private bool IsInstanceReuseable(FstInstance inst)
{
return(inst.State.Arcs.All(a => !a.Input.IsEpsilon));
}
public override IEnumerable <FstResult <TData, TOffset> > Traverse(ref Annotation <TOffset> ann, NullableValue <TOffset>[,] initRegisters, IList <TagMapCommand> initCmds, ISet <Annotation <TOffset> > initAnns)
{
Stack <FstInstance> instStack = InitializeStack(ref ann, initRegisters, initCmds, initAnns);
var curResults = new List <FstResult <TData, TOffset> >();
while (instStack.Count != 0)
{
FstInstance inst = instStack.Pop();
if (inst.Annotation != null)
{
VariableBindings varBindings = null;
foreach (Arc <TData, TOffset> arc in inst.State.Arcs)
{
if (arc.Input.IsEpsilon)
{
TData output = inst.Output;
IDictionary <Annotation <TOffset>, Annotation <TOffset> > mappings = inst.Mappings;
Queue <Annotation <TOffset> > queue = inst.Queue;
NullableValue <TOffset>[,] registers = inst.Registers;
if (IsInstanceReuseable(inst))
{
if (varBindings == null)
{
varBindings = inst.VariableBindings;
}
}
else
{
registers = (NullableValue <TOffset> [, ])inst.Registers.Clone();
output = inst.Output.DeepClone();
Dictionary <Annotation <TOffset>, Annotation <TOffset> > outputMappings = inst.Output.Annotations.SelectMany(a => a.GetNodesBreadthFirst())
.Zip(output.Annotations.SelectMany(a => a.GetNodesBreadthFirst())).ToDictionary(t => t.Item1, t => t.Item2);
mappings = inst.Mappings.ToDictionary(kvp => kvp.Key, kvp => outputMappings[kvp.Value]);
queue = new Queue <Annotation <TOffset> >(inst.Queue);
if (varBindings == null)
{
varBindings = inst.VariableBindings.DeepClone();
}
}
ExecuteOutputs(arc.Outputs, output, mappings, queue);
instStack.Push(EpsilonAdvanceFst(inst.Annotation, registers, output, mappings, queue, varBindings, arc, curResults));
varBindings = null;
}
else
{
if (varBindings == null)
{
varBindings = IsInstanceReuseable(inst) ? inst.VariableBindings : inst.VariableBindings.DeepClone();
}
if (CheckInputMatch(arc, inst.Annotation, varBindings))
{
TData output = inst.Output;
IDictionary <Annotation <TOffset>, Annotation <TOffset> > mappings = inst.Mappings;
Queue <Annotation <TOffset> > queue = inst.Queue;
if (!IsInstanceReuseable(inst))
{
output = inst.Output.DeepClone();
Dictionary <Annotation <TOffset>, Annotation <TOffset> > outputMappings = inst.Output.Annotations.SelectMany(a => a.GetNodesBreadthFirst())
.Zip(output.Annotations.SelectMany(a => a.GetNodesBreadthFirst())).ToDictionary(t => t.Item1, t => t.Item2);
mappings = inst.Mappings.ToDictionary(kvp => kvp.Key, kvp => outputMappings[kvp.Value]);
queue = new Queue <Annotation <TOffset> >(inst.Queue);
}
for (int i = 0; i < arc.Input.EnqueueCount; i++)
{
queue.Enqueue(inst.Annotation);
}
ExecuteOutputs(arc.Outputs, output, mappings, queue);
foreach (FstInstance ni in AdvanceFst(inst.Annotation, inst.Registers, output, mappings, queue, varBindings, arc, curResults))
{
instStack.Push(ni);
}
break;
}
}
}
}
}
return(curResults);
}
private bool IsInstanceReuseable(FstInstance inst)
{
return(inst.State.Arcs.Count <= 1);
}
