A monad is a monoid in the category of endofunctors, what’s the problem?

Re:A monad is a monoid in the category of endofunctors, what... by platz on Sunday February 10, 2019 @11:03AM (#19128291)

Basically what's going on:

with monoids, you can combine things, and then monads result from choosing a clever combining operation in a certain contexts

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Re:A monad is a monoid in the category of endofunctors, what... by krapp on Sunday February 10, 2019 @11:14AM (#19128344)

That makes them sound like union types to me, but I'm guessing they're not like union types, otherwise that's what they would be called.

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Re:A monad is a monoid in the category of endofunctors, what... by mlevental on Sunday February 10, 2019 @11:22AM (#19128379)

Union/sum types don't combine things though? you can only have ever one variant at a time. it's a misnomer. monads and monoids combine things in the sense of joining them. e.g. lists are a monoid because you can concatenate (they're also a monad for the same reason).

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