Package net.sf.saxon.type

Class TypeHierarchy

java.lang.Object

net.sf.saxon.type.TypeHierarchy

Direct Known Subclasses:

SubsumptionEE

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. The actual logic for computing relationships (without any cache) is in class Subsumption.

Field Summary

Fields

Modifier and Type	Field	Description
protected Configuration	config

Constructor Summary

Constructors

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

Method Summary

Modifier and Type	Method	Description
Configuration	getConfiguration()	Get the Saxon configuration to which this type hierarchy belongs
static SchemaType	getNearestNamedType(SchemaType type)	Get the nearest named type in the type hierarchy, that is, the nearest type that is not anonymous.
boolean	isSubType(ItemType subtype, ItemType supertype)	Determine whether type A is type B or one of its subtypes, recursively.
static ItemType	normalizeItemType(ItemType in)	Replace an item type, where necessary, by one that can safely be stored in the cache without causing garbage collection problems.
Affinity	relationship(ItemType t1, ItemType t2)	Determine the relationship of one item type to another.
static <X> Set<X>	toSet(Iterable<X> in)	Convert a collection to a set

Methods inherited from class java.lang.Object

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

Field Details

config

protected Configuration config

Constructor Details

TypeHierarchy

public TypeHierarchy(Configuration config)

Create the type hierarchy cache for a configuration

Parameters:

config - the configuration

Method Details

getNearestNamedType

public static SchemaType getNearestNamedType(SchemaType type)

Get the nearest named type in the type hierarchy, that is, the nearest type that is not anonymous. (In practice, since types cannot be derived from anonymous types, this will either the type itself, or its immediate base type).

Returns:

the nearest type, found by following the getBaseType() relation recursively, that is not an anonymous type

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 Affinity 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:

One of:

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

normalizeItemType

public static ItemType normalizeItemType(ItemType in)

Replace an item type, where necessary, by one that can safely be stored in the cache without causing garbage collection problems. Specifically, a SameNameTest cannot be stored in the cache because it contains a reference to a node in a document.

Parameters:

in - the supplied item type

Returns:

either the supplied item type, or an equivalent that can safely be cached.

toSet

public static <X> Set<X> toSet(Iterable<X> in)

Convert a collection to a set

Type Parameters:

X - the member type of the collection

Parameters:

in - the input collection

Returns:

a set with the same members as the supplied collection