public void GetFollowGraph()
{
var analyzer = Analyzers.CreateFirstSymbolsAnalyzer(Grammar);
var(initSets, graph) = DigraphAlgorithm.GetFollowGraph(Grammar, analyzer);
// INITFOLLOW(S)
initSets[0].ShouldBeEmpty();
// INITFOLLOW(E)
initSets[1].ShouldSetEqual(Grammar.Ts(Sym.PLUS, Sym.RPARAN, Sym.EOF));
// INITFOLLOW(T)
initSets[2].ShouldSetEqual(Grammar.Ts(Sym.ASTERISK));
// INITFOLLOW(F)
initSets[3].ShouldBeEmpty();
var closureSets = DigraphAlgorithm.Traverse(graph, new[]
{
// trick to inspect closure (unions)
new Set <string> {
"S"
},
new Set <string> {
"E"
},
new Set <string> {
"T"
},
new Set <string> {
"F"
}
});
// FOLLOW(S) = INITFOLLOW(S)
closureSets[0].ShouldSetEqual("S");
// FOLLOW(E) = INITFOLLOW(S) ∪ INITFOLLOW(E)
closureSets[1].ShouldSetEqual("S", "E");
// FOLLOW(T) = INITFOLLOW(S) ∪ INITFOLLOW(E) ∪ INITFOLLOW(T) ∪ INITFOLLOW(F)
closureSets[2].ShouldSetEqual("S", "E", "T", "F");
// FOLLOW(F) = INITFOLLOW(S) ∪ INITFOLLOW(E) ∪ INITFOLLOW(T) ∪ INITFOLLOW(F)
closureSets[3].ShouldSetEqual("S", "E", "T", "F");
}
public void GetFirstGraph()
{
var analyzer = Analyzers.CreateErasableSymbolsAnalyzer(Grammar);
var(initSets, graph) = DigraphAlgorithm.GetFirstGraph(Grammar, analyzer);
// INITFIRST(S)
initSets[0].ShouldBeEmpty();
// INITFIRST(E)
initSets[1].ShouldBeEmpty();
// INITFIRST(T)
initSets[2].ShouldBeEmpty();
// INITFIRST(F)
initSets[3].ShouldSetEqual(Grammar.Ts(Sym.LPARAN, Sym.MINUS, Sym.ID));
var closureSets = DigraphAlgorithm.Traverse(graph, new[]
{
// trick to inspect closure (unions)
new Set <string> {
"S"
},
new Set <string> {
"E"
},
new Set <string> {
"T"
},
new Set <string> {
"F"
}
});
// FIRST(S) = INITFIRST(S) ∪ INITFIRST(E) ∪ INITFIRST(T) ∪ INITFIRST(F)
closureSets[0].ShouldSetEqual("S", "E", "T", "F");
// FIRST(E) = INITFIRST(E) ∪ INITFIRST(T) ∪ INITFIRST(F)
closureSets[1].ShouldSetEqual("E", "T", "F");
// FIRST(T) = INITFIRST(T) ∪ INITFIRST(F)
closureSets[2].ShouldSetEqual("T", "F");
// FIRST(F) = INITFIRST(F)
closureSets[3].ShouldSetEqual("F");
}