Clojure Assoc-in, Part 2

In a previous post, Clojure Assoc-in, I discussed adding items to a Clojure nested map. I came up with an alternative solution.

Let’s define the original map (again):

(def movie {:movie {:info {:name "Little Trouble in Big Manhattan"
                           :year "2020"
                           :format "BR-1000"}}})
=> #'ns-movies-db/movie

To recap, we want to add the following to the above map, under the :info key:

{:actor "JeSuis VonBraun"
 :language "French"}

Here’s the previous solution:

(assoc-in (assoc-in movie [:movie :info :actor] "JeSuis VonBraun")
          [:movie :info :language] "French")
=>{:movie {:info {:name "Little Trouble in Big Manhattan",
                  :year "2020",
                  :format "BR-1000",
                  :actor "JeSuis VonBraun",
                  :language "French"}}}

And now, the updated one (drumroll please!):

(-> (assoc-in movie [:movie :info :actor] "JeSuis VonBraun")
    (assoc-in [:movie :info :language] "French"))
=>
{:movie {:info {:name "Little Trouble in Big Manhattan",
                :year "2020",
                :format "BR-1000",
                :actor "JeSuis VonBraun",
                :language "French"}}}

Ok, I know, not terribly exciting, but it’s a little easier to understand (at least for me). And yes, we are using a thread-first macro like we discussed in a previous post on threading macros.

In Closing…

I am still not happy with this solution, and I’m sure there is still a more elegant way to solve this one. Stay tuned!