Felipe Lessa wrote:
<$$> will be as concise and useful as <$>, maybe even more, because `flip fmap` isn't valid.
2) Simmetry, as the ticket says.
If we want to keep the analogies complete then we'll need to add ($$)=flip($) as well. As a prefix function it has a perspicuous type (type raising (Smullyan's thrush), aka CPS translation) and I've used it in a number of projects because of that. All the same, I would not consider it worthwhile to add to any library (excepting one which contains Data.Smullyan :) And it only opens the way for defining (!$$), and then why not add (), (),... Every combinator has its place, but often that place is in a local module so that users/maintainers can easily figure out what your line noise means. -- Live well, ~wren