PrecedenceNode createPrecedenceNode(TTokenType type)
{
var pn = new PrecedenceNode(type);
precedenceNodes.Add(type, pn);
return(pn);
}
public bool IsChild(PrecedenceNode pn)
{
foreach (PrecedenceNode child in Children)
{
if (child == pn || child.IsChild(pn))
{
return(true);
}
}
return(false);
}
public bool IsParent(PrecedenceNode pn)
{
foreach (PrecedenceNode parent in Parents)
{
if (parent == pn || parent.IsParent(pn))
{
return(true);
}
}
return(false);
}
public void AddPrecedenceRule(TTokenType firstType, TTokenType secondType)
{
var first = precedenceNodes.ContainsKey(firstType) ? precedenceNodes[firstType] : null;
var second = precedenceNodes.ContainsKey(secondType) ? precedenceNodes[secondType] : null;
if (first == null || second == null)
{
first = first ?? createPrecedenceNode(firstType);
second = second ?? createPrecedenceNode(secondType);
}
else
{
if (first.IsParent(second))
{
throw new Exception("Conflicting precedence rule detected");
}
if (first.IsChild(second))
{
return;
}
}
PrecedenceNode.Connect(first, second);
}
public bool IsParentOrChild(PrecedenceNode pn)
{
return(IsParent(pn) || IsChild(pn));
}
public static void Connect(PrecedenceNode parent, PrecedenceNode child)
{
parent.Children.Add(child);
child.Parents.Add(parent);
}
