Thanks for the pointers. I've gotten as far as grouping the keys by the
prefix using `group-by`, and added clunky support for keys that aren't
nested like so:
``` clj
(defn- nested-key [k]
(some-> (re-matches #"^(.*)--(.*)$" (name k))
second
keyword))
(defn nest-relations
"Walks the given hash-map, and moves any keys of the form
<group>--<key> into a nested hash-map."
[m]
(let [grouped (group-by (fn [[k _]] (or (nested-key k) ::top)) m)
top (::top grouped)]
(-> grouped
(dissoc ::top)
(merge top))))
```
I end up with vectors instead of hash-maps, and I'm particularly happy with
the code, but it's getting there.
On Thursday, 16 January 2014 13:58:45 UTC, Jim foo.bar wrote:
>
> You could do something like this:
>
>
> (def v {:a--id 1 :a--name "A" :b--id 2 :b--name "B"})
>
> (group-by #(-> % first str second str keyword) v)
>
> =>{:b [[:b--name "B"] [:b--id 2]], :a [[:a--id 1] [:a--name "A"]]}
>
> (reduce-kv #(assoc % %2 (into {} %3)) {} *1)
>
> => {:a {:a--id 1, :a--name "A"}, :b {:b--name "B", :b--id 2}}
>
> all that's left is the names in the inner map...
>
> HTH,
>
> Jim
>
>
> On 16/01/14 13:46, James Conroy-Finn wrote:
> > Hello all,
> >
> > I've found myself stuck trying to move matching keys in a hash into a
> > nested hash.
> >
> > For example,:
> >
> > {:a--id 1 :a--name "A" :b--id 2 :b--name "B"} ;=> {:a {:id 1 :name
> > "A"} :b {:id 2 :name "B"}}
> >
> > I've tried `clojure.walk`, I've tried building the args to `assoc-in`,
> > and using `apply`. I honestly feel like I'm missing something really
> > obvious, like something with group-by.
> >
> > Any tips would be greatly appreciated. I'll keep hammering away.
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