Great stuff! I love the format of iterating on implementations and criticisms.

Clojure also has de-nesting shortcuts via -> and related macros, but while the first argument to nest is the outermost expression, the first argument to -> and similar is the innermost expression. This makes it convenient for expressing function composition. However, it seems backward to use it for binding. These two expressions are equivalent:

(let [x 1 y 2]
   (when (even? y)
      x))

(->> x
     (when (even? y))
     (let [x 1 y 2]))

Which reminds me of Haskell’s where.

Similarly, the author illustrates the utility of nest with binding forms, but using it for function composition may feel backwards. If I understand nest correctly, then these should be equivalent:

(reduce + (filter odd? (map inc [1 2 3 4])))

(nest (reduce +)
      (filter odd?)
      (map inc)
      [1 2 3 4])

But, this outermost-first order is the usual order of function composition in math, Haskell, and others.

It’s interesting that you can express either binding or composition in either order.

PS: nest is implemented in a library for Clojure as <<-