Re: Text and changing number primops in GHC 9.2
David Feuer <[email protected]>
| Newsgroups | gmane.comp.lang.haskell.libraries |
|---|---|
| Message-ID | <CAMgWh9vTsZ5u05sZcaBOa4KNp8=6pq5kN1VJfR_wA_KrTFLBew@mail.gmail.com> |
I still don't understand why GHC is making this change in such a breaky way without even going through the proposal process. On Wed, Feb 17, 2021, 12:35 PM John Ericson <[email protected]> wrote: > Hi all, > > First, background. I have a PR > https://gitlab.haskell.org/ghc/ghc/-/merge_requests/4492 that is one of > the moving pieces for https://gitlab.haskell.org/ghc/ghc/-/issues/19026, > which is slated for 9.2 according to Ben's email > https://mail.haskell.org/pipermail/ghc-devs/2021-February/019478.html. (I > just added the milestone to the issue to reflect this.) > > Despite this being a breaking change (to unstable interfaces) containers, > bytestring, and binary could all updated in a way that didn't used CPP. > (See the linked PRs in the GHC !4492's description). Text is a different > case, because the unboxed computation there is more pervasive. The current > PR is https://github.com/haskell/text/pull/305, and uses CPP for 9.2. We > have a few different options: > > - Keep as is. There will surely be no perf regressions this way on any > of the supported compilers. This does however mean adding CPP for 9.2 > before the associated GHC change lands in master. I think that's > fine---inevitable even based on the current policy for how GHC submodules > are bumped---but it's given many library maintainers the heebie jeebies. > - Try the same tricks in the other PRs of using hyper-local unboxing > that is easy to unbox away. This will be a bit ugly however than the other > cases, and I am not sure whether it won't be a regression for the oldest > supported GHCs. > - Do the above, but bump the base version to the point where there are > no perf regressions with the oldest supported GHCs (because those compilers > are no longer supported). If we bump the version more aggressively, perhaps > we can get rid of much of the unboxing altogether / otherwise get rid of > the ugliness. > > We'll need to reach some sort of decision here to move forward. > > I'll also add that while Oleg Grenrus has helped merge a preparatory PR, > Oleg expressed a *dis*interest in being de facto text maintainer, so I am > emailing the list in part so this does not fall upon Oleg alone any longer. > > John > _______________________________________________ > Libraries mailing list > [email protected] > http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries > _______________________________________________ Libraries mailing list [email protected] http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries