[Haskell-cafe] Commutative monads vs Applicative functors
Ronald Guida
oddron at gmail.com
Wed May 14 14:06:13 EDT 2008
David Menendez wrote:
> To summarize: some applicative functors are commutative, some
> applicative functors are monads, and the ones that are both are
> commutative monads.
OK, so commutativity is orthogonal to "idiom vs monad". Commutativity
depends on whether or not the order of side effects is important.
Being a monad or just an idiom depends on whether or not "join" is
supported. Examples can be constructed for all 4 possibilities of
{idiom, monad} (x) {non-commutative, commutative}.
Thank you all for clearing this up for me.
More information about the Haskell-Cafe
mailing list