package net.sf.saxon.instruct;
import net.sf.saxon.Configuration;
import net.sf.saxon.Platform;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.expr.*;
import net.sf.saxon.om.EmptyIterator;
import net.sf.saxon.om.Item;
import net.sf.saxon.om.SequenceIterator;
import net.sf.saxon.om.StandardNames;
import net.sf.saxon.pattern.EmptySequenceTest;
import net.sf.saxon.regex.RegexIterator;
import net.sf.saxon.regex.RegularExpression;
import net.sf.saxon.regex.JRegularExpression;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.type.*;
import net.sf.saxon.value.SequenceType;
import java.util.ArrayList;
import java.util.Iterator;
/**
* An xsl:analyze-string element in the stylesheet. New at XSLT 2.0
*/
public class AnalyzeString extends Instruction {
private Expression select;
private Expression regex;
private Expression flags;
private Expression matching;
private Expression nonMatching;
private RegularExpression pattern;
/**
* Construct an AnalyzeString instruction
*
* @param select the expression containing the input string
* @param regex the regular expression
* @param flags the flags parameter
* @param matching actions to be applied to a matching substring
* @param nonMatching actions to be applied to a non-matching substring
* @param pattern the compiled regular expression, if it was known statically
*/
public AnalyzeString(Expression select,
Expression regex,
Expression flags,
Expression matching,
Expression nonMatching,
RegularExpression pattern) {
this.select = select;
this.regex = regex;
this.flags = flags;
this.matching = matching;
this.nonMatching = nonMatching;
this.pattern = pattern;
Iterator kids = iterateSubExpressions();
while (kids.hasNext()) {
Expression child = (Expression)kids.next();
adoptChildExpression(child);
}
}
public int getInstructionNameCode() {
return StandardNames.XSL_ANALYZE_STRING;
}
/**
* An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().
* This method indicates which of these methods is prefered.
*/
public int getImplementationMethod() {
return Expression.PROCESS_METHOD | Expression.ITERATE_METHOD;
}
/**
* Get the expression used to process matching substrings
* @return the expression used to process matching substrings
*/
public Expression getMatchingExpression() {
return matching;
}
/**
* Get the expression used to process non-matching substrings
* @return the expression used to process non-matching substrings
*/
public Expression getNonMatchingExpression() {
return nonMatching;
}
/**
* Simplify an expression. This performs any static optimization (by rewriting the expression
* as a different expression).
*
* @return the simplified expression
* @throws XPathException if an error is discovered during expression
* rewriting
* @param visitor an expression visitor
*/
public Expression simplify(ExpressionVisitor visitor) throws XPathException {
select = visitor.simplify(select);
regex = visitor.simplify(regex);
flags = visitor.simplify(flags);
matching = visitor.simplify(matching);
nonMatching = visitor.simplify(nonMatching);
return this;
}
public Expression typeCheck(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
select = visitor.typeCheck(select, contextItemType);
adoptChildExpression(select);
regex = visitor.typeCheck(regex, contextItemType);
adoptChildExpression(regex);
flags = visitor.typeCheck(flags, contextItemType);
adoptChildExpression(flags);
if (matching != null) {
matching = visitor.typeCheck(matching, BuiltInAtomicType.STRING);
adoptChildExpression(matching);
}
if (nonMatching != null) {
nonMatching = visitor.typeCheck(nonMatching, BuiltInAtomicType.STRING);
adoptChildExpression(nonMatching);
}
// Following type checking has already been done in the case of XSLT xsl:analyze-string, but is
// needed where the instruction is generated from saxon:analyze-string extension function
RoleLocator role =
new RoleLocator(RoleLocator.INSTRUCTION, "analyze-string/select", 0);
//role.setSourceLocator(this);
select = TypeChecker.staticTypeCheck(select, SequenceType.SINGLE_STRING, false, role, visitor);
role = new RoleLocator(RoleLocator.INSTRUCTION, "analyze-string/regex", 0);
//role.setSourceLocator(this);
regex = TypeChecker.staticTypeCheck(regex, SequenceType.SINGLE_STRING, false, role, visitor);
role = new RoleLocator(RoleLocator.INSTRUCTION, "analyze-string/flags", 0);
//role.setSourceLocator(this);
flags = TypeChecker.staticTypeCheck(flags, SequenceType.SINGLE_STRING, false, role, visitor);
return this;
}
public Expression optimize(ExpressionVisitor visitor, ItemType contextItemType) throws XPathException {
select = visitor.optimize(select, contextItemType);
adoptChildExpression(select);
regex = visitor.optimize(regex, contextItemType);
adoptChildExpression(regex);
flags = visitor.optimize(flags, contextItemType);
adoptChildExpression(flags);
if (matching != null) {
matching = matching.optimize(visitor, BuiltInAtomicType.STRING);
adoptChildExpression(matching);
}
if (nonMatching != null) {
nonMatching = nonMatching.optimize(visitor, BuiltInAtomicType.STRING);
adoptChildExpression(nonMatching);
}
if (pattern == null && regex instanceof StringLiteral && flags instanceof StringLiteral) {
try {
final Platform platform = Configuration.getPlatform();
final CharSequence regex = ((StringLiteral)this.regex).getStringValue();
final CharSequence flagstr = ((StringLiteral)flags).getStringValue();
final int xmlVersion = visitor.getConfiguration().getXMLVersion();
int flagBits = JRegularExpression.setFlags(flagstr);
pattern = new JRegularExpression(regex, xmlVersion, RegularExpression.XPATH_SYNTAX, flagBits);
if (pattern.matches("")) {
// prevent it being reported more than once
pattern = new JRegularExpression("x", xmlVersion, RegularExpression.XPATH_SYNTAX, flagBits);
invalidRegex("The regular expression must not be one that matches a zero-length string", "XTDE1150");
}
} catch (XPathException err) {
if ("XTDE1150".equals(err.getErrorCodeLocalPart())) {
throw err;
}
if ("FORX0001".equals(err.getErrorCodeLocalPart())) {
invalidRegex("Error in regular expression flags: " + err, "XTDE1145");
} else {
invalidRegex("Error in regular expression: " + err, "XTDE1140");
}
}
}
return this;
}
private void invalidRegex(String message, String errorCode) throws XPathException {
pattern = null;
XPathException err = new XPathException(message, errorCode);
err.setLocator(this);
throw err;
}
/**
* Copy an expression. This makes a deep copy.
*
* @return the copy of the original expression
*/
public Expression copy() {
throw new UnsupportedOperationException("copy");
}
/**
* Check that any elements and attributes constructed or returned by this expression are acceptable
* in the content model of a given complex type. It's always OK to say yes, since the check will be
* repeated at run-time. The process of checking element and attribute constructors against the content
* model of a complex type also registers the type of content expected of those constructors, so the
* static validation can continue recursively.
*/
public void checkPermittedContents(SchemaType parentType, StaticContext env, boolean whole) throws XPathException {
if (matching != null) {
matching.checkPermittedContents(parentType, env, false);
}
if (nonMatching != null) {
nonMatching.checkPermittedContents(parentType, env, false);
}
}
/**
* Get the item type of the items returned by evaluating this instruction
*
* @return the static item type of the instruction
* @param th the type hierarchy cache
*/
public ItemType getItemType(TypeHierarchy th) {
if (matching != null) {
if (nonMatching != null) {
return Type.getCommonSuperType(matching.getItemType(th), nonMatching.getItemType(th), th);
} else {
return matching.getItemType(th);
}
} else {
if (nonMatching != null) {
return nonMatching.getItemType(th);
} else {
return EmptySequenceTest.getInstance();
}
}
}
/**
* Compute the dependencies of an expression, as the union of the
* dependencies of its subexpressions. (This is overridden for path expressions
* and filter expressions, where the dependencies of a subexpression are not all
* propogated). This method should be called only once, to compute the dependencies;
* after that, getDependencies should be used.
*
* @return the depencies, as a bit-mask
*/
public int computeDependencies() {
// some of the dependencies in the "action" part and in the grouping and sort keys aren't relevant,
// because they don't depend on values set outside the for-each-group expression
int dependencies = 0;
dependencies |= select.getDependencies();
dependencies |= regex.getDependencies();
dependencies |= flags.getDependencies();
if (matching != null) {
dependencies |= (matching.getDependencies() &~
(StaticProperty.DEPENDS_ON_FOCUS | StaticProperty.DEPENDS_ON_REGEX_GROUP));
}
if (nonMatching != null) {
dependencies |= (nonMatching.getDependencies() &~
(StaticProperty.DEPENDS_ON_FOCUS | StaticProperty.DEPENDS_ON_REGEX_GROUP));
}
return dependencies;
}
/**
* Handle promotion offers, that is, non-local tree rewrites.
*
* @param offer The type of rewrite being offered
* @throws XPathException
*/
protected void promoteInst(PromotionOffer offer) throws XPathException {
select = doPromotion(this, select, offer);
regex = doPromotion(this, regex, offer);
flags = doPromotion(this, flags, offer);
if (matching != null) {
matching = doPromotion(this, matching, offer);
}
if (nonMatching != null) {
nonMatching = doPromotion(this, nonMatching, offer);
}
}
/**
* Get all the XPath expressions associated with this instruction
* (in XSLT terms, the expression present on attributes of the instruction,
* as distinct from the child instructions in a sequence construction)
*/
public Iterator<Expression> iterateSubExpressions() {
ArrayList list = new ArrayList(5);
list.add(select);
list.add(regex);
list.add(flags);
if (matching != null) {
list.add(matching);
}
if (nonMatching != null) {
list.add(nonMatching);
}
return list.iterator();
}
/**
* Get the immediate sub-expressions of this expression that are evaluated with the
* same focus (context item, position, and size) as the parent expression.
* @return an iterator containing those sub-expressions of this expression that are
* evaluated with the same focus as the parent expression
*/
public Iterator<Expression> iterateSameFocusSubExpressions() {
ArrayList list = new ArrayList(5);
list.add(select);
list.add(regex);
list.add(flags);
return list.iterator();
}
/**
* Given an expression that is an immediate child of this expression, test whether
* the evaluation of the parent expression causes the child expression to be
* evaluated repeatedly
* @param child the immediate subexpression
* @return true if the child expression is evaluated repeatedly
*/
public boolean hasLoopingSubexpression(Expression child) {
return child == matching || child == nonMatching;
}
/**
* Replace one subexpression by a replacement subexpression
* @param original the original subexpression
* @param replacement the replacement subexpression
* @return true if the original subexpression is found
*/
public boolean replaceSubExpression(Expression original, Expression replacement) {
boolean found = false;
if (select == original) {
select = replacement;
found = true;
}
if (regex == original) {
regex = replacement;
found = true;
}
if (flags == original) {
flags = replacement;
found = true;
}
if (matching == original) {
matching = replacement;
found = true;
}
if (nonMatching == original) {
nonMatching = replacement;
found = true;
}
return found;
}
/**
* ProcessLeavingTail: called to do the real work of this instruction. This method
* must be implemented in each subclass. The results of the instruction are written
* to the current Receiver, which can be obtained via the Controller.
* @param context The dynamic context of the transformation, giving access to the current node,
* the current variables, etc.
* @return null if the instruction has completed execution; or a TailCall indicating
* a function call or template call that is delegated to the caller, to be made after the stack has
* been unwound so as to save stack space.
*/
public TailCall processLeavingTail(XPathContext context) throws XPathException {
RegexIterator iter = getRegexIterator(context);
XPathContextMajor c2 = context.newContext();
c2.setOrigin(this);
c2.setCurrentIterator(iter);
c2.setCurrentRegexIterator(iter);
while (true) {
Item it = iter.next();
if (it == null) {
break;
}
if (iter.isMatching()) {
if (matching != null) {
matching.process(c2);
}
} else {
if (nonMatching != null) {
nonMatching.process(c2);
}
}
}
return null;
}
/**
* Get an iterator over the substrings defined by the regular expression
*
* @param context the evaluation context
* @return an iterator that returns matching and nonmatching substrings
* @throws XPathException
*/
private RegexIterator getRegexIterator(XPathContext context) throws XPathException {
CharSequence input = select.evaluateAsString(context);
RegularExpression re = pattern;
if (re == null) {
CharSequence flagstr = flags.evaluateAsString(context);
final Platform platform = Configuration.getPlatform();
final int xmlVersion = context.getConfiguration().getXMLVersion();
int flagBits = JRegularExpression.setFlags(flagstr);
re = new JRegularExpression(regex.evaluateAsString(context), xmlVersion, RegularExpression.XPATH_SYNTAX, flagBits);
if (re.matches("")) {
dynamicError("The regular expression must not be one that matches a zero-length string",
"XTDE1150", context);
}
}
return re.analyze(input);
}
/**
* Return an Iterator to iterate over the values of a sequence. The value of every
* expression can be regarded as a sequence, so this method is supported for all
* expressions. This default implementation handles iteration for expressions that
* return singleton values: for non-singleton expressions, the subclass must
* provide its own implementation.
*
* @param context supplies the context for evaluation
* @return a SequenceIterator that can be used to iterate over the result
* of the expression
* @throws net.sf.saxon.trans.XPathException
* if any dynamic error occurs evaluating the
* expression
*/
public SequenceIterator iterate(XPathContext context) throws XPathException {
RegexIterator iter = getRegexIterator(context);
XPathContextMajor c2 = context.newContext();
c2.setOrigin(this);
c2.setCurrentIterator(iter);
c2.setCurrentRegexIterator(iter);
AnalyzeMappingFunction fn = new AnalyzeMappingFunction(iter, c2);
return new ContextMappingIterator(fn, c2);
}
/**
* Diagnostic print of expression structure. The abstract expression tree
* is written to the supplied output destination.
*/
public void explain(ExpressionPresenter out) {
out.startElement("analyzeString");
out.startSubsidiaryElement("select");
select.explain(out);
out.endSubsidiaryElement();
out.startSubsidiaryElement("regex");
regex.explain(out);
out.endSubsidiaryElement();
out.startSubsidiaryElement("flags");
flags.explain(out);
out.endSubsidiaryElement();
if (matching != null) {
out.startSubsidiaryElement("matching");
matching.explain(out);
out.endSubsidiaryElement();
}
if (nonMatching != null) {
out.startSubsidiaryElement("nonMatching");
nonMatching.explain(out);
out.endSubsidiaryElement();
}
out.endElement();
}
/**
* Mapping function that maps the sequence of matching/non-matching strings to the
* sequence delivered by applying the matching-substring and non-matching-substring
* expressions respectively to each such string
*/
private class AnalyzeMappingFunction implements ContextMappingFunction {
private RegexIterator base;
private XPathContext c2;
public AnalyzeMappingFunction(RegexIterator base, XPathContext c2) {
this.base = base;
this.c2 = c2;
}
/**
* Map one item to a sequence.
*
* @param context The processing context. Some mapping functions use this because they require
* context information. Some mapping functions modify the context by maintaining the context item
* and position. In other cases, the context may be null.
* @return either (a) a SequenceIterator over the sequence of items that the supplied input
* item maps to, or (b) an Item if it maps to a single item, or (c) null if it maps to an empty
* sequence.
*/
public SequenceIterator map(XPathContext context) throws XPathException {
if (base.isMatching()) {
if (matching != null) {
return matching.iterate(c2);
}
} else {
if (nonMatching != null) {
return nonMatching.iterate(c2);
}
}
return EmptyIterator.getInstance();
}
}
}
//
// The contents of this file are subject to the Mozilla Public License Version 1.0 (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.mozilla.org/MPL/
//
// Software distributed under the License is distributed on an "AS IS" basis,
// WITHOUT WARRANTY OF ANY KIND, either express or implied.
// See the License for the specific language governing rights and limitations under the License.
//
// The Original Code is: all this file.
//
// The Initial Developer of the Original Code is Michael H. Kay
//
// Portions created by (your name) are Copyright (C) (your legal entity). All Rights Reserved.
//
// Contributor(s):
//