Container Prefixes
I realised that I've spent quite a bit of time working on the difference code, and I've been getting frustrated. The problem has not been writing my code, but rather the need to read and learn other people's code in the joining framework. My recent round of debugging was a good example: the Difference class appears to work correctly, but the sorting code does not want to recognise it. This means I have to learn the sorting code more carefully.

One of the problems of working on my own is that there is rarely anything to encourage me to poke my head up and look at the world around me. So I thought a little break might be good for my perspective, and I might improve my productivity while I was at it.

Consequently, today I've spent the day working on a new resolver for finding all collection predicates. These are the URIs which follow the pattern: rdf:_*.

The code to do this is easy and a lot of it is relatively boilerplate, so it hasn't been hard to do. It is very like the "Node Type" resolver, only it needs to find sections in the string pool using different mechanisms. NodeTypeResolver was easier as it could perform selections using type comparators which were already available in the string pool, but it should not be too difficult to write the new one that can select by prefix instead. However, it does make it more complex. I hope to finish it in the next few days, and then I can go back to debugging the sort.