/**
*
*/
package edu.cmu.sphinx.fst.operations;
import edu.cmu.sphinx.fst.Arc;
import edu.cmu.sphinx.fst.Fst;
import edu.cmu.sphinx.fst.ImmutableFst;
import edu.cmu.sphinx.fst.State;
/**
* Project operation.
*
* @author John Salatas <jsalatas@users.sourceforge.net>
*
*/
public class Project {
/**
* Default Constructor
*/
private Project() {
}
/**
* Projects an fst onto its domain or range by either copying each arc's
* input label to its output label or vice versa.
*
*
* @param fst
* @param pType
*/
public static void apply(Fst fst, ProjectType pType) {
if (pType == ProjectType.INPUT) {
fst.setOsyms(fst.getIsyms());
} else if (pType == ProjectType.OUTPUT) {
fst.setIsyms(fst.getOsyms());
}
int numStates = fst.getNumStates();
for (int i = 0; i < numStates; i++) {
State s = fst.getState(i);
// Immutable fsts hold an additional (null) arc
int numArcs = (fst instanceof ImmutableFst) ? s.getNumArcs() - 1: s
.getNumArcs();
for (int j = 0; j < numArcs; j++) {
Arc a = s.getArc(j);
if (pType == ProjectType.INPUT) {
a.setOlabel(a.getIlabel());
} else if (pType == ProjectType.OUTPUT) {
a.setIlabel(a.getOlabel());
}
}
}
}
}