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java.lang.Object net.sf.saxon.expr.Expression net.sf.saxon.expr.FunctionCall net.sf.saxon.expr.UserFunctionCall
public class UserFunctionCall
This class represents a call to a user-defined function in the stylesheet or query.
Field Summary | |
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static int |
FOREIGN_TAIL_CALL
|
static int |
NOT_TAIL_CALL
|
static int |
SELF_TAIL_CALL
|
Fields inherited from class net.sf.saxon.expr.FunctionCall |
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argument |
Fields inherited from class net.sf.saxon.expr.Expression |
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EFFECTIVE_BOOLEAN_VALUE, EVALUATE_METHOD, EVENT_FEED_METHOD, ITEM_FEED_METHOD, ITERATE_METHOD, locationId, MAX_SEQUENCE_LENGTH, MAX_STRING_LENGTH, PROCESS_METHOD, PUSH_SELECTION, staticProperties, UNBOUNDED_LOWER, UNBOUNDED_UPPER, WATCH_METHOD |
Constructor Summary | |
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UserFunctionCall()
Create a function call to a user-written function in a query or stylesheet |
Method Summary | |
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PathMap.PathMapNodeSet |
addToPathMap(PathMap pathMap,
PathMap.PathMapNodeSet pathMapNodeSet)
Add a representation of this expression to a PathMap. |
void |
checkArguments(ExpressionVisitor visitor)
Method called during the type checking phase |
void |
checkFunctionCall(UserFunction compiledFunction,
ExpressionVisitor visitor)
Check the function call against the declared function signature |
void |
computeArgumentEvaluationModes()
Compute the evaluation mode of each argument |
int |
computeCardinality()
Determine the cardinality of the result |
protected int |
computeSpecialProperties()
Compute the special properties of this expression. |
Expression |
copy()
Copy an expression. |
ValueRepresentation |
dynamicCall(ValueRepresentation[] suppliedArguments,
XPathContext context)
Call the function dynamically. |
ValueRepresentation[] |
evaluateArguments(XPathContext c)
|
Item |
evaluateItem(XPathContext c)
Call the function, returning the value as an item. |
void |
evaluatePendingUpdates(XPathContext context,
PendingUpdateList pul)
Evaluate an updating expression, adding the results to a Pending Update List. |
void |
explain(ExpressionPresenter out)
Diagnostic print of expression structure. |
int[] |
getArgumentEvaluationModes()
Get the evaluation modes that have been determined for each of the arguments |
int |
getConstructType()
Get the type of this expression for use in tracing and diagnostics |
UserFunction |
getFunction()
Get the function that is being called by this function call |
StructuredQName |
getFunctionName()
Get the qualified of the function being called |
int |
getImplementationMethod()
An implementation of Expression must provide at least one of the methods evaluateItem(), iterate(), or process(). |
int |
getIntrinsicDependencies()
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions. |
ItemType |
getItemType(TypeHierarchy th)
Determine the data type of the expression, if possible |
int |
getLineNumber(long locationId)
Get the line number within the document or module containing a particular location |
StructuredQName |
getObjectName()
Get a name identifying the object of the expression, for example a function name, template name, variable name, key name, element name, etc. |
Object |
getProperty(String name)
Get the value of a particular property of the instruction. |
String |
getSystemId(long locationId)
Get the URI of the document or module containing a particular location |
boolean |
isRecursiveTailCall()
|
boolean |
isTailCall()
Determine whether this is a tail call (not necessarily a recursive tail call) |
boolean |
isUpdatingExpression()
Determine whether this is an updating expression as defined in the XQuery update specification |
SequenceIterator |
iterate(XPathContext c)
Call the function, returning an iterator over the results. |
EventIterator |
iterateEvents(XPathContext context)
Process the function call in pull mode |
int |
markTailFunctionCalls(StructuredQName qName,
int arity)
Mark tail-recursive calls on stylesheet functions. |
Expression |
optimize(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Perform optimisation of an expression and its subexpressions. |
Expression |
preEvaluate(ExpressionVisitor visitor)
Pre-evaluate a function at compile time. |
void |
process(XPathContext context)
Process the function call in push mode |
Expression |
promote(PromotionOffer offer,
Expression parent)
Promote this expression if possible |
void |
setFunction(UserFunction compiledFunction)
Create the reference to the function to be called |
void |
setStaticType(SequenceType type)
Set the static type |
Expression |
typeCheck(ExpressionVisitor visitor,
ExpressionVisitor.ContextItemType contextItemType)
Type-check the expression. |
Methods inherited from class net.sf.saxon.expr.FunctionCall |
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addExternalFunctionCallToPathMap, checkArgumentCount, equals, getArguments, getDisplayName, getExpressionName, getNumberOfArguments, hashCode, iterateSubExpressions, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString |
Methods inherited from class java.lang.Object |
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clone, finalize, getClass, notify, notifyAll, wait, wait, wait |
Field Detail |
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public static final int NOT_TAIL_CALL
public static final int FOREIGN_TAIL_CALL
public static final int SELF_TAIL_CALL
Constructor Detail |
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public UserFunctionCall()
Method Detail |
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public void setStaticType(SequenceType type)
type
- the static type of the result of the function callpublic void setFunction(UserFunction compiledFunction)
compiledFunction
- the function being calledpublic void checkFunctionCall(UserFunction compiledFunction, ExpressionVisitor visitor) throws XPathException
compiledFunction
- the function being calledvisitor
- an expression visitor
XPathException
public UserFunction getFunction()
public boolean isTailCall()
public boolean isRecursiveTailCall()
public void checkArguments(ExpressionVisitor visitor) throws XPathException
checkArguments
in class FunctionCall
visitor
- the expression visitor
XPathException
- if the arguments are incorrectpublic final StructuredQName getFunctionName()
getFunctionName
in class FunctionCall
public int[] getArgumentEvaluationModes()
public Expression preEvaluate(ExpressionVisitor visitor)
preEvaluate
in class FunctionCall
visitor
- an expression visitor
public ItemType getItemType(TypeHierarchy th)
getItemType
in class Expression
th
- the type hierarchy cache
public int getIntrinsicDependencies()
Expression
getIntrinsicDependencies
in class Expression
public boolean isUpdatingExpression()
isUpdatingExpression
in class Expression
protected int computeSpecialProperties()
StaticProperty
. 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.
computeSpecialProperties
in class Expression
public Expression copy()
copy
in class Expression
public int computeCardinality()
computeCardinality
in class Expression
StaticProperty.ALLOWS_ZERO_OR_ONE
,
StaticProperty.EXACTLY_ONE
, StaticProperty.ALLOWS_ONE_OR_MORE
,
StaticProperty.ALLOWS_ZERO_OR_MORE
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
FunctionCall
typeCheck
in class FunctionCall
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 to
Type.ITEM_TYPE
XPathException
- if an error is discovered during this phase
(typically a type error)public Expression optimize(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException
FunctionCall
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.
optimize
in class FunctionCall
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 to
Type.ITEM_TYPE
XPathException
- if an error is discovered during this phase
(typically a type error)public Expression promote(PromotionOffer offer, Expression parent) throws XPathException
promote
in class FunctionCall
offer
- details of the offer, for example the offer to move
expressions that don't depend on the context to an outer level in
the containing expressionparent
- the containing expression in the expression tree
XPathException
- if any error is detectedpublic void computeArgumentEvaluationModes()
public PathMap.PathMapNodeSet addToPathMap(PathMap pathMap, PathMap.PathMapNodeSet pathMapNodeSet)
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.
addToPathMap
in class Expression
pathMap
- the PathMap to which the expression should be addedpathMapNodeSet
- the PathMapNodeSet to which the paths embodied in this expression should be added
public int markTailFunctionCalls(StructuredQName qName, int arity)
markTailFunctionCalls
in class Expression
qName
- the name of the functionarity
- the arity (number of parameters) of the function
NOT_TAIL_CALL
if no tail call was found;
FOREIGN_TAIL_CALL
if a tail call on a different function was found;public int getImplementationMethod()
Expression
getImplementationMethod
in class Expression
Expression.ITERATE_METHOD
or Expression.EVALUATE_METHOD
or
Expression.PROCESS_METHOD
public Item evaluateItem(XPathContext c) throws XPathException
evaluateItem
in class Expression
c
- The context in which the expression is to be evaluated
XPathException
- if any dynamic error occurs evaluating the
expressionpublic SequenceIterator iterate(XPathContext c) throws XPathException
iterate
in class Expression
c
- supplies the context for evaluation
XPathException
- if any dynamic error occurs evaluating the
expressionpublic void evaluatePendingUpdates(XPathContext context, PendingUpdateList pul) throws XPathException
evaluatePendingUpdates
in class Expression
context
- the XPath dynamic evaluation contextpul
- the pending update list to which the results should be written
XPathException
- if evaluation failspublic void process(XPathContext context) throws XPathException
process
in class Expression
context
- the XPath dynamic context
XPathException
public EventIterator iterateEvents(XPathContext context) throws XPathException
iterateEvents
in class Expression
context
- the XPath dynamic context
XPathException
public ValueRepresentation[] evaluateArguments(XPathContext c) throws XPathException
XPathException
public ValueRepresentation dynamicCall(ValueRepresentation[] suppliedArguments, XPathContext context) throws XPathException
SuppliedParameterReference
objects. The actual arguments are placed on the
callee's stack, and the type conversion takes place "in situ".
suppliedArguments
- the values to be used for the arguments of the functioncontext
- the dynamic evaluation context
XPathException
public void explain(ExpressionPresenter out)
explain
in class FunctionCall
out
- the expression presenter used to display the structurepublic int getConstructType()
Expression
getConstructType
in interface InstructionInfo
getConstructType
in class Expression
Location
public Object getProperty(String name)
InstructionInfo
getProperty
in interface InstructionInfo
getProperty
in class Expression
name
- The name of the required property
public StructuredQName getObjectName()
InstructionInfo
getObjectName
in interface InstructionInfo
getObjectName
in class Expression
public int getLineNumber(long locationId)
getLineNumber
in interface LocationProvider
getLineNumber
in class Expression
locationId
- identifier of the location in question (as passed down the Receiver pipeline)
public String getSystemId(long locationId)
getSystemId
in interface LocationProvider
getSystemId
in class Expression
locationId
- identifier of the location in question (as passed down the Receiver pipeline)
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