Sorry, I got the semantics of the grouping-fn wrong. My code assumes that the
key is always first in the elements and my grouping is more like a merging-fn.
> On Aug 14, 2016, at 2:53 PM, miner <stevemi...@gmail.com> wrote:
>
> If your data elements are essentially map-entries (key-value pairs), I'd use
> reduce. Maybe something like this would work for you...
>
> (defn mapping-group-by [grouping-fn mapping-fn coll]
> (reduce (fn [res [k v]] (update res k grouping-fn (mapping-fn v)))
> {}
> coll))
>
> (def foos [[:a "foo"] [:b "bar"] [:a "baz"]])
>
> (mapping-group-by conj clojure.string/upper-case foos)
> ;;=> {:a ("BAZ" "FOO"), :b ("BAR")}
>
> If you need vector values, you can wrap `conj` with `fnil` to get a vector.
>
> (mapping-group-by (fnil conj []) clojure.string/upper-case foos)
> ;;=> {:a ["FOO" "BAZ"] :b ["BAR"]}
>
>
> --
> 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
> <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
> <mailto:clojure+unsubscr...@googlegroups.com>.
> For more options, visit https://groups.google.com/d/optout
> <https://groups.google.com/d/optout>.
--
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/d/optout.
