This does not necessarily mean it must be strictly H'98 compliant, but that would be a good approximation of the common language. What is that "good approximation"?
Haskell'98 + HierarchicalModules + FFI + CPP + ExistentialTypes is pretty well supported across all implementations as far as I know.
These are the options:
I forgot, time already requires CPP... 1. time to require Haskell 98 + FFI + CPP + Rank2Types, include Data instances
Rank-2 is not yet universal.
2. time to require Haskell 98 + FFI + CPP, content depends on compiler 3. time to require Haskell 98 + FFI + CPP, a time-extras package with orphan Data instances
Of these two options, I don't mind, but many people express an anti- preference for orphan instances. Regards, Malcolm