hlt.language.design.types

Class CollectionType

java.lang.Object

hlt.language.design.types.Type

hlt.language.design.types.StaticType

hlt.language.design.types.ConstructedType

hlt.language.design.types.CollectionType

All Implemented Interfaces:

Collection, Valuable

Direct Known Subclasses:

BagType, ListType, SetType

public abstract class CollectionType
extends ConstructedType
implements Collection

This is the mother class of all types denoting collections. Types deriving from this class consist of collection types whose elements are of any base type (including collection types - thus enabling higher-order collections - and type parameters - thus enabling polymorphic collections).

Field Summary

Fields inherited from class hlt.language.design.types.Type

ARRAY, BAG, BOOLEAN, BOXABLE, CHAR, CLASS, COLLECTION, CONSTANT, DEFINED, FUNCTION, INT, INT_RANGE, INT_SORT, LIST, NAMED_TUPLE, OBJECT_SORT, PARAMETER, REAL, REAL_RANGE, REAL_SORT, SET, STRING, TUPLE, VOID, VOID_SORT

Constructor Summary

Constructors

Constructor and Description
CollectionType()

Method Summary

Methods

Modifier and Type	Method and Description
Type	baseType() Returns the base type's value; that is, the current type binding of the collection's elements.
Type	baseTypeRef() Returns the undereferenced base type.
void	checkOccurrence(TypeParameter parameter, Type context, TypeChecker typeChecker) Throws a FailedUnificationException if the specified type parameter occurs in this type.
Type	copy(java.util.HashMap parameters) Returns a copy of this type with a consistent renaming of all free type parameters, and identyfing bound type parameters with their values.
int	eqCode() Returns a hash code for this type - the reason for using the name eqCode (rather than overriding hashCode), is that it is important to preserve the implementation of java.lang.Object.hashCode for type parameters (to be compatible with ==).
Type	flatten() Returns a flattened form of this type by uncurrying all the domains of all function types that occur in it.
java.util.HashSet	getParameters(java.util.HashSet set) Returns the specified set augmented with all the unbound type parameters that occur in this type.
Type	instantiate(java.util.HashMap substitution) Returns a copy of this type with all free type parameters bound as per the specified type substitution.
boolean	isEqualTo(Type type) Returns true iff this type is structurally isomorphic to the specified type.
boolean	isEqualTo(Type type, java.util.HashMap parameters) Returns true iff this type is structurally isomorphic to the specified type, under the renaming of type parameters specified by the given HashMap.
boolean	isPolymorphic() Returns true iff this collection type's base type is polymorphic.
abstract CollectionType	newCollectionType(Type baseType) Returns a new collection type of same kind with the specified base type.
int	numberOfTypeComponents() Returns the number of type components making up this type.
void	setTypeRefComponent(int n, Type type) Sets the n-th undereferenced type component of this type to the specified type; throws a NoSuchTypeComponentException otherwise.
Type	typeRefComponent(int n) Returns the n-th undereferenced type component in this type, if any; throws a NoSuchTypeComponentException otherwise.
boolean	unify(Type type) This unifies this type with the specified type with no possibility of undoing any effects.
void	unify(Type type, TypeChecker typeChecker) Unifies this collection type against the specifed type in the context of the given type checker.

Methods inherited from class hlt.language.design.types.Type

actualType, array, array, BOOLEAN, BOXED_BOOLEAN, BOXED_CHAR, BOXED_INT, BOXED_REAL, boxSort, CHAR, copy, curry, equals, findValue, getParameters, getValue, INT, is, isBag, isBoolean, isBoxedType, isChar, isCollection, isGlobalUnsafe, isInt, isList, isPrimitive, isReal, isSet, isString, isVoid, kind, kindString, rank, REAL, resetNames, setBoxed, shadowType, sort, standardize, toFullString, toQuantifiedString, toQuantifiedString, typeComponent, unwrapper, value, wrapper

Methods inherited from class java.lang.Object

getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Constructor Detail

CollectionType

public CollectionType()

Method Detail

newCollectionType

public abstract CollectionType newCollectionType(Type baseType)

Returns a new collection type of same kind with the specified base type.

numberOfTypeComponents

public final int numberOfTypeComponents()

Description copied from class: Type

Returns the number of type components making up this type.

Specified by:

numberOfTypeComponents in class Type

typeRefComponent

public final Type typeRefComponent(int n)
                            throws NoSuchTypeComponentException

Description copied from class: Type

Returns the n-th undereferenced type component in this type, if any; throws a NoSuchTypeComponentException otherwise.

Specified by:

typeRefComponent in class Type

Throws:

NoSuchTypeComponentException

setTypeRefComponent

public final void setTypeRefComponent(int n,
                       Type type)
                               throws NoSuchTypeComponentException

Description copied from class: Type

Sets the n-th undereferenced type component of this type to the specified type; throws a NoSuchTypeComponentException otherwise.

Specified by:

setTypeRefComponent in class Type

Throws:

NoSuchTypeComponentException

baseTypeRef

public final Type baseTypeRef()

Returns the undereferenced base type.

Specified by:

baseTypeRef in interface Collection

Overrides:

baseTypeRef in class Type

baseType

public final Type baseType()

Returns the base type's value; that is, the current type binding of the collection's elements.

Specified by:

baseType in interface Collection

Overrides:

baseType in class Type

isPolymorphic

public final boolean isPolymorphic()

Returns true iff this collection type's base type is polymorphic.

Overrides:

isPolymorphic in class Type

flatten

public final Type flatten()

Description copied from class: Type

Returns a flattened form of this type by uncurrying all the domains of all function types that occur in it. It also trims all binding chains of type parameters that may occur in it. The form returned is the canonical form used for all types of defined symbols and is assumed for type equality tests to work.

N.B.: The following definition specifies only the default behavior for this method. Specific subclasses are generally expected to override this method.

Overrides:

flatten in class Type

copy

public final Type copy(java.util.HashMap parameters)

Description copied from class: Type

Returns a copy of this type with a consistent renaming of all free type parameters, and identyfing bound type parameters with their values.

N.B.: The following definition specifies only the default behavior for this method. Specific subclasses are generally expected to override this method.

Overrides:

copy in class Type

instantiate

public final Type instantiate(java.util.HashMap substitution)

Description copied from class: Type

Returns a copy of this type with all free type parameters bound as per the specified type substitution.

N.B.: The following definition specifies only the default behavior for this method. Specific subclasses are generally expected to override this method.

Overrides:

instantiate in class Type

unify

public final void unify(Type type,
         TypeChecker typeChecker)
                 throws FailedUnificationException

Unifies this collection type against the specifed type in the context of the given type checker.

Specified by:

unify in class Type

Throws:

FailedUnificationException

unify

public final boolean unify(Type type)

Description copied from class: Type

This unifies this type with the specified type with no possibility of undoing any effects. This method is meant to be used on types that are fresh copies independent of any type-checker because it will side-effect the structures it traverses. It returns true iff unification succeeds. NB: This method does not perform the "occurs-check" test.

Specified by:

unify in class Type

checkOccurrence

public final void checkOccurrence(TypeParameter parameter,
                   Type context,
                   TypeChecker typeChecker)
                           throws FailedUnificationException

Description copied from class: Type

Throws a FailedUnificationException if the specified type parameter occurs in this type. The type context is the outermost type enclosing this.

N.B.: The following definition specifies only the default behavior for this method. Specific subclasses are generally expected to override this method.

Overrides:

checkOccurrence in class Type

Throws:

FailedUnificationException

getParameters

public final java.util.HashSet getParameters(java.util.HashSet set)

Description copied from class: Type

Returns the specified set augmented with all the unbound type parameters that occur in this type.

Overrides:

getParameters in class Type

eqCode

public final int eqCode()

Description copied from class: Type

Returns a hash code for this type - the reason for using the name eqCode (rather than overriding hashCode), is that it is important to preserve the implementation of java.lang.Object.hashCode for type parameters (to be compatible with ==). All we require with this new code is that it be compatible with type equality as defined by isEqualTo - and it is! Incidentally, the same reason goes for preserving equals for type parameters to be compatible with == - and it is (see TypeParameter).

Specified by:

eqCode in class Type

isEqualTo

public final boolean isEqualTo(Type type)

Returns true iff this type is structurally isomorphic to the specified type. Type parameters that occur in all types will be considered equal only if they are identical objects (i.e., same pointers).

Specified by:

isEqualTo in class Type

isEqualTo

public final boolean isEqualTo(Type type,
                java.util.HashMap parameters)

Returns true iff this type is structurally isomorphic to the specified type, under the renaming of type parameters specified by the given HashMap.

Specified by:

isEqualTo in class Type