polyglot.ext.jl.types
Class NullType_c

java.lang.Object
  polyglot.ext.jl.types.TypeObject_c
      polyglot.ext.jl.types.Type_c
          polyglot.ext.jl.types.NullType_c

All Implemented Interfaces:

java.io.Serializable, java.lang.Cloneable, NullType, Qualifier, Type, TypeObject, Copy

public class NullType_c
extends Type_c
implements NullType

A NullType represents the type of the Java keyword null.

See Also:

Serialized Form

Field Summary

Fields inherited from class polyglot.ext.jl.types.TypeObject_c

position, ts

Constructor Summary

protected	NullType_c() Used for deserializing types.
	NullType_c(TypeSystem ts)

Method Summary

boolean	descendsFromImpl(Type ancestor) Return true if this type descends from ancestor.
boolean	equalsImpl(TypeObject t) Default implementation is pointer equality.
int	hashCode()
boolean	isCanonical() Return true if the type object contains no unknown/ambiguous types.
boolean	isCastValidImpl(Type toType) Requires: all type arguments are canonical.
boolean	isImplicitCastValidImpl(Type toType) Return true if a value of this type can be assigned to a variable of type toType.
boolean	isNull() Return true if a null type.
NullType	toNull() Returns a non-null iff isNull() returns true.
java.lang.String	toString() Yields a string representing this type.
java.lang.String	translate(Resolver c) Return a string into which to translate the type.

Methods inherited from class polyglot.ext.jl.types.Type_c

arrayOf, arrayOf, descendsFrom, isArray, isBoolean, isByte, isCastValid, isChar, isClass, isComparable, isDouble, isFloat, isImplicitCastValid, isInt, isIntOrLess, isLong, isLongOrLess, isNumeric, isPackage, isPrimitive, isReference, isShort, isSubtype, isSubtypeImpl, isThrowable, isType, isUncheckedException, isVoid, numericConversionValid, numericConversionValid, numericConversionValidImpl, numericConversionValidImpl, toArray, toClass, toPackage, toPrimitive, toReference, toType

Methods inherited from class polyglot.ext.jl.types.TypeObject_c

copy, equals, position, typeSystem

Methods inherited from class java.lang.Object

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

Methods inherited from interface polyglot.types.Type

arrayOf, arrayOf, descendsFrom, isArray, isBoolean, isByte, isCastValid, isChar, isClass, isComparable, isDouble, isFloat, isImplicitCastValid, isInt, isIntOrLess, isLong, isLongOrLess, isNumeric, isPrimitive, isReference, isShort, isSubtype, isSubtypeImpl, isThrowable, isUncheckedException, isVoid, numericConversionValid, numericConversionValid, numericConversionValidImpl, numericConversionValidImpl, toArray, toClass, toPrimitive, toReference

Methods inherited from interface polyglot.types.Qualifier

isPackage, isType, toPackage, toType

Methods inherited from interface polyglot.types.TypeObject

position, typeSystem

Methods inherited from interface polyglot.util.Copy

copy

Constructor Detail

NullType_c

protected NullType_c()

Used for deserializing types.

NullType_c

public NullType_c(TypeSystem ts)

Method Detail

translate

public java.lang.String translate(Resolver c)

Description copied from class: Type_c

Return a string into which to translate the type.

Specified by:

translate in interface Type

Specified by:

translate in class Type_c

Parameters:

c - A resolver in which to lookup this type to determine if the type is unique in the given resolver.

toString

public java.lang.String toString()

Description copied from class: Type_c

Yields a string representing this type. The string should be consistent with equality. That is, if this.equals(anotherType), then it should be that this.toString().equals(anotherType.toString()). The string does not have to be a legal Java identifier. It is suggested, but not required, that it be an easily human readable representation, and thus useful in error messages and generated output.

Specified by:

toString in interface Type

Specified by:

toString in class Type_c

equalsImpl

public boolean equalsImpl(TypeObject t)

Description copied from class: TypeObject_c

Default implementation is pointer equality.

Specified by:

equalsImpl in interface TypeObject

Overrides:

equalsImpl in class TypeObject_c

See Also:

TypeObject_c.equalsImpl(TypeObject), Object.hashCode()

hashCode

public int hashCode()

Overrides:

hashCode in class TypeObject_c

isCanonical

public boolean isCanonical()

Description copied from interface: TypeObject

Return true if the type object contains no unknown/ambiguous types.

Specified by:

isCanonical in interface TypeObject

Overrides:

isCanonical in class Type_c

isNull

public boolean isNull()

Description copied from interface: Type

Return true if a null type.

Specified by:

isNull in interface Type

Overrides:

isNull in class Type_c

toNull

public NullType toNull()

Description copied from class: Type_c

Returns a non-null iff isNull() returns true.

Specified by:

toNull in interface Type

Overrides:

toNull in class Type_c

descendsFromImpl

public boolean descendsFromImpl(Type ancestor)

Description copied from class: Type_c

Return true if this type descends from ancestor.

Specified by:

descendsFromImpl in interface Type

Overrides:

descendsFromImpl in class Type_c

isImplicitCastValidImpl

public boolean isImplicitCastValidImpl(Type toType)

Description copied from class: Type_c

Return true if a value of this type can be assigned to a variable of type toType.

Specified by:

isImplicitCastValidImpl in interface Type

Overrides:

isImplicitCastValidImpl in class Type_c

isCastValidImpl

public boolean isCastValidImpl(Type toType)

Requires: all type arguments are canonical. ToType is not a NullType. Returns true iff a cast from this to toType is valid; in other words, some non-null members of this are also members of toType.

Specified by:

isCastValidImpl in interface Type

Overrides:

isCastValidImpl in class Type_c