On Fri, Nov 14, 2008 at 8:17 PM, samppi <[EMAIL PROTECTED]> wrote:
>
> Yeah, I need to be able to do this to easily manage trees of maps. I
> meant, how would you idiomatically implement their algorithms?
>
> Fold isn't build into Clojure, but they should still somehow be
> possible...right?
>
> On Nov 14, 9:12 pm, Michel Salim <[EMAIL PROTECTED]> wrote:
>> On Nov 14, 10:56 pm, samppi <[EMAIL PROTECTED]> wrote:> I'm trying to figure
>> out how to do this:
>>
>> > (flat-map-seq {:a 3, :b 1, :c 2}) ; returns (:a 3 :b 1 :c 2)
>>
>> (defn flat-map-seq [m]
>> (if (empty? m) '()
>> (let [kv (first m)]
>> (lazy-cons (kv 0) (lazy-cons (kv 1) (flat-map-seq (rest m)))))))>
>> ...and vice versa:
>>
>> > (map-from-flat-collection {} [:a 3 :b 1 :c 2]) ; returns {:a 3, :b
>> > 1, :c 2}
>>
>> (defn map-from-flat-collection [c]
>> (if (empty? c) {}
>> (conj (map-from-flat-collection (rrest c)) [(first c) (frest
>> c)])))
>>
>> > Anyone have any idiomatic ideas?
>>
>> Well, not sure how idiomatic this is; apart from conj, this is how
>> you'd do it in Lisp/Scheme. I'd use fold to do the first function if
>> it's built into Clojure.
>>
>> Regards,
>>
>> --
>> Michel
> >
>
(apply assoc {} [:a 1 :b 2 :c 3])
-> {:c 3, :b 2, :a 1}
--
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