/// <summary>
/// Merge two nodes. Both of them become equiualent.
///
/// In complex situation, 'secondary' node becomes reference to 'main' node, if it is possible
/// </summary>
public static void MergeInplace(TicNode main, TicNode secondary)
{
if (main == secondary)
{
return;
}
if (main.State is StateRefTo)
{
var nonreferenceMain = main.GetNonReference();
var nonreferenceSecondary = secondary.GetNonReference();
MergeInplace(nonreferenceMain, nonreferenceSecondary);
return;
}
if (secondary.GetNonReference() == main)
{
return;
}
var res = GetMergedStateOrNull(main.State, secondary.State);
if (res == null)
{
throw TicErrors.CannotMerge(main, secondary);
}
main.State = res;
if (res is ITypeState t && t.IsSolved)
{
secondary.State = res;
return;
}
main.AddAncestors(secondary.Ancestors.Where(a => a != main));
secondary.ClearAncestors();
secondary.State = new StateRefTo(main);
}
public static void BecomeReferenceFor(this TicNode referencedNode, TicNode original)
{
referencedNode = referencedNode.GetNonReference();
original = original.GetNonReference();
if (referencedNode.Type == TicNodeType.SyntaxNode)
{
MergeInplace(original, referencedNode);
}
else
{
MergeInplace(referencedNode, original);
}
}
public static bool Destruction(TicNode descendantNode, TicNode ancestorNode)
{
var nonRefAncestor = ancestorNode.GetNonReference();
var nonRefDescendant = descendantNode.GetNonReference();
if (nonRefDescendant == nonRefAncestor)
{
return(true);
}
return(nonRefAncestor.State.ApplyDescendant(
DestructionFunctions.Singletone,
nonRefAncestor,
nonRefDescendant));
}