protected internal override Expression VisitOperatorNot(OperatorNot node)
{
if (node.Operand is Predicate)
{
return(node);
}
else if (node.Operand is OperatorNot)
{
// Cancel double negation
return(((OperatorNot)node.Operand).Operand);
}
else if (node.Operand is OperatorAnd)
{
// Apply de Morgan's law
var op = node.Operand as OperatorAnd;
return(Visit(new OperatorOr(new OperatorNot(op.Left), new OperatorNot(op.Right))));
}
else if (node.Operand is OperatorOr)
{
// Apply de Morgan's law
var op = node.Operand as OperatorOr;
return(Visit(new OperatorAnd(new OperatorNot(op.Left), new OperatorNot(op.Right))));
}
else
{
throw new NotImplementedException();
}
}
protected internal override Expression VisitOperatorNot(OperatorNot node)
{
if (node.Operand is Predicate)
{
return node;
}
else if (node.Operand is OperatorNot)
{
// Cancel double negation
return ((OperatorNot)node.Operand).Operand;
}
else if (node.Operand is OperatorAnd)
{
// Apply de Morgan's law
var op = node.Operand as OperatorAnd;
return Visit(new OperatorOr(new OperatorNot(op.Left), new OperatorNot(op.Right)));
}
else if (node.Operand is OperatorOr)
{
// Apply de Morgan's law
var op = node.Operand as OperatorOr;
return Visit(new OperatorAnd(new OperatorNot(op.Left), new OperatorNot(op.Right)));
}
else
{
throw new NotImplementedException();
}
}
protected internal virtual Expression VisitOperatorNot(OperatorNot node)
{
var op = Visit(node.Operand);
if (op == node.Operand)
{
return node;
}
else
{
return new OperatorNot(op);
}
}
protected internal virtual Expression VisitOperatorNot(OperatorNot node)
{
var op = Visit(node.Operand);
if (op == node.Operand)
{
return(node);
}
else
{
return(new OperatorNot(op));
}
}