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The XSLT and XQuery Processor
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
// Copyright (c) 2018-2023 Saxonica Limited
// This Source Code Form is subject to the terms of the Mozilla Public License, v. 2.0.
// If a copy of the MPL was not distributed with this file, You can obtain one at http://mozilla.org/MPL/2.0/.
// This Source Code Form is "Incompatible With Secondary Licenses", as defined by the Mozilla Public License, v. 2.0.
////////////////////////////////////////////////////////////////////////////////////////////////////////////////////
package net.sf.saxon.expr.accum;
import net.sf.saxon.expr.Component;
import net.sf.saxon.expr.Expression;
import net.sf.saxon.expr.Literal;
import net.sf.saxon.expr.instruct.Actor;
import net.sf.saxon.expr.instruct.Block;
import net.sf.saxon.expr.instruct.SlotManager;
import net.sf.saxon.om.NamespaceUri;
import net.sf.saxon.om.StandardNames;
import net.sf.saxon.om.StructuredQName;
import net.sf.saxon.trace.ExpressionPresenter;
import net.sf.saxon.trans.Mode;
import net.sf.saxon.trans.SimpleMode;
import net.sf.saxon.trans.SymbolicName;
import net.sf.saxon.trans.XPathException;
import net.sf.saxon.value.SequenceType;
import java.util.Map;
/**
* Represents a single accumulator declared in an XSLT 3.0 stylesheet
*/
public class Accumulator extends Actor {
private StructuredQName accumulatorName;
private SimpleMode preDescentRules;
private SimpleMode postDescentRules;
private Expression initialValueExpression;
private SequenceType type;
private boolean streamable;
private boolean universallyApplicable;
private int importPrecedence;
private boolean tracing;
private SlotManager slotManagerForInitialValueExpression;
public Accumulator() {
preDescentRules = new SimpleMode(new StructuredQName("saxon", NamespaceUri.SAXON, "preDescent"));
postDescentRules = new SimpleMode(new StructuredQName("saxon", NamespaceUri.SAXON, "postDescent"));
// The "body" of an accumulator is an artificial expression that contains all the constituent expressions, for ease of management.
body = Literal.makeEmptySequence();
}
/**
* Get the symbolic name of the component
*
* @return the symbolic name
*/
@Override
public SymbolicName getSymbolicName() {
return new SymbolicName(StandardNames.XSL_ACCUMULATOR, getAccumulatorName());
}
/**
* Ask whether the accumulator is declared streamable
*
* @return true if it is declared with streamable="yes"
*/
public boolean isDeclaredStreamable() {
return streamable;
}
/**
* Say whether the accumulator is declared streamable
*
* @param streamable true if it is declared with streamable="yes"
*/
public void setDeclaredStreamable(boolean streamable) {
this.streamable = streamable;
}
/**
* Get the name of the accumulator
*
* @return the accumulator name
*/
public StructuredQName getAccumulatorName() {
return accumulatorName;
}
/**
* Set the name of the pre-descent function
*
* @param firstName the function name (always present)
*/
public void setAccumulatorName(StructuredQName firstName) {
this.accumulatorName = firstName;
}
/**
* Get the import precedence
* @return the import precedence of the accumulator
*/
public int getImportPrecedence() {
return importPrecedence;
}
/**
* Set the import precedence
* @param importPrecedence the import precedence of the accumulator
*/
public void setImportPrecedence(int importPrecedence) {
this.importPrecedence = importPrecedence;
}
/**
* Say whether this accumulator is universally appicable to all documents
* @param universal true if this accumulator is universally applicable
*/
public void setUniversallyApplicable(boolean universal) {
this.universallyApplicable = universal;
}
/**
* Ask whether this accumulator is universally appicable to all documents
* @return true if this accumulator is universally applicable
*/
public boolean isUniversallyApplicable() {
return universallyApplicable;
}
/**
* Ask whether diagnostic tracing is enabled for this accumulator
* @return true if diagnostic tracing is enabled
*/
public boolean isTracing() {
return tracing;
}
/**
* Say whether diagnostic tracing is to be enabled for this accumulator
* @param tracing true if diagnostic tracing is to be enabled
*/
public void setTracing(boolean tracing) {
this.tracing = tracing;
}
/**
* Get the slotManager to be used for evaluating the initial-value expression
* @return the slotManager for the initial-value expression (defining any local variables declared and used
* within this expression)
*/
public SlotManager getSlotManagerForInitialValueExpression() {
return slotManagerForInitialValueExpression;
}
/**
* Set the slotManager to be used for evaluating the initial-value expression
* @param slotManagerForInitialValueExpression the slotManager for the initial-value expression
* (defining any local variables declared and used within this expression)
*/
public void setSlotManagerForInitialValueExpression(SlotManager slotManagerForInitialValueExpression) {
this.slotManagerForInitialValueExpression = slotManagerForInitialValueExpression;
}
/**
* Get the set of rules for phase="start", held in the form of a Mode object
*
* @return the Mode object containing all the rules that apply to phase="start"
*/
public SimpleMode getPreDescentRules() {
return preDescentRules;
}
/**
* Set the set of rules for phase="start", held in the form of a Mode object
*
* @param preDescentRules the Mode object containing all the rules that apply to phase="start"
*/
public void setPreDescentRules(SimpleMode preDescentRules) {
this.preDescentRules = preDescentRules;
}
/**
* Get the set of rules for phase="end", held in the form of a Mode object
*
* @return the Mode object containing all the rules that apply to phase="end"
*/
public SimpleMode getPostDescentRules() {
return postDescentRules;
}
/**
* Set the set of rules for phase="end", held in the form of a Mode object
*
* @param postDescentRules the Mode object containing all the rules that apply to phase="end"
*/
public void setPostDescentRules(SimpleMode postDescentRules) {
this.postDescentRules = postDescentRules;
}
/**
* Get the expression that computes the initial value of the accumulator
*
* @return the initial value expression
*/
public Expression getInitialValueExpression() {
return initialValueExpression;
}
/**
* Set the expression that computes the initial value of the accumulator
*
* @param initialValueExpression the initial value expression
*/
public void setInitialValueExpression(Expression initialValueExpression) {
this.initialValueExpression = initialValueExpression;
}
/**
* Add an expression to the list of expressions used by this accumulator
* @param expression the expression to be added to the list
*/
public void addChildExpression(Expression expression) {
Expression e = Block.makeBlock(getBody(), expression);
setBody(e);
}
/**
* Get the declared type of the accumulator. The initial value and all intermediate values
* must conform to this type
*
* @return the declared type of the accumulator
*/
public SequenceType getType() {
return type;
}
/**
* Set the declared type of the accumulator. The initial value and all intermediate values
* must conform to this type
*
* @param type the declared type of the accumulator
*/
public void setType(SequenceType type) {
this.type = type;
}
/**
* Determine whether this accumulator is compatible with one that it overrides
* @param other the accumlator that this one overrides
* @return true if they are compatible, as defined in the XSLT 3.0 specification
*/
public boolean isCompatible(Accumulator other) {
return getAccumulatorName().equals(other.getAccumulatorName());
}
/**
* Get a name identifying the object of the expression, for example a function name, template name,
* variable name, key name, element name, etc. This is used only where the name is known statically.
*
* @return the QName of the object declared or manipulated by this instruction or expression
*/
public StructuredQName getObjectName() {
return accumulatorName;
}
/**
* Export expression structure. The abstract expression tree
* is written to the supplied outputstream.
*
* @param presenter the expression presenter used to generate the XML representation of the structure
*/
@Override
public void export(ExpressionPresenter presenter) throws XPathException {
export(presenter, null);
}
/**
* Export expression structure. The abstract expression tree
* is written to the supplied outputstream.
*
* @param out the expression presenter used to display the structure
* @param componentIdMap map from components to component IDs
* @throws XPathException if any error occurs
*/
public void export(final ExpressionPresenter out, Map componentIdMap) throws XPathException {
out.startElement("accumulator");
out.emitAttribute("name", getObjectName());
out.emitAttribute("line", getLineNumber() + "");
out.emitAttribute("module", getSystemId());
out.emitAttribute("as", type.toAlphaCode());
out.emitAttribute("streamable", streamable ? "1" : "0");
out.emitAttribute("slots", getSlotManagerForInitialValueExpression().getNumberOfVariables()+"");
if (componentIdMap != null) {
out.emitAttribute("binds", "" + getDeclaringComponent().listComponentReferences(componentIdMap));
}
if (isUniversallyApplicable()) {
out.emitAttribute("flags", "u");
}
out.setChildRole("init");
initialValueExpression.export(out);
Mode.RuleAction action = r -> {
out.startElement("accRule");
out.emitAttribute("slots", ((AccumulatorRule)r.getAction()).getStackFrameMap().getNumberOfVariables()+"");
out.emitAttribute("rank", ""+r.getRank());
if (((AccumulatorRule) r.getAction()).isCapturing()) {
out.emitAttribute("flags", "c");
}
r.getPattern().export(out);
r.getAction().export(out);
out.endElement();
};
try {
out.startElement("pre");
out.emitAttribute("slots", preDescentRules.getStackFrameSlotsNeeded()+"");
preDescentRules.processRules(action);
out.endElement();
out.startElement("post");
out.emitAttribute("slots", postDescentRules.getStackFrameSlotsNeeded() + "");
postDescentRules.processRules(action);
out.endElement();
} catch (XPathException e) {
throw new AssertionError(e);
}
out.endElement();
}
}