Data commit

Task/Calculating-the-value-of-e/JavaScript/calculating-the-value-of-e-1.js

@@ -0,0 +1,55 @@
+(() => {
+    "use strict";
+
+    // - APPROXIMATION OF E OBTAINED AFTER N ITERATIONS --
+
+    // eApprox : Int -> Float
+    const eApprox = n =>
+        sum(
+            scanl(mul)(1)(
+                enumFromTo(1)(n)
+            )
+            .map(x => 1 / x)
+        );
+
+
+    // ---------------------- TEST -----------------------
+    const main = () =>
+        eApprox(20);
+
+
+    // ---------------- GENERIC FUNCTIONS ----------------
+
+    // enumFromTo :: Int -> Int -> [Int]
+    const enumFromTo = m =>
+        n => Array.from({
+            length: 1 + n - m
+        }, (_, i) => m + i);
+
+
+    // mul (*) :: Num a => a -> a -> a
+    const mul = a =>
+        // The arithmetic product of a and b.
+        b => a * b;
+
+
+    // scanl :: (b -> a -> b) -> b -> [a] -> [b]
+    const scanl = f => startValue => xs =>
+        // The series of interim values arising
+        // from a catamorphism. Parallel to foldl.
+        xs.reduce((a, x) => {
+            const v = f(a[0])(x);
+
+            return [v, a[1].concat(v)];
+        }, [startValue, [startValue]])[1];
+
+
+    // sum :: [Num] -> Num
+    const sum = xs =>
+        // The numeric sum of all values in xs.
+        xs.reduce((a, x) => a + x, 0);
+
+
+    // MAIN ---
+    return main();
+})();

Task/Calculating-the-value-of-e/JavaScript/calculating-the-value-of-e-2.js

@@ -0,0 +1,32 @@
+(() => {
+    "use strict";
+
+    // --------------- APPROXIMATION OF E ----------------
+
+    const eApprox = n =>
+        // Approximation of E obtained after Nth iteration.
+        enumFromTo(1)(n).reduce(
+            ([fl, e], x) => (
+                flx => [flx, e + (1 / flx)]
+            )(
+                fl * x
+            ),
+            [1, 1]
+        )[1];
+
+    // ---------------------- TEST -----------------------
+    // main :: IO ()
+    const main = () =>
+        eApprox(20);
+
+    // --------------------- GENERIC ---------------------
+
+    // enumFromTo :: Int -> Int -> [Int]
+    const enumFromTo = m =>
+        n => Array.from({
+            length: 1 + n - m
+        }, (_, i) => m + i);
+
+    // MAIN ---
+    return main();
+})();