[Haskell-cafe] Re: Maybe to Either -- is there a better way?

[Ertugrul Soeylemez]

Tom Davies <tgdavies at gmail.com> wrote:

> I find it convenient sometimes to convert a Maybe value to an Either
> thus (excuse the syntax, it's CAL, not Haskell):
>
> maybeToEither :: a -> Maybe b -> Either a b;
> maybeToEither errorValue = maybe (Left errorValue) (\x -> Right x);

As a side note, this is perfectly valid Haskell code, even though it's
quite verbose.  The equivalent:

  maybeToEither :: a -> Maybe b -> Either a b
  maybeToEither leftValue = maybe (Left leftValue) Right

Honestly I find this better than the completely points-free variants
posted in the other subthread.  They demonstrate overusing points-free
style.


Greets,
Ertugrul


-- 
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