Planning for the 7.12 release

[Elliot Cameron]

I can't seem to find the exact trac ticket, but the ability to swap out "Integer" implementations at link time would be a huge relief on Windows, which suffers from various problems with dynamic linking. I believe it was originally slated for 7.12. Can someone find it? Here's what I did find: https://ghc.haskell.org/trac/ghc/wiki/ReplacingGMPNotes

A related discussion: https://github.com/commercialhaskell/stack/issues/399

As it stands, we've been trying hard to find good ways to provide custom GHC variants more easily to end users.

________________________________________
From: ghc-devs <ghc-devs-bounces at haskell.org> on behalf of Ben Gamari <ben at well-typed.com>
Sent: Thursday, August 27, 2015 11:38 AM
To: GHC developers
Subject: Planning for the 7.12 release

Hello everyone!

With the 7.10.1 release nearly six months behind us and 7.10.2 out of the
way, now is a good time to begin looking forward to 7.12. In keeping
with the typical release pace, we are aiming to have a release
candidate ready in mid-December 2015 and a final release in January
2016.

The items that that we currently believe have a good chance of making it
in to 7.12 are listed on the release status page [1], which I've
summarized below (in no particular order),


    * Support for implicit parameters providing callstacks and source
      locations

    * Support for wildcards in data and type family instances

    * A new, type-indexed type representation, data TTypeRep (a :: k).

    * Introduction of visible type application

    * Support for reasoning about kind equalities

    * Support for Injective Type Families

    * Support for the Strict language extension

    * Support for Overloaded Record Fields, allowing multiple uses of
      the same field name and a form of type-directed name resolution.

    * A huge improvement to pattern matching (including much better
      coverage of GADTs)

    * Backpack is chugging along; we have a new user-facing syntax which
      allows multiple modules to be defined a single file, and are
      hoping to release at least the ability to publish multiple "units"
      in a single Cabal file.

    * Support for Applicative Do, allowing GHC to desugar do-notation to
      Applicative where possible.

    * Improved DWARF based debugging support including backtraces from
      Haskell code

    * An Improved LLVM Backend that ships with every major Tier 1 platform.


These items are a bit less certain but may make it in if the authors
push forward quickly enough,


    * Support for Type Signature Sections, allowing you to write (:: ty)
      as a shorthand for (\x -> x :: ty).

    * A (possible) overhaul of GHC's build system to use Shake instead
      of Make.

    * A DEPRECATED pragma for exports


Is your pet project missing from this list? If you have a patch that you
believe is on-track to make it in for 7.12, please let us know.

Moreover, if you have an issue that you urgently need fixed in 7.12,
please express you interest on the appropriate ticket. User feedback
helps us immensely in figuring out how to best place our priorities.

Cheers,

- Ben


[1] https://ghc.haskell.org/trac/ghc/wiki/Status/GHC-7.12.1