Re: Control.Monad proposal: Add whenJust

On Sat, May 18, 2013 at 03:08:33PM +0100, Ian Lynagh wrote:

On Wed, May 15, 2013 at 10:40:45PM +0200, Bas van Dijk wrote:

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On 15 May 2013 18:14, Edward Kmett wrote:

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Personally, I'd be all for just moving Foldable (and Traversable) into the Prelude and retiring the monomorphic versions of the functions they supply.

I'd prefer to remove the monomorphic functions, but not to add anything to Prelude.

The issue here is that his would make it very hard to write backward compatible code. We already have seen this by removing Prelude.catch. GHC HQ mitigated this by making a "hidden import" a warning. But if you want -Wall-sane code you still need to always import Control.Exception qualified. Personally I'm strongly against removing the monomorphic versions without providing suitable alternatives. Cheers, Simon