Re: [Haskell-cafe] ghc should be able to deduce correct use of partial functions and not give a warning in such cases

21 Apr 2024

      On Sun, Apr 21, 2024 at 01:17:26PM +1200, Richard O'Keefe wrote:
...
The clearest way that I know to write that code fragment is
  case break (== ch) str of
    (_,[]) -> []
    (xs,(_:ys)) -> [(xs,ys)]
I'd also consider changing the return type from `[([a], [a])]` to
`Maybe ([a], [a])`, as in:

    maybeSplit :: Eq a => a -> [a] -> Maybe ([a], [a])
    maybeSplit sep xs = case break (== sep) xs of
        (ys, (_:zs)) -> Just (ys, zs)
        _            -> Nothing

A list of at most one element begs to be a `Maybe` instead.

-- 
    Viktor.

Re: [Haskell-cafe] ghc should be able to deduce correct use of partial functions and not give a warning in such cases

Viktor Dukhovni