Hi all, I'm constructing a vector using a map like so

(mapv #(let [ {:keys [a b c]} %]
          [b c "foo" a]
          ) data)

[
  [1 b c "foo" a]
  [2 b c "foo" a]
  [3 b c "foo" a]
  ...
]

yes, something like mapv your-fn data (range)

now your-fn gets two arguments, the map and the index

user=> (mapv (fn [m i] [(:a m) (inc i)]) [{:a "a"} {:a "b"}] (range))
[["a" 1] ["b" 2]]

woah, yeah! prefect! thank you!

My imperative brain started thinking about maintaining a counter variable...

but you stopped yourself before it was too late! 😄

The struggle is real 😄

@rakhim you can also use map-indexed too (map-indexed (fn [i m] [(:a m) (inc i)]) [{:a "a"} {:a "b"}])

produces the same effect

Wait... but why?.. (range) returns a lazy seq, and then... (inc i), I don't quite understand how this works

oh I see

I wonder how come mapv ever stops since (range) is infinite?

you are passing 2 args to map: [{:a "a"} {:a "b"}] and (range). so map runs till one of them finishes. in this case its the first param

got it!

@rahul080327 thanks, this is even better, although requires an into or something to convert it to a vector since there's no mapv-indexed

yeah thats a catch

How can it be that this tests comparing two numbers fails?

expected: 3 to be an instance of java.lang.Long
was: 3 is an instance of java.lang.Integer
       [praha bRno]

      (testing "case insensitive"
        (let [xs (contacts/get-all {:city ["praha" "bRno"] :lang_id "cs"})]
          (is (= 2 (count xs)))

boot.user=> (is (= (Long. 2) (Integer. 2)))
true

@carr0t it's a list of maps

boot.user=> (require '[clojure.test :refer :all])
nil
boot.user=> (is (= 2 (count '({:a "a"} {:b "b"}))))
true
boot.user=> (is (= 2 (count [{:a "a"} {:b "b"}])))
true
boot.user=> (is (= (Long. 2) (count '({:a "a"} {:b "b"}))))
true
boot.user=> (is (= (Integer. 2) (count '({:a "a"} {:b "b"}))))
true

No idea what's happening with your one... Are you using clojure.spec or is the newer version of clojure.test? Might be that the specfile somewhere is saying that the compared value must be a Long

How do you parse JSON using multiple values in Json?

@cpfiro are you asking how to parse json?

@noisesmith yes but using two keys to pull out two values

usually with jvm clojure I would parse first (using the cheshire library, or clojure.data.json), and then pull the keys out of the resulting map

unless you are talking about cljs, where I would use the built in JSON class for interop

Oh I meant values

(((get_url_response url) :body) :offset ))

but instead of just pulling out offset value, to pull offset and limit values

exampe : {:limit 2, :offset 0, :total 7439, :more true}

right, so you can use select-keys once you have a map

oh

but that's not json any more, it's just clojure data

user=> (select-keys {:a 0 :b 1 :c "more"} [:a :b])
{:a 0, :b 1}

often your http lib will convert the json for you

ah, thank you

select-keys is exactly what I was hoping for, thank you!