Having made over-use of Wouter's expression idioms, I decided to hack it into extensible records. It's not documented, it's probably got holes in its usability, but I thought I'd post it so people can play with it (and give suggestions before I rewrite my code to use it!). I know there are other extensible record systems, but I wondered how this stacks up. Notably, it looks like in HList the records are only extensible in one direction (tacking fields onto the end), although they have a much more developed syntax (if you're into that sort of thing). Current problems: * Defining a new field is rather bulky - currently it takes lines. Definitions are bulky in Wouter's extensible expressions, too, but I could probably shorten the get/set convenience functions to something more readable. * Construction of new records is only convenient by using the defaulting system. Maybe that makes sense, maybe it doesn't. A side benefit: Record access functions are reusable between record types (as long as they have the same type). Anyway, thanks again, Wouter! -Ron