/**
* /// Returns the list of successors to this state
*
* /// @return a list of SearchState objects
*/
public override ISearchStateArc[] GetSuccessors()
{
ISearchStateArc[] arcs = GetCachedArcs();
if (arcs == null)
{
HMMNode[] nodes = Parent.GetHMMNodes(GetEndNode());
arcs = new ISearchStateArc[nodes.Length];
if (Parent.GenerateUnitStates)
{
for (int i = 0; i < nodes.Length; i++)
{
arcs[i] = new LexTreeUnitState(nodes[i],
WordHistory, SmearTerm,
SmearProb, Parent.LogOne, Parent.LogOne,
GetNode(), Parent);
}
}
else
{
for (int i = 0; i < nodes.Length; i++)
{
IHMM hmm = nodes[i].HMM;
arcs[i] = new LexTreeHmmState(nodes[i],
WordHistory, SmearTerm,
SmearProb, hmm.GetInitialState(),
Parent.LogOne, Parent.LogOne, GetNode(), Parent);
}
}
PutCachedArcs(arcs);
}
return(arcs);
}
/**
* /// Returns the list of successors to this state
*
* /// @return a list of SearchState objects
*/
public override ISearchStateArc[] GetSuccessors()
{
ISearchStateArc[] arcs = new ISearchStateArc[1];
IHMM hmm = GetHMMNode().HMM;
arcs[0] = new LexTreeHmmState(GetHMMNode(), WordHistory,
SmearTerm, SmearProb, hmm.GetInitialState(),
_parent.LogOne, _parent.LogOne, _parentNode, _parent);
return(arcs);
}
/**
* /// Creates a unit search state for the given unit node
*
* /// @param hmmNode the unit node
*
* /// @return the search state
*/
public ISearchStateArc CreateUnitStateArc(HMMNode hmmNode, LexTreeState previous)
{
ISearchStateArc arc;
float insertionProbability = Parent.CalculateInsertionProbability(hmmNode);
float smearProbability = Parent.GetUnigramSmear(hmmNode) + previous.SmearTerm;
float languageProbability = smearProbability - previous.SmearProb;
//if we want a unit state create it, otherwise
//get the first hmm state of the unit
if (Parent.GenerateUnitStates)
{
arc = new LexTreeUnitState(hmmNode, WordHistory, previous.SmearTerm, smearProbability, languageProbability,
insertionProbability, Parent);
}
else
{
IHMM hmm = hmmNode.HMM;
arc = new LexTreeHmmState(hmmNode, WordHistory, previous.SmearTerm, smearProbability, hmm.GetInitialState(),
languageProbability, insertionProbability, null, Parent);
}
return(arc);
}
/**
* /// Retrieves the set of successors for this state
*
* /// @return the list of successor states
*/
public override ISearchStateArc[] GetSuccessors()
{
var nextStates = GetCachedArcs();
if (nextStates == null)
{
//if this is an exit state, we are transitioning to a
//new unit or to a word end.
if (HmmState.IsExitState())
{
if (_parentNode == null)
{
nextStates = base.GetSuccessors();
}
else
{
nextStates = base.GetSuccessors(_parentNode);
}
}
else
{
//The current hmm state is not an exit state, so we
//just go through the next set of successors
var arcs = HmmState.GetSuccessors();
nextStates = new ISearchStateArc[arcs.Length];
for (var i = 0; i < arcs.Length; i++)
{
var arc = arcs[i];
if (arc.HmmState.IsEmitting)
{
//if its a self loop and the prob. matches
//reuse the state
if (arc.HmmState == HmmState &&
_logInsertionProbability == arc.LogProbability)
{
nextStates[i] = this;
}
else
{
nextStates[i] = new LexTreeHmmState(
(HMMNode)GetNode(), WordHistory,
SmearTerm, SmearProb,
arc.HmmState, Parent.LogOne,
arc.LogProbability, _parentNode, Parent);
}
}
else
{
nextStates[i] = new LexTreeNonEmittingHMMState(
(HMMNode)GetNode(), WordHistory,
SmearTerm, SmearProb,
arc.HmmState,
arc.LogProbability, _parentNode, Parent);
}
}
}
PutCachedArcs(nextStates);
}
return(nextStates);
}
