net.sf.saxon.type

Class TypeHierarchy

java.lang.Object

net.sf.saxon.type.TypeHierarchy

Direct Known Subclasses:

TypeHierarchyPE

public class TypeHierarchy
extends Object

This class exists to provide answers to questions about the type hierarchy. Because such questions are potentially expensive, it caches the answers. There is one instance of this class for a Configuration.

Field Summary

Fields

Modifier and Type	Field and Description
protected Configuration	config
static int	DISJOINT Constant denoting relationship between two types: A is disjoint from B
static int	OVERLAPS Constant denoting relationship between two types: A overlaps B
static int	SAME_TYPE Constant denoting relationship between two types: A is the same type as B
static int	SUBSUMED_BY Constant denoting relationship between two types: A is subsumed by B
static int	SUBSUMES Constant denoting relationship between two types: A subsumes B

Constructor Summary

Constructors

Constructor and Description
TypeHierarchy(Configuration config) Create the type hierarchy cache for a configuration

Method Summary

Methods

Modifier and Type	Method and Description
protected SequenceIterator	applyFunctionCoercion(SequenceIterator iterator, ItemType suppliedItemType, ItemType requiredItemType, Location locator) Apply function coercion when function items are supplied as arguments to a function call.
Sequence	applyFunctionConversionRules(Sequence value, SequenceType requiredType, RoleDiagnostic role, Location locator) Apply the function conversion rules to a value, given a required type.
protected int	computeContentRelationship(ItemType t1, ItemType t2, IntSet n1, IntSet n2) Compute the relationship between the allowed content-types of two types, for example attribute(*, xs:integer) and attribute(xs:string).
Configuration	getConfiguration() Get the Saxon configuration to which this type hierarchy belongs
ItemType	getGenericFunctionItemType()
boolean	isSubType(ItemType subtype, ItemType supertype) Determine whether type A is type B or one of its subtypes, recursively.
int	relationship(ItemType t1, ItemType t2) Determine the relationship of one item type to another.
int	schemaTypeRelationship(SchemaType s1, SchemaType s2) Get the relationship of two schema types to each other
int	sequenceTypeRelationship(SequenceType s1, SequenceType s2) Get the relationship of two sequence types to each other

Methods inherited from class java.lang.Object

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

Field Detail

config

protected Configuration config

SAME_TYPE

public static final int SAME_TYPE

Constant denoting relationship between two types: A is the same type as B

See Also:

Constant Field Values

SUBSUMES

public static final int SUBSUMES

Constant denoting relationship between two types: A subsumes B

See Also:

Constant Field Values

SUBSUMED_BY

public static final int SUBSUMED_BY

Constant denoting relationship between two types: A is subsumed by B

See Also:

Constant Field Values

OVERLAPS

public static final int OVERLAPS

Constant denoting relationship between two types: A overlaps B

See Also:

Constant Field Values

DISJOINT

public static final int DISJOINT

Constant denoting relationship between two types: A is disjoint from B

See Also:

Constant Field Values

Constructor Detail

TypeHierarchy

public TypeHierarchy(Configuration config)

Create the type hierarchy cache for a configuration

Parameters:

config - the configuration

Method Detail

applyFunctionConversionRules

public Sequence applyFunctionConversionRules(Sequence value,
                                    SequenceType requiredType,
                                    RoleDiagnostic role,
                                    Location locator)
                                      throws XPathException

Apply the function conversion rules to a value, given a required type.

Parameters:

value - a value to be converted

requiredType - the required type

role - identifies the value to be converted in error messages

locator - identifies the location for error messages

Returns:

the converted value

Throws:

XPathException - if the value cannot be converted to the required type

applyFunctionCoercion

protected SequenceIterator applyFunctionCoercion(SequenceIterator iterator,
                                     ItemType suppliedItemType,
                                     ItemType requiredItemType,
                                     Location locator)

Apply function coercion when function items are supplied as arguments to a function call. This does not happen in Saxon-HE, so the implementation is subclassed in Saxon-PE/EE

Parameters:

iterator - An iterator over the supplied value of the parameter

suppliedItemType - the item type of the supplied value

requiredItemType - the required item type (typically a function item type)

locator - information for diagnostics

Returns:

an iterator over the converted value

getConfiguration

public Configuration getConfiguration()

Get the Saxon configuration to which this type hierarchy belongs

Returns:

the configuration

isSubType

public boolean isSubType(ItemType subtype,
                ItemType supertype)

Determine whether type A is type B or one of its subtypes, recursively. "Subtype" here means a type that is subsumed, that is, a type whose instances are a subset of the instances of the other type.

Parameters:

subtype - identifies the first type

supertype - identifies the second type

Returns:

true if the first type is the second type or is subsumed by the second type

relationship

public int relationship(ItemType t1,
               ItemType t2)

Determine the relationship of one item type to another.

Parameters:

t1 - the first item type

t2 - the second item type

Returns:

SAME_TYPE if the types are the same; SUBSUMES if the first type subsumes the second (that is, all instances of the second type are also instances of the first); SUBSUMED_BY if the second type subsumes the first; OVERLAPS if the two types overlap (have a non-empty intersection, but neither subsumes the other); DISJOINT if the two types are disjoint (have an empty intersection)

computeContentRelationship

protected int computeContentRelationship(ItemType t1,
                             ItemType t2,
                             IntSet n1,
                             IntSet n2)

Compute the relationship between the allowed content-types of two types, for example attribute(*, xs:integer) and attribute(xs:string). Note that although such types are fairly meaningless in a non-schema-aware environment, they are permitted, and supported in Saxon-HE.

Parameters:

t1 - the first type

t2 - the second types

n1 - the set of element names allowed by the first type

n2 - the set of element names allowed by the second type

Returns:

the relationship (same type, subsumes, overlaps, subsumed-by)

sequenceTypeRelationship

public int sequenceTypeRelationship(SequenceType s1,
                           SequenceType s2)

Get the relationship of two sequence types to each other

Parameters:

s1 - the first type

s2 - the second type

Returns:

the relationship, as one of the constants SAME_TYPE, SUBSUMES, SUBSUMED_BY, DISJOINT, OVERLAPS

schemaTypeRelationship

public int schemaTypeRelationship(SchemaType s1,
                         SchemaType s2)

Get the relationship of two schema types to each other

Parameters:

s1 - the first type

s2 - the second type

Returns:

the relationship of the two types, as one of the constants SAME_TYPE, SUBSUMES, SUBSUMED_BY, DISJOINT

getGenericFunctionItemType

public ItemType getGenericFunctionItemType()