The main example for recur on the special forms page (http://
clojure.org/special_forms#Special%20Forms--(recur%20exprs*)) is:
(def factorial
(fn [n]
(loop [cnt n acc 1]
(if (zero? cnt)
acc
(recur (dec cnt) (* acc cnt))))))
I may not be be clojure jedi, but I've been learning the language for
a while. I've never come across the notion that this is a code
smell. I thought that the loop recur form was perfectly orthodox.
Also, the fact that the form above doesn't compile in the equal branch
does make me a little uneasy.
Rob
On Jun 19, 5:13 pm, David Nolen <dnolen.li...@gmail.com> wrote:
> On Sat, Jun 19, 2010 at 4:10 PM, Michał Marczyk
>
> <michal.marc...@gmail.com> wrote:
> > (defn fact [n]
> > (loop [n n r 1]
> > (if (zero? n)
> > r
> > (recur (dec n) (* r n)))))
>
> Huh? That doesn't look like it's going to work at all.
>
> 1) 1 is primitive, we know that, accept it
> 2) we don't know the type of n, what will (* r n) be?
> 3) BOOM!
>
> My suggestion is to stop it with the contrived examples. Start showing some
> real code, real problems in your real programs. Using loop/recur is already
> the beginning of code smell for anything that is not performance sensitive.
>
> (defn fact
> ([n] (fact n 1))
> ([n r] (if (zero? n)
> r
> (recur (dec n) (* r n)))))
>
> Sleep soundly.
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