001package org.biopax.paxtools.query.model;
002
003/**
004 * Wrapper interface for edges in a graph to be queried.
005 *
006 * @author Ozgun Babur
007 */
008public interface Edge extends GraphObject
009{
010        /**
011         * @return The target node
012         */
013        Node getTargetNode();
014
015        /**
016         * @return The source node
017         */
018        Node getSourceNode();
019
020        /**
021         * Algorithms may need a sign for the edge. 1: positive, -1 negative, 0: signless.
022         * @return The sign of the edge
023         */
024        public int getSign();
025
026        /**
027         * @return Whether this edge indicates a transcriptional relation
028         */
029        public boolean isTranscription();
030}