RE: The size of things

Yes, I see. Would it be possible to have a standard strict list, i.e. something equivalent of

data SList a = SNil | SCons !a SList

(which could be a member of the same class as the normal lists, and have the usual functions (length, ++, isPrefixOf...) overloaded)?

Yes, it would be possible, but we can't do it without making sweeping changes to standard libraries and deviating from Haskell 98 quite a bit. It's something to bear in mind should the topic of Haskell 2 come up, though. Cheers, Simon