// Fill FIRST set for the chain of tokens.
// Returns true if anything was added, false otherwise.
private bool InternalAddFirsts(IEnumerable <int> chain, MutableIntSet result)
{
bool changed = false;
bool nullable = true;
foreach (int item in chain)
{
bool itemNullable = false;
foreach (var f in firsts[item].ToArray())
{
if (f == PredefinedTokens.Epsilon)
{
itemNullable = true; // current part is nullable
continue;
}
if (!result.Contains(f))
{
result.Add(f);
changed = true;
}
}
if (!itemNullable)
{
nullable = false;
break;
}
}
if (nullable && !result.Contains(PredefinedTokens.Epsilon))
{
result.Add(PredefinedTokens.Epsilon);
changed = true;
}
return(changed);
}
public void set_has_correct_content_after_adding_value(IntSet set, int value)
{
MutableIntSet editedSet = set.EditCopy();
Assert.AreEqual(set.Contains(value), editedSet.Contains(value));
editedSet.Add(value);
Assert.IsTrue(editedSet.Contains(value));
Assert.IsTrue(editedSet.Contains(value));
Assert.IsTrue(set.Union(IntSet.Of(value)).SetEquals(editedSet));
IntSet result = editedSet.CompleteAndDestroy();
Assert.IsTrue(result.Contains(value));
Assert.IsTrue(set.IsSubsetOf(result));
Assert.IsTrue(set.Union(IntSet.Of(value)).SetEquals(result));
}