Morning

So glad to be actually able to greet you in the morning now. It's good to be back.

Morning!

Oh, the perils of multi-arity fns.

You call the fn with the wrong arity, and clj-kondo is not there to help you, because it’s nothing it can do.

you probably mean varargs

clj-kondo can see multi-arity errors

Ah, but no, and I’m not blaming clj-kondo here, only myself:

(defn foo
  ([one] ...)
  ([one two] ...))

ah yes, but with the transducer stuff clj-kondo does actually help in some cases :) e.g. (first (map inc)) gives a warning

wrt to mult-arity fns - the usual answer is passing a map - the map can be spec'ed and / or checked with :pre ... still can FU though :man-shrugging::skin-tone-3:

One thing I haven't pondered much is that we tend to not recommend fns which change their return type depending on the params. But all the transducer fns in core do exactly that.

Yeah, unfortunately.

Perhaps the thinking was that you could easily migrate from thread last to comp.