a reliable way of dropping levity args?

[Richard Eisenberg]

On Jan 28, 2016, at 5:48 PM, Ömer Sinan Ağacan <omeragacan at gmail.com> wrote:
> 
>    | Just (tc, args) <- splitTyConApp_maybe ty
>    , isUnboxedTupleTyCon tc
>    = pprTrace "elimUbxSumRepTypes"
>        (text "orig args:" <+> ppr args $$
>         text "dropWhile isLevityTy args = " <+> ppr (dropWhile
> isLevityTy args)) $
>      concatMap go (drop (length args `div` 2) args)

You want (dropWhile (isLevityTy . typeKind) args). isLevityTy simply checks if its argument is exactly `Levity`.

Does that work?

Richard