I don’t know, but my instinct is to stick to the monomorphic version for now, it that’s all you need.

 

Simon

 

From: ghc-devs [mailto:ghc-devs-bounces@haskell.org] On Behalf Of Alan & Kim Zimmerman
Sent: 20 October 2017 18:33
To: ghc-devs@haskell.org
Subject: haddock specializeInstHead

 

I am working the next stage of Trees that Grow into GHC [1], and need to update Haddock.

The `Specialize` module[2] exports a single function, `specializeInstHead` which is called once, specialised to `GhcRn`.

So all it needs to be for haddock use is

specializeInstHead :: InstHead GhcRn -> InstHead GhcRn

But the entire module is polymorphic in the AST parameter, so it has the following instead

 

specializeInstHead :: (Ord (IdP name), DataId name, SetName (IdP name),

                                NamedThing (IdP name))

                       => InstHead name -> InstHead name

 

Question: does it need to be so polymorphic?

 

I am hitting issues getting the type parameter change worked through, and it seems a bit pointless to slog on with it if it is unnecessary.

 

Alan

 

[1] https://github.com/ghc/ghc/tree/wip/ttg-2017-10-13

[2] https://github.com/haskell/haddock/blob/a5bdb46185b7c0b3fced9a7fac9a62883d9d57b7/haddock-api/src/Haddock/Interface/Specialize.hs#L87