// Ritorna una relazione contenente coppie (xi, yi) tali per cui in solution.assignments
// esiste una variabile il cui valore assegnato è xi
private Relation FulfilledRelation(Solution solution, Relation rel)
{
Relation fulRel = new Relation();
foreach (KeyValuePair <string, string> assignment in solution.assignments)
{
foreach (Tuple <string, string> pair in rel.relation)
{
if (assignment.Value == pair.Item1)
{
fulRel.AddPair(pair.Item1, pair.Item2);
}
}
}
return(fulRel);
}
// Pair ::= "(" val "," val ")"
void Pair(Relation r)
{
if (ts.Current.kind != Kind.LEFT_PARENT)
{
return;
}
Expect(Kind.LEFT_PARENT);
string x = ts.Current.value;
Expect(Kind.VALUE);
Expect(Kind.COMMA);
string y = ts.Current.value;
Expect(Kind.VALUE);
Expect(Kind.RIGHT_PARENT);
r.AddPair(x, y);
}
// Pair ::= "(" val "," val ")"
void Pair(Relation r)
{
if (ts.Current.kind != Kind.LEFT_PARENT) return;
Expect(Kind.LEFT_PARENT);
string x = ts.Current.value;
Expect(Kind.VALUE);
Expect(Kind.COMMA);
string y = ts.Current.value;
Expect(Kind.VALUE);
Expect(Kind.RIGHT_PARENT);
r.AddPair(x, y);
}