Time for an 2014 update…

Task/String-length/Clojure/string-length-1.clj

@@ -1,2 +1,8 @@
-(count (.getBytes "Hello, world!")) ; 13 bytes
-(count (.getBytes "π")) ; two bytes
+(def utf-8-octet-length #(-> % (.getBytes "UTF-8") count))
+(map utf-8-octet-length  ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (7 28 14)
+
+(def utf-16-octet-length (comp (partial * 2) count))
+(map utf-16-octet-length ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (10 28 18)
+
+(def code-unit-length count)
+(map code-unit-length    ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (5 14 9)

Task/String-length/Clojure/string-length-2.clj

@@ -1 +1,2 @@
-(count "Hello, world!")
+(def character-length #(.codePointCount % 0 (count %)))
+(map character-length    ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (5 7 9)

Task/String-length/Clojure/string-length-3.clj

@@ -0,0 +1,8 @@
+(def grapheme-length
+  #(->> (doto (java.text.BreakIterator/getCharacterInstance)
+          (.setText %))
+        (partial (memfn next))
+        repeatedly
+        (take-while (partial not= java.text.BreakIterator/DONE))
+        count))
+(map grapheme-length     ["møøse" "𝔘𝔫𝔦𝔠𝔬𝔡𝔢" "J\u0332o\u0332s\u0332e\u0301\u0332"]) ; (5 7 4)