/* 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. */
package cc.mallet.types;
import java.io.Serializable;
import java.io.ObjectOutputStream;
import java.io.IOException;
import java.io.ObjectInputStream;
/**
* A simple {@link Sequence} implementation where all of the
* elements must be Labels. Provides a convenient type-safe accessor {@link #getLabels}.
* Instances of LabelsSequence are immutable.
*
* @author Andrew McCallum <a href="mailto:mccallum@cs.umass.edu">mccallum@cs.umass.edu</a>
*/
public class LabelsSequence implements Sequence, AlphabetCarrying, Serializable
{
Labels[] seq;
/**
* Create a LabelsSequence from an array. The array is shallow-copied.
*/
public LabelsSequence (Labels[] seq)
{
for (int i = 0; i < seq.length-1; i++)
if (!Alphabet.alphabetsMatch(seq[i], seq[i+1]))
throw new IllegalArgumentException ("Alphabets do not match");
this.seq = new Labels[seq.length];
System.arraycopy (seq, 0, this.seq, 0, seq.length);
}
public LabelsSequence (LabelSequence seq)
{
this.seq = new Labels[seq.size()];
for (int i = 0; i < seq.length; i++) {
this.seq[i] = new Labels (new Label[] { seq.getLabelAtPosition (i) });
}
}
public Alphabet getAlphabet () { return seq[0].getAlphabet(); }
public Alphabet[] getAlphabets () { return seq[0].getAlphabets(); }
public int size () { return seq.length; }
public Object get (int i) { return seq[i]; }
public Labels getLabels (int i) { return seq[i]; }
public String toString ()
{
String ret = "LabelsSequence:\n";
for (int i = 0; i < seq.length; i++) {
ret += i+": ";
ret += seq[i].toString();
ret += "\n";
}
return ret;
}
// Serialization
private static final long serialVersionUID = 1;
private static final int CURRENT_SERIAL_VERSION = 0;
private void writeObject (ObjectOutputStream out) throws IOException {
out.writeInt(CURRENT_SERIAL_VERSION);
out.defaultWriteObject ();
}
private void readObject (ObjectInputStream in) throws IOException, ClassNotFoundException {
int version = in.readInt ();
in.defaultReadObject ();
}
}