public abstract class ScalarSystemFunction extends SystemFunction
Modifier and Type | Field and Description |
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static ZeroOrOne<StringValue> |
ZERO_LENGTH_STRING
Static constant representing a zero-length string
|
Constructor and Description |
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ScalarSystemFunction() |
Modifier and Type | Method and Description |
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ZeroOrOne<? extends AtomicValue> |
call(XPathContext context,
Sequence[] arguments)
Evaluate the expression
|
abstract AtomicValue |
evaluate(Item arg,
XPathContext context)
Abstract method that must be supplied in subclasses to perform the evaluation
|
Expression |
makeFunctionCall(Expression[] arguments)
Make an expression that either calls this function, or that is equivalent to a call
on this function
|
ZeroOrOne<? extends AtomicValue> |
resultWhenEmpty()
Method that may be supplied in subclasses, to indicate the result that is returned
when an empty sequence is supplied as the argument value.
|
dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCardinality, getCompilerName, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, importAttributes, isTrustedResultType, makeCall, makeFunction, makeOptimizedFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, typeCheckCaller
atomize, deepEquals, effectiveBooleanValue, getAnnotations, getStringValue, getStringValueCS, isArray, isMap, makeNewContext, simplify, typeCheck
getLength, head, isStreamed, itemAt, iterate, reduce, subsequence
clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait
getLength, head, itemAt, reduce, subsequence
public static final ZeroOrOne<StringValue> ZERO_LENGTH_STRING
public abstract AtomicValue evaluate(Item arg, XPathContext context) throws XPathException
arg
- the supplied argumentcontext
- the dynamic contextXPathException
- if a dynamic error occurspublic ZeroOrOne<? extends AtomicValue> resultWhenEmpty()
public final ZeroOrOne<? extends AtomicValue> call(XPathContext context, Sequence[] arguments) throws XPathException
context
- the dynamic evaluation contextarguments
- the values of the arguments, supplied as SequencesXPathException
- if a dynamic error occurs during the evaluation of the expressionpublic Expression makeFunctionCall(Expression[] arguments)
SystemFunction
makeFunctionCall
in class SystemFunction
arguments
- the supplied arguments to the function callCopyright (c) 2004-2018 Saxonica Limited. All rights reserved.