ptolemy.moml.unit
Class UnitExpr

java.lang.Object
  ptolemy.moml.unit.UnitExpr

All Implemented Interfaces:

UnitPresentation

public class UnitExpr
extends java.lang.Object
implements UnitPresentation

A UnitExpr contains UnitTerms.

Since:

Ptolemy II 8.0

Version:

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

Author:

Rowland R Johnson

Accepted Rating:

Red (rowland)

Proposed Rating:

Red (rowland)

Field Summary

(package private) boolean	_isFlat
(package private) java.util.Vector	_uTerms

Constructor Summary

UnitExpr()
Construct an empty (i.e. no UnitTerms) UnitExpr.

UnitExpr(IOPort ioPort)
Construct a UnitTerm from an IOPort.

Method Summary

private void	_flatten()
protected void	_setUTerms(java.util.Vector uTerms)
void	addUnitTerm(UnitTerm uTerm) Add a UnitTerm to the expression.
UnitExpr	copy() Create a copy of this UnitExpr.
java.lang.String	descriptiveForm() The expression of the UnitExpr that is commonly used by humans.
Unit	getSingleUnit() If this UnitExpr has one term and it is a Unit then return that Unit.
java.util.Vector	getUTerms() Get the UnitTerms in this UnitExpr.
UnitExpr	invert() Create a new UnitExpr that is the inverse of this UnitExpr.
UnitExpr	reduce() Reduce a UnitExpr to produce a UnitExpr that has at most one Unit.
java.lang.String	toString()

Methods inherited from class java.lang.Object

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

Field Detail

_isFlat

boolean _isFlat

_uTerms

java.util.Vector _uTerms

Constructor Detail

UnitExpr

public UnitExpr()

Construct an empty (i.e. no UnitTerms) UnitExpr.

UnitExpr

public UnitExpr(IOPort ioPort)

Construct a UnitTerm from an IOPort. The constructed UnitExpr will have one UnitTerm and it will be a variable with the name being that of the port.

Parameters:

ioPort - The IOPort.

Method Detail

addUnitTerm

public void addUnitTerm(UnitTerm uTerm)

Add a UnitTerm to the expression.

Parameters:

uTerm - The UnitTerm.

copy

public UnitExpr copy()

Create a copy of this UnitExpr.

Returns:

The new UnitExpr.

descriptiveForm

public java.lang.String descriptiveForm()

The expression of the UnitExpr that is commonly used by humans.

Specified by:

descriptiveForm in interface UnitPresentation

Returns:

The descriptive form.

See Also:

UnitPresentation.descriptiveForm()

getSingleUnit

public Unit getSingleUnit()

If this UnitExpr has one term and it is a Unit then return that Unit.

Returns:

The Unit if there is a single UnitTerm, and it is a Unit, null otherwise.

getUTerms

public java.util.Vector getUTerms()

Get the UnitTerms in this UnitExpr.

Returns:

The UnitTerms.

invert

public UnitExpr invert()

Create a new UnitExpr that is the inverse of this UnitExpr.

Returns:

The inverse of this UnitExpr.

reduce

public UnitExpr reduce()

Reduce a UnitExpr to produce a UnitExpr that has at most one Unit. Any embedded UnitExpr is first transformed so that all embedded UnitExprs are replaced with Units. This intermediate result is a mixture of Units and variables. The Units are then replaced with their product. The result is a single Unit and all of the original variables.

Returns:

The reduced UnitExpr.

toString

public java.lang.String toString()

Specified by:

toString in interface UnitPresentation

Overrides:

toString in class java.lang.Object

_setUTerms

protected void _setUTerms(java.util.Vector uTerms)

_flatten

private void _flatten()