Lazy idempotent monadic actions

[tomjaguarpaw]

For reference, here’s a discussion about a combinator to run an action exactly once (rather than at most once):

What is a good name for `foo kv m = m >>= kv . return`?

Interesting. What sort of kvs are you using this with? I don’t think I’ve come across the need for this pattern. If I was using this I’d probably try to write it as an operator on m actions rather than as a higher order function, for example, as squeezeDry :: Applicative m => m a -> m (m a) squeezeDry = fmap pure Then I’d use it as squeezeDry m >>= kv.