2016 Update

Task/Roman-numerals-Encode/JavaScript/roman-numerals-encode-4.js

@@ -0,0 +1,55 @@
+(() => {
+    'use strict';
+
+    // roman :: Int -> String
+    const roman = n => [
+            [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"]
+        ]
+        .reduce((a, lstPair) => {
+            const m = a.remainder,
+                v = lstPair[0];
+            return (v > m ? a : {
+                remainder: m % v,
+                roman: a.roman + Array(
+                        Math.floor(m / v) + 1
+                    )
+                    .join(lstPair[1])
+            });
+        }, {
+            remainder: n,
+            roman: ''
+        })
+        .roman;
+
+    // TEST
+
+    // If the input is a decimal string, pass any delimiters through
+    // romanTranscription :: (Int | String) -> String
+    const romanTranscription = a => {
+        if (typeof a === 'string') {
+            const ps = a.split(/\d+/),
+                dlm = ps.length > 1 ? ps[1] : undefined;
+
+            return (dlm ? a.split(dlm)
+                    .map(Number) : [a])
+                .map(roman)
+                .join(dlm);
+        } else return roman(a);
+    }
+
+    // TEST
+    return [2016, 1990, 2008, "14.09.2015", 2000, 1666]
+        .map(romanTranscription);
+})();