Currently with-meta doesn't work for varargs fns (which works in Clojure):
(apply (with-meta #(-> %&) {}) 0 1 2 (range 30))
Given JS is so flexible I'd propose the following implementation of meta fn:
`
(defn meta-fn
[f m]
(let [new-f (goog/bind f #js{})]
(goog/mixin new-f f)
(specify! new-f IMeta (-meta [_] m))
new-f))
`
The goog/bind creates a copy, and the goog/mixin is just for performance reasons (copy any IFn protocol or applyTo).
Benefits:
- Slightly faster
- Much simpler and smaller code (the 20 arities of MetaFn are emitted 3 times (.call, .apply, prototype.IFn)
- Works with varargs.
