Same story, no libraries using this.

Looks good.

Curious: is this the way the nesting comes out of a nested backticked operator (infixr, I think)?

No, a 'foo' c 'foo' d will come out infixl 9, I think.

That might be a reason for making these left-associative. Actually, I originally wanted to make both nested tuples and nested eithers left-associative, because then you get the most useful definitions for Functor, et al. e.g. Tuple4 a b c d operates on d naturally, because by associativity it's Tuple (((Tuple a) b) c) d.

I asked around and discovered that right-associative was the most common way to define these, but still don't have a good reason for it. I'd be happy to change both nested modules to left-associative, if you think that's a good change.

I think those are both good reasons to prefer left associative, if infix operators do in fact give things that way round.

OK, will amend this one and submit another one to change associativity.

Amended & ready to merge, PR coming up for tuples.

👍 Thanks!