Package it.unive.lisa.type

Class NullType

java.lang.Object

it.unive.lisa.type.NullType

All Implemented Interfaces:

PointerType, Type

public final class NullType
extends java.lang.Object
implements PointerType

The Null type, that is the type of {#link NullLiteral}. It implements the singleton design pattern, that is the instances of this type are unique. The unique instance of this type can be retrieved by INSTANCE. It implements the singleton design pattern, that is the instances of this type are unique. The unique instance of this type can be retrieved by INSTANCE.

Field Summary

Fields

Modifier and Type	Field	Description
static NullType	INSTANCE	Unique instance of NullType.

Method Summary

Modifier and Type	Method	Description
java.util.Collection<Type>	allInstances()	Yields all possible instances of this type, including itself.
boolean	canBeAssignedTo(Type other)	Determines if the type represented by this Type object is either the same as, or is a subtype of, the type represented by other.
Type	commonSupertype(Type other)	Yields the most specific common supertype between this Type and the given one.
boolean	equals(java.lang.Object other)
int	hashCode()
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Methods inherited from interface it.unive.lisa.type.Type

asArrayType, asBooleanType, asNullType, asNumericType, asPointerType, asStringType, asTypeTokenType, asUnitType, asUntyped, asVoidType, isArrayType, isBooleanType, isNullType, isNumericType, isPointerType, isStringType, isTypeTokenType, isUnitType, isUntyped, isVoidType

Field Detail

INSTANCE

public static final NullType INSTANCE

Unique instance of NullType.

Method Detail

toString

public java.lang.String toString()

Overrides:

toString in class java.lang.Object

equals

public boolean equals(java.lang.Object other)

Overrides:

equals in class java.lang.Object

hashCode

public int hashCode()

Overrides:

hashCode in class java.lang.Object

canBeAssignedTo

public boolean canBeAssignedTo(Type other)

Description copied from interface: Type

Determines if the type represented by this Type object is either the same as, or is a subtype of, the type represented by other. It returns true if so, and returns false otherwise.

Specified by:

canBeAssignedTo in interface Type

Parameters:

other - the other type

Returns:

true if that condition holds

commonSupertype

public Type commonSupertype(Type other)

Description copied from interface: Type

Yields the most specific common supertype between this Type and the given one. If no common supertype exists, this method returns Untyped.INSTANCE.

Specified by:

commonSupertype in interface Type

Parameters:

other - the other type

Returns:

the most specific common supertype between this and other

allInstances

public java.util.Collection<Type> allInstances()

Description copied from interface: Type

Yields all possible instances of this type, including itself.

Specified by:

allInstances in interface Type

Returns:

the possible instances