[Haskell-cafe] GHC plugin: custom wired-in package, module, and type class

[Amos Robinson]

Hi,
We tried to do something similar a few years ago and couldn't get a nice
solution for this.
We ended up just requiring the user code to define a binding with a
hard-coded name as a struct containing everything. I got the impression
that the plugin ran too late in the pipeline to load new modules, so we
couldn't add an import for the module we wanted.

https://github.com/DDCSF/repa/blob/master/icebox/abandoned/repa-plugin/Data/Array/Repa/Plugin/Primitives.hs#L142
https://github.com/DDCSF/repa/blob/master/icebox/abandoned/repa-plugin/test/01-Simple/Main.hs#L11

On Fri, 18 Nov 2016 at 19:36 J. Stutterheim <j.stutterheim at me.com> wrote:

> Hi all,
>
> I'm looking for a way to add my own wired-in package/module/type class for
> use in a core-to-core plugin.
>
> My first challenge is to identify the type class that I want to find. I
> have the following code:
>
>         myPkgUnitId :: UnitId
>         myPkgUnitId = fsToUnitId (fsLit "mypackage")
>
>         mkMyModule :: FastString -> Module
>         mkMyModule m = mkModule myPkgUnitId (mkModuleNameFS m)
>
>         myModule :: Module
>         myModule = mkMyModule (fsLit "My.Module")
>
>         myClassName :: Name
>         myClassName = clsQual myModule (fsLit "MyClass") myClassKey
>
>         myClassKey  :: Unique -- How do I get this?
>
> Here the missing piece is the myClassKey. Looking at how this is done for,
> e.g., the Monad class:
>
>         monadClassKey  :: Unique
>         monadClassKey = mkPreludeClassUnique 8
>
> we see that it has a hard-coded unique identifier. Is there a way to do
> the same for my own type class? Or to somehow find the Unique key
> dynamically?
>
> The second challenge is more or less the same in that I want to identify a
> member of MyClass:
>
>         myFunMName :: Name
>         myFunMName = varQual myModule (fsLit "myFun") myFunMClassOpKey
>
>         myFunMClassOpKey :: Unique -- How do I get this?
>
> Again, the identifier is hard-coded for, e.g., ">>=".
>
> Any insights will be much appreciated.
>
> Best regards,
>
> Jurriën_______________________________________________
> Haskell-Cafe mailing list
> To (un)subscribe, modify options or view archives go to:
> http://mail.haskell.org/cgi-bin/mailman/listinfo/haskell-cafe
> Only members subscribed via the mailman list are allowed to post.
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://mail.haskell.org/pipermail/haskell-cafe/attachments/20161118/02b48833/attachment.html>