private Graph MergeBind(Bind rightBind, BindState rightState)
{
//HORRORS BELOW
var x = this;
var leftBinds = rightState.Nodes
.Select(n => x.NodeBinds.TryGetValue(n, out var found) ? found : null)
.Where(n => n != null)
.ToArray();
var leftStates = leftBinds
.SelectMany(b => x.BindStates.TryGetValue(b, out var found) ? new[] { found } : new BindState[0])
.ToArray();
var allStates = leftStates.Concat(new[] { rightState });
var allNodes = allStates.SelectMany(s => s.Nodes);
var bind = leftBinds.Concat(new[] { rightBind }).First();
var state = allStates.Aggregate(BindState.Empty, (ac, s) => ac.MergeWith(s));
return(new Graph(
allNodes
.Aggregate(NodeBinds, (ac, n) => ac.SetItem(n, bind)),
BindStates
.SetItem(bind, state)
)
.Propagate(bind, state));
}
private Graph Propagate(Bind b, BindState s, Node n0 = null)
{
if (s.Nodes.IsEmpty)
{
return(this);
}
else
{
var g = this;
var v0 = s.Val;
_depth++;
Log.WriteLine($"{Prefix}PROP {s}");
_depth++;
Log.Write($"{Prefix}{v0}");
var nodes = s.Nodes.ToArray();
int i = 0, j = 0;
var v = v0;
while (true)
{
var n = nodes[i];
if (n != n0 || !v.Equals(v0))
{
Log.WriteLine($" -> {n}");
var(g2, v2) = n.Impel(g, v);
var v3 = Val.Combine(v, v2);
Log.Write($"{Prefix}{v3}");
if (!v3.Equals(v))
{
j = i;
}
g = g2;
v = v3;
}
i = (i + 1) % nodes.Length;
if (i == j)
{
break;
}
}
Log.WriteLine();
_depth -= 2;
return(new Graph(
g.NodeBinds,
g.BindStates.SetItem(b, s.WithVal(v))
));
}
}
public BindState MergeWith(BindState other)
=> new BindState(
Nodes.Union(other.Nodes),
Val.Combine(Val, other.Val));