Runtime representation of (# a #)

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TheMatten

2020-06-10 13:05:03

What's the runtime representation of 'TupleRep '[ 'LiftedRep] (that is, (# a #) type)?

Sandy Maguire

2020-06-10 17:30:26

i'm having a hard time parsing this

TheMatten

2020-06-10 20:27:11

Basically, "how's (# a #) represented at runtime" :sweat_smile:
chessai pointed me to this comment: https://github.com/mckeankylej/unpacked-maybe/issues/3#issuecomment-567167058

design discussion · Issue #3 · mckeankylej/unpacked-maybe

we could use a type family to make sure users can't nest Maybe's, but then we can't write a functor instance or we could do the following, using unboxed sums: data Maybe a = Maybe (# (#...

TheMatten

2020-06-10 20:56:47

Here're official docs linked by Joe Kachmar: https://gitlab.haskell.org/ghc/ghc/-/blob/master/compiler/GHC/Stg/Unarise.hs

compiler/GHC/Stg/Unarise.hs · master · Glasgow Haskell Compiler / GHC

The Glorious Glasgow Haskell Compiler.

Runtime representation of (# a #) - Haskell