/// <summary>
/// Compiles the grammar into a sentence HMM. A GrammarJob is created for the
/// initial grammar node and added to the GrammarJob queue. While there are
/// jobs left on the grammar job queue, a job is removed from the queue and
/// the associated grammar node is expanded and attached to the tails.
/// GrammarJobs for the successors are added to the grammar job queue.
/// </summary>
/// <returns></returns>
protected HashSet <SentenceHMMState> CompileGrammar()
{
InitialGrammarState = Grammar.InitialNode;
NodeStateMap = new HashMap <GrammarNode, GState>();
// create in declaration section (22.12.2014)
ArcPool = new Cache <SentenceHMMStateArc>();
var gstateList = new List <GState>();
TimerPool.GetTimer(this, "Compile").Start();
// get the nodes from the grammar and create states
// for them. Add the non-empty gstates to the gstate list.
TimerPool.GetTimer(this, "Create States").Start();
foreach (var grammarNode in Grammar.GrammarNodes)
{
var gstate = CreateGState(grammarNode);
gstateList.Add(gstate);
}
TimerPool.GetTimer(this, "Create States").Stop();
AddStartingPath();
// ensures an initial path to the start state
// Prep all the gstates, by gathering all of the contexts up
// this allows each gstate to know about its surrounding contexts
TimerPool.GetTimer(this, "Collect Contexts").Start();
foreach (var gstate in gstateList)
{
gstate.CollectContexts();
}
TimerPool.GetTimer(this, "Collect Contexts").Stop();
// now all gstates know all about their contexts, we can expand them fully
TimerPool.GetTimer(this, "Expand States").Start();
foreach (var gstate in gstateList)
{
gstate.Expand();
}
TimerPool.GetTimer(this, "Expand States").Stop();
// now that all states are expanded fully, we can connect all the states up
TimerPool.GetTimer(this, "Connect Nodes").Start();
foreach (var gstate in gstateList)
{
gstate.Connect();
}
TimerPool.GetTimer(this, "Connect Nodes").Stop();
var initialState = FindStartingState();
// add an out-of-grammar branch if configured to do so
if (AddOutOfGrammarBranch)
{
var phoneLoop = new CIPhoneLoop(PhoneLoopAcousticModel, LogPhoneInsertionProbability);
var firstBranchState = (SentenceHMMState)phoneLoop.GetSearchGraph().InitialState;
initialState.Connect(GetArc(firstBranchState, LogOne, LogOutOfGrammarBranchProbability));
}
_searchGraph = new FlatSearchGraph(initialState);
TimerPool.GetTimer(this, "Compile").Stop();
// Now that we are all done, dump out some interesting
// information about the process
if (_dumpGStates)
{
foreach (var grammarNode in Grammar.GrammarNodes)
{
var gstate = GetGState(grammarNode);
gstate.DumpInfo();
}
}
NodeStateMap = null;
ArcPool = null;
return(SentenceHMMState.CollectStates(initialState));
}
