Proposal to deprecate and then drop fromJust

Erik de Castro Lopo mle+hs at
Tue Feb 24 05:42:22 UTC 2015

Hi all,

We currently have in the Data.Maybe module from base:

     fromJust :: Maybe a -> a

which newbies often find using hoogle or other search tools and is
a huge trap. *Every* usage of the above can be replaced by using

      fromMaybe :: a -> Maybe a -> a

which forces the user to provide a default value for the case where
the Maybe a is a Nothing.

The idea would be to deprecate fromMaybe for 7.12 and remove it
completely later.


Erik de Castro Lopo

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