ptolemy.data.type
Class FunctionType

java.lang.Object
  ptolemy.data.type.StructuredType
      ptolemy.data.type.FunctionType

All Implemented Interfaces:

Type

public class FunctionType
extends StructuredType

A class representing the type of a FunctionToken.

Since:

Ptolemy II 3.0

Version:

$Id: FunctionType.java,v 1.32 2007/12/07 06:31:48 cxh Exp $

Author:

Steve Neuendorffer

Accepted Rating:

Red (cxh)

Proposed Rating:

Red (neuendor)

Field Summary

Fields inherited from class ptolemy.data.type.StructuredType

MAXDEPTHBOUND

Fields inherited from interface ptolemy.data.type.Type

HASH_INVALID, HASH_MAX

Constructor Summary

FunctionType(Type[] types, Type returnType)
Construct a new FunctionType with the specified argument types and the given return type.

Method Summary

protected int	_compare(StructuredType type) Compare this type with the specified type.
protected StructuredType	_getRepresentative() Return a static instance of FunctionType.
protected StructuredType	_greatestLowerBound(StructuredType type) Return the greatest lower bound of this type with the specified type.
protected StructuredType	_leastUpperBound(StructuredType type) Return the least upper bound of this type with the specified type.
java.lang.Object	clone() Return a deep copy of this FunctionType if it is a variable, or itself if it is a constant.
Token	convert(Token token) Convert the argument token into a FunctionToken having this type, if lossless conversion can be done.
boolean	equals(java.lang.Object object) Determine if the argument represents the same FunctionType as this object.
int	getArgCount() Return the number of arguments in this type.
Type	getArgType(int i) Return the type of the given argument.
ptolemy.data.type.FunctionType.FieldTypeTerm	getArgTypeTerm(int i) Return the InequalityTerm representing the type of the given argument.
Type	getReturnType() Return the type of the specified label.
java.lang.Class	getTokenClass() Return the class for tokens that this type represents.
int	hashCode() Return a hash code value for this object.
void	initialize(Type type) Set the elements that have declared type BaseType.UNKNOWN (the leaf type variable) to the specified type.
boolean	isAbstract() Test if this type corresponds to an abstract token class.
boolean	isCompatible(Type type) Test if the argument type is compatible with this type.
boolean	isConstant() Test if this FunctionType is a constant.
boolean	isInstantiable() Test if this type corresponds to an instantiable token class.
boolean	isSubstitutionInstance(Type type) Test if the specified type is a substitution instance of this type.
java.lang.String	toString() Return the string representation of this type.
void	updateType(StructuredType newType) Update this type to the specified FunctionType.

Methods inherited from class ptolemy.data.type.StructuredType

add, depth, divide, getTypeHash, modulo, multiply, one, subtract, zero

Methods inherited from class java.lang.Object

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

Constructor Detail

FunctionType

public FunctionType(Type[] types,
                    Type returnType)

Construct a new FunctionType with the specified argument types and the given return type. To leave the types of some fields undeclared, use BaseType.UNKNOWN. To construct the type for a function of no arguments, set the length of the argument array to 0.

Parameters:

types - An array of Type.

returnType - An type.

Throws:

java.lang.IllegalArgumentException - If the labels and types do not have the same size.

java.lang.NullPointerException - If one of the arguments is null.

Method Detail

clone

public java.lang.Object clone()

Return a deep copy of this FunctionType if it is a variable, or itself if it is a constant.

Specified by:

clone in interface Type

Specified by:

clone in class StructuredType

Returns:

A FunctionType.

convert

public Token convert(Token token)
              throws IllegalActionException

Convert the argument token into a FunctionToken having this type, if lossless conversion can be done. The argument must be an FunctionToken, and its type must be a subtype of this record type.

Parameters:

token - A token.

Returns:

An FunctionToken.

Throws:

IllegalActionException - If lossless conversion cannot be done.

equals

public boolean equals(java.lang.Object object)

Determine if the argument represents the same FunctionType as this object. Two function types are equal if they have the same field names and the type of each field is the same, and they have the same return type.

Specified by:

equals in interface Type

Overrides:

equals in class java.lang.Object

Parameters:

object - Another object.

Returns:

True if the argument represents the same FunctionType as this object.

getArgCount

public int getArgCount()

Return the number of arguments in this type.

Returns:

The number of arguments.

getArgType

public Type getArgType(int i)

Return the type of the given argument.

Parameters:

i - The index of the type.

Returns:

a Type.

getReturnType

public Type getReturnType()

Return the type of the specified label.

Returns:

a Type.

getTokenClass

public java.lang.Class getTokenClass()

Return the class for tokens that this type represents.

Returns:

The class for tokens that this type represents.

getArgTypeTerm

public ptolemy.data.type.FunctionType.FieldTypeTerm getArgTypeTerm(int i)

Return the InequalityTerm representing the type of the given argument.

Parameters:

i - The index of the type.

Returns:

An InequalityTerm.

See Also:

InequalityTerm

hashCode

public int hashCode()

Return a hash code value for this object.

Overrides:

hashCode in class java.lang.Object

initialize

public void initialize(Type type)

Set the elements that have declared type BaseType.UNKNOWN (the leaf type variable) to the specified type.

Specified by:

initialize in class StructuredType

Parameters:

type - the type to set the leaf type variable to.

isAbstract

public boolean isAbstract()

Test if this type corresponds to an abstract token class. A FunctionType is abstract only if it is not instantiable.

Specified by:

isAbstract in interface Type

Overrides:

isAbstract in class StructuredType

Returns:

True if this type is abstract.

isCompatible

public boolean isCompatible(Type type)

Test if the argument type is compatible with this type. The given type will be compatible with this type if it is BaseType.UNKNOWN, or...

Parameters:

type - An instance of Type.

Returns:

True if the argument is compatible with this type.

isConstant

public boolean isConstant()

Test if this FunctionType is a constant. A FunctionType is a constant if the declared type of all of its fields are constant.

Returns:

True if this type is a constant.

isInstantiable

public boolean isInstantiable()

Test if this type corresponds to an instantiable token class. A FunctionType is instantiable if all of its fields are instantiable.

Returns:

True if this type is instantiable.

isSubstitutionInstance

public boolean isSubstitutionInstance(Type type)

Test if the specified type is a substitution instance of this type. One function is a substitution instance of another if they have arguments with the same types and each field of the given type is a substitution instance of the corresponding field in this type.

Parameters:

type - A Type.

Returns:

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

See Also:

Type.isSubstitutionInstance(ptolemy.data.type.Type)

toString

public java.lang.String toString()

Return the string representation of this type. The format is function(a0:<type>, a1:<type>, ...) <type> Note that the function argument names are not semantically significant.

Specified by:

toString in interface Type

Overrides:

toString in class java.lang.Object

Returns:

A String.

updateType

public void updateType(StructuredType newType)
                throws IllegalActionException

Update this type to the specified FunctionType. The specified type must be a FunctionType and have the same structure as this one. This method will only update the component whose declared type is BaseType.UNKNOWN, and leave the constant part of this type intact.

Overrides:

updateType in class StructuredType

Parameters:

newType - A StructuredType.

Throws:

IllegalActionException - If the specified type is not a FunctionType or it does not have the same structure as this one.

_compare

protected int _compare(StructuredType type)

Compare this type with the specified type. The specified type must be a FunctionType, otherwise an exception will be thrown. This method returns one of ptolemy.graph.CPO.LOWER, ptolemy.graph.CPO.SAME, ptolemy.graph.CPO.HIGHER, ptolemy.graph.CPO.INCOMPARABLE, indicating this type is lower than, equal to, higher than, or incomparable with the specified type in the type hierarchy, respectively.

Specified by:

_compare in class StructuredType

Parameters:

type - a FunctionType.

Returns:

An integer.

Throws:

java.lang.IllegalArgumentException - If the specified type is not a FunctionType.

_getRepresentative

protected StructuredType _getRepresentative()

Return a static instance of FunctionType.

Specified by:

_getRepresentative in class StructuredType

Returns:

a FunctionType.

_greatestLowerBound

protected StructuredType _greatestLowerBound(StructuredType type)

Return the greatest lower bound of this type with the specified type. The specified type must be a FunctionType, otherwise an exception will be thrown.

Specified by:

_greatestLowerBound in class StructuredType

Parameters:

type - a FunctionType.

Returns:

a FunctionType.

Throws:

java.lang.IllegalArgumentException - If the specified type is not a FunctionType.

_leastUpperBound

protected StructuredType _leastUpperBound(StructuredType type)

Return the least upper bound of this type with the specified type. The specified type must be a FunctionType, otherwise an exception will be thrown.

Specified by:

_leastUpperBound in class StructuredType

Parameters:

type - a FunctionType.

Returns:

a FunctionType.

Throws:

java.lang.IllegalArgumentException - If the specified type is not a FunctionType.