17 Sep
2020
17 Sep
'20
5:13 p.m.
On Thu, Sep 17, 2020 at 5:59 PM Jon Purdy
{ fromMaybe, fromLeft, fromRight, fromEither, fromThese, fromDynamic, … } extracts “the” value out of a { Maybe, These, Dynamic, … } with a suitable default if “it” isn’t present.
Hm. A weird thing about fromEither compared to (I think) all the rest of these, is that the type of the Either isn't fully general. That is, fromLeft and fromRight take an `Either a b`; fromThese takes a `These a b`. But the proposed `fromEither` takes an `Either a a`. This maybe isn't a big deal. Just seemed worth noting.