Class UserFunctionCall
- java.lang.Object
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- net.sf.saxon.expr.Expression
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- net.sf.saxon.expr.FunctionCall
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- net.sf.saxon.expr.UserFunctionCall
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- All Implemented Interfaces:
ComponentInvocation,ContextOriginator,ExportAgent,Locatable,UserFunctionResolvable,IdentityComparable,Traceable
public class UserFunctionCall extends FunctionCall implements UserFunctionResolvable, ComponentInvocation, ContextOriginator
This class represents a call to a user-defined function in the stylesheet or query.
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Field Summary
Fields Modifier and Type Field Description static intFOREIGN_TAIL_CALLstatic intNOT_TAIL_CALLstatic intSELF_TAIL_CALL-
Fields inherited from class net.sf.saxon.expr.Expression
EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, MAX_COST, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, UPDATE_METHOD, WATCH_METHOD
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Constructor Summary
Constructors Constructor Description UserFunctionCall()Create a function call to a user-written function in a query or stylesheet
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Method Summary
All Methods Instance Methods Concrete Methods Modifier and Type Method Description PathMap.PathMapNodeSetaddToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)Add a representation of this expression to a PathMap.voidallocateArgumentEvaluators()intcomputeCardinality()Determine the cardinality of the resultprotected intcomputeSpecialProperties()Compute the special properties of this expression.Expressioncopy(RebindingMap rebindings)Copy an expression.Sequence[]evaluateArguments(XPathContext c)Sequence[]evaluateArguments(XPathContext c, boolean streamed)ItemevaluateItem(XPathContext c)Call the function, returning the value as an item.voidevaluatePendingUpdates(XPathContext context, PendingUpdateList pul)Evaluate an updating expression, adding the results to a Pending Update List.voidexport(ExpressionPresenter out)Diagnostic print of expression structure.Evaluator[]getArgumentEvaluators()intgetBindingSlot()Get the binding slot to be used.java.lang.StringgetExpressionName()Get a name identifying the kind of expression, in terms meaningful to a user.ComponentgetFixedTarget()Get the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original.UserFunctiongetFunction()Get the function that is being called by this function call.StructuredQNamegetFunctionName()Get the qualified of the function being calledintgetImplementationMethod()An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process().intgetIntrinsicDependencies()Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.ItemTypegetItemType()Determine the data type of the expression, if possibleStructuredQNamegetObjectName()Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc.java.lang.ObjectgetProperty(java.lang.String name)UTypegetStaticUType(UType contextItemType)Get the static type of the expression as a UType, following precisely the type inference rules defined in the XSLT 3.0 specification.SymbolicNamegetSymbolicName()Get the symbolic name of the component that this invocation referencesComponentgetTarget()ComponentgetTargetComponent(XPathContext context)UserFunctiongetTargetFunction(XPathContext context)Get the target function to be calledbooleanisBeingInlined()booleanisRecursiveTailCall()booleanisTailCall()Determine whether this is a tail call (not necessarily a recursive tail call)booleanisUpdatingExpression()Determine whether this is an updating expression as defined in the XQuery update specificationSequenceIteratoriterate(XPathContext c)Call the function, returning an iterator over the results.intmarkTailFunctionCalls(StructuredQName qName, int arity)Mark tail-recursive calls on stylesheet functions.Expressionoptimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType)Perform optimisation of an expression and its subexpressions.ExpressionpreEvaluate(ExpressionVisitor visitor)Pre-evaluate a function at compile time.voidprocess(Outputter output, XPathContext context)Process the function call in push modevoidresetLocalStaticProperties()Reset the static properties of the expression to -1, so that they have to be recomputed next time they are used.voidsetArgumentEvaluationModes(EvaluationMode[] evalModes)Set the argument evaluation modesvoidsetBeingInlined(boolean beingInlined)voidsetBindingSlot(int slot)Set the binding slot to be used.voidsetFunction(UserFunction compiledFunction)Create the reference to the function to be calledvoidsetFunctionName(StructuredQName name)Set the name of the function being calledvoidsetStaticType(SequenceType type)Set the static typeExpressiontypeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo)Type-check the expression.-
Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, adjustRequiredType, checkArgumentCount, checkArguments, checkFunctionCall, computeHashCode, equals, getArg, getArguments, getArity, getDisplayName, getNetCost, getOperanda, operands, pluralArguments, preEvaluateIfConstant, setArg, setArguments, setOperanda, setOperanda, simplifyArguments, toShortString, toString
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Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getLocalRetainedStaticContext, getLocation, getPackageData, getParentExpression, getProperties, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStreamerName, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isInstruction, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isVacuousExpression, operandList, operandSparseList, optimizeChildren, prepareForStreaming, restoreParentPointers, setEvaluationMethod, setExtraProperty, setFiltered, setFlattened, setLocation, setParentExpression, setRetainedStaticContext, setRetainedStaticContextLocally, setRetainedStaticContextThoroughly, setStaticProperty, simplify, simplifyChildren, staticTypeCheck, suppressValidation, toPattern, typeCheckChildren, typeError, unordered, verifyParentPointers
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Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
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Methods inherited from interface net.sf.saxon.trace.Traceable
gatherProperties
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Field Detail
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NOT_TAIL_CALL
public static final int NOT_TAIL_CALL
- See Also:
- Constant Field Values
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FOREIGN_TAIL_CALL
public static final int FOREIGN_TAIL_CALL
- See Also:
- Constant Field Values
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SELF_TAIL_CALL
public static final int SELF_TAIL_CALL
- See Also:
- Constant Field Values
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Method Detail
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isBeingInlined
public boolean isBeingInlined()
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setBeingInlined
public void setBeingInlined(boolean beingInlined)
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setFunctionName
public final void setFunctionName(StructuredQName name)
Set the name of the function being called- Parameters:
name- the name of the function
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setStaticType
public void setStaticType(SequenceType type)
Set the static type- Parameters:
type- the static type of the result of the function call
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setFunction
public void setFunction(UserFunction compiledFunction)
Create the reference to the function to be called- Specified by:
setFunctionin interfaceUserFunctionResolvable- Parameters:
compiledFunction- the function being called
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setBindingSlot
public void setBindingSlot(int slot)
Set the binding slot to be used. This is the offset within the binding vector of the containing component where the actual target template is to be found. The target function is not held directly in the UserFunctionCall expression itself because it can be overridden in a using package.- Specified by:
setBindingSlotin interfaceComponentInvocation- Parameters:
slot- the offset in the binding vector of the containing package where the target template can be found.
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getBindingSlot
public int getBindingSlot()
Get the binding slot to be used. This is the offset within the binding vector of the containing component where the actual target template is to be found.- Specified by:
getBindingSlotin interfaceComponentInvocation- Returns:
- the offset in the binding vector of the containing package where the target template can be found.
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getFunction
public UserFunction getFunction()
Get the function that is being called by this function call. This is the provisional binding: the actual function might be an override of this one.- Returns:
- the function being called
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getFixedTarget
public Component getFixedTarget()
Description copied from interface:ComponentInvocationGet the target component if this is known in advance, that is, if the target component is private or final, or in some other cases such as xsl:original. Otherwise, return null.- Specified by:
getFixedTargetin interfaceComponentInvocation- Returns:
- the bound component if the binding has been fixed
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isTailCall
public boolean isTailCall()
Determine whether this is a tail call (not necessarily a recursive tail call)- Returns:
- true if this function call is a tail call
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isRecursiveTailCall
public boolean isRecursiveTailCall()
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getFunctionName
public final StructuredQName getFunctionName()
Get the qualified of the function being called- Specified by:
getFunctionNamein classFunctionCall- Returns:
- the qualified name
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getSymbolicName
public SymbolicName getSymbolicName()
Description copied from interface:ComponentInvocationGet the symbolic name of the component that this invocation references- Specified by:
getSymbolicNamein interfaceComponentInvocation- Returns:
- the symbolic name of the target component, or null if there is no component referenced
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getTarget
public Component getTarget()
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setArgumentEvaluationModes
public void setArgumentEvaluationModes(EvaluationMode[] evalModes)
Set the argument evaluation modes- Parameters:
evalModes- the argument evaluation modes to be used
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allocateArgumentEvaluators
public void allocateArgumentEvaluators()
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getArgumentEvaluators
public Evaluator[] getArgumentEvaluators()
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preEvaluate
public Expression preEvaluate(ExpressionVisitor visitor)
Pre-evaluate a function at compile time. This version of the method suppresses early evaluation by doing nothing.- Overrides:
preEvaluatein classFunctionCall- Parameters:
visitor- an expression visitor- Returns:
- the result of the early evaluation, or the original expression, or potentially a simplified expression
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getItemType
public ItemType getItemType()
Determine the data type of the expression, if possible- Specified by:
getItemTypein classExpression- Returns:
- Type.ITEM (meaning not known in advance)
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getStaticUType
public UType getStaticUType(UType contextItemType)
Get the static type of the expression as a UType, following precisely the type inference rules defined in the XSLT 3.0 specification.- Overrides:
getStaticUTypein classExpression- Parameters:
contextItemType- the static type of the context item- Returns:
- the static item type of the expression according to the XSLT 3.0 defined rules
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getIntrinsicDependencies
public int getIntrinsicDependencies()
Description copied from class:ExpressionDetermine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. For example, position() has an intrinsic dependency on the context position, while (position()+1) does not. The default implementation of the method returns 0, indicating "no dependencies".- Overrides:
getIntrinsicDependenciesin classExpression- Returns:
- a set of bit-significant flags identifying the "intrinsic" dependencies. The flags are documented in class net.sf.saxon.value.StaticProperty
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isUpdatingExpression
public boolean isUpdatingExpression()
Determine whether this is an updating expression as defined in the XQuery update specification- Overrides:
isUpdatingExpressionin classExpression- Returns:
- true if this is an updating expression
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computeSpecialProperties
protected int computeSpecialProperties()
Compute the special properties of this expression. These properties are denoted by a bit-significant integer, possible values are in classStaticProperty. The "special" properties are properties other than cardinality and dependencies, and most of them relate to properties of node sequences, for example whether the nodes are in document order.- Overrides:
computeSpecialPropertiesin classExpression- Returns:
- the special properties, as a bit-significant integer
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copy
public Expression copy(RebindingMap rebindings)
Copy an expression. This makes a deep copy.- Specified by:
copyin classExpression- Parameters:
rebindings- variable bindings that need to be changed- Returns:
- the copy of the original expression
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computeCardinality
public int computeCardinality()
Determine the cardinality of the result- Specified by:
computeCardinalityin classExpression- Returns:
- the computed cardinality, as one of the values
StaticProperty.ALLOWS_ZERO_OR_ONE,StaticProperty.EXACTLY_ONE,StaticProperty.ALLOWS_ONE_OR_MORE,StaticProperty.ALLOWS_ZERO_OR_MORE. May also returnStaticProperty.ALLOWS_ZEROif the result is known to be an empty sequence, orStaticProperty.ALLOWS_MANYif if is known to return a sequence of length two or more.
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typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo) throws XPathException
Description copied from class:FunctionCallType-check the expression. This also calls preEvaluate() to evaluate the function if all the arguments are constant; functions that do not require this behavior can override the preEvaluate method.- Overrides:
typeCheckin classFunctionCall- Parameters:
visitor- an expression visitorcontextInfo- Information available statically about the context item: whether it is (possibly) absent; its static type; its streaming posture.- Returns:
- the original expression, rewritten to perform necessary run-time type checks, and to perform other type-related optimizations
- Throws:
XPathException- if an error is discovered during this phase (typically a type error)
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optimize
public Expression optimize(ExpressionVisitor visitor, ContextItemStaticInfo contextItemType) throws XPathException
Description copied from class:FunctionCallPerform optimisation of an expression and its subexpressions.This method is called after all references to functions and variables have been resolved to the declaration of the function or variable, and after all type checking has been done.
- Overrides:
optimizein classFunctionCall- Parameters:
visitor- an expression visitorcontextItemType- the static type of "." at the point where this expression is invoked. The parameter is set to null if it is known statically that the context item will be undefined. If the type of the context item is not known statically, the argument is set toType.ITEM_TYPE- Returns:
- the original expression, rewritten if appropriate to optimize execution
- Throws:
XPathException- if an error is discovered during this phase (typically a type error)
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resetLocalStaticProperties
public void resetLocalStaticProperties()
Reset the static properties of the expression to -1, so that they have to be recomputed next time they are used.- Overrides:
resetLocalStaticPropertiesin classExpression
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addToPathMap
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of this expression to a PathMap. The PathMap captures a map of the nodes visited by an expression in a source tree.The default implementation of this method assumes that an expression does no navigation other than the navigation done by evaluating its subexpressions, and that the subexpressions are evaluated in the same context as the containing expression. The method must be overridden for any expression where these assumptions do not hold. For example, implementations exist for AxisExpression, ParentExpression, and RootExpression (because they perform navigation), and for the doc(), document(), and collection() functions because they create a new navigation root. Implementations also exist for PathExpression and FilterExpression because they have subexpressions that are evaluated in a different context from the calling expression.
- Overrides:
addToPathMapin classExpression- Parameters:
pathMap- the PathMap to which the expression should be addedpathMapNodeSet- the PathMapNodeSet to which the paths embodied in this expression should be added- Returns:
- the pathMapNode representing the focus established by this expression, in the case where this expression is the first operand of a path expression or filter expression. For an expression that does navigation, it represents the end of the arc in the path map that describes the navigation route. For other expressions, it is the same as the input pathMapNode.
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markTailFunctionCalls
public int markTailFunctionCalls(StructuredQName qName, int arity)
Mark tail-recursive calls on stylesheet functions. This marks the function call as tailRecursive if if is a call to the containing function, and in this case it also returns "true" to the caller to indicate that a tail call was found.- Overrides:
markTailFunctionCallsin classExpression- Parameters:
qName- the name of the functionarity- the arity (number of parameters) of the function- Returns:
NOT_TAIL_CALLif no tail call was found;FOREIGN_TAIL_CALLif a tail call on a different function was found;SELF_TAIL_CALLif a tail recursive call was found and if this call accounts for the whole of the value.
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getImplementationMethod
public int getImplementationMethod()
Description copied from class:FunctionCallAn implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). This method indicates which of these methods is provided directly. The other methods will always be available indirectly, using an implementation that relies on one of the other methods.- Overrides:
getImplementationMethodin classFunctionCall- Returns:
- the implementation method, for example
Expression.ITERATE_METHODorExpression.EVALUATE_METHODorExpression.PROCESS_METHOD
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evaluateItem
public Item evaluateItem(XPathContext c) throws XPathException
Call the function, returning the value as an item. This method will be used only when the cardinality is zero or one. If the function is tail recursive, it returns an Object representing the arguments to the next (recursive) call- Overrides:
evaluateItemin classExpression- Parameters:
c- The context in which the expression is to be evaluated- Returns:
- the node or atomic value that results from evaluating the expression; or null to indicate that the result is an empty sequence
- Throws:
XPathException- if any dynamic error occurs evaluating the expression
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iterate
public SequenceIterator iterate(XPathContext c) throws XPathException
Call the function, returning an iterator over the results. (But if the function is tail recursive, it returns an iterator over the arguments of the recursive call)- Overrides:
iteratein classFunctionCall- Parameters:
c- supplies the context for evaluation- Returns:
- a SequenceIterator that can be used to iterate over the result of the expression
- Throws:
XPathException- if any dynamic error occurs evaluating the expression
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evaluatePendingUpdates
public void evaluatePendingUpdates(XPathContext context, PendingUpdateList pul) throws XPathException
Evaluate an updating expression, adding the results to a Pending Update List. The default implementation of this method, which is used for non-updating expressions, throws an UnsupportedOperationException- Overrides:
evaluatePendingUpdatesin classExpression- Parameters:
context- the XPath dynamic evaluation contextpul- the pending update list to which the results should be written- Throws:
XPathException- if evaluation fails
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process
public void process(Outputter output, XPathContext context) throws XPathException
Process the function call in push mode- Overrides:
processin classExpression- Parameters:
output- the destination for the resultcontext- the XPath dynamic context- Throws:
XPathException- if a dynamic error occurs
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getTargetComponent
public Component getTargetComponent(XPathContext context)
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getTargetFunction
public UserFunction getTargetFunction(XPathContext context)
Description copied from class:FunctionCallGet the target function to be called- Specified by:
getTargetFunctionin classFunctionCall- Parameters:
context- the dynamic evaluation context- Returns:
- the target function
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evaluateArguments
public Sequence[] evaluateArguments(XPathContext c) throws XPathException
- Overrides:
evaluateArgumentsin classFunctionCall- Throws:
XPathException
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evaluateArguments
public Sequence[] evaluateArguments(XPathContext c, boolean streamed) throws XPathException
- Throws:
XPathException
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export
public void export(ExpressionPresenter out) throws XPathException
Diagnostic print of expression structure. The abstract expression tree is written to the supplied output destination.- Specified by:
exportin interfaceExportAgent- Overrides:
exportin classFunctionCall- Parameters:
out- the expression presenter used to display the structure- Throws:
XPathException- if the export fails, for example if an expression is found that won't work in the target environment.
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getExpressionName
public java.lang.String getExpressionName()
Get a name identifying the kind of expression, in terms meaningful to a user.- Overrides:
getExpressionNamein classFunctionCall- Returns:
- a name identifying the kind of expression, in terms meaningful to a user. The name will always be in the form of a lexical XML QName, and should match the name used in explain() output displaying the expression.
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getProperty
public java.lang.Object getProperty(java.lang.String name)
- Overrides:
getPropertyin classExpression
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getObjectName
public StructuredQName getObjectName()
Description copied from interface:TraceableGet 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.- Specified by:
getObjectNamein interfaceTraceable- Overrides:
getObjectNamein classExpression- Returns:
- the QName of the object declared or manipulated by this instruction or expression
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