[calibraxis]

Oddly enough I never used this, but maybe named fns might help? (http://clojure.org/special_forms#Special%20Forms--%28fn%20na...)

    (fn my-name []
      (throw (Exception. "boom")))

(Sorry, I don't know Clojure internals well enough to have great answers to your explicit questions.)

[Edited: thanks to jerf for pointing out the inconsistency in a term I used.]

[jerf]

Named... anonymous... functions? Wuzzah fuzzah?

[weavejester]

They allow you to use recursion without the need for a Y-combinator.

[awj]

Yeah, that's a terminology issue. They mean lexically scoped named functions. Versus the default in Clojure of global or namespace scope.

[larholm]

Just like in Javascript.

[emidln]

Named anonymous functions are there to allow you to call the function recursively while inside it.

i.e.

    (= ((fn factorial [x] 
          (if (<= x 1) 
              1 
              (* x (factorial (dec x))))) 5)
     120)

Note, this isn't run under TCO (see loop/recur).

[ufo]

Also, in your example, the recursive call is not in tail position. You would first need to rewrite it to use an acumulator parameter.