GHC API: getting the unfolding of a "strange" Id

Christiaan Baaij christiaan.baaij at gmail.com
Fri Mar 28 09:57:29 UTC 2014


> I don't really get why this GHC.TypeLits constraint is a bottom dictionary...
> Is it because all Coercions/Constraints are bottom?
> Is there perhaps a set of flags I can use so that I can see the Core term corresponding to CLaSH.Sized.Fixed.$fNumFixed2 during compilation?


I guess I straight away answer my own question, sorry for the noise:

CLaSH.Sized.Fixed.$fNumFixed2
  :: forall (n_a5SH :: GHC.TypeLits.Nat). 1 GHC.TypeLits.<= n_a5SH
[GblId, Str=DmdType b]
CLaSH.Sized.Fixed.$fNumFixed2 =
  \ (@ (n_a5SH :: GHC.TypeLits.Nat)) ->
    Control.Exception.Base.absentError
      @ (1 GHC.TypeLits.<= n_a5SH)
      "ww_s9JT{v} [lid] 1 base:GHC.TypeLits.<={tc r1W} n{tv a5SH} [tv]"#

I must say... I have never seen, in any of my programs, the error that Control.Exception.Base.absentError is supposed to give:
absentError s = error ("Oops!  Entered absent arg " ++ unpackCStringUtf8# s)

-- Christiaan


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