net.sf.saxon.ma.map

Class TupleItemType

java.lang.Object

net.sf.saxon.type.AnyFunctionType

net.sf.saxon.ma.map.TupleItemType

All Implemented Interfaces:

TupleType, FunctionItemType, ItemType

public class TupleItemType
extends AnyFunctionType
implements TupleType

An instance of this class represents a specific tuple item type, for example tuple(x: xs:double, y: element(employee)). Tuple types are a Saxon extension introduced in Saxon 9.8. The syntax for constructing a tuple type requires Saxon-PE or higher, but the supporting code is included in Saxon-HE for convenience.

Nested Class Summary

Nested classes/interfaces inherited from interface net.sf.saxon.type.ItemType

ItemType.WithSequenceTypeCache

Field Summary

Fields inherited from class net.sf.saxon.type.AnyFunctionType

ANY_FUNCTION

Constructor Summary

Constructors

Constructor and Description
TupleItemType(List<String> names, List<SequenceType> types)
TupleItemType(List<String> names, List<SequenceType> types, Set<String> optionalFields, boolean extensible)

Method Summary

Modifier and Type	Method and Description
boolean	equals(Object other) Test whether this function type equals another function type
Optional<String>	explainMismatch(Item item, TypeHierarchy th) Get extra diagnostic information about why a supplied item does not conform to this item type, if available.
String	generateJavaScriptItemTypeTest(ItemType knownToBe, int targetVersion) Generate Javascript code to test whether an item conforms to this item type
SequenceType[]	getArgumentTypes() Get the argument types of this map, viewed as a function
int	getArity() Get the arity (number of arguments) of this function type
Iterable<String>	getFieldNames() Get the names of all the fields
SequenceType	getFieldType(String field) Get the type of a given field
Genre	getGenre() Determine the Genre (top-level classification) of this type
SequenceType	getResultType() Get the result type of this tuple type, viewed as a function
int	hashCode() Returns a hash code value for the object.
boolean	isArrayType() Ask whether this function item type is an array type.
boolean	isExtensible() Ask whether the tuple type is extensible, that is, whether fields other than those named are permitted
boolean	isMapType() Ask whether this function item type is a map type.
boolean	isOptional(String field) Ask whether a particular field is optional (that is, allowed to be absent from the map)
Expression	makeFunctionSequenceCoercer(Expression exp, RoleDiagnostic role) Create an expression whose effect is to apply function coercion to coerce a function from this type to another type
boolean	matches(Item item, TypeHierarchy th) Test whether a given item conforms to this type
int	relationship(FunctionItemType other, TypeHierarchy th) Determine the relationship of one function item type to another
String	toExportString() Return a string representation of this ItemType suitable for use in stylesheet export files.
String	toString() Produce a representation of this type name for use in error messages.

Methods inherited from class net.sf.saxon.type.AnyFunctionType

generateJavaScriptItemTypeAcceptor, getAlphaCode, getAnnotationAssertions, getAtomizedItemType, getInstance, getPrimitiveItemType, getPrimitiveType, getUType, isAtomicType, isAtomizable, isPlainType

Methods inherited from class java.lang.Object

clone, finalize, getClass, notify, notifyAll, wait, wait, wait

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

getAnnotationAssertions

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

generateJavaScriptItemTypeAcceptor, getAlphaCode, getAtomizedItemType, getPrimitiveItemType, getPrimitiveType, getUType, isAtomicType, isAtomizable, isPlainType, isTrueItemType

Constructor Detail

TupleItemType

public TupleItemType(List<String> names,
                     List<SequenceType> types)

TupleItemType

public TupleItemType(List<String> names,
                     List<SequenceType> types,
                     Set<String> optionalFields,
                     boolean extensible)

Method Detail

getGenre

public Genre getGenre()

Determine the Genre (top-level classification) of this type

Specified by:

getGenre in interface FunctionItemType

Specified by:

getGenre in interface ItemType

Returns:

the Genre to which this type belongs, specifically Genre.MAP

isMapType

public boolean isMapType()

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

Specified by:

isMapType in interface FunctionItemType

Overrides:

isMapType in class AnyFunctionType

Returns:

true if this FunctionItemType is a map type

isArrayType

public boolean isArrayType()

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

Specified by:

isArrayType in interface FunctionItemType

Overrides:

isArrayType in class AnyFunctionType

Returns:

true if this FunctionItemType is an array type

getFieldNames

public Iterable<String> getFieldNames()

Get the names of all the fields

Specified by:

getFieldNames in interface TupleType

Returns:

the names of the fields (in arbitrary order)

getFieldType

public SequenceType getFieldType(String field)

Get the type of a given field

Specified by:

getFieldType in interface TupleType

Parameters:

field - the name of the field

Returns:

the type of the field if it is defined, or null otherwise

isOptional

public boolean isOptional(String field)

Description copied from interface: TupleType

Ask whether a particular field is optional (that is, allowed to be absent from the map)

Specified by:

isOptional in interface TupleType

Parameters:

field - the name of the field

Returns:

true if the field is optional

isExtensible

public boolean isExtensible()

Ask whether the tuple type is extensible, that is, whether fields other than those named are permitted

Specified by:

isExtensible in interface TupleType

Returns:

true if fields other than the named fields are permitted to appear

matches

public boolean matches(Item item,
                       TypeHierarchy th)
                throws XPathException

Test whether a given item conforms to this type

Specified by:

matches in interface ItemType

Overrides:

matches in class AnyFunctionType

Parameters:

item - The item to be tested

th - type hierarchy data

Returns:

true if the item is an instance of this type; false otherwise

Throws:

XPathException

getArity

public int getArity()

Get the arity (number of arguments) of this function type

Returns:

the number of argument types in the function signature

getArgumentTypes

public SequenceType[] getArgumentTypes()

Get the argument types of this map, viewed as a function

Specified by:

getArgumentTypes in interface FunctionItemType

Overrides:

getArgumentTypes in class AnyFunctionType

Returns:

the list of argument types of this map, viewed as a function

getResultType

public SequenceType getResultType()

Get the result type of this tuple type, viewed as a function

Specified by:

getResultType in interface FunctionItemType

Overrides:

getResultType in class AnyFunctionType

Returns:

the result type of this tuple type, viewed as a function

toString

public String toString()

Produce a representation of this type name for use in error messages.

Specified by:

toString in interface ItemType

Overrides:

toString in class AnyFunctionType

Returns:

a string representation of the type, in notation resembling but not necessarily identical to XPath syntax

toExportString

public String toExportString()

Return a string representation of this ItemType suitable for use in stylesheet export files. This differs from the result of toString() in that it will not contain any references to anonymous types. Note that it may also use the Saxon extended syntax for union types and tuple types.

Specified by:

toExportString in interface ItemType

Returns:

the string representation as an instance of the XPath ItemType construct

equals

public boolean equals(Object other)

Test whether this function type equals another function type

Overrides:

equals in class Object

hashCode

public int hashCode()

Returns a hash code value for the object.

Overrides:

hashCode in class Object

relationship

public int relationship(FunctionItemType other,
                        TypeHierarchy th)

Determine the relationship of one function item type to another

Specified by:

relationship in interface FunctionItemType

Overrides:

relationship in class AnyFunctionType

Returns:

for example TypeHierarchy.SUBSUMES, TypeHierarchy.SAME_TYPE

explainMismatch

public Optional<String> explainMismatch(Item item,
                                        TypeHierarchy th)

Get extra diagnostic information about why a supplied item does not conform to this item type, if available. If extra information is returned, it should be in the form of a complete sentence, minus the closing full stop. No information should be returned for obvious cases.

Specified by:

explainMismatch in interface ItemType

Parameters:

item - the item being matched

th - the type hierarchy cache

Returns:

optionally, a message explaining why the item does not match the type

makeFunctionSequenceCoercer

public Expression makeFunctionSequenceCoercer(Expression exp,
                                              RoleDiagnostic role)
                                       throws XPathException

Description copied from class: AnyFunctionType

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

Specified by:

makeFunctionSequenceCoercer in interface FunctionItemType

Overrides:

makeFunctionSequenceCoercer in class AnyFunctionType

Parameters:

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

role - information for use in diagnostics

Returns:

the sequence of coerced functions, each on a function that calls the corresponding original function after checking the parameters

Throws:

XPathException

generateJavaScriptItemTypeTest

public String generateJavaScriptItemTypeTest(ItemType knownToBe,
                                             int targetVersion)
                                      throws XPathException

Generate Javascript code to test whether an item conforms to this item type

Specified by:

generateJavaScriptItemTypeTest in interface ItemType

Overrides:

generateJavaScriptItemTypeTest in class AnyFunctionType

Parameters:

knownToBe - a type that this item is known to conform to

targetVersion - the target version of Saxon-JS

Returns:

a Javascript instruction or sequence of instructions, which can be used as the body of a Javascript function, and which returns a boolean indication whether the value of the variable "item" is an instance of this item type.

Throws:

XPathException - if JS code cannot be generated for this item type, for example because the test is schema-aware.