001/* Interface that specifies the way Units, etc are presented.
002
003 Copyright (c) 2003-2014 The Regents of the University of California.
004 All rights reserved.
005 Permission is hereby granted, without written agreement and without
006 license or royalty fees, to use, copy, modify, and distribute this
007 software and its documentation for any purpose, provided that the above
008 copyright notice and the following two paragraphs appear in all copies
009 of this software.
010
011 IN NO EVENT SHALL THE UNIVERSITY OF CALIFORNIA BE LIABLE TO ANY PARTY
012 FOR DIRECT, INDIRECT, SPECIAL, INCIDENTAL, OR CONSEQUENTIAL DAMAGES
013 ARISING OUT OF THE USE OF THIS SOFTWARE AND ITS DOCUMENTATION, EVEN IF
014 THE UNIVERSITY OF CALIFORNIA HAS BEEN ADVISED OF THE POSSIBILITY OF
015 SUCH DAMAGE.
016
017 THE UNIVERSITY OF CALIFORNIA SPECIFICALLY DISCLAIMS ANY WARRANTIES,
018 INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF
019 MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE. THE SOFTWARE
020 PROVIDED HEREUNDER IS ON AN "AS IS" BASIS, AND THE UNIVERSITY OF
021 CALIFORNIA HAS NO OBLIGATION TO PROVIDE MAINTENANCE, SUPPORT, UPDATES,
022 ENHANCEMENTS, OR MODIFICATIONS.
023
024 PT_COPYRIGHT_VERSION_3
025 COPYRIGHTENDKEY
026 @Pt.ProposedRating Red (rowland)
027 @Pt.AcceptedRating Red (rowland)
028 */
029package ptolemy.moml.unit;
030
031//////////////////////////////////////////////////////////////////////////
032//// UnitPresentation
033
034/** The methods necessary to present Units, UnitConstraints, UnitExprs, etc. so
035 that developers, and humans can understand the results generated by the
036 system.
037 @author Rowland R Johnson
038 @version $Id$
039 @since Ptolemy II 8.0
040 @Pt.ProposedRating Red (cxh)
041 @Pt.AcceptedRating Red (cxh)
042 */
043public interface UnitPresentation {
044    /** This method generates the descriptive form.
045     * In addition to the internal form used by the system Units,
046     * UnitConstraints, UnitExprs, etc. have a descriptive form that is used by
047     * humans. This method generates that form so that humans can
048     * easily understand the results generated by the system. For example, an
049     * internal representation of a Unit could be 4.1868E7*<2, 1, 1, 0, 0>
050     * and its descriptive form would be "calorie".
051     * <p>
052     * The descriptive form is invariant across Unit Systems. That is, calorie
053     * is calorie regardless of the Unit System. But, the internal form may be
054     * 4.1868E7*&lt;2, 1, 1, 0, 0&gt; in one Unit System, and
055     * 1.0*&lt;2, 1, 1, 0, 0&gt; in another. Therefore the descriptive form is
056     * used as the external representation. This makes it
057     * possible to save a model under one Unit System, and then load it under a
058     * different Unit System.
059     * @return The descriptive form.
060     */
061    public String descriptiveForm();
062
063    @Override
064    public String toString();
065}