This Christmas, I want to gift you something practical. Something useful. None of that artsy nonsense from last year.

I recommend enjoying the implementation with a glass of your favourite spirit.

Merry Christmas!

#f

Have you ever wanted to nest #() anonymous functions in Clojure?

With #f, you can!

(require 'hash-f)
(map #f(map #f(* $1 2) $1) [[1 2] [3 4]])
  ==> ((2 4) (6 8))

You can even refer to arguments of enclosing #f functions!

(-> {:pages [{:page 1} {:page 2} {:page 3}]}
    (update :pages #f(mapv #f(update $1 :page #f(str $1 "/" (count $$$1)))
                           $1)))
  ==> {:pages [{:page "1/3"} {:page "2/3"} {:page "3/3"}]}

Just add #f to your deps.edn!

{:deps
 {io.github.opqdonut/hash-f {:git/sha "<commit hash here>"}}}