Ah, I misunderstood your requirements, but I'm glad it led you in the
right direction!
On Fri, Aug 16, 2013 at 10:40 PM, David Chelimsky <dchelim...@gmail.com> wrote:
> Thanks for the suggestions Sean and Ben. I learned new functions from both
> of you!
>
> Sean, your suggestion yields the following:
>
> (to-consolidated-map [[:a 1] [:b 2] [:a 3]])
> ; {:a (1 3) :b (2)}
>
> So it still needs to reduce the vals using +. That led me to this:
>
> (defn to-consolidated-map [parts]
> (apply merge-with + (map (fn [[k v]] {k v}) parts)))
>
> Which led me to this:
>
> (defn to-consolidated-map [parts]
> (apply merge-with + (map (partial apply hash-map) parts)))
>
> I like this one because it describes the solution the way I thought about it
> - I just didn't know about merge-with. It also has the benefit of using core
> fns rather than anonymous fns. WDYT?
>
> On Sat, Aug 17, 2013 at 7:23 AM, Sean Corfield <seancorfi...@gmail.com>
> wrote:
>>
>> How about this:
>>
>> (defn to-consolidated-map [parts]
>> (apply merge-with concat
>> (map (fn [[k v]] {k (list v)}) parts)))
>>
>> On Fri, Aug 16, 2013 at 9:57 PM, David Chelimsky <dchelim...@gmail.com>
>> wrote:
>> > I've got a vector of 2-element vectors e.g. [[:a 1] [:b 2]] where the
>> > first
>> > val of any vec might appear in another vec e.g. [[:a 1] [:b 2] [:a 3]].
>> > I
>> > need a fn that will consolidate this into a hash-map with the vals
>> > consolidated e.g.
>> >
>> > (to-consolidated-map [[:a 1] [:b 2] [:a 3]])
>> > ; {:a 4 :b 2}
>> >
>> > I've got two candidate implementations and I'm curious which you like
>> > better
>> > and why, or if I'm missing a better way:
>> >
>> > (defn to-consolidated-map [parts]
>> > (reduce (fn [h [k v]]
>> > (if (contains? h k)
>> > (assoc h k (+ (k h) v))
>> > (assoc h k v)))
>> > {} parts))
>> >
>> > (defn to-consolidated-map [parts]
>> > (->> parts
>> > (group-by first)
>> > (map (fn [[k v]] [k (->> v (map last) (reduce +))]))))
>> >
>> > TIA,
>> > David
>> >
>> > --
>> > --
>> > You received this message because you are subscribed to the Google
>> > Groups "Clojure" group.
>> > To post to this group, send email to clojure@googlegroups.com
>> > Note that posts from new members are moderated - please be patient with
>> > your
>> > first post.
>> > To unsubscribe from this group, send email to
>> > clojure+unsubscr...@googlegroups.com
>> > For more options, visit this group at
>> > http://groups.google.com/group/clojure?hl=en
>> > ---
>> > You received this message because you are subscribed to the Google
>> > Groups
>> > "Clojure" group.
>> > To unsubscribe from this group and stop receiving emails from it, send
>> > an
>> > email to clojure+unsubscr...@googlegroups.com.
>> > For more options, visit https://groups.google.com/groups/opt_out.
>>
>>
>>
>> --
>> Sean A Corfield -- (904) 302-SEAN
>> An Architect's View -- http://corfield.org/
>> World Singles, LLC. -- http://worldsingles.com/
>>
>> "Perfection is the enemy of the good."
>> -- Gustave Flaubert, French realist novelist (1821-1880)
>>
>> --
>> --
>> You received this message because you are subscribed to the Google
>> Groups "Clojure" group.
>> To post to this group, send email to clojure@googlegroups.com
>> Note that posts from new members are moderated - please be patient with
>> your first post.
>> To unsubscribe from this group, send email to
>> clojure+unsubscr...@googlegroups.com
>> For more options, visit this group at
>> http://groups.google.com/group/clojure?hl=en
>> ---
>> You received this message because you are subscribed to the Google Groups
>> "Clojure" group.
>> To unsubscribe from this group and stop receiving emails from it, send an
>> email to clojure+unsubscr...@googlegroups.com.
>> For more options, visit https://groups.google.com/groups/opt_out.
>
>
> --
> --
> You received this message because you are subscribed to the Google
> Groups "Clojure" group.
> To post to this group, send email to clojure@googlegroups.com
> Note that posts from new members are moderated - please be patient with your
> first post.
> To unsubscribe from this group, send email to
> clojure+unsubscr...@googlegroups.com
> For more options, visit this group at
> http://groups.google.com/group/clojure?hl=en
> ---
> You received this message because you are subscribed to the Google Groups
> "Clojure" group.
> To unsubscribe from this group and stop receiving emails from it, send an
> email to clojure+unsubscr...@googlegroups.com.
> For more options, visit https://groups.google.com/groups/opt_out.
--
Sean A Corfield -- (904) 302-SEAN
An Architect's View -- http://corfield.org/
World Singles, LLC. -- http://worldsingles.com/
"Perfection is the enemy of the good."
-- Gustave Flaubert, French realist novelist (1821-1880)
--
--
You received this message because you are subscribed to the Google
Groups "Clojure" group.
To post to this group, send email to clojure@googlegroups.com
Note that posts from new members are moderated - please be patient with your
first post.
To unsubscribe from this group, send email to
clojure+unsubscr...@googlegroups.com
For more options, visit this group at
http://groups.google.com/group/clojure?hl=en
---
You received this message because you are subscribed to the Google Groups
"Clojure" group.
To unsubscribe from this group and stop receiving emails from it, send an email
to clojure+unsubscr...@googlegroups.com.
For more options, visit https://groups.google.com/groups/opt_out.
