/// <summary>
/// Negates an expression.
/// If possible, replaces the operator of exp if exp is a negatable OperatorExpression,
/// else return a new OperatorExpression of type Not that wraps exp.
/// </summary>
public static VisitedExpression Negate(VisitedExpression exp, bool useNewPrecedences)
{
OperatorExpression expOp = exp as OperatorExpression;
if (expOp != null)
{
Operator op = expOp.op;
Operator newOp = null;
if (Operator.NegateDict.TryGetValue(op, out newOp))
{
expOp.op = newOp;
return(expOp);
}
if (expOp.op == Operator.Not)
{
return(expOp.right);
}
}
return(OperatorExpression.Build(Operator.Not, useNewPrecedences, exp));
}
internal void And(VisitedExpression andAlso)
{
// useNewPrecedence doesn't matter here since there was no change with the AND operator
_where = OperatorExpression.Build(Operator.And, true, _where, andAlso);
}
internal void And(VisitedExpression andAlso)
{
_where = OperatorExpression.Build(Operator.And, _where, andAlso);
}