Proposal: Add readMaybe (and possibly readEither) to Prelude, make Haddocks for read more cautionary

Simon Jakobi simon.jakobi at
Mon Jan 2 15:10:27 UTC 2017

2016-12-30 5:51 GMT+01:00 Edward Kmett <ekmett at>:
> I'm a weak +1 on adding re-export of the existing readMaybe and readEither
> to the Prelude, possibly after a warning period.

What would such a warning period look like? Does it simply mean that
there is an announcement on the Haskell mailing lists "Heads up, we'll
add readMaybe and readEither to the Prelude in base-4.11"?

> They are sufficiently
> obscure names that I'm personally not expecting many name conflicts at all

There are quite a few packages [1] that define their private version
of readMaybe, but I don't think that these should be counted as
arguments _against_ adding the function to Prelude.



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