private bool GeneratePatternNfa(State <TData, TOffset> startState, Pattern <TData, TOffset> pattern, string parentName,
Func <Match <TData, TOffset>, bool>[] acceptables, ref int nextPriority)
{
bool deterministic = true;
string name = parentName == null ? pattern.Name : parentName + "*" + pattern.Name;
if (pattern.Acceptable != null)
{
acceptables = acceptables.Concat(pattern.Acceptable).ToArray();
}
if (pattern.Children.All(node => node is Pattern <TData, TOffset>))
{
foreach (Pattern <TData, TOffset> childExpr in pattern.Children)
{
if (!GeneratePatternNfa(startState, childExpr, name, acceptables, ref nextPriority))
{
deterministic = false;
}
}
}
else
{
startState = _fsa.CreateTag(startState, _fsa.CreateState(), EntireMatch, true);
bool hasVariables;
startState = pattern.GenerateNfa(_fsa, startState, out hasVariables);
if (hasVariables)
{
deterministic = false;
}
startState = _fsa.CreateTag(startState, _fsa.CreateState(), EntireMatch, false);
Func <TData, FstResult <TData, TOffset>, bool> acceptable = null;
if (acceptables.Length > 0)
{
acceptable = (input, match) =>
{
Match <TData, TOffset> patMatch = CreatePatternMatch(input, match);
return(acceptables.All(a => a(patMatch)));
};
}
State <TData, TOffset> acceptingState = _fsa.CreateAcceptingState(name, acceptable, nextPriority++);
startState.Arcs.Add(acceptingState);
}
return(deterministic);
}
internal override State <TData, TOffset> GenerateNfa(Fst <TData, TOffset> fsa, State <TData, TOffset> startState, out bool hasVariables)
{
if (IsLeaf)
{
hasVariables = false;
return(startState);
}
if (_name != null)
{
startState = fsa.CreateTag(startState, fsa.CreateState(), _name, true);
}
startState = base.GenerateNfa(fsa, startState, out hasVariables);
startState = _name != null?fsa.CreateTag(startState, fsa.CreateState(), _name, false) : startState.Arcs.Add(fsa.CreateState());
return(startState);
}