net.sf.saxon.type
Interface FunctionItemType

All Superinterfaces:

ItemType, Serializable

All Known Implementing Classes:

AnyFunctionType, FunctionType, MapType

public interface FunctionItemType
extends ItemType

Higher-order functions in XPath 3.0 introduce a third kind of Item, namely a Function Item. This type is represented here by a placeholder interfaces. The implementation of this type is found only in Saxon-EE

Method Summary

SequenceType[]	getArgumentTypes() Get the argument types of the function
SequenceType	getResultType() Get the result type of the function
boolean	isMapType() Ask whether this function item type is a map type.
Expression	makeFunctionSequenceCoercer(Expression exp, RoleLocator role, TypeCheckerEnvironment visitor) Create an expression whose effect is to apply function coercion to coerce a function to this function type
int	relationship(FunctionItemType other, TypeHierarchy th) Determine the relationship of one function item type to another

Methods inherited from interface net.sf.saxon.type.ItemType

getAtomizedItemType, getDefaultPriority, getPrimitiveItemType, getPrimitiveType, getSuperType, isAtomicType, isAtomizable, isPlainType, matches, matchesItem, toString, visitNamedSchemaComponents

Method Detail

getArgumentTypes

SequenceType[] getArgumentTypes()

Get the argument types of the function

Returns:

the argument types, as an array of SequenceTypes; or null if this is the generic function type function(*)

getResultType

SequenceType getResultType()

Get the result type of the function

Returns:

the result type, as a SequenceType

relationship

int relationship(FunctionItemType other,
                 TypeHierarchy th)

Determine the relationship of one function item type to another

Returns:

for example TypeHierarchy.SUBSUMES, TypeHierarchy.SAME_TYPE

makeFunctionSequenceCoercer

Expression makeFunctionSequenceCoercer(Expression exp,
                                       RoleLocator role,
                                       TypeCheckerEnvironment visitor)
                                       throws XPathException

Create an expression whose effect is to apply function coercion to coerce a function to this function type

Parameters:

exp - the expression that delivers the supplied sequence of function items (the ones in need of coercion)

role - information for use in diagnostics

visitor - the expression visitor, supplies context information

Returns:

the coerced function, a function that calls the original function after checking the parameters

Throws:

XPathException

isMapType

boolean isMapType()

Ask whether this function item type is a map type. In this case function coercion (to the map type) will never succeed.

Returns:

true if this FunctionItemType is a map type