public SetDomain <T> Join(SetDomain <T> that, bool widening, out bool weaker)
{
if (this.set == that.set)
{
weaker = false;
return(this);
}
if (IsBottom)
{
weaker = !that.IsBottom;
return(that);
}
if (that.IsBottom || IsTop)
{
weaker = false;
return(this);
}
if (that.IsTop)
{
weaker = !IsTop;
return(that);
}
IImmutableSet <T> join = this.set.Intersect(that.set);
weaker = join.Count < this.set.Count;
return(new SetDomain <T> (join));
}
public SetDomain <T> Join(SetDomain <T> that)
{
SetDomain <T> result;
if (this.TryTrivialJoin(that, out result))
{
return(result);
}
return(new SetDomain <T> (set.Intersect(that.set)));
}
public SetDomain <T> Meet(SetDomain <T> that)
{
SetDomain <T> result;
if (this.TryTrivialMeet(that, out result))
{
return(result);
}
return(new SetDomain <T> (set.Union(that.set)));
}
public bool LessEqual(SetDomain <T> that)
{
if (IsBottom)
{
return(true);
}
if (that.IsBottom)
{
return(false);
}
return(that.set.IsContainedIn(this.set));
}
public SetDomain <T> Meet(SetDomain <T> that)
{
if (this.set == that.set || IsBottom || that.IsTop)
{
return(this);
}
if (that.IsBottom || IsTop)
{
return(that);
}
return(new SetDomain <T> (this.set.Union(that.set)));
}
public SetDomain <T> Widen(SetDomain <T> that)
{
//no widening - finite lattice
return(Join(that));
}