Span.java

/* Copyright (C) 2002 Univ. of Massachusetts Amherst, Computer Science Dept.
   This file is part of "MALLET" (MAchine Learning for LanguagE Toolkit).
   http://www.cs.umass.edu/~mccallum/mallet
   This software is provided under the terms of the Common Public License,
   version 1.0, as published by http://www.opensource.org.  For further
   information, see the file `LICENSE' included with this distribution. */

/** 
 @author Andrew McCallum <a href="mailto:mccallum@cs.umass.edu">mccallum@cs.umass.edu</a>
 */

// Rename to Segment, (then also Segmentation, SegmentSequence, SegmentList)
// Alternatively, think about names: Annotation, AnnotationList, 

package edu.nd.nina.extract;

/**
 * A sub-section of a document, either linear or two-dimensional. Spans are
 * immutable.
 */

public interface Span {

	/**
	 * Returns a textual representatio of the span, suitable for XML output,
	 * e.g.
	 */
	String getText();

	/** Returns a new span that is the intersection of this span and another. */
	Span intersection(Span r);

	Object getDocument();

	boolean intersects(Span r);

	boolean isSubspan(Span r);

	/**
	 * Returns an integer index identifying the start of this span. Beware that
	 * in some cases (e.g., for images), this may not correspond directly to a
	 * sequence index.
	 */
	int getStartIdx();

	/**
	 * Returns an integer index identifying the end of this span. Beware that in
	 * some cases (e.g., for images), this may not correspond directly to a
	 * sequence index.
	 */
	int getEndIdx();

}