Define currencies in terms of union type

[3noch]

Since you already have Alpha, you could write a single function (maybe fromAlpha) which defines all currencies as a case over all Alphas. Then currencies becomes fromAlpha <$> [minBound..maxBound] and each currency function is either unnecessary or trivial (e.g. usd = fromAlpha USD).

[KtorZ]

This. I like.

Thanks for the suggestion. I wanted to rework a bit the implementation anyway (noticed that compilation & runtime can be rather slow because of the default Read instance, writing it "by hand" speeds up things a lot. It seems that GHC doesn't like much big ADTs like this).

[KtorZ]

Closed with eca59c3 👍

[3noch]

Cool!