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Ah ok that makes sense, and if you choose to use `Sum Int` you'd be technically implementing the Monoid abstraction for that type. In practice because the `Int`

Ah ok that makes sense, and if you choose to use `Sum Int` you'd be technically implementing the Monoid abstraction for that type. In practice because the `Int` type is a signed, fixed-size integer it would break the laws for all integers. In that case it would still be a useful abstraction but you would have to be aware that your `Int` will wrap around for large values which kind of makes `Int` a poor choice. `Integer` would be better but is still somewhat finite because computers.

a1369209993 4y ago
> In practice because the `Int` type is a signed, fixed-size integer it would break the laws for all integers. No. `Sum Int` (unlike, pedantically, `Sum Integer` or `[a]`) is a valid (non-leaky-abstraction) monoid. It adds `Int`s, which is a monoidal operation that satisfies `(a<>b)<>c==a<>(b<>c)` for all (2^(3*MACHINE_BIT_WIDTH) distinct triplets (a,b,c) of) Ints, due to 2s-complement truncation on overflow. > your `Int` will wrap around for large values Yes, that's what `Int` means. > `Integer` will fail to terminate when adding sufficiently large values (in theory with a out of memory error, although in practice operations just get slower and slower until you abort them with ^C or a timeout), a property not shared by addition of `Int`.