ptolemy.moml.unit

Class UnitTerm

java.lang.Object

ptolemy.moml.unit.UnitTerm

All Implemented Interfaces:

UnitPresentation

public class UnitTerm
extends java.lang.Object
implements UnitPresentation

UnitTerm represents a term in a Unit Expression. A UnitTerm has 1) an exponent and 2) an element. The element can be either 1) a Unit, 2) a variable, or 3) a Unit Expression. These choices for element are mutually exclusive. UnitTerms are usually constructed as a result of parsing a Unit Expression.

Since:

Ptolemy II 8.0

Version:

$Id$

Author:

Rowland R Johnson

Pt.AcceptedRating:

Red (rowland)

Pt.ProposedRating:

Red (rowland)

Constructor Summary

Constructors

Constructor and Description
UnitTerm() Construct a UnitTerm with no element.
UnitTerm(Unit unit) Construct an instance where the contained element is a Unit.

Method Summary

Modifier and Type	Method and Description
protected void	_setType(int type)
UnitTerm	copy() Make a shallow copy of this UnitTerm.
java.lang.String	descriptiveForm() Create a String that is understandable by a human.
int	getExponent()
Unit	getUnit() Get the element if it is a Unit.
UnitExpr	getUnitExpr() Get the element if it is a UnitExpr.
java.lang.String	getVariable() Get the element if it is a variable.
UnitTerm	invert() Invert this UnitTerm.
boolean	isUnit() True if this is a Unit.
boolean	isUnitExpr() True is this is a UnitExpr.
boolean	isVariable() True if this a variable.
void	setExponent(int exponent) Set the exponent.
void	setUnit(Unit unit) Set the element to be a Unit.
void	setUnitExpr(UnitExpr expr) Set the element to be a UnitExpr.
void	setVariable(java.lang.String v) Set the element to be a variable
java.lang.String	toString()
java.lang.Object	visit(EquationVisitor visitor) Visit an instance of UnitTerm.

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, wait, wait, wait

Constructor Detail

UnitTerm

public UnitTerm()

Construct a UnitTerm with no element.

UnitTerm

public UnitTerm(Unit unit)

Construct an instance where the contained element is a Unit.

Parameters:

unit - The Unit that will be the element of this instance.

Method Detail

copy

public UnitTerm copy()

Make a shallow copy of this UnitTerm. That is, the underlying Unit or UnitExpr is not copied.

Returns:

The copy of this UnitTerm

descriptiveForm

public java.lang.String descriptiveForm()

Create a String that is understandable by a human.

Specified by:

descriptiveForm in interface UnitPresentation

Returns:

The descriptive form.

See Also:

UnitPresentation.descriptiveForm()

getExponent

public int getExponent()

Returns:

The exponent.

getUnit

public Unit getUnit()

Get the element if it is a Unit.

Returns:

The Unit if the element is a Unit, otherwise null.

getUnitExpr

public UnitExpr getUnitExpr()

Get the element if it is a UnitExpr.

Returns:

The UnitExpr if the element is a UnitExpr, otherwise null.

getVariable

public java.lang.String getVariable()

Get the element if it is a variable.

Returns:

The variable if the element is a variable, null otherwise.

invert

public UnitTerm invert()

Invert this UnitTerm.

Returns:

The inverse of this UnitTerm.

isUnit

public boolean isUnit()

True if this is a Unit.

Returns:

True if this is a Unit.

isUnitExpr

public boolean isUnitExpr()

True is this is a UnitExpr.

Returns:

True is this is a UnitExpr.

isVariable

public boolean isVariable()

True if this a variable.

Returns:

True if this a variable.

setExponent

public void setExponent(int exponent)

Set the exponent.

Parameters:

exponent - The exponent.

setUnit

public void setUnit(Unit unit)

Set the element to be a Unit.

Parameters:

unit - The Unit.

setUnitExpr

public void setUnitExpr(UnitExpr expr)

Set the element to be a UnitExpr.

Parameters:

expr - The Unit Expression.

setVariable

public void setVariable(java.lang.String v)

Set the element to be a variable

Parameters:

v - The variable.

toString

public java.lang.String toString()

Specified by:

toString in interface UnitPresentation

Overrides:

toString in class java.lang.Object

visit

public java.lang.Object visit(EquationVisitor visitor)
                       throws IllegalActionException

Visit an instance of UnitTerm.

Parameters:

visitor - The visitor.

Returns:

The result of visiting the UnitTerm.

Throws:

IllegalActionException

_setType

protected void _setType(int type)

Parameters:

type - The Unit type.