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Merge pull request #14 from HantonSacu/HantonSacu-12

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Solve sequence comprehensions
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Kenneth Kostrešević 2021-12-16 16:24:53 +01:00 committed by GitHub
commit d816dec5ad
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1 changed files with 6 additions and 7 deletions
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13
src/koans/12_sequence_comprehensions.clj
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@ -3,7 +3,7 @@
(meditations
"Sequence comprehensions can bind each element in turn to a symbol"
(= __
(= '(0 1 2 3 4 5)
(for [x (range 6)]
x))
@ -12,25 +12,24 @@
(map (fn [x] (* x x))
(range 6))
(for [x (range 6)]
__))
(* x x)))
"And also filtering"
(= '(1 3 5 7 9)
(filter odd? (range 10))
(for [x __ :when (odd? x)]
(for [x (range 10) :when (odd? x)]
x))
"Combinations of these transformations is trivial"
(= '(1 9 25 49 81)
(map (fn [x] (* x x))
(filter odd? (range 10)))
(for [x (range 10) :when __]
__))
(for [x (range 10) :when (odd? x)]
(* x x)))
"More complex transformations simply take multiple binding forms"
(= [[:top :left] [:top :middle] [:top :right]
[:middle :left] [:middle :middle] [:middle :right]
[:bottom :left] [:bottom :middle] [:bottom :right]]
(for [row [:top :middle :bottom]
column [:left :middle :right]]
__)))
column [:left :middle :right]] [row column])))