Package net.sf.saxon.functions
Class IntegratedFunctionCall
java.lang.Object
net.sf.saxon.expr.Expression
net.sf.saxon.expr.FunctionCall
net.sf.saxon.functions.IntegratedFunctionCall
- All Implemented Interfaces:
Serializable
,SourceLocator
,LocationProvider
,SaxonLocator
,CallableExpression
,InstructionInfo
,Locator
Expression representing a call to a user-written extension
function implemented as a subtype of
ExtensionFunctionCall
- See Also:
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Field Summary
Fields inherited from class net.sf.saxon.expr.FunctionCall
argument
Fields inherited from class net.sf.saxon.expr.Expression
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
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Constructor Summary
Constructors -
Method Summary
Modifier and TypeMethodDescriptionSequenceIterator
<? extends Item> call
(SequenceIterator<? extends Item>[] arguments, XPathContext context) Evaluate the expressionvoid
checkArguments
(ExpressionVisitor visitor) Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read.protected int
Compute the static cardinality of this expressionprotected int
Compute the special properties of this expression.copy()
Copy an expression.boolean
effectiveBooleanValue
(XPathContext context) Get the effective boolean value of the expression.Get the ExtensionFunctionCall object supplied by the applicationint
Determine the intrinsic dependencies of an expression, that is, those which are not derived from the dependencies of its subexpressions.Determine the data type of the expression, if possible.iterate
(XPathContext context) Return an Iterator to iterate over the values of a sequence.preEvaluate
(ExpressionVisitor visitor) Pre-evaluate a function at compile time.void
setContainer
(Container container) Mark an expression as being in a given Container.typeCheck
(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) Type-check the expression.Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, checkArgumentCount, equals, explain, getArguments, getDisplayName, getExpressionName, getFunctionName, getNumberOfArguments, hashCode, iterateSubExpressions, optimize, promote, replaceSubExpression, setArguments, setFunctionName, simplify, simplifyArguments, toString
Methods inherited from class net.sf.saxon.expr.Expression
addToPathMap, adoptChildExpression, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeStaticProperties, doPromotion, dynamicError, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, getCardinality, getColumnNumber, getColumnNumber, getConstructType, getContainer, getDependencies, getEvaluationMethod, getExecutable, getHostLanguage, getImplementationMethod, getIntegerBounds, getLineNumber, getLineNumber, getLocationId, getLocationProvider, getObjectName, getProperties, getProperty, getPublicId, getSlotsUsed, getSpecialProperties, getSystemId, getSystemId, hasLoopingSubexpression, hasVariableBinding, implementsStaticTypeCheck, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, iterateEvents, iterateSameFocusSubExpressions, markTailFunctionCalls, process, resetLocalStaticProperties, setEvaluationMethod, setFiltered, setFlattened, setLocationId, staticTypeCheck, suppressValidation, typeError
Methods inherited from class java.lang.Object
clone, finalize, getClass, notify, notifyAll, wait, wait, wait
Methods inherited from interface net.sf.saxon.expr.CallableExpression
getArguments
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Constructor Details
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IntegratedFunctionCall
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Method Details
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getFunction
Get the ExtensionFunctionCall object supplied by the application- Returns:
- the ExtensionFunctionCall object
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setContainer
Mark an expression as being in a given Container. This link is used primarily for diagnostics: the container links to the location map held in the executable.This affects the expression and all its subexpressions. Any subexpressions that are not in the same container are marked with the new container, and this proceeds recursively. However, any subexpression that is already in the correct container is not modified.
- Overrides:
setContainer
in classExpression
- Parameters:
container
- The container of this expression.
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checkArguments
Method supplied by each class of function to check arguments during parsing, when all the argument expressions have been read. This implementation of the method checks the arguments of the supplied function call against the argument types declared as part of the extension function definition, and generates code to do the conversion if necessary.- Specified by:
checkArguments
in classFunctionCall
- Parameters:
visitor
- the expression visitor- Throws:
XPathException
- if the arguments are statically determined to be incompatible with the declared argument types of the function.
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typeCheck
public Expression typeCheck(ExpressionVisitor visitor, ExpressionVisitor.ContextItemType contextItemType) throws XPathException Type-check the expression.- Overrides:
typeCheck
in 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 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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preEvaluate
Pre-evaluate a function at compile time. Functions that do not allow pre-evaluation, or that need access to context information, can override this method.- Overrides:
preEvaluate
in classFunctionCall
- Parameters:
visitor
- an expression visitor- Returns:
- the result of the early evaluation, or the original expression, or potentially a simplified expression
- Throws:
XPathException
- if evaluation fails
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getItemType
Determine the data type of the expression, if possible. All expression return sequences, in general; this method determines the type of the items within the sequence, assuming that (a) this is known in advance, and (b) it is the same for all items in the sequence.This method should always return a result, though it may be the best approximation that is available at the time.
- Specified by:
getItemType
in classExpression
- Parameters:
th
- the type hierarchy cache- Returns:
- a value such as Type.STRING, Type.BOOLEAN, Type.NUMBER, Type.NODE, or Type.ITEM (meaning not known at compile time)
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computeCardinality
protected int computeCardinality()Compute the static cardinality of this expression- Specified by:
computeCardinality
in 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
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getIntrinsicDependencies
public int getIntrinsicDependencies()Determine 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:
getIntrinsicDependencies
in 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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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:
computeSpecialProperties
in classExpression
- Returns:
- the special properties, as a bit-significant integer
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copy
Copy an expression. This makes a deep copy.- Specified by:
copy
in classExpression
- Returns:
- the copy of the original expression
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iterate
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.- Overrides:
iterate
in classExpression
- Parameters:
context
- 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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effectiveBooleanValue
Get the effective boolean value of the expression. This returns false if the value is the empty sequence, a zero-length string, a number equal to zero, or the boolean false. Otherwise it returns true.- Overrides:
effectiveBooleanValue
in classExpression
- Parameters:
context
- The context in which the expression is to be evaluated- Returns:
- the effective boolean value
- Throws:
XPathException
- if any dynamic error occurs evaluating the expression
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call
public SequenceIterator<? extends Item> call(SequenceIterator<? extends Item>[] arguments, XPathContext context) throws XPathException Description copied from interface:CallableExpression
Evaluate the expression- Specified by:
call
in interfaceCallableExpression
- Parameters:
arguments
- the values of the arguments, supplied as SequenceIteratorscontext
- the dynamic evaluation context- Returns:
- the result of the evaluation, in the form of a SequenceIterator
- Throws:
XPathException
- if a dynamic error occurs during the evaluation of the expression
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