Class XPathFunctionCall
- 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.xpath.XPathFunctionCall
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- All Implemented Interfaces:
Callable,ExportAgent,Locatable,IdentityComparable,Traceable
public class XPathFunctionCall extends FunctionCall implements Callable
This class is an expression that calls an external function supplied using the JAXP XPathFunction interface
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Field Summary
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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 XPathFunctionCall(StructuredQName name, javax.xml.xpath.XPathFunction function)Default constructor
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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.Sequencecall(XPathContext context, Sequence[] argValues)Call an extension function previously identified using the bind() method.intcomputeCardinality()Determine the cardinality of the resultExpressioncopy(RebindingMap rebindings)Copy an expression.StructuredQNamegetFunctionName()Get the qualified name of the function being calledintgetIntrinsicDependencies()Determine which aspects of the context the expression depends on.ItemTypegetItemType()Determine the data type of the expression, if possible.FunctiongetTargetFunction(XPathContext context)Get the target function to be calledSequenceIteratoriterate(XPathContext context)Evaluate the function.ExpressionpreEvaluate(ExpressionVisitor visitor)preEvaluate: this method suppresses compile-time evaluation by doing nothing (because the external function might have side-effects and might use the context)-
Methods inherited from class net.sf.saxon.expr.FunctionCall
addExternalFunctionCallToPathMap, adjustRequiredType, checkArgumentCount, checkArguments, checkFunctionCall, computeHashCode, equals, evaluateArguments, export, getArg, getArguments, getArity, getDisplayName, getExpressionName, getImplementationMethod, getNetCost, getOperanda, operands, optimize, pluralArguments, preEvaluateIfConstant, setArg, setArguments, setOperanda, setOperanda, simplifyArguments, toShortString, toString, typeCheck
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Methods inherited from class net.sf.saxon.expr.Expression
adoptChildExpression, allowExtractingCommonSubexpressions, checkedOperands, checkForUpdatingSubexpressions, checkPermittedContents, computeDependencies, computeSpecialProperties, computeStaticProperties, dynamicError, effectiveBooleanValue, evaluateAsString, evaluateItem, evaluatePendingUpdates, explain, getCardinality, getConfiguration, getCost, getDependencies, getEvaluationMethod, getExtraProperty, getIntegerBounds, getInterpretedExpression, getLocalRetainedStaticContext, getLocation, getObjectName, getPackageData, getParentExpression, getProperties, getProperty, getRetainedStaticContext, getScopingExpression, getSlotsUsed, getSpecialProperties, getStaticBaseURI, getStaticBaseURIString, getStaticType, getStaticUType, getStreamerName, getTracingTag, hasCompatibleStaticContext, hashCode, hasSpecialProperty, hasVariableBinding, identityHashCode, implementsStaticTypeCheck, isCallOn, isEqual, isIdentical, isInstruction, isLiftable, isMultiThreaded, isStaticPropertiesKnown, isSubtreeExpression, isUpdatingExpression, isVacuousExpression, markTailFunctionCalls, operandList, operandSparseList, optimizeChildren, prepareForStreaming, process, resetLocalStaticProperties, 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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Constructor Detail
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XPathFunctionCall
public XPathFunctionCall(StructuredQName name, javax.xml.xpath.XPathFunction function)
Default constructor
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Method Detail
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getFunctionName
public StructuredQName getFunctionName()
Get the qualified name of the function being called- Specified by:
getFunctionNamein classFunctionCall- Returns:
- the qualified name
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getTargetFunction
public Function getTargetFunction(XPathContext context)
Get the target function to be called- Specified by:
getTargetFunctionin classFunctionCall- Parameters:
context- the dynamic evaluation context- Returns:
- always null
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preEvaluate
public Expression preEvaluate(ExpressionVisitor visitor)
preEvaluate: this method suppresses compile-time evaluation by doing nothing (because the external function might have side-effects and might use the context)- 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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getIntrinsicDependencies
public int getIntrinsicDependencies()
Determine which aspects of the context the expression depends on. XPath external functions are given no access to context information so they cannot have any dependencies on it.- 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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copy
public Expression copy(RebindingMap rebindings)
Copy an expression. This makes a deep copy.- Specified by:
copyin classExpression- Parameters:
rebindings- variables that need to be re-bound- Returns:
- the copy of the original expression
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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-- 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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iterate
public SequenceIterator iterate(XPathContext context) throws XPathException
Evaluate the function.- Overrides:
iteratein classFunctionCall- Parameters:
context- The context in which the function is to be evaluated- Returns:
- a Value representing the result of the function.
- Throws:
XPathException- if the function cannot be evaluated.
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call
public Sequence call(XPathContext context, Sequence[] argValues) throws XPathException
Call an extension function previously identified using the bind() method. A subclass can override this method.- Specified by:
callin interfaceCallable- Parameters:
context- The XPath dynamic contextargValues- The values of the arguments- Returns:
- The value returned by the extension function
- Throws:
XPathException- if a dynamic error occurs during the evaluation of the expression
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getItemType
public ItemType getItemType()
Determine the data type of the expression, if possible. All expressions 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 will always return a result, though it may be the best approximation that is available at the time.
- Specified by:
getItemTypein classExpression- Returns:
- the item type
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computeCardinality
public int computeCardinality()
Determine the cardinality of the result- Specified by:
computeCardinalityin classExpression- Returns:
- ZERO_OR_MORE (we don't know)
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