2 ms·

I'm not sure I follow, sorry. The line says that we also pledge to produce a Semiring from this Foldable structure. Given it's a length function it's about as g

I'm not sure I follow, sorry. The line says that we also pledge to produce a Semiring from this Foldable structure. Given it's a length function it's about as general a specification I think you can give it without becoming something completely different.

mcguire 9y ago
To the first question, a Semiring has two operations, + and × conventionally (along with ...). That seems to be more than length needs. A Monoid is just an operation and its identity, which should be exactly what you need for length. For the second question, traditional (+,×,...) is a Semiring for integers; so is (&,|,...) (bitwise boolean operations). How can you define both Semiring implementations without getting them confused? There is another reply to my comment that I haven't digested yet. Maybe it answers the second.
- mcguire 9y ago
  "A Monoid is just an operation and its identity, which should be exactly what you need for length." And I'm wrong about that. You need a zero and a one, right. What would that structure be?