Re: MonadFail instance for Either

What about?: instance Read e => MonadFail (Either e) where fail = Left . read 2018년 10월 25일 (목) 오후 12:42, David Feuer 님이 작성:

FWIW, I think I'm weakly opposed. Either is Haskell 98. MonadFail is solidly "standards-track" material, to the extent that designation is meaningful at the moment. IsString ... isn't. On Wed, Oct 24, 2018 at 10:44 PM Daniel Bergey wrote:

...

Is there still consensus in favor of adding this instance?

instance IsString str => MonadFail (Either str) where fail = Left . fromString

In 2016 there was some discussion, and my reading is that there was

consensus in favor at the time:

...

Trac: https://ghc.haskell.org/trac/ghc/ticket/12160 libaries mailing list: https://mail.haskell.org/pipermail/libraries/2016-August/027248.html

Does anyone know of a later decision not to add it, or was it simply no one's top priority?

What is the next step to move this proposal forward? Is more discussion in order? Should I just submit a patch?

Thanks, bergey _______________________________________________ Libraries mailing list Libraries@haskell.org http://mail.haskell.org/cgi-bin/mailman/listinfo/libraries

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