}

	/**
	* Set the raw expression object for this object.
	*
	*
	* @param exp the raw Expression object, which should not normally be null.
	*/
	public void setExpression(Expression exp)
	{
	if(null != m_mainExp)
	exp.exprSetParent(m_mainExp.exprGetParent()); // a bit bogus
	m_mainExp = exp;
	}

	/**
	* Get the SourceLocator on the expression object.
	*
	*
	* @return the SourceLocator on the expression object, which may be null.
	*/
	public SourceLocator getLocator()
	{
	return m_mainExp;
	}

	// /**
	// * Set the SourceLocator on the expression object.
	// *
	// *
	// * @param l the SourceLocator on the expression object, which may be null.
	// */
	// public void setLocator(SourceLocator l)
	// {
	// // Note potential hazards -- l may not be serializable, or may be changed
	// // after being assigned here.
	// m_mainExp.setSourceLocator(l);
	// }

	/** The pattern string, mainly kept around for diagnostic purposes.
	* @serial */
	String m_patternString;

	/**
	* Return the XPath string associated with this object.
	*
	*
	* @return the XPath string associated with this object.
	*/
	public String getPatternString()
	{
	return m_patternString;
	}

	/** Represents a select type expression. */
	public static final int SELECT = 0;

	/** Represents a match type expression. */
	public static final int MATCH = 1;

	/**
	* Construct an XPath object.
	*
	* (Needs review -sc) This method initializes an XPathParser/
	* Compiler and compiles the expression.
	* @param exprString The XPath expression.
	* @param locator The location of the expression, may be null.
	* @param prefixResolver A prefix resolver to use to resolve prefixes to
	* namespace URIs.
	* @param type one of {@link #SELECT} or {@link #MATCH}.
	* @param errorListener The error listener, or null if default should be used.
	*
	* @throws javax.xml.transform.TransformerException if syntax or other error.
	*/
	public XPath(
	String exprString, SourceLocator locator, PrefixResolver prefixResolver, int type,
	ErrorListener errorListener)
	throws javax.xml.transform.TransformerException
	{
	initFunctionTable();
	if(null == errorListener)
	errorListener = new com.sun.org.apache.xml.internal.utils.DefaultErrorHandler();

	m_patternString = exprString;

	XPathParser parser = new XPathParser(errorListener, locator);
	Compiler compiler = new Compiler(errorListener, locator, m_funcTable);

	if (SELECT == type)
	parser.initXPath(compiler, exprString, prefixResolver);
	else if (MATCH == type)
	parser.initMatchPattern(compiler, exprString, prefixResolver);
	else
	throw new RuntimeException(XSLMessages.createXPATHMessage(XPATHErrorResources.ER_CANNOT_DEAL_XPATH_TYPE, new Object[]{Integer.toString(type)})); //"Can not deal with XPath type: " + type);

	// System.out.println("----------------");
	Expression expr = compiler.compile(0);

	// System.out.println("expr: "+expr);
	this.setExpression(expr);

	if((null != locator) && locator instanceof ExpressionNode)
	{
	expr.exprSetParent((ExpressionNode)locator);
	}

	}

	/**
	* Construct an XPath object.
	*
	* (Needs review -sc) This method initializes an XPathParser/
	* Compiler and compiles the expression.
	* @param exprString The XPath expression.
	* @param locator The location of the expression, may be null.
	* @param prefixResolver A prefix resolver to use to resolve prefixes to
	* namespace URIs.
	* @param type one of {@link #SELECT} or {@link #MATCH}.
	* @param errorListener The error listener, or null if default should be used.
	*
	* @throws javax.xml.transform.TransformerException if syntax or other error.
	*/
	public XPath(
	String exprString, SourceLocator locator,
	PrefixResolver prefixResolver, int type,
	ErrorListener errorListener, FunctionTable aTable)
	throws javax.xml.transform.TransformerException
	{
	m_funcTable = aTable;
	if(null == errorListener)
	errorListener = new com.sun.org.apache.xml.internal.utils.DefaultErrorHandler();

	m_patternString = exprString;

	XPathParser parser = new XPathParser(errorListener, locator);
	Compiler compiler = new Compiler(errorListener, locator, m_funcTable);

	if (SELECT == type)
	parser.initXPath(compiler, exprString, prefixResolver);
	else if (MATCH == type)
	parser.initMatchPattern(compiler, exprString, prefixResolver);
	else
	throw new RuntimeException(XSLMessages.createXPATHMessage(
	XPATHErrorResources.ER_CANNOT_DEAL_XPATH_TYPE,
	new Object[]{Integer.toString(type)}));
	//"Can not deal with XPath type: " + type);

	// System.out.println("----------------");
	Expression expr = compiler.compile(0);

	// System.out.println("expr: "+expr);
	this.setExpression(expr);

	if((null != locator) && locator instanceof ExpressionNode)
	{
	expr.exprSetParent((ExpressionNode)locator);
	}

	}

	/**
	* Construct an XPath object.
	*
	* (Needs review -sc) This method initializes an XPathParser/
	* Compiler and compiles the expression.
	* @param exprString The XPath expression.
	* @param locator The location of the expression, may be null.
	* @param prefixResolver A prefix resolver to use to resolve prefixes to
	* namespace URIs.
	* @param type one of {@link #SELECT} or {@link #MATCH}.
	*
	* @throws javax.xml.transform.TransformerException if syntax or other error.
	*/
	public XPath(
	String exprString, SourceLocator locator, PrefixResolver prefixResolver, int type)
	throws javax.xml.transform.TransformerException
	{
	this(exprString, locator, prefixResolver, type, null);
	}

	/**
	* Construct an XPath object.
	*
	* @param expr The Expression object.
	*
	* @throws javax.xml.transform.TransformerException if syntax or other error.
	*/
	public XPath(Expression expr)
	{
	this.setExpression(expr);
	initFunctionTable();
	}

	/**
	* Given an expression and a context, evaluate the XPath
	* and return the result.
	*
	* @param xctxt The execution context.
	* @param contextNode The node that "." expresses.
	* @param namespaceContext The context in which namespaces in the
	* XPath are supposed to be expanded.
	*
	* @return The result of the XPath or null if callbacks are used.
	* @throws TransformerException thrown if
	* the error condition is severe enough to halt processing.
	*
	* @throws javax.xml.transform.TransformerException
	* @xsl.usage experimental
	*/
	public XObject execute(
	XPathContext xctxt, org.w3c.dom.Node contextNode,
	PrefixResolver namespaceContext)
	throws javax.xml.transform.TransformerException
	{
	return execute(
	xctxt, xctxt.getDTMHandleFromNode(contextNode),
	namespaceContext);
	}


	/**
	* Given an expression and a context, evaluate the XPath
	* and return the result.
	*
	* @param xctxt The execution context.
	* @param contextNode The node that "." expresses.
	* @param namespaceContext The context in which namespaces in the
	* XPath are supposed to be expanded.
	*
	* @throws TransformerException thrown if the active ProblemListener decides
	* the error condition is severe enough to halt processing.
	*
	* @throws javax.xml.transform.TransformerException
	* @xsl.usage experimental
	*/
	public XObject execute(
	XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
	throws javax.xml.transform.TransformerException
	{

	xctxt.pushNamespaceContext(namespaceContext);

	xctxt.pushCurrentNodeAndExpression(contextNode, contextNode);

	XObject xobj = null;

	try
	{
	xobj = m_mainExp.execute(xctxt);
	}
	catch (TransformerException te)
	{
	te.setLocator(this.getLocator());
	ErrorListener el = xctxt.getErrorListener();
	if(null != el) // defensive, should never happen.
	{
	el.error(te);
	}
	else
	throw te;
	}
	catch (Exception e)
	{
	while (e instanceof com.sun.org.apache.xml.internal.utils.WrappedRuntimeException)
	{
	e = ((com.sun.org.apache.xml.internal.utils.WrappedRuntimeException) e).getException();
	}
	// e.printStackTrace();

	String msg = e.getMessage();

	if (msg == null \|\| msg.length() == 0) {
	msg = XSLMessages.createXPATHMessage(
	XPATHErrorResources.ER_XPATH_ERROR, null);

	}
	TransformerException te = new TransformerException(msg,
	getLocator(), e);
	ErrorListener el = xctxt.getErrorListener();
	// te.printStackTrace();
	if(null != el) // defensive, should never happen.
	{
	el.fatalError(te);
	}
	else
	throw te;
	}
	finally
	{
	xctxt.popNamespaceContext();

	xctxt.popCurrentNodeAndExpression();
	}

	return xobj;
	}

	/**
	* Given an expression and a context, evaluate the XPath
	* and return the result.
	*
	* @param xctxt The execution context.
	* @param contextNode The node that "." expresses.
	* @param namespaceContext The context in which namespaces in the
	* XPath are supposed to be expanded.
	*
	* @throws TransformerException thrown if the active ProblemListener decides
	* the error condition is severe enough to halt processing.
	*
	* @throws javax.xml.transform.TransformerException
	* @xsl.usage experimental
	*/
	public boolean bool(
	XPathContext xctxt, int contextNode, PrefixResolver namespaceContext)
	throws javax.xml.transform.TransformerException
	{

	xctxt.pushNamespaceContext(namespaceContext);

	xctxt.pushCurrentNodeAndExpression(contextNode, contextNode);

	try
	{
	return m_mainExp.bool(xctxt);
	}
	catch (TransformerException te)
	{
	te.setLocator(this.getLocator());
	ErrorListener el = xctxt.getErrorListener();
	if(null != el) // defensive, should never happen.
	{
	el.error(te);
	}
	else
	throw te;
	}
	catch (Exception e)
	{
	while (e instanceof com.sun.org.apache.xml.internal.utils.WrappedRuntimeException)
	{
	e = ((com.sun.org.apache.xml.internal.utils.WrappedRuntimeException) e).getException();
	}
	// e.printStackTrace();

	String msg = e.getMessage();

	if (msg == null \|\| msg.length() == 0) {
	msg = XSLMessages.createXPATHMessage(
	XPATHErrorResources.ER_XPATH_ERROR, null);

	}

	TransformerException te = new TransformerException(msg,
	getLocator(), e);
	ErrorListener el = xctxt.getErrorListener();
	// te.printStackTrace();
	if(null != el) // defensive, should never happen.
	{
	el.fatalError(te);
	}
	else
	throw te;
	}
	finally
	{
	xctxt.popNamespaceContext();

	xctxt.popCurrentNodeAndExpression();
	}

	return false;
	}

	/** Set to true to get diagnostic messages about the result of
	* match pattern testing. */
	private static final boolean DEBUG_MATCHES = false;

	/**
	* Get the match score of the given node.
	*
	* @param xctxt XPath runtime context.
	* @param context The current source tree context node.
	*
	* @return score, one of {@link #MATCH_SCORE_NODETEST},
	* {@link #MATCH_SCORE_NONE}, {@link #MATCH_SCORE_OTHER},
	* or {@link #MATCH_SCORE_QNAME}.
	*
	* @throws javax.xml.transform.TransformerException
	*/
	public double getMatchScore(XPathContext xctxt, int context)
	throws javax.xml.transform.TransformerException
	{

	xctxt.pushCurrentNode(context);
	xctxt.pushCurrentExpressionNode(context);

	try
	{
	XObject score = m_mainExp.execute(xctxt);

	if (DEBUG_MATCHES)
	{
	DTM dtm = xctxt.getDTM(context);
	System.out.println("score: " + score.num() + " for "
	+ dtm.getNodeName(context) + " for xpath "
	+ this.getPatternString());
	}

	return score.num();
	}
	finally
	{
	xctxt.popCurrentNode();
	xctxt.popCurrentExpressionNode();
	}

	// return XPath.MATCH_SCORE_NONE;
	}


	/**
	* Warn the user of an problem.
	*
	* @param xctxt The XPath runtime context.
	* @param sourceNode Not used.
	* @param msg An error msgkey that corresponds to one of the constants found
	* in {@link com.sun.org.apache.xpath.internal.res.XPATHErrorResources}, which is
	* a key for a format string.
	* @param args An array of arguments represented in the format string, which
	* may be null.
	*
	* @throws TransformerException if the current ErrorListoner determines to
	* throw an exception.
	*/
	public void warn(
	XPathContext xctxt, int sourceNode, String msg, Object[] args)
	throws javax.xml.transform.TransformerException
	{

	String fmsg = XSLMessages.createXPATHWarning(msg, args);
	ErrorListener ehandler = xctxt.getErrorListener();

	if (null != ehandler)
	{

	// TO DO: Need to get stylesheet Locator from here.
	ehandler.warning(new TransformerException(fmsg, (SAXSourceLocator)xctxt.getSAXLocator()));
	}
	}

	/**
	* Tell the user of an assertion error, and probably throw an
	* exception.
	*
	* @param b If false, a runtime exception will be thrown.
	* @param msg The assertion message, which should be informative.
	*
	* @throws RuntimeException if the b argument is false.
	*/
	public void assertion(boolean b, String msg)
	{

	if (!b)
	{
	String fMsg = XSLMessages.createXPATHMessage(
	XPATHErrorResources.ER_INCORRECT_PROGRAMMER_ASSERTION,
	new Object[]{ msg });

	throw new RuntimeException(fMsg);
	}
	}

	/**
	* Tell the user of an error, and probably throw an
	* exception.
	*
	* @param xctxt The XPath runtime context.
	* @param sourceNode Not used.
	* @param msg An error msgkey that corresponds to one of the constants found
	* in {@link com.sun.org.apache.xpath.internal.res.XPATHErrorResources}, which is
	* a key for a format string.
	* @param args An array of arguments represented in the format string, which
	* may be null.
	*
	* @throws TransformerException if the current ErrorListoner determines to
	* throw an exception.
	*/
	public void error(
	XPathContext xctxt, int sourceNode, String msg, Object[] args)
	throws javax.xml.transform.TransformerException
	{

	String fmsg = XSLMessages.createXPATHMessage(msg, args);
	ErrorListener ehandler = xctxt.getErrorListener();

	if (null != ehandler)
	{
	ehandler.fatalError(new TransformerException(fmsg,
	(SAXSourceLocator)xctxt.getSAXLocator()));
	}
	else
	{
	SourceLocator slocator = xctxt.getSAXLocator();
	System.out.println(fmsg + "; file " + slocator.getSystemId()
	+ "; line " + slocator.getLineNumber() + "; column "
	+ slocator.getColumnNumber());
	}
	}

	/**
	* This will traverse the heararchy, calling the visitor for
	* each member. If the called visitor method returns
	* false, the subtree should not be called.
	*
	* @param owner The owner of the visitor, where that path may be
	* rewritten if needed.
	* @param visitor The visitor whose appropriate method will be called.
	*/
	public void callVisitors(ExpressionOwner owner, XPathVisitor visitor)
	{
	m_mainExp.callVisitors(this, visitor);
	}

	/**
	* The match score if no match is made.
	* @xsl.usage advanced
	*/
	public static final double MATCH_SCORE_NONE = Double.NEGATIVE_INFINITY;

	/**
	* The match score if the pattern has the form
	* of a QName optionally preceded by an @ character.
	* @xsl.usage advanced
	*/
	public static final double MATCH_SCORE_QNAME = 0.0;

	/**
	* The match score if the pattern pattern has the form NCName:*.
	* @xsl.usage advanced
	*/
	public static final double MATCH_SCORE_NSWILD = -0.25;

	/**
	* The match score if the pattern consists of just a NodeTest.
	* @xsl.usage advanced
	*/
	public static final double MATCH_SCORE_NODETEST = -0.5;

	/**
	* The match score if the pattern consists of something
	* other than just a NodeTest or just a qname.
	* @xsl.usage advanced
	*/
	public static final double MATCH_SCORE_OTHER = 0.5;
	}

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