[Haskell-cafe] Why does Haskell have both `Maybe a` and `Either a ()`?

Albert Krewinkel albert+haskell at zeitkraut.de
Fri May 29 14:49:39 UTC 2020

Wiebe-Marten Wijnja writes:

> My question: Is the difference between `Maybe a` and `Either a ()` only
> semantic and are they functionally equivalent,
> or are there differences in functionality as well?

One difference that comes to mind is that there is only one way to write
the failing case for `Maybe a` (namely `Nothing`), but two ways for
`Either a ()`: `Right ()` and `Right ⊥`.

Albert Krewinkel
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