Is it OK to have a namespace name which exists at two points in the tree?

Question

Is this OK:

namespace Simple.OData
{
    // Common OData functionality
}

namespace Simple.Data.OData
{
    // The Simple.Data adapter for OData
}

It feels like it might be wrong, but I'm not sure.

Answer 1

It's certainly valid - consider System.Xml.Linq and System.Linq. I can't immediately foresee any problems... but that's not to say it's necessarily a good idea.

Personally I prefer Simple.Data.OData over Simple.OData.Data, as I suspect this is primarily aimed at people who are using Simple.Data, but happen to be using OData - not people who are focused on OData. Again, this is like LINQ: System.Xml.Linq is an XML API which plays will with LINQ; it's not a LINQ "provider" as such.

Basically it's the same sort of problem as "I have a converter to convert from type A to type B; do I put it near type A or type B?" - but with namespaces. My experience is that usually more head-scratching goes into thinking of the best thing to do than the problems that would be caused by taking either approach...

Answer 2

More correct would be, namespace Simple.OData.Data.

This is because the Data namespace should be grouped with the other classes relating to OData.

If you're thinking along with lines of System.Data, System.Data.SqlClient then it's pretty much because they are a part of the System.Data.dll assembly, and are an integrated part of it. My own implementation of the IDbCommand etc classes live in MyNamespace.SubNamespace.AdoWrapper namespace, if that gives you some context.

In your case, Simple.Data presumably doesn't exist or have much in it, unlike System.Data ..