ptolemy.data.type
Class FixType

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

All Implemented Interfaces:

java.io.Serializable, Type

public class FixType
extends StructuredType
implements java.io.Serializable

This class represents the type of fix point token objects. Generally the type of a fix point token includes the precision of the token, along with the rounding and quantization techniques that are being applied.

Since:

Ptolemy II 2.1

Version:

$Id: FixType.java,v 1.46 2007/12/07 06:31:54 cxh Exp $

Author:

Steve Neuendorffer

See Also:

Serialized Form

Accepted Rating:

Red

Proposed Rating:

Red (neuendor)

Field Summary

static FixType

BOTTOM The bottom fix type.

Fields inherited from class ptolemy.data.type.StructuredType

MAXDEPTHBOUND

Fields inherited from interface ptolemy.data.type.Type

HASH_INVALID, HASH_MAX

Constructor Summary

FixType()
Construct a new fix type, with no integer bits and no fractional bits.

FixType(Precision precision)
Construct a new fix type.

Method Summary

protected void	_checkPrecision() Check the precision.
protected int	_compare(StructuredType type) Compare this type with the specified type.
protected StructuredType	_getRepresentative() Return a static instance of this structured type.
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.
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 this, that is, return the reference to this object.
Token	convert(Token token) Convert the specified token to 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 FixType as this object.
Precision	getPrecision() Return the precision associated with this FixType.
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 to the specified 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() Test if this type corresponds to an instantiable token classes.
boolean	isSubstitutionInstance(Type type) Test if the argument 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.
void	updateType(StructuredType newType) Update this StructuredType to the specified Structured Type.
Type	zero() Return the type of the additive identity for elements of this type.

Methods inherited from class ptolemy.data.type.StructuredType

depth, getTypeHash

Methods inherited from class java.lang.Object

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

Field Detail

BOTTOM

public static final FixType BOTTOM

The bottom fix type.

Constructor Detail

FixType

public FixType()

Construct a new fix type, with no integer bits and no fractional bits. This (rather useless) type represents the bottom of the FixPoint type lattice.

FixType

public FixType(Precision precision)

Construct a new fix type.

Parameters:

precision - The precision.

Method Detail

add

public 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.

Specified by:

add in interface Type

Overrides:

add in class StructuredType

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

public java.lang.Object clone()

Return this, that is, return the reference to this object.

Specified by:

clone in interface Type

Specified by:

clone in class StructuredType

Returns:

A FixType.

convert

public Token convert(Token token)
              throws IllegalActionException

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

Specified by:

convert in interface Type

Parameters:

token - A token.

Returns:

A token.

Throws:

IllegalActionException - If lossless conversion cannot be done.

divide

public 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.

Specified by:

divide in interface Type

Overrides:

divide in class StructuredType

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

public boolean equals(java.lang.Object object)

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

Specified by:

equals in interface Type

Overrides:

equals in class java.lang.Object

Parameters:

object - A Type.

Returns:

Always return true

getPrecision

public Precision getPrecision()

Return the precision associated with this FixType.

Returns:

A Precision.

getTokenClass

public java.lang.Class getTokenClass()

Return the class for tokens that this type represents.

Specified by:

getTokenClass in interface Type

Returns:

The class representing ptolemy.data.token.FixToken.

hashCode

public int hashCode()

Return a hash code value for this object.

Overrides:

hashCode in class java.lang.Object

Returns:

The hash code for the token class of this type.

initialize

public void initialize(Type type)

Set the elements that have declared type BaseType.UNKNOWN to the specified type.

Specified by:

initialize in class StructuredType

Parameters:

type - A Type.

isAbstract

public 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. This method should be overridden in derived classes to return true only for types which are not abstract.

Specified by:

isAbstract in interface Type

Overrides:

isAbstract in class StructuredType

Returns:

true.

isCompatible

public boolean isCompatible(Type type)

Test if the argument type is compatible with this type. The method returns true if this type is UNKNOWN, since any type is a substitution instance of it. If this type is not UNKNOWN, this method returns true if the argument type is less than or equal to this type in the type lattice, and false otherwise.

Specified by:

isCompatible in interface Type

Parameters:

type - An instance of Type.

Returns:

True if the argument is compatible with this type.

isConstant

public 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.

Specified by:

isConstant in interface Type

Returns:

False.

isInstantiable

public boolean isInstantiable()

Test if this type corresponds to an instantiable token classes.

Specified by:

isInstantiable in interface Type

Returns:

True if the precision of this fix type has any bits.

isSubstitutionInstance

public boolean isSubstitutionInstance(Type type)

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

Specified by:

isSubstitutionInstance in interface Type

Parameters:

type - A Type.

Returns:

False.

modulo

public 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.

Specified by:

modulo in interface Type

Overrides:

modulo in class StructuredType

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

public 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. The resulting Precision of a multiply between two FixType arguments is as follows: the integer location is the sum of the integer locations of the two arguments and the fractional location is the sum of the fractional locations of the two arguments.

Specified by:

multiply in interface Type

Overrides:

multiply in class StructuredType

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

public Type one()

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

Specified by:

one in interface Type

Overrides:

one in class StructuredType

Returns:

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

subtract

public 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.

Specified by:

subtract in interface Type

Overrides:

subtract in class StructuredType

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

public java.lang.String toString()

Return the string representation of this type.

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 StructuredType to the specified Structured Type. The specified type must have the same structure as this type. This method will only update the component type that 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 has a different structure.

zero

public Type zero()

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

Specified by:

zero in interface Type

Overrides:

zero in class StructuredType

Returns:

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

_compare

protected int _compare(StructuredType type)

Compare this type with the specified type. The specified type must be of the same structured type, 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 StructuredType.

Returns:

An integer.

Throws:

java.lang.IllegalArgumentException - If the specified type is not the same structured type as this one.

_getRepresentative

protected StructuredType _getRepresentative()

Return a static instance of this structured type. The return value is used by TypeLattice to represent this type.

Specified by:

_getRepresentative in class StructuredType

Returns:

a StructuredType.

_greatestLowerBound

protected StructuredType _greatestLowerBound(StructuredType type)

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

Specified by:

_greatestLowerBound in class StructuredType

Parameters:

type - a StructuredType.

Returns:

a StructuredType.

Throws:

java.lang.IllegalArgumentException - If the specified type is not the same structured type as this one.

_leastUpperBound

protected StructuredType _leastUpperBound(StructuredType type)

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

Specified by:

_leastUpperBound in class StructuredType

Parameters:

type - a StructuredType.

Returns:

a StructuredType.

Throws:

java.lang.IllegalArgumentException - If the specified type is not the same structured type as this one.

_checkPrecision

protected void _checkPrecision()

Check the precision. If the number of bits is greater than 128, throw an exception.