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: UnitTerm.java 57044 2010-01-27 22:41:05Z cxh $

Author:

Rowland R Johnson

Accepted Rating:

Red (rowland)

Proposed Rating:

Red (rowland)

Field Summary

private int	_exponent
private int	_type
private Unit	_unit
private static int	_UNIT
private UnitExpr	_unitExpr
private static int	_UNITEXPR
private java.lang.String	_variable
private static int	_VARIABLE

Constructor Summary

UnitTerm()
Construct a UnitTerm with no element.

UnitTerm(Unit unit)
Construct an instance where the contained element is a Unit.

Method Summary

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

Field Detail

_UNIT

private static final int _UNIT

See Also:

Constant Field Values

_UNITEXPR

private static final int _UNITEXPR

See Also:

Constant Field Values

_VARIABLE

private static final int _VARIABLE

See Also:

Constant Field Values

_exponent

private int _exponent

_type

private int _type

_unit

private Unit _unit

_unitExpr

private UnitExpr _unitExpr

_variable

private java.lang.String _variable

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.