[Haskell-cafe] MonadFail with type parameter for error message
Daneel Yaitskov
dyaitskov at gmail.com
Tue Nov 30 19:16:14 UTC 2021
Dear Cafe,
MonadFail.fail takes String.
I wasn't able to find MonadFail for custom error type.
Is there any proposals to base?
Let's say Data.Text, which gains popularity with OverloadedStrings
extensions.
class MonadFail m where
fail :: String -> m a
Why not ?
class MonadFail m where
fail :: (forall s. IsString s => s) -> m a
class MonadFailWith m s where
fail :: s -> m a
--
Best regards,
Daniil Iaitskov
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