On 13/02/13 07:06, wren ng thornton wrote:
On 2/12/13 3:37 AM, Simon Marlow wrote:
One reason for the major version bumps is that base is a big conglomeration of modules, ranging from those that hardly ever change (Prelude) to those that change frequently (GHC.*). For example, the new IO manager that is about to get merged in will force a major bump of base, because it changes GHC.Event. The unicode support in the IO library was similar: although it only added to the external APIs that most people use, it also changed stuff inside GHC.* that we expose for a few clients.
The solution to this would be to split up base further, but of course doing that is itself a major upheaval. However, having done that, it might be more feasible to have non-API-breaking releases.
While it will lead to much wailing and gnashing of teeth in the short term, if it's feasible to break GHC.* off into its own package, then I think we should. The vast majority of base seems quite stable or else is rolling along at a reasonable pace. And yet, every time a new GHC comes out, there's a new wave of fiddling the knobs on cabal files because nothing really changed. On the other hand, GHC.* moves rather quickly. Nevertheless, GHC.* is nice to have around, so we don't want to just hide that churning. The impedance mismatch here suggests that they really should be separate packages. I wonder whether GHC.* should be moved in with ghc-prim, or whether they should remain separate...
But again, this depends on how feasible it would be to actually split the packages apart. Is it feasible?
So I think we'd need to add another package, call it ghc-base perhaps. The reason is that ghc-prim sits below the integer package (integer-simple or integer-gmp). It's feasible to split base, but to a first approximation what you end up with is base renamed to ghc-base, and then the new base contains just stub modules that re-export stuff from ghc-base. In fact, maybe you want to do it exactly like this for simplicity - all the code goes in ghc-base. There would be some impact on compilation time, as we'd have twice as many interfaces to read. I believe Ian has done some experiments with splitting base further, so he might have more to add here. Cheers, Simon