Re: Newcomer looking for help with changes to kind system

Hi Ben, Thanks for the reply

Incidentally, the collapse of LiftedRep and UnliftedRep will happen in GHC 9.2 (turning into `BoxedRep :: Levity -> RuntimeRep`).

Yes I believe this change was accidentally merged a few months ago then reverted? I will keep that in mind.

Can you provide a program that your patch rejects, as well as the full error that is produced?

My error is in stage 1 in the building of the ghc-bignum library. I have attached the full error as well as the patch itself. Thanks, Shant On Mon, Apr 5, 2021 at 7:41 PM Ben Gamari wrote:

Shant Hairapetian writes:

...

Hello,

I’m a master’s student working on implementing the changes outlined in “Kinds are Calling Conventions“ ( https://www.microsoft.com/en-us/research/uploads/prod/2020/03/kacc.pdf). I have been working directly with Paul Downen but have hit some roadblocks.

To sum up the changes to the kind system, I am attempting to modify the “TYPE” type constructor to accept, rather than just a RuntimeRep, a record type (called RuntimeInfo) comprised of a RuntimeRep and a CallingConv (calling convention). The calling convention has an “Eval” constructor which accepts a levity (effectively moving the levity information from the representation to the calling convention. LiftedRep and UnliftedRep would also be collapsed into a single PtrRep constructor) and a “Call” constructor (denoting the arity of primitive, extensional functions, see: Making a Faster Curry with Extensional Types < https://www.microsoft.com/en-us/research/uploads/prod/2019/07/arity-haskell-... ) which accepts a list of RuntimeRep’s. I have created and wired-in the new RuntimeInfo and CallingConv types in GHC.Builtin.Types, as well as the corresponding primitive types in GHC.Builtin.Types.Prim and have modified the “TYPE” constructor to accept a RuntimeInfo rather than a RuntimeRep.

Hi Shant,

It would be helpful to have a bit more information on the nature of your failure. Can you provide a program that your patch rejects, as well as the full error that is produced?

Incidentally, the collapse of LiftedRep and UnliftedRep will happen in GHC 9.2 (turning into `BoxedRep :: Levity -> RuntimeRep`).

Cheers,

- Ben

-- Shant Hairapetian