practicalli / practicalli/clojure

Sorting a collection - year and month

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clojure-core
Dominant language
Makefile
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Description

I have the following structure {[2019 10] 21, [2020 9] 17} where format of each item is "[year month] amount". How best to sort this structure such that I have the latest "month" last? Data is sorted first by year and then by month

Data generated by

   (->> data (map #(assoc % :grouping [(:year %) (:month %)]))
        (group-by :grouping)
        (map (fn [[g t]]
               [g (->> t (map :amount) (reduce +))]))
        (into {})))

(group-by (juxt :year :month)) is shorter
e.g. no need for the first map

use (into (sorted-map)) instead of (into {}) to sort by keys

 (->> data 
             (group-by (juxt :year :month)) 
             (map (juxt key #(->> % val (map :amount) (reduce +)))) 
             (into (sorted-map)))
 {[2019 10] 21, [2020 9] 17}

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Research direction

No file, test, or entry point is identified. Review the repository's relevant Clojure learning content for collection-sorting examples and compare it with the year/month grouping example in this issue. Done means the intended ordering guidance is documented in the appropriate location.

Written by the indexing model from the issue text.

Assessment

Tech stack
clojure
Domain
documentation
Issue type
Documentation
Difficulty
2/5
Estimated time
1-3 hours
Activity status
Stale
Clarity
Needs clarification
Newbie friendliness
28/100

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