On Sep 7, 9:00 am, Thomas wrote:
> I've also been using my own version of a map-to-values function
> extensively and it would be really nice to have something like that,
> either in contrib or in core. It comes in handy surprisingly often.
+1
I find myself writing functions like map-values and f
I've also been using my own version of a map-to-values function
extensively and it would be really nice to have something like that,
either in contrib or in core. It comes in handy surprisingly often.
Best,
Thomas
On Sep 6, 5:40 pm, Nicolas Oury wrote:
> Dear all,
>
> is there a function to map
Different reactions:
1. The reduce solution is O(n .log n) + time of mapping elements, as
inserting in a map is O(log n). A tree with n leafs and arity at least
binary is of size at most 2n. So a map on a map could be done
in O(n) + time of mapping elements, but it would need a bit of
support fro
On Mon, Sep 6, 2010 at 10:47 AM, Robert McIntyre wrote:
> Why is it that clojure maps aren't lazy though?
> Wouldn't that be just as useful an abstraction as lazy sequences?
> Aren't map really just lists of pairs in the end anyway?
>
how can laziness benefit map usage pattern ? efficient search r
Why is it that clojure maps aren't lazy though?
Wouldn't that be just as useful an abstraction as lazy sequences?
Aren't map really just lists of pairs in the end anyway?
--Robert McIntyre
On Mon, Sep 6, 2010 at 1:19 PM, Michał Marczyk wrote:
> On 6 September 2010 18:49, Robert McIntyre wrote:
On Sep 6, 11:40 am, Nicolas Oury wrote:
> is there a function to map a function to all values in a map, keeping
> the same keys?
I like "reduce" because you can modify both the key and the value, and
even choose to omit or add certain keys:
(reduce (fn [[k v] m] (assoc m k (...do stuff with
On 6 September 2010 18:49, Robert McIntyre wrote:
> I thought that since into uses reduce, it would be lazy, but I was wrong.
> reduce just plows through everything with a non-lazy recursion.
Well, there's another reason in that the concept of a lazy map is
problematic. In Clojure, at any rate, e
On Mon, Sep 6, 2010 at 10:09 AM, Justin Kramer wrote:
> reduce returns a single value; there's no collection to make lazy.
> There is reductions, which returns the intermediate results of reduce
> as a lazy sequence.
>
if f = cons in 'reduce f a seq', there is a collection. Though in this
case, on
reduce returns a single value; there's no collection to make lazy.
There is reductions, which returns the intermediate results of reduce
as a lazy sequence.
Justin
On Sep 6, 12:49 pm, Robert McIntyre wrote:
> I thought that since into uses reduce, it would be lazy, but I was wrong.
> reduce just
On Mon, Sep 6, 2010 at 9:49 AM, Robert McIntyre wrote:
> I thought that since into uses reduce, it would be lazy, but I was wrong.
> reduce just plows through everything with a non-lazy recursion.
>
> Why is reduce not lazy?
>
reduce in clojure == foldl in Haskell
and as far as I know, there are
I thought that since into uses reduce, it would be lazy, but I was wrong.
reduce just plows through everything with a non-lazy recursion.
Why is reduce not lazy?
--Robert McIntyre
On Mon, Sep 6, 2010 at 12:37 PM, Michał Marczyk
wrote:
> On 6 September 2010 18:29, Robert McIntyre wrote:
>> walk
On 6 September 2010 18:29, Robert McIntyre wrote:
> walk is good but it's not lazy. If you want to preserve laziness you can do:
This won't be lazy, because (into {} ...) is a strict operation.
I'd suggest something like
(defn mmap [f m]
(zipmap (keys m) (map f (vals m
f is expected to c
walk is good but it's not lazy. If you want to preserve laziness you can do:
(defn map-vals
"transform a map by mapping it's keys to different values."
[f m]
(into {} (map (fn [[key val]] [key (f val)]) m)))
This is also nice because you can then write functions whose arguments
are [val] in
(clojure.walk/walk (fn [[key val]] [key (* 2 val)]) identity {:a 1 :b 2})
On Mon, Sep 6, 2010 at 9:26 PM, Sunil S Nandihalli <
sunil.nandiha...@gmail.com> wrote:
> Nicolas
> I am not sure of the performance characteristics.. but you may want to look
> at
>
> *(clojure.walk/walk #(do (println "in
Nicolas
I am not sure of the performance characteristics.. but you may want to look
at
*(clojure.walk/walk #(do (println "inner : " %) %) #(do (println "outer : "
%) %) {:a 1 :b 2})
*
Best regards,
Sunil.
On Mon, Sep 6, 2010 at 9:10 PM, Nicolas Oury wrote:
> Dear all,
>
> is there a function to
Dear all,
is there a function to map a function to all values in a map, keeping
the same keys?
Reducing from the seqed map seems a bit slower that what could be done
directly...
Best,
Nicolas.
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