Clojurians Log v2

Thanks for the help everyone!

Hey everyone, if I wish to have the value of a nested key within the map replaced, and return the entire map with the updated nested value, what are the best relevant core functions? (map #(replace old-taxonomy->new (get-in % [:attributes :hobbies])) (slurp-blob)) The above returns a list of the replaced value instead of an entire map. Can't seem to figure out how I can retain the original map structure

Try update-in and assoc-in

update-in looks promising, thanks @kslvsunil! How do I pass in the current iteration's collection to replace ? (update-in (slurp-blob) [:attrs :hobbies] (replace old-taxonomy->new <coll>))

Mind sharing how the value of :hobbies looks like and how you want it transformed?

It looks like {:hobbies ["Cycling", "Swimming"]} old-taxonomy->new is a map which looks like {"Cycling" "Cycle" "Swimming" "Swim"}

I essentially want the end result to look like

{:attrs {:id "1234" :hobbies ["Cycle" "Swim"]}}

(map (fn [m]
        (update-in m [:attributes :hobbies] #(replace old-taxonomy->new %)))
      (slurp-blob))

Learnt how to use update-in and a new way of defining anonymous functions. Thanks @kslvsunil!

Hey, is it possible to model a spec "type" which shape depends on another spec? For example, to model an entity like this

(s/def ::entity
  (s/keys
   :req
   [::number-a
    ::number-b-always-greater-than-number-a]))

I have a vector with a bunch of maps [{:s "aa"} {:s "bb"}] how do I get {:s "bb"}? I can do (first (filter #(=(:s %) "bb") [{:s "aa"} {:s "bb"}])) . In javascript I would use Array.find but in clojure I can not find function like that. It could also be that I'm thinking in a not clojure way about this problem.

you could do (some #(when (= (:s %) "bb") %) l)

Also a beginner. I would model it with s/and in ::entity with an inlined spec that checks for this dependency. Why? because the dependency only makes sense in the context of ::entity .

do you want to know if a map is part of the vector? or is it something more like a look up by id?

I think your`(first (filter...` approach is a good one. It can also be written without the anonymous function and less nesting as: (->> [{:s "aa"} {:s "bb"}] (filter (comp #{"bb"} :s)) first)

@osman.cea Its more like an fine element by id kind of the. In this specific case I have a vector of maps with one of the maps not having the keyword :price I need to get the value that is in :asset

[{:asset "BTC", :free 0.01371726}
                   {:asset "BAT", :free 2.73 :price 0.002222}
                   {:asset "BNB", :free 1.48792745 :price 0.003333}]

@archibald.pontier_clo I played around with some but it did not give me what I wanted I think, I got the transformed value.

Hey, this is a good Idea. Thank you.

note that the when form returns % (the unchanged input), but it really is no different than filter + first I think (because of lazyness)

That's a good suggestion @rupert also a nice trick with comp

using first on filter is an idiomatic way of doing this. The expectation of using Array.prototype.find is that it would terminate at the first truthy value and return the respective element. In Clojure using first on filter does essentially the same thing, because filter returns a lazy sequence. You are just looking at the first filtered element.

@archibald.pontier_clo sorry for that you code did work. Thanks

Thanks for the clarification @denis.baudinot

When I get an error (as opposed to a failure) in my tests, I get an “uncaught error not in assertion”. Is there anyway to get the (testing... context reported when this happens

oh wait, I see the context has been highlighted in emacs

that’s nice

@rickheere Taking a step back, when such a situation arises, it’s good to evaluate whether there’s a better data structure that is more appropriate for the problem at hand; for example, Clojure supports map keys which can be any data structure themselves:

(let [m {{:s "aa"} {:x 42}
         {:s "bb"} {:y 43}}]
 (get m {:s "aa"}))
;=> {:x 42}