public override void Visit(NegationNode node)
{
if (node.Target is TermNode)
{
writer.Write("~");
}
else
{
writer.WriteLine(node.OpCode);
}
}
protected override IAstTreeNode Xform(NegationNode node)
{
if (node.Target is AndNode || node.Target is OrNode)
{
var equiv = node.Target is AndNode ? (IAstTreeNode)new OrNode() : (IAstTreeNode)new AndNode();
node.Target.Children.ForEach(child => equiv.Children.Add(!(ExpressionNode)child));
return equiv;
}
if (node.Target is NegationNode)
{
var equiv = ((NegationNode)node.Target).Target.Clone();
return (IAstTreeNode)equiv;
}
return null;
}
public virtual void Visit(NegationNode node){}
protected virtual IAstTreeNode Xform(NegationNode node) { return null; }
public sealed override void Visit(NegationNode node) { VisitAndXform(node, Xform(node)); }