public EnvironmentDomain <Key, Val> Remove(Key key)
{
if (map == null)
{
throw new InvalidOperationException();
}
return(new EnvironmentDomain <Key, Val>(map.Remove(key)));
}
public EnvironmentDomain <Key, Val> Join(EnvironmentDomain <Key, Val> newState, out bool weaker, bool widen)
{
if (map == newState.map)
{
weaker = false; return(this);
}
bool resultWeaker = false;
if (this.IsTop)
{
weaker = false; return(this);
}
if (newState.IsTop)
{
weaker = !this.IsTop; return(newState);
}
if (this.IsBottom)
{
weaker = !newState.IsBottom; return(newState);
}
if (newState.IsBottom)
{
weaker = false; return(this);
}
// compare pointwise
IFunctionalMap <Key, Val> smaller;
IFunctionalMap <Key, Val> larger;
if (map.Count < newState.map.Count)
{
smaller = map;
larger = newState.map;
}
else
{
smaller = newState.map;
larger = map;
}
IFunctionalMap <Key, Val> result = smaller;
foreach (Key k in smaller.Keys)
{
if (!larger.Contains(k))
{
result = result.Remove(k);
}
else
{
bool joinWeaker;
Val join = smaller[k].Join(larger[k], out joinWeaker, widen);
if (joinWeaker)
{
resultWeaker = true;
if (join.IsTop)
{
result = result.Remove(k);
}
else
{
result = result.Add(k, join);
}
}
}
}
weaker = resultWeaker || (result.Count < map.Count);
return(new EnvironmentDomain <Key, Val>(result));
}