public override object VisitUnaryOperatorExpression(UnaryOperatorExpression unary, object data)
{
// lifted operators can't be transformed
if (unary.Annotation <LiftedOperator>() != null || unary.Expression.Annotation <LiftedOperator>() != null)
{
return(base.VisitUnaryOperatorExpression(unary, data));
}
// Remove double negation
// !!a
if (unary.Operator == UnaryOperatorType.Not &&
unary.Expression is UnaryOperatorExpression &&
(unary.Expression as UnaryOperatorExpression).Operator == UnaryOperatorType.Not)
{
AstNode newNode = (unary.Expression as UnaryOperatorExpression).Expression;
unary.ReplaceWith(newNode.WithAnnotation(unary.GetAllILRanges()));
return(newNode.AcceptVisitor(this, data));
}
// Push through binary operation
// !((a) op (b))
BinaryOperatorExpression binaryOp = unary.Expression as BinaryOperatorExpression;
if (unary.Operator == UnaryOperatorType.Not && binaryOp != null)
{
bool successful = true;
switch (binaryOp.Operator)
{
case BinaryOperatorType.Equality:
binaryOp.Operator = BinaryOperatorType.InEquality;
break;
case BinaryOperatorType.InEquality:
binaryOp.Operator = BinaryOperatorType.Equality;
break;
case BinaryOperatorType.GreaterThan: // TODO: these are invalid for floats (stupid NaN)
binaryOp.Operator = BinaryOperatorType.LessThanOrEqual;
break;
case BinaryOperatorType.GreaterThanOrEqual:
binaryOp.Operator = BinaryOperatorType.LessThan;
break;
case BinaryOperatorType.LessThanOrEqual:
binaryOp.Operator = BinaryOperatorType.GreaterThan;
break;
case BinaryOperatorType.LessThan:
binaryOp.Operator = BinaryOperatorType.GreaterThanOrEqual;
break;
default:
successful = false;
break;
}
if (successful)
{
unary.ReplaceWith(binaryOp.WithAnnotation(unary.GetAllILRanges()));
return(binaryOp.AcceptVisitor(this, data));
}
successful = true;
switch (binaryOp.Operator)
{
case BinaryOperatorType.ConditionalAnd:
binaryOp.Operator = BinaryOperatorType.ConditionalOr;
break;
case BinaryOperatorType.ConditionalOr:
binaryOp.Operator = BinaryOperatorType.ConditionalAnd;
break;
default:
successful = false;
break;
}
if (successful)
{
binaryOp.Left.ReplaceWith(e => new UnaryOperatorExpression(UnaryOperatorType.Not, e));
binaryOp.Right.ReplaceWith(e => new UnaryOperatorExpression(UnaryOperatorType.Not, e));
unary.ReplaceWith(binaryOp.WithAnnotation(unary.GetAllILRanges()));
return(binaryOp.AcceptVisitor(this, data));
}
}
return(base.VisitUnaryOperatorExpression(unary, data));
}
