[I'm spamming libraries@haskell.org too, in case anyone interested in generics is not on generics@haskell.org.]
Given the low number of responders on generics@, it may well be easier to continue on libraries@, cc-ing anyone on generics@ who isn't on libraries@.
As you know, Claus has offered a somewhat-detailed proposal for changes to the SYB library (below). But I don't think that we have an active maintainer for any of the generic-programming libraries (esp SYB) apart from Uniplate. Then there's the related question of what generic-programming technology to promote for clients of the GHC API.
Thanks for raising this, Simon. I've actually been holding an email summarizing several issues (not just performance of default traversal schemes) that I'd like to see adressed in Syb (holding because the Syb authors were/are away, and because my performance improvement experiments are currently stuck on a GHC optimization issue). I'll send that email separately now.
The obvious candidates are Claus himself, or Alexey Rodriguez, or Thomas Schilling; but perhaps there are others too? Maybe no one has stepped forward because you all think that I'm on the job! But I'm not... I'm busy with GHC itself, and would love a maintainer for SYB and associated gubbins. I fear that otherwise we may lose the benefits of Claus's homework.
I'm quite willing to continue pursueing the issues I've raised until I can make concrete suggestions for improving Syb, including summing up the code changes I've been adding to my various messages (certainly there should be patches to accompany proposal tickets in the library process, and I should collect all the strands of text into a single document). I have been waiting for the original Syb authors to return from their well-earned summer camps, but there should probably be a Wiki page somewhere specifically for discussing Syb-related issues and solutions (meanwhile, I've started collecting links/info related to GHC Api type traversals here, including the main Syb issues: http://hackage.haskell.org/trac/ghc/wiki/GhcApiAstTraversals , please feel free to copy stuff from there to a Syb-specific page). But I wouldn't want to take on ownership of Syb at this point, for two reasons, both motivational: (a) it helps to have someone else to "blame" when the consequences of gfoldl's type once again hurt my brain;-), (b) it is really frustrating to get so little interest in these issues, well, we haven't even managed to start a proper discussion on any of the lists I've tried, and as long as there is a Syb owner other than myself, at least I won't be talking entirely to myself!-) Claus