Question:
What's the simplest way to create a vector of distinct refs?
Using (repeat 5 (ref nil)) will return a list, but they will all reference the same ref:
user=> (repeat 5 (ref nil)) (#<Ref@16ef71: nil> #<Ref@16ef71: nil> #<Ref@16ef71: nil> #<Ref@16ef71: nil> #<R ef@16ef71: nil>) Same result with (replicate 5 (ref nil)):
user=> (replicate 5 (ref nil)) (#<Ref@1d88db7: nil> #<Ref@1d88db7: nil> #<Ref@1d88db7: nil> #<Ref@1d88db7: nil> #<Ref@1d88db7: nil>)
Solution:1
user> (doc repeatedly) ------------------------- clojure.core/repeatedly ([f]) Takes a function of no args, presumably with side effects, and returns an infinite lazy sequence of calls to it nil user> (take 5 (repeatedly #(ref nil))) (#<Ref@1f10a67: nil> #<Ref@1e2161d: nil> #<Ref@1a034d: nil> #<Ref@1cee792: nil> #<Ref@c5577c: nil>) us
Solution:2
Ok, this is pretty gross, but it works:
user=> (map (fn [_] (ref nil)) (range 5)) (#<Ref@27147d: nil> #<Ref@b248c8: nil> #<Ref@c86116: nil> #<Ref@5e06ef: nil> #<Ref@19719f: nil>) That returns a LazySeq, so if you want/need a Vector, then just use:
user=> (vec (map (fn [_] (ref nil)) (range 5))) [#<Ref@5bf9cf: nil> #<Ref@6dbfb0: nil> #<Ref@43f787: nil> #<Ref@2fe9bf: nil> #<Ref@9b1e15: nil>] Note:If u also have question or solution just comment us below or mail us on toontricks1994@gmail.com
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