Clojure: Working with vector and ref

Question

Please someone who worked with ref and vector could help-me ?

This vector in each line there is a (ref {:desc "text" :amount double}):

[#<Ref@1cda773e: {:desc "DESC1", :amount 100}
 #<Ref@468dd81: {:desc "DESC2", :amount 200}
 #<Ref@1e95e716: {:desc "DESC3",:amount -50}>]

Is it possible take all amounts above and put it in a new vector like this : [100, 200, -50].

Working with refs is quite difficult and I don't know to to access them.

Have you tried deref? https://clojuredocs.org/clojure.core/deref — jmargolisvt, Jan 13 '17 at 19:23
Yes, I did. Its hard to access each one of the refs take the amount and transform in a vector — junis087678, Jan 13 '17 at 19:48

score 1 · Accepted Answer · answered Jan 13 '17 at 20:14

1

Here's one way to do it:

user=> (def data [{:desc "DESC1", :amount 100} {:desc "DESC2", :amount 200} {:desc "DESC3",:amount -50}])
#'user/data
user=> (def my-refs (map #(ref %) data))
#'user/my-refs
user=> (vec (map #(-> % deref :amount) my-refs))
[100 200 -50]

answered Jan 13 '17 at 20:14

jmargolisvt

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Thank you for your time ! now I can finish here. – junis087678 Jan 13 '17 at 21:09
2

`vec` + `map` could be replaced with `mapv`: `(mapv #(-> % deref :amount) my-refs)` .. or like this: `(mapv (comp :amount deref) my-refs)` – leetwinski Jan 13 '17 at 21:35

Clojure: Working with vector and ref

1 Answers1