net.sf.saxon.ma.map

Class MapFunctionSet.MapGet

java.lang.Object

net.sf.saxon.om.AbstractItem

net.sf.saxon.functions.AbstractFunction

net.sf.saxon.functions.SystemFunction

net.sf.saxon.ma.map.MapFunctionSet.MapGet

All Implemented Interfaces:

Callable, Function, GroundedValue, Item, Sequence

Enclosing class:

MapFunctionSet

public static class MapFunctionSet.MapGet
extends SystemFunction

Implementation of the XPath 3.1 function map:get(Map, key) => value

Constructor Summary

Constructors

Constructor and Description
MapGet()

Method Summary

Modifier and Type	Method and Description
Sequence	call(XPathContext context, Sequence[] arguments) Invoke the function
int	getCardinality(Expression[] args) Get the cardinality, given knowledge of the actual arguments
ItemType	getResultItemType(Expression[] args) Get the return type, given knowledge of the actual arguments
Expression	makeOptimizedFunctionCall(ExpressionVisitor visitor, ContextItemStaticInfo contextInfo, Expression... arguments) Allow the function to create an optimized call based on the values of the actual arguments

Methods inherited from class net.sf.saxon.functions.SystemFunction

dependsOnContextItem, dynamicCall, equals, export, exportAdditionalArguments, exportAttributes, fixArguments, getArity, getCompilerName, getContextNode, getDescription, getDetails, getErrorCodeForTypeErrors, getFunctionItemType, getFunctionName, getIntegerBounds, getNetCost, getOperandRoles, getRequiredType, getResultItemType, getRetainedStaticContext, getSpecialProperties, getStaticBaseUriString, getStreamerName, importAttributes, isTrustedResultType, makeCall, makeFunction, makeFunctionCall, resultIfEmpty, setArity, setDetails, setRetainedStaticContext, supplyTypeInformation, typeCheckCaller

Methods inherited from class net.sf.saxon.functions.AbstractFunction

atomize, deepEquals, effectiveBooleanValue, getAnnotations, getStringValue, getStringValueCS, isArray, isMap, makeNewContext, simplify, typeCheck

Methods inherited from class net.sf.saxon.om.AbstractItem

getLength, head, isStreamed, itemAt, iterate, reduce, subsequence

Methods inherited from class java.lang.Object

clone, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Methods inherited from interface net.sf.saxon.om.Function

iterate

Methods inherited from interface net.sf.saxon.om.Item

head

Methods inherited from interface net.sf.saxon.om.GroundedValue

getLength, head, itemAt, reduce, subsequence

Constructor Detail

MapGet

public MapGet()

Method Detail

getResultItemType

public ItemType getResultItemType(Expression[] args)

Get the return type, given knowledge of the actual arguments

Overrides:

getResultItemType in class SystemFunction

Parameters:

args - the actual arguments supplied

Returns:

the best available item type that the function will return

getCardinality

public int getCardinality(Expression[] args)

Get the cardinality, given knowledge of the actual arguments

Overrides:

getCardinality in class SystemFunction

Parameters:

args - the actual arguments supplied

Returns:

the most precise available cardinality that the function will return

makeOptimizedFunctionCall

public Expression makeOptimizedFunctionCall(ExpressionVisitor visitor,
                                            ContextItemStaticInfo contextInfo,
                                            Expression... arguments)
                                     throws XPathException

Allow the function to create an optimized call based on the values of the actual arguments

Overrides:

makeOptimizedFunctionCall in class SystemFunction

Parameters:

visitor - the expression visitor

contextInfo - information about the context item

arguments - the supplied arguments to the function call. Note: modifying the contents of this array should not be attempted, it is likely to have no effect.

Returns:

either a function call on this function, or an expression that delivers the same result, or null indicating that no optimization has taken place

Throws:

XPathException - if an error is detected

call

public Sequence call(XPathContext context,
                     Sequence[] arguments)
              throws XPathException

Description copied from interface: Function

Invoke the function

Parameters:

context - the XPath dynamic evaluation context

arguments - the actual arguments to be supplied

Returns:

the result of invoking the function

Throws:

XPathException - if a dynamic error occurs within the function