001/*
002 *                    BioJava development code
003 *
004 * This code may be freely distributed and modified under the
005 * terms of the GNU Lesser General Public Licence.  This should
006 * be distributed with the code.  If you do not have a copy,
007 * see:
008 *
009 *      http://www.gnu.org/copyleft/lesser.html
010 *
011 * Copyright for this code is held jointly by the individual
012 * authors.  These should be listed in @author doc comments.
013 *
014 * For more information on the BioJava project and its aims,
015 * or to join the biojava-l mailing list, visit the home page
016 * at:
017 *
018 *      http://www.biojava.org/
019 *
020 */
021
022
023package org.biojava.bio.symbol;
024
025/**
026 * A translation table that can also translate from the target to source
027 * alphabet.
028 * <p>
029 * I guess this is encapsulates an invertible function, and the untranslate
030 * method is the inverse operation to translate.
031 * <p>
032 * It is assumed that untranslate(translate(x)) = x for all x in the source
033 * alphabet, and that translate(untranslate(y)) = y for all y in the target
034 * alphabet. Note, one interesting sub-set of reversible transforms are of the
035 * form translate(x) = untranslate(x), and represent 'mirror image'
036 * transformations.
037 *
038 * @author Matthew Pocock
039 */
040public interface ReversibleTranslationTable extends TranslationTable {
041  /**
042   * Translate a single symbol from target alphabet to the source alphabet.
043   *
044   * @param sym the Symbol to translate (member of target alphabet)
045   * @return the translated version of sym (member of source alphabet)
046   * @throws IllegalSymbolException if sym is not a member of the target
047   *         alphabet
048   */
049  public Symbol untranslate(Symbol sym) throws IllegalSymbolException;
050}