public override TResult Accept <TResult>(IParseTreeVisitor <TResult> visitor)
{
IExprVisitor <TResult> typedVisitor = visitor as IExprVisitor <TResult>;
if (typedVisitor != null)
{
return(typedVisitor.VisitAddSub(this));
}
else
{
return(visitor.VisitChildren(this));
}
}