Re: [Haskell-cafe] Downsides to disabling unticked-promoted-constructor warning?

I've created a ticket to request disabling this warning by default: https://gitlab.haskell.org/ghc/ghc/-/issues/20531 I'm not sure if this needs a full ghc-proposal. Cheers, Adam On 18/10/2021 03:19, Richard Eisenberg wrote:

As its author, I think -Wunticked-promoted-constructors is a misfeature. It was motivated by the fact that writing [True] when you mean '[True] produces a cascade of obscure kind errors, and so I thought it was good to encourage people to always write the ticks. But the feature does not achieve its goal: because errors squelch warnings, we do not see the warnings if there are any errors. Furthermore, I agree with Adam's post that I've come to prefer a style where we leave off the ticks (where possible).

Bottom line: feel free to turn this warning off.

Richard

...

On Oct 16, 2021, at 5:55 AM, Markus Läll wrote:

Hi!

Is there any consensus on unticked promoted constructors -- are they generally safe to use?

Currently the warning is part of -Wall, but having promoted constructors unticked is just aesthetically nicer.

Thanks,

-- Markus Läll

-- Adam Gundry, Haskell Consultant Well-Typed LLP, https://www.well-typed.com/ Registered in England & Wales, OC335890 118 Wymering Mansions, Wymering Road, London W9 2NF, England