Coincidentally a related discussion came up on Reddit this morning: https://np.reddit.com/r/haskell/comments/cpdlbr/how_would_i_go_about_printin... On Mon, Aug 12, 2019, at 12:14 PM, Taylor Fausak wrote:
I originally made this suggestion on GitLab, but I was told to make it here instead.
https://gitlab.haskell.org/ghc/ghc/issues/17042
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# Add list singleton function
## Motivation
Sometimes it is convenient to have a function to wrap an element in a list. There are many ways to do this already, but none of them are as clear as a separate monomorphic function.
- `pure`: Polymorphic, works for any `Functor`. - `pure @[]`: Noisy, requires `-XTypeApplications`. - `(: [])`: Subjectively ugly. - `(\x -> [x])`: Syntactically noisy.
This Twitter thread includes some additional commentary: https://twitter.com/taylorfausak/status/1159264862247280640
## Proposal
I would like to add a `singleton` function to `Data.List` that mirrors the `singleton` function for other containers: https://www.stackage.org/lts-14.0/hoogle?q=singleton
``` hs singleton :: a -> [a] singleton x = [x] ```
Other Haskell-like languages include this function:
- PureScript: https://pursuit.purescript.org/packages/purescript-lists/5.4.0/docs/Data.Lis... - Elm: https://package.elm-lang.org/packages/elm/core/latest/List#singleton _______________________________________________ Libraries mailing list Libraries@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries