ptolemy.data.type
Interface Type

All Known Implementing Classes:

ActorType, ArrayType, BaseType, BaseType.ArrayBottomType, BaseType.BooleanType, BaseType.ComplexType, BaseType.DoubleType, BaseType.EventType, BaseType.FloatType, BaseType.GeneralType, BaseType.IntType, BaseType.LongType, BaseType.NilType, BaseType.PetiteType, BaseType.ScalarType, BaseType.ShortType, BaseType.StringType, BaseType.UnknownType, BaseType.UnsignedByteType, BaseType.UnsizedFixType, BaseType.XmlTokenType, FixType, FunctionType, KeyToken.KeyType, LocationType, MatrixType, MatrixType.BooleanMatrixType, MatrixType.ComplexMatrixType, MatrixType.DoubleMatrixType, MatrixType.FixMatrixType, MatrixType.IntMatrixType, MatrixType.LongMatrixType, ObjectType, PointerToken.PointerType, RecordType, Scene2DToken.Scene2DType, SceneGraphToken.SceneGraphType, StructuredType, UnionType

public interface Type

An interface representing the type of a Token.

Since:

Ptolemy II 0.4

Version:

$Id: Type.java 57040 2010-01-27 20:52:32Z cxh $

Author:

Yuhong Xiong, Steve Neuendorffer

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (neuendor)

Field Summary

static int	HASH_INVALID Used to indicate that the type comparison cache is invalid.
static int	HASH_MAX The maximum size of the type hash.

Method Summary

Type	add(Type rightArgumentType) Return a new type which represents the type that results from adding a token of this type and a token of the given argument type.
java.lang.Object	clone() Return a deep clone of this type.
Token	convert(Token token) Convert the specified token into a token having the type represented by this object.
Type	divide(Type rightArgumentType) Return a new type which represents the type that results from dividing a token of this type and a token of the given argument type.
boolean	equals(java.lang.Object object) Determine if the argument represents the same type as this object.
java.lang.Class	getTokenClass() Return the class for tokens that this type represents.
int	getTypeHash() Return a perfect hash for this type.
boolean	isAbstract() Return true if this type does not correspond to a single token class.
boolean	isCompatible(Type type) Test if the argument type is compatible with this type.
boolean	isConstant() Test if this Type is a constant.
boolean	isInstantiable() Determine if this Type corresponds to an instantiable token class.
boolean	isSubstitutionInstance(Type type) Return true if the specified type is a substitution instance of this type.
Type	modulo(Type rightArgumentType) Return a new type which represents the type that results from moduloing a token of this type and a token of the given argument type.
Type	multiply(Type rightArgumentType) Return a new type which represents the type that results from multiplying a token of this type and a token of the given argument type.
Type	one() Return the type of the multiplicative identity for elements of this type.
Type	subtract(Type rightArgumentType) Return a new type which represents the type that results from subtracting a token of this type and a token of the given argument type.
java.lang.String	toString() Return the string representation of this type.
Type	zero() Return the type of the additive identity for elements of this type.

Field Detail

HASH_INVALID

static final int HASH_INVALID

Used to indicate that the type comparison cache is invalid.

Since:

Ptolemy II 2.1

See Also:

Constant Field Values

HASH_MAX

static final int HASH_MAX

The maximum size of the type hash.

See Also:

Constant Field Values

Method Detail

add

Type add(Type rightArgumentType)

Return a new type which represents the type that results from adding a token of this type and a token of the given argument type.

Parameters:

rightArgumentType - The type to add to this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.

clone

java.lang.Object clone()
                       throws java.lang.CloneNotSupportedException

Return a deep clone of this type.

Returns:

A Type.

Throws:

java.lang.CloneNotSupportedException - If an instance cannot be cloned.

convert

Token convert(Token token)
              throws IllegalActionException

Convert the specified token into a token having the type represented by this object.

Parameters:

token - a token.

Returns:

a token.

Throws:

IllegalActionException - If lossless conversion cannot be done.

divide

Type divide(Type rightArgumentType)

Return a new type which represents the type that results from dividing a token of this type and a token of the given argument type.

Parameters:

rightArgumentType - The type to add to this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.

equals

boolean equals(java.lang.Object object)

Determine if the argument represents the same type as this object.

Overrides:

equals in class java.lang.Object

Parameters:

object - A Type.

Returns:

True if the argument represents the same type as this object; false otherwise.

getTypeHash

int getTypeHash()

Return a perfect hash for this type. This number corresponds uniquely to a particular type, and is used to improve performance of certain operations in the TypeLattice class. All instances of a particular type (e.g. integer array) must return the same number. Types that return HASH_INVALID will not have results in TypeLattice cached. Note that it is safer to return HASH_INVALID, than to return a number that is not unique, or different number for the same type from different instances.

Returns:

A number between 0 and HASH_MAX, or HASH_INVALID.

getTokenClass

java.lang.Class getTokenClass()

Return the class for tokens that this type represents.

Returns:

The class for tokens that this type represents.

isAbstract

boolean isAbstract()

Return true if this type does not correspond to a single token class. This occurs if the type is not instantiable, or it represents either an abstract base class or an interface.

Returns:

True if this type does not correspond to a single token class.

isCompatible

boolean isCompatible(Type type)

Test if the argument type is compatible with this type. Compatible is defined as follows: If this type is a constant, the argument is compatible if it is the same or less than this type in the type lattice; If this type is a variable, the argument is compatible if it is a substitution instance of this type.

Parameters:

type - An instance of Type.

Returns:

True if the argument is compatible with this type.

isConstant

boolean isConstant()

Test if this Type is a constant. A Type is a constant if it does not contain BaseType.UNKNOWN in any level within it.

Returns:

True if this type is a constant.

isInstantiable

boolean isInstantiable()

Determine if this Type corresponds to an instantiable token class.

Returns:

True if this type corresponds to an instantiable token class.

isSubstitutionInstance

boolean isSubstitutionInstance(Type type)

Return true if the specified type is a substitution instance of this type. For the argument to be a substitution instance, it must be either the same as this type, or it must be a type that can be obtained by replacing the BaseType.UNKNOWN component of this type by another type.

Parameters:

type - A Type.

Returns:

True if the argument is a substitution instance of this type.

modulo

Type modulo(Type rightArgumentType)

Return a new type which represents the type that results from moduloing a token of this type and a token of the given argument type.

Parameters:

rightArgumentType - The type to add to this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.

multiply

Type multiply(Type rightArgumentType)

Return a new type which represents the type that results from multiplying a token of this type and a token of the given argument type.

Parameters:

rightArgumentType - The type to add to this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.

one

Type one()

Return the type of the multiplicative identity for elements of this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.

subtract

Type subtract(Type rightArgumentType)

Return a new type which represents the type that results from subtracting a token of this type and a token of the given argument type.

Parameters:

rightArgumentType - The type to add to this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.

toString

java.lang.String toString()

Return the string representation of this type.

Overrides:

toString in class java.lang.Object

Returns:

A String.

zero

Type zero()

Return the type of the additive identity for elements of this type.

Returns:

A new type, or BaseType.GENERAL, if the operation does not make sense for the given types.