Google Git
Sign in
apache / xalan-j / 084d5ec9fb7cec1821748a9d6ddea8d2e77cf082 / . / src / org / apache / xpath / compiler / Compiler.java
blob: 28424f7a52539a9d97ebf1a864d9d91d6b08dada [file] [log] [blame]
/*
* The Apache Software License, Version 1.1
*
*
* Copyright (c) 1999 The Apache Software Foundation. All rights
* reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
*
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
*
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in
* the documentation and/or other materials provided with the
* distribution.
*
* 3. The end-user documentation included with the redistribution,
* if any, must include the following acknowledgment:
* "This product includes software developed by the
* Apache Software Foundation (http://www.apache.org/)."
* Alternately, this acknowledgment may appear in the software itself,
* if and wherever such third-party acknowledgments normally appear.
*
* 4. The names "Xalan" and "Apache Software Foundation" must
* not be used to endorse or promote products derived from this
* software without prior written permission. For written
* permission, please contact apache@apache.org.
*
* 5. Products derived from this software may not be called "Apache",
* nor may "Apache" appear in their name, without prior written
* permission of the Apache Software Foundation.
*
* THIS SOFTWARE IS PROVIDED ``AS IS'' AND ANY EXPRESSED OR IMPLIED
* WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
* OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL THE APACHE SOFTWARE FOUNDATION OR
* ITS CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
* SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
* LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF
* USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY,
* OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT
* OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
* SUCH DAMAGE.
* ====================================================================
*
* This software consists of voluntary contributions made by many
* individuals on behalf of the Apache Software Foundation and was
* originally based on software copyright (c) 1999, Lotus
* Development Corporation., http://www.lotus.com. For more
* information on the Apache Software Foundation, please see
* <http://www.apache.org/>.
*/
package org.apache.xpath.compiler;
import org.apache.xpath.operations.And;
import org.apache.xpath.operations.Bool;
import org.apache.xpath.operations.Div;
import org.apache.xpath.operations.Equals;
import org.apache.xpath.operations.Gt;
import org.apache.xpath.operations.Gte;
import org.apache.xpath.operations.Lt;
import org.apache.xpath.operations.Lte;
import org.apache.xpath.operations.Minus;
import org.apache.xpath.operations.Mod;
import org.apache.xpath.operations.Mult;
import org.apache.xpath.operations.Neg;
import org.apache.xpath.operations.NotEquals;
import org.apache.xpath.operations.Operation;
import org.apache.xpath.operations.Or;
import org.apache.xpath.operations.Plus;
import org.apache.xpath.operations.UnaryOperation;
import org.apache.xpath.operations.Variable;
import org.apache.xpath.objects.*;
import org.apache.xpath.axes.*;
import org.apache.xpath.patterns.*;
import org.apache.xpath.functions.Function;
import org.apache.xpath.functions.FuncExtFunction;
import org.apache.xpath.functions.WrongNumberArgsException;
import org.apache.xpath.*;
import org.apache.xpath.res.XPATHErrorResources;
import org.apache.xalan.res.XSLMessages;
import org.apache.xml.utils.QName;
import org.apache.xml.utils.PrefixResolver;
import javax.xml.transform.TransformerConfigurationException;
import javax.xml.transform.SourceLocator;
import org.apache.xml.utils.SAXSourceLocator;
import org.apache.xml.dtm.DTMFilter;
import org.apache.xml.dtm.DTMIterator;
import org.apache.xml.dtm.Axis;
import javax.xml.transform.ErrorListener;
import javax.xml.transform.TransformerException;
/**
* <meta name="usage" content="advanced"/>
* An instance of this class compiles an XPath string expression into
* a Expression object. This class compiles the string into a sequence
* of operation codes (op map) and then builds from that into an Expression
* tree.
*/
public class Compiler extends OpMap
{
/**
* Construct a Compiler object with a specific ErrorListener and
* SourceLocator where the expression is located.
*
* @param errorHandler Error listener where messages will be sent, or null
* if messages should be sent to System err.
* @param locator The location object where the expression lives, which
* may be null, but which, if not null, must be valid over
* the long haul, in other words, it will not be cloned.
*/
public Compiler(ErrorListener errorHandler, SourceLocator locator)
{
m_errorHandler = errorHandler;
m_locator = locator;
}
/**
* Construct a Compiler instance that has a null error listener and a
* null source locator.
*/
public Compiler()
{
m_errorHandler = null;
m_locator = null;
}
/**
* <meta name="usage" content="advanced"/>
* Execute the XPath object from a given opcode position.
* @param xctxt The execution context.
* @param context The current source tree context node.
* @param opPos The current position in the xpath.m_opMap array.
* @param callback Interface that implements the processLocatedNode method.
* @param callbackInfo Object that will be passed to the processLocatedNode method.
* @return The result of the XPath.
*
* @throws TransformerException if there is a syntax or other error.
*/
public Expression compile(int opPos) throws TransformerException
{
int op = getOp(opPos);
Expression expr = null;
// System.out.println(getPatternString()+"op: "+op);
switch (op)
{
case OpCodes.OP_XPATH :
expr = compile(opPos + 2); break;
case OpCodes.OP_OR :
expr = or(opPos); break;
case OpCodes.OP_AND :
expr = and(opPos); break;
case OpCodes.OP_NOTEQUALS :
expr = notequals(opPos); break;
case OpCodes.OP_EQUALS :
expr = equals(opPos); break;
case OpCodes.OP_LTE :
expr = lte(opPos); break;
case OpCodes.OP_LT :
expr = lt(opPos); break;
case OpCodes.OP_GTE :
expr = gte(opPos); break;
case OpCodes.OP_GT :
expr = gt(opPos); break;
case OpCodes.OP_PLUS :
expr = plus(opPos); break;
case OpCodes.OP_MINUS :
expr = minus(opPos); break;
case OpCodes.OP_MULT :
expr = mult(opPos); break;
case OpCodes.OP_DIV :
expr = div(opPos); break;
case OpCodes.OP_MOD :
expr = mod(opPos); break;
// case OpCodes.OP_QUO :
// expr = quo(opPos); break;
case OpCodes.OP_NEG :
expr = neg(opPos); break;
case OpCodes.OP_STRING :
expr = string(opPos); break;
case OpCodes.OP_BOOL :
expr = bool(opPos); break;
case OpCodes.OP_NUMBER :
expr = number(opPos); break;
case OpCodes.OP_UNION :
expr = union(opPos); break;
case OpCodes.OP_LITERAL :
expr = literal(opPos); break;
case OpCodes.OP_VARIABLE :
expr = variable(opPos); break;
case OpCodes.OP_GROUP :
expr = group(opPos); break;
case OpCodes.OP_NUMBERLIT :
expr = numberlit(opPos); break;
case OpCodes.OP_ARGUMENT :
expr = arg(opPos); break;
case OpCodes.OP_EXTFUNCTION :
expr = compileExtension(opPos); break;
case OpCodes.OP_FUNCTION :
expr = compileFunction(opPos); break;
case OpCodes.OP_LOCATIONPATH :
expr = locationPath(opPos); break;
case OpCodes.OP_PREDICATE :
expr = null; break; // should never hit this here.
case OpCodes.OP_MATCHPATTERN :
expr = matchPattern(opPos + 2); break;
case OpCodes.OP_LOCATIONPATHPATTERN :
expr = locationPathPattern(opPos); break;
case OpCodes.OP_QUO:
error(XPATHErrorResources.ER_UNKNOWN_OPCODE,
new Object[]{ "quo" }); //"ERROR! Unknown op code: "+m_opMap[opPos]);
break;
default :
error(XPATHErrorResources.ER_UNKNOWN_OPCODE,
new Object[]{ Integer.toString(getOp(opPos)) }); //"ERROR! Unknown op code: "+m_opMap[opPos]);
}
// if(null != expr)
// expr.setSourceLocator(m_locator);
return expr;
}
/**
* Bottle-neck compilation of an operation with left and right operands.
*
* @param operation non-null reference to parent operation.
* @param opPos The op map position of the parent operation.
*
* @return reference to {@link org.apache.xpath.operations.Operation} instance.
*
* @throws TransformerException if there is a syntax or other error.
*/
private Expression compileOperation(Operation operation, int opPos)
throws TransformerException
{
int leftPos = getFirstChildPos(opPos);
int rightPos = getNextOpPos(leftPos);
operation.setLeftRight(compile(leftPos), compile(rightPos));
return operation;
}
/**
* Bottle-neck compilation of a unary operation.
*
* @param unary The parent unary operation.
* @param opPos The position in the op map of the parent operation.
*
* @return The unary argument.
*
* @throws TransformerException if syntax or other error occurs.
*/
private Expression compileUnary(UnaryOperation unary, int opPos)
throws TransformerException
{
int rightPos = getFirstChildPos(opPos);
unary.setRight(compile(rightPos));
return unary;
}
/**
* Compile an 'or' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Or} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression or(int opPos) throws TransformerException
{
return compileOperation(new Or(), opPos);
}
/**
* Compile an 'and' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.And} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression and(int opPos) throws TransformerException
{
return compileOperation(new And(), opPos);
}
/**
* Compile a '!=' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.NotEquals} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression notequals(int opPos) throws TransformerException
{
return compileOperation(new NotEquals(), opPos);
}
/**
* Compile a '=' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Equals} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression equals(int opPos) throws TransformerException
{
return compileOperation(new Equals(), opPos);
}
/**
* Compile a '<=' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Lte} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression lte(int opPos) throws TransformerException
{
return compileOperation(new Lte(), opPos);
}
/**
* Compile a '<' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Lt} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression lt(int opPos) throws TransformerException
{
return compileOperation(new Lt(), opPos);
}
/**
* Compile a '>=' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Gte} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression gte(int opPos) throws TransformerException
{
return compileOperation(new Gte(), opPos);
}
/**
* Compile a '>' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Gt} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression gt(int opPos) throws TransformerException
{
return compileOperation(new Gt(), opPos);
}
/**
* Compile a '+' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Plus} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression plus(int opPos) throws TransformerException
{
return compileOperation(new Plus(), opPos);
}
/**
* Compile a '-' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Minus} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression minus(int opPos) throws TransformerException
{
return compileOperation(new Minus(), opPos);
}
/**
* Compile a '*' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Mult} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression mult(int opPos) throws TransformerException
{
return compileOperation(new Mult(), opPos);
}
/**
* Compile a 'div' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Div} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression div(int opPos) throws TransformerException
{
return compileOperation(new Div(), opPos);
}
/**
* Compile a 'mod' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Mod} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression mod(int opPos) throws TransformerException
{
return compileOperation(new Mod(), opPos);
}
/*
* Compile a 'quo' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Quo} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
// protected Expression quo(int opPos) throws TransformerException
// {
// return compileOperation(new Quo(), opPos);
// }
/**
* Compile a unary '-' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Neg} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression neg(int opPos) throws TransformerException
{
return compileUnary(new Neg(), opPos);
}
/**
* Compile a 'string(...)' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.String} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression string(int opPos) throws TransformerException
{
return compileUnary(new org.apache.xpath.operations.String(), opPos);
}
/**
* Compile a 'boolean(...)' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Bool} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression bool(int opPos) throws TransformerException
{
return compileUnary(new org.apache.xpath.operations.Bool(), opPos);
}
/**
* Compile a 'number(...)' operation.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Number} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression number(int opPos) throws TransformerException
{
return compileUnary(new org.apache.xpath.operations.Number(), opPos);
}
/**
* Compile a literal string value.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.objects.XString} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression literal(int opPos)
{
opPos = getFirstChildPos(opPos);
return (XString) getTokenQueue().elementAt(getOp(opPos));
}
/**
* Compile a literal number value.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.objects.XNumber} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression numberlit(int opPos)
{
opPos = getFirstChildPos(opPos);
return (XNumber) getTokenQueue().elementAt(getOp(opPos));
}
/**
* Compile a variable reference.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.operations.Variable} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression variable(int opPos) throws TransformerException
{
Variable var = new Variable();
opPos = getFirstChildPos(opPos);
int nsPos = getOp(opPos);
java.lang.String namespace
= (OpCodes.EMPTY == nsPos) ? null
: (java.lang.String) getTokenQueue().elementAt(nsPos);
java.lang.String localname
= (java.lang.String) getTokenQueue().elementAt(getOp(opPos+1));
QName qname = new QName(namespace, localname);
var.setQName(qname);
return var;
}
/**
* Compile an expression group.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to the contained expression.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression group(int opPos) throws TransformerException
{
// no-op
return compile(opPos + 2);
}
/**
* Compile a function argument.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to the argument expression.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression arg(int opPos) throws TransformerException
{
// no-op
return compile(opPos + 2);
}
/**
* Compile a location path union. The UnionPathIterator itself may create
* {@link org.apache.xpath.axes.LocPathIterator} children.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.axes.LocPathIterator} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression union(int opPos) throws TransformerException
{
locPathDepth++;
try
{
return UnionPathIterator.createUnionIterator(this, opPos);
}
finally
{
locPathDepth--;
}
}
private int locPathDepth = -1;
/**
* Get the level of the location path or union being constructed.
* @return 0 if it is a top-level path.
*/
public int getLocationPathDepth()
{
return locPathDepth;
}
/**
* Compile a location path. The LocPathIterator itself may create
* {@link org.apache.xpath.axes.AxesWalker} children.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.axes.LocPathIterator} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
public Expression locationPath(int opPos) throws TransformerException
{
locPathDepth++;
try
{
DTMIterator iter = WalkerFactory.newDTMIterator(this, opPos, (locPathDepth == 0));
return (Expression)iter; // cast OK, I guess.
}
finally
{
locPathDepth--;
}
}
/**
* Compile a location step predicate expression.
*
* @param opPos The current position in the m_opMap array.
*
* @return the contained predicate expression.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
public Expression predicate(int opPos) throws TransformerException
{
return compile(opPos + 2);
}
/**
* Compile an entire match pattern expression.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.patterns.UnionPattern} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected Expression matchPattern(int opPos) throws TransformerException
{
locPathDepth++;
try
{
// First, count...
int nextOpPos = opPos;
int i;
for (i = 0; getOp(nextOpPos) == OpCodes.OP_LOCATIONPATHPATTERN; i++)
{
nextOpPos = getNextOpPos(nextOpPos);
}
if (i == 1)
return compile(opPos);
UnionPattern up = new UnionPattern();
StepPattern[] patterns = new StepPattern[i];
for (i = 0; getOp(opPos) == OpCodes.OP_LOCATIONPATHPATTERN; i++)
{
nextOpPos = getNextOpPos(opPos);
patterns[i] = (StepPattern) compile(opPos);
opPos = nextOpPos;
}
up.setPatterns(patterns);
return up;
}
finally
{
locPathDepth--;
}
}
/**
* Compile a location match pattern unit expression.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.patterns.StepPattern} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
public Expression locationPathPattern(int opPos)
throws TransformerException
{
opPos = getFirstChildPos(opPos);
return stepPattern(opPos, 0, null);
}
/**
* Get a {@link org.w3c.dom.traversal.NodeFilter} bit set that tells what
* to show for a given node test.
*
* @param opPos the op map position for the location step.
*
* @return {@link org.w3c.dom.traversal.NodeFilter} bit set that tells what
* to show for a given node test.
*/
public int getWhatToShow(int opPos)
{
int axesType = getOp(opPos);
int testType = getOp(opPos + 3);
// System.out.println("testType: "+testType);
switch (testType)
{
case OpCodes.NODETYPE_COMMENT :
return DTMFilter.SHOW_COMMENT;
case OpCodes.NODETYPE_TEXT :
// return DTMFilter.SHOW_TEXT | DTMFilter.SHOW_COMMENT;
return DTMFilter.SHOW_TEXT | DTMFilter.SHOW_CDATA_SECTION ;
case OpCodes.NODETYPE_PI :
return DTMFilter.SHOW_PROCESSING_INSTRUCTION;
case OpCodes.NODETYPE_NODE :
// return DTMFilter.SHOW_ALL;
switch (axesType)
{
case OpCodes.FROM_NAMESPACE:
return DTMFilter.SHOW_NAMESPACE;
case OpCodes.FROM_ATTRIBUTES :
case OpCodes.MATCH_ATTRIBUTE :
return DTMFilter.SHOW_ATTRIBUTE;
case OpCodes.FROM_SELF:
case OpCodes.FROM_ANCESTORS_OR_SELF:
case OpCodes.FROM_DESCENDANTS_OR_SELF:
return DTMFilter.SHOW_ALL;
default:
if (getOp(0) == OpCodes.OP_MATCHPATTERN)
return ~DTMFilter.SHOW_ATTRIBUTE
& ~DTMFilter.SHOW_DOCUMENT
& ~DTMFilter.SHOW_DOCUMENT_FRAGMENT;
else
return ~DTMFilter.SHOW_ATTRIBUTE;
}
case OpCodes.NODETYPE_ROOT :
return DTMFilter.SHOW_DOCUMENT | DTMFilter.SHOW_DOCUMENT_FRAGMENT;
case OpCodes.NODETYPE_FUNCTEST :
return NodeTest.SHOW_BYFUNCTION;
case OpCodes.NODENAME :
switch (axesType)
{
case OpCodes.FROM_NAMESPACE :
return DTMFilter.SHOW_NAMESPACE;
case OpCodes.FROM_ATTRIBUTES :
case OpCodes.MATCH_ATTRIBUTE :
return DTMFilter.SHOW_ATTRIBUTE;
// break;
case OpCodes.MATCH_ANY_ANCESTOR :
case OpCodes.MATCH_IMMEDIATE_ANCESTOR :
return DTMFilter.SHOW_ELEMENT;
// break;
default :
return DTMFilter.SHOW_ELEMENT;
}
default :
// System.err.println("We should never reach here.");
return DTMFilter.SHOW_ALL;
}
}
private static final boolean DEBUG = false;
/**
* Compile a step pattern unit expression, used for both location paths
* and match patterns.
*
* @param opPos The current position in the m_opMap array.
* @param stepCount The number of steps to expect.
* @param ancestorPattern The owning StepPattern, which may be null.
*
* @return reference to {@link org.apache.xpath.patterns.StepPattern} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
protected StepPattern stepPattern(
int opPos, int stepCount, StepPattern ancestorPattern)
throws TransformerException
{
int startOpPos = opPos;
int stepType = getOp(opPos);
if (OpCodes.ENDOP == stepType)
{
return null;
}
boolean addMagicSelf = true;
int endStep = getNextOpPos(opPos);
// int nextStepType = getOpMap()[endStep];
StepPattern pattern;
// boolean isSimple = ((OpCodes.ENDOP == nextStepType) && (stepCount == 0));
int argLen;
switch (stepType)
{
case OpCodes.OP_FUNCTION :
if(DEBUG)
System.out.println("MATCH_FUNCTION: "+m_currentPattern);
addMagicSelf = false;
argLen = getOp(opPos + OpMap.MAPINDEX_LENGTH);
pattern = new FunctionPattern(compileFunction(opPos), Axis.PARENT, Axis.CHILD);
break;
case OpCodes.FROM_ROOT :
if(DEBUG)
System.out.println("FROM_ROOT, "+m_currentPattern);
addMagicSelf = false;
argLen = getArgLengthOfStep(opPos);
opPos = getFirstChildPosOfStep(opPos);
pattern = new StepPattern(DTMFilter.SHOW_DOCUMENT |
DTMFilter.SHOW_DOCUMENT_FRAGMENT,
Axis.PARENT, Axis.CHILD);
break;
case OpCodes.MATCH_ATTRIBUTE :
if(DEBUG)
System.out.println("MATCH_ATTRIBUTE: "+getStepLocalName(startOpPos)+", "+m_currentPattern);
argLen = getArgLengthOfStep(opPos);
opPos = getFirstChildPosOfStep(opPos);
pattern = new StepPattern(DTMFilter.SHOW_ATTRIBUTE,
getStepNS(startOpPos),
getStepLocalName(startOpPos),
Axis.PARENT, Axis.ATTRIBUTE);
break;
case OpCodes.MATCH_ANY_ANCESTOR :
if(DEBUG)
System.out.println("MATCH_ANY_ANCESTOR: "+getStepLocalName(startOpPos)+", "+m_currentPattern);
argLen = getArgLengthOfStep(opPos);
opPos = getFirstChildPosOfStep(opPos);
int what = getWhatToShow(startOpPos);
// bit-o-hackery, but this code is due for the morgue anyway...
if(0x00000500 == what)
addMagicSelf = false;
pattern = new StepPattern(getWhatToShow(startOpPos),
getStepNS(startOpPos),
getStepLocalName(startOpPos),
Axis.ANCESTOR, Axis.CHILD);
break;
case OpCodes.MATCH_IMMEDIATE_ANCESTOR :
if(DEBUG)
System.out.println("MATCH_IMMEDIATE_ANCESTOR: "+getStepLocalName(startOpPos)+", "+m_currentPattern);
argLen = getArgLengthOfStep(opPos);
opPos = getFirstChildPosOfStep(opPos);
pattern = new StepPattern(getWhatToShow(startOpPos),
getStepNS(startOpPos),
getStepLocalName(startOpPos),
Axis.PARENT, Axis.CHILD);
break;
default :
error(XPATHErrorResources.ER_UNKNOWN_MATCH_OPERATION, null); //"unknown match operation!");
return null;
}
pattern.setPredicates(getCompiledPredicates(opPos + argLen));
if(null == ancestorPattern)
{
// This is the magic and invisible "." at the head of every
// match pattern, and corresponds to the current node in the context
// list, from where predicates are counted.
// So, in order to calculate "foo[3]", it has to count from the
// current node in the context list, so, from that current node,
// the full pattern is really "self::node()/child::foo[3]". If you
// translate this to a select pattern from the node being tested,
// which is really how we're treating match patterns, it works out to
// self::foo/parent::node[child::foo[3]]", or close enough.
/* if(addMagicSelf && pattern.getPredicateCount() > 0)
{
StepPattern selfPattern = new StepPattern(DTMFilter.SHOW_ALL,
Axis.PARENT, Axis.CHILD);
// We need to keep the new nodetest from affecting the score...
XNumber score = pattern.getStaticScore();
pattern.setRelativePathPattern(selfPattern);
pattern.setStaticScore(score);
selfPattern.setStaticScore(score);
}*/
}
else
{
// System.out.println("Setting "+ancestorPattern+" as relative to "+pattern);
pattern.setRelativePathPattern(ancestorPattern);
}
StepPattern relativePathPattern = stepPattern(endStep, stepCount + 1,
pattern);
return (null != relativePathPattern) ? relativePathPattern : pattern;
}
/**
* Compile a zero or more predicates for a given match pattern.
*
* @param opPos The position of the first predicate the m_opMap array.
*
* @return reference to array of {@link org.apache.xpath.Expression} instances.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
public Expression[] getCompiledPredicates(int opPos)
throws TransformerException
{
int count = countPredicates(opPos);
if (count > 0)
{
Expression[] predicates = new Expression[count];
compilePredicates(opPos, predicates);
return predicates;
}
return null;
}
/**
* Count the number of predicates in the step.
*
* @param opPos The position of the first predicate the m_opMap array.
*
* @return The number of predicates for this step.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
public int countPredicates(int opPos) throws TransformerException
{
int count = 0;
while (OpCodes.OP_PREDICATE == getOp(opPos))
{
count++;
opPos = getNextOpPos(opPos);
}
return count;
}
/**
* Compiles predicates in the step.
*
* @param opPos The position of the first predicate the m_opMap array.
* @param predicates An empty pre-determined array of
* {@link org.apache.xpath.Expression}s, that will be filled in.
*
* @throws TransformerException
*/
private void compilePredicates(int opPos, Expression[] predicates)
throws TransformerException
{
for (int i = 0; OpCodes.OP_PREDICATE == getOp(opPos); i++)
{
predicates[i] = predicate(opPos);
opPos = getNextOpPos(opPos);
}
}
/**
* Compile a built-in XPath function.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.functions.Function} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
Expression compileFunction(int opPos) throws TransformerException
{
int endFunc = opPos + getOp(opPos + 1) - 1;
opPos = getFirstChildPos(opPos);
int funcID = getOp(opPos);
opPos++;
if (-1 != funcID)
{
Function func = FunctionTable.getFunction(funcID);
func.postCompileStep(this);
try
{
int i = 0;
for (int p = opPos; p < endFunc; p = getNextOpPos(p), i++)
{
// System.out.println("argPos: "+ p);
// System.out.println("argCode: "+ m_opMap[p]);
func.setArg(compile(p), i);
}
func.checkNumberArgs(i);
}
catch (WrongNumberArgsException wnae)
{
java.lang.String name = FunctionTable.m_functions[funcID].getName();
m_errorHandler.fatalError( new TransformerException(
XSLMessages.createXPATHMessage(XPATHErrorResources.ER_ONLY_ALLOWS,
new Object[]{name, wnae.getMessage()}), m_locator));
//"name + " only allows " + wnae.getMessage() + " arguments", m_locator));
}
return func;
}
else
{
error(XPATHErrorResources.ER_FUNCTION_TOKEN_NOT_FOUND, null); //"function token not found.");
return null;
}
}
/**
* Compile an extension function.
*
* @param opPos The current position in the m_opMap array.
*
* @return reference to {@link org.apache.xpath.functions.FuncExtFunction} instance.
*
* @throws TransformerException if a error occurs creating the Expression.
*/
private Expression compileExtension(int opPos)
throws TransformerException
{
int endExtFunc = opPos + getOp(opPos + 1) - 1;
opPos = getFirstChildPos(opPos);
java.lang.String ns = (java.lang.String) getTokenQueue().elementAt(getOp(opPos));
opPos++;
java.lang.String funcName =
(java.lang.String) getTokenQueue().elementAt(getOp(opPos));
opPos++;
// We create a method key to uniquely identify this function so that we
// can cache the object needed to invoke it. This way, we only pay the
// reflection overhead on the first call.
Function extension = new FuncExtFunction(ns, funcName,
String.valueOf(opPos)
+ String.valueOf(hashCode())
+ String.valueOf(System.currentTimeMillis()));
try
{
int i = 0;
while (opPos < endExtFunc)
{
int nextOpPos = getNextOpPos(opPos);
extension.setArg(this.compile(opPos), i);
opPos = nextOpPos;
i++;
}
}
catch (WrongNumberArgsException wnae)
{
; // should never happen
}
return extension;
}
/**
* Warn the user of an problem.
*
* @param msg An error msgkey that corresponds to one of the constants found
* in {@link org.apache.xpath.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(String msg, Object[] args) throws TransformerException
{
java.lang.String fmsg = XSLMessages.createXPATHWarning(msg, args);
if (null != m_errorHandler)
{
m_errorHandler.warning(new TransformerException(fmsg, m_locator));
}
else
{
System.out.println(fmsg
+"; file "+m_locator.getSystemId()
+"; line "+m_locator.getLineNumber()
+"; column "+m_locator.getColumnNumber());
}
}
/**
* 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, java.lang.String msg)
{
if (!b)
{
java.lang.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 msg An error msgkey that corresponds to one of the constants found
* in {@link org.apache.xpath.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(String msg, Object[] args) throws TransformerException
{
java.lang.String fmsg = XSLMessages.createXPATHMessage(msg, args);
if (null != m_errorHandler)
{
m_errorHandler.fatalError(new TransformerException(fmsg, m_locator));
}
else
{
// System.out.println(te.getMessage()
// +"; file "+te.getSystemId()
// +"; line "+te.getLineNumber()
// +"; column "+te.getColumnNumber());
throw new TransformerException(fmsg, (SAXSourceLocator)m_locator);
}
}
/**
* The current prefixResolver for the execution context.
*/
private PrefixResolver m_currentPrefixResolver = null;
/**
* Get the current namespace context for the xpath.
*
* @return The current prefix resolver, *may* be null, though hopefully not.
*/
public PrefixResolver getNamespaceContext()
{
return m_currentPrefixResolver;
}
/**
* Set the current namespace context for the xpath.
*
* @param pr The resolver for prefixes in the XPath expression.
*/
public void setNamespaceContext(PrefixResolver pr)
{
m_currentPrefixResolver = pr;
}
/** The error listener where errors will be sent. If this is null, errors
* and warnings will be sent to System.err. May be null. */
ErrorListener m_errorHandler;
/** The source locator for the expression being compiled. May be null. */
SourceLocator m_locator;
}