Initial data commit

Task/Cantor-set/JavaScript/cantor-set-1.js

@@ -0,0 +1,88 @@
+(() => {
+    "use strict";
+
+    // -------------- CANTOR BOOL-INT PAIRS --------------
+
+    // cantor :: [(Bool, Int)] -> [(Bool, Int)]
+    const cantor = xs => {
+        const go = ([bln, n]) =>
+            bln && 1 < n ? (() => {
+                const x = Math.floor(n / 3);
+
+                return [
+                    [true, x],
+                    [false, x],
+                    [true, x]
+                ];
+            })() : [
+                [bln, n]
+            ];
+
+        return xs.flatMap(go);
+    };
+
+    // ---------------------- TEST -----------------------
+    // main :: IO ()
+    const main = () =>
+        cantorLines(5);
+
+
+    // --------------------- DISPLAY ---------------------
+
+    // cantorLines :: Int -> String
+    const cantorLines = n =>
+        take(n)(
+            iterate(cantor)([
+                [true, 3 ** (n - 1)]
+            ])
+        )
+        .map(showCantor)
+        .join("\n");
+
+
+    // showCantor :: [(Bool, Int)] -> String
+    const showCantor = xs =>
+        xs.map(
+            ([bln, n]) => (
+                bln ? (
+                    "*"
+                ) : " "
+            ).repeat(n)
+        )
+        .join("");
+
+    // ---------------- GENERIC FUNCTIONS ----------------
+
+    // iterate :: (a -> a) -> a -> Gen [a]
+    const iterate = f =>
+        // An infinite list of repeated
+        // applications of f to x.
+        function* (x) {
+            let v = x;
+
+            while (true) {
+                yield v;
+                v = f(v);
+            }
+        };
+
+
+    // take :: Int -> [a] -> [a]
+    // take :: Int -> String -> String
+    const take = n =>
+        // The first n elements of a list,
+        // string of characters, or stream.
+        xs => "GeneratorFunction" !== xs
+        .constructor.constructor.name ? (
+            xs.slice(0, n)
+        ) : [].concat(...Array.from({
+            length: n
+        }, () => {
+            const x = xs.next();
+
+            return x.done ? [] : [x.value];
+        }));
+
+    // MAIN ---
+    return main();
+})();