public void TestComplementarySetUnionWith()
{
var cset = new ComplementarySet<string>(new string[] { Value0, Value1 });
Assert.False(cset.Contains(Value0), "set doesn't contain Value0");
Assert.False(cset.Contains(Value1), "set doesn't contain Value1");
var set = new HashSet<string>(new string[] { Value1, Value2 });
cset.UnionWith(set);
Assert.False(cset.Contains(Value0), "union still doesn't contain Value0");
Assert.True(cset.Contains(Value1), "union contains Value1");
Assert.True(cset.Contains(Value2), "union contains Value2");
}
internal override ISet<char?> ComputeFirst(ISet<Parser> seen)
{
if (seen.Contains(this))
{
return null;
}
else
{
var newSeen = new HashSet<Parser>(seen);
newSeen.Add(this);
var setLeft = Left.ComputeFirst(newSeen);
if (setLeft != null)
{
if (setLeft.Count == 0 || setLeft.Contains(null))
{
var setRight = Right.ComputeFirst(newSeen);
if (setRight != null)
{
if (setLeft.IsComplement())
{
var newSet = new ComplementarySet<char?>(setLeft as ComplementarySet<char?>);
newSet.Remove(null);
newSet.UnionWith(setRight);
return newSet;
}
else
{
var newSetLeft = new HashSet<char?>(setLeft);
newSetLeft.Remove(null);
var newSetRight = new HashSet<char?>(setRight);
newSetRight.UnionWith(newSetLeft);
return newSetRight;
}
}
}
}
return setLeft;
}
}
