private Dictionary <Nonterminal, Set <Terminal <TTokenKind> > > ComputeFirst(
Grammar <TTokenKind, TNonterminal> grammar, IErasableSymbolsAnalyzer analyzer)
{
var(initFirstSets, graph) = DigraphAlgorithm.GetFirstGraph(grammar, analyzer);
var firstSets = DigraphAlgorithm.Traverse(graph, initFirstSets);
var firstMap = grammar.Nonterminals.ToDictionary(v => v, v => firstSets[v.Index]);
return(firstMap);
}
