Initial commit

.gitignore

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+/target
+/lib
+/classes
+/checkouts
+pom.xml
+*.jar
+*.class
+.lein-deps-sum
+.lein-failures
+.lein-plugins

README.md

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+# recursion
+
+I'm an app. Or maybe I'm a library? I haven't decided yet. 
+
+The choice is up to you!
+
+## Usage
+
+FIXME
+
+## License
+
+Copyright © 2012 FIXME
+
+Distributed under the Eclipse Public License, the same as Clojure.

project.clj

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+(defproject structured-data "0.1.0-SNAPSHOT"
+  :dependencies [[org.clojure/clojure "1.4.0"]]
+  :profiles {:dev {:dependencies [[midje "1.4.0"]]
+                   :plugins [[lein-midje "2.0.0-SNAPSHOT"]]}})

src/recursion.clj

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+(ns recursion)
+
+(defn product [coll]
+  :-)
+
+(defn last-element [coll]
+  :-)
+
+(defn sequence-contains? [elem a-seq]
+  :-)
+
+(defn seq= [a-seq b-seq]
+  :-)
+
+(defn power [a b]
+  :-)
+
+(defn fib [n]
+  :-)
+
+(defn my-range [up-to]
+  :-)
+
+(defn map-1 [f a-seq]
+  :-)
+
+(defn tails [a-seq]
+  :-)
+
+(defn inits [a-seq]
+  :-)
+
+(defn split-into-monotonics [a-seq]
+  :-)
+
+(defn rotations [a-seq]
+  :-)
+
+(defn my-frequencies [a-seq]
+  :-)
+
+(defn un-frequencies [a-map]
+  :-)
+
+(defn seq-merge [a-seq b-seq]
+  :-)
+
+(defn mergesort [a-seq]
+  :-)
+
+(defn permutations [a-seq]
+  :-)
+
+(defn powerset [a-seq]
+  :-)
+
+; %_____%

test/recursion_test.clj

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+(ns recursion-test
+  (:use recursion
+        midje.sweet))
+
+(facts "product"
+  (product [])        => 1
+  (product [1 2 3])   => 6
+  (product [1 2 3 4]) => 24
+  (product [0 1 2])   => 0
+  (product #{2 3 4})  => 24)
+
+(facts "last-element"
+  (last-element [])      => nil
+  (last-element [1 2 3]) => 3
+  (last-element [2 5])   => 5)
+
+(facts "sequence-contains?"
+  (sequence-contains? 3 [1 2 3]) => true
+  (sequence-contains? 3 [4 7 9]) => false
+  (sequence-contains? :pony [])  => false)
+
+(facts "seq="
+  (seq= [1 2 4] '(1 2 4))  => true
+  (seq= [1 2 3] [1 2 3 4]) => false
+  (seq= [1 3 5] [])        => false)
+
+(facts "power"
+  (power 2 2)  => 4
+  (power 5 3)  => 125
+  (power 7 0)  => 1
+  (power 0 10) => 0)
+
+(facts "fib"
+  (fib 0) => 0
+  (fib 1) => 1
+  (fib 2) => 1
+  (fib 3) => 2
+  (fib 4) => 3
+  (fib 5) => 5
+  (fib 6) => 8
+  (fib 10) => 55)
+
+(facts "my-range"
+  (my-range 0)  => nil
+  (my-range 1)  => [0]
+  (my-range 2)  => [1 0]
+  (my-range 3)  => [2 1 0])
+
+(facts "map-1"
+  (map-1 identity [])                 => empty?
+  (map-1 identity [1 2 3])            => [1 2 3]
+  (map-1 count ["aaa" "bb" "cccc"])   => [3 2 4]
+  (map-1 first [[1 2] [4] [7 12 28]]) => [1 4 7]
+  (map-1 zero? [0 2 0 13 4 0])
+  => [true false true false false true])
+
+(facts "tails"
+  (tails [1 2 3 4])   => (just [[1 2 3 4] [2 3 4] [3 4] [4] empty?] :in-any-order)
+  (tails [])          => (just [empty?] :in-any-order)
+  (tails [1])         => (just [[1] empty?] :in-any-order))
+
+(facts "inits"
+  (inits [1 2 3 4])   => (just [empty? [1] [1 2] [1 2 3] [1 2 3 4]] :in-any-order)
+  (inits [])          => (just [empty?] :in-any-order)
+  (inits [1])         => (just [empty? [1]] :in-any-order))
+
+(facts "split-into-monotonics"
+  (split-into-monotonics [0 1 2 1 0])   => '((0 1 2) (1 0))
+  (split-into-monotonics [0 5 4 7 1 3]) => '((0 5) (4 7) (1 3)))
+
+(facts "rotations"
+  (rotations [])      => empty?
+  (rotations [1 2 3]) => (just [[1 2 3] [2 3 1] [3 1 2]] :in-any-order)
+  (rotations [:a :b]) => (just [[:a :b] [:b :a]] :in-any-order)
+  (rotations [1 5 9 2]) => (just '(1 5 9 2) '(2 1 5 9)
+                                 '(9 2 1 5) '(5 9 2 1)
+                                 :in-any-order)
+  (count (rotations [6 5 8 9 2])) => 5)
+
+(facts "my-frequencies"
+  (my-frequencies []) => {}
+  (my-frequencies [1 1 2 2 :D :D :D]) => {1 2, 2 2, :D 3}
+  (my-frequencies [:a "moi" :a "moi" "moi" :a 1])
+  => {:a 3, "moi" 3, 1 1})
+
+(facts "un-frequencies"
+  (un-frequencies {:a 3 :b 2 "^_^" 1})
+  => (just [:a :a :a "^_^" :b :b] :in-any-order)
+  (un-frequencies (my-frequencies [:a :b :c :a]))
+  => (just [:a :a :b :c] :in-any-order)
+  (my-frequencies (un-frequencies {:a 100 :b 10}))
+  => {:a 100 :b 10})
+
+(facts "seq-merge"
+  (seq-merge [4] [1 2 6 7])        => '(1 2 4 6 7)
+  (seq-merge [1 5 7 9] [2 2 8 10]) => '(1 2 2 5 7 8 9 10))
+
+(facts "mergesort"
+  (mergesort [])                 => empty?
+  (mergesort [1 2 3])            => '(1 2 3)
+  (mergesort [5 3 4 17 2 100 1]) => '(1 2 3 4 5 17 100))
+
+(facts "permutations"
+  (permutations [])      => empty?
+  (permutations [1 5 3])
+  => (just [[1 5 3] [5 1 3] [5 3 1] [1 3 5] [3 1 5] [3 5 1]]
+           :in-any-order))
+
+(facts "powerset"
+  (powerset [])      => '(())
+  (powerset [1 2 4]) => (just [empty? [4] [2] [2 4] [1] [1 4] [1 2] [1 2 4]] :in-any-order))