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ulsa/destructuring1.clj

Created August 4, 2012 17:04
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Decimal to Roman Numeral converter
Raw
destructuring1.clj
(let [lst (filter odd? [1 2 3 4 5])
fst (first lst)
snd (second lst)]
(println fst snd))
=> 1 3
Raw
filter1.clj
(filter #(>= 6 (first %)) mapping)
=> ([5 "V"] [4 "IV"] [1 "I"])
(filter #(>= 4 (first %)) mapping)
=> ([4 "IV"] [1 "I"])
Raw
filter2.clj
(filter odd? [1 2 3 4 5])
=> (1 3 5)
Raw
fn1.clj
(fn [x]
(>= i (first x)))
Raw
fn2.clj
#(>= i (first %))
Raw
mapping1.clj
{10 "X" 9 "IX" 5 "V" 4 "IV" 1 "I"}
=> {1 "I", 10 "X", 4 "IV", 5 "V", 9 "IX"}
Raw
mapping2.clj
(sorted-map 10 "X" 9 "IX" 5 "V" 4 "IV" 1 "I")
=> {1 "I", 4 "IV", 5 "V", 9 "IX", 10 "X"}
Raw
mapping3.clj
(sorted-map-by > 10 "X" 9 "IX" 5 "V" 4 "IV" 1 "I")
=> {10 "X", 9 "IX", 5 "V", 4 "IV", 1 "I"}
Raw
roman.clj
(def mapping (sorted-map-by > 1000 "M" 900 "CM" 500 "D" 400 "CD"
100 "C" 90 "XC" 50 "L" 40 "XL"
10 "X" 9 "IX" 5 "V" 4 "IV" 1 "I"))
(defn roman-numeral [i]
(loop [i i s ""]
(if (zero? i)
s
(let [[[n c]] (filter #(>= i (first %)) mapping)]
(recur (- i n) (str s c))))))
Raw
seqmapping.clj
(seq (sorted-map-by > 10 "X" 9 "IX" 5 "V" 4 "IV" 1 "I"))
=> ([10 "X"] [9 "IX"] [5 "V"] [4 "IV"] [1 "I"])
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