Perfect numbers: Difference between revisions

Content added Content deleted

Inline

@@ Line 981: / Line 981: @@
 <lang JavaScript>(function (nFrom, nTo) {
-    // MONADIC CHAIN (bind) IN LIEU OF FILTER
+  // MONADIC CHAIN (bind) IN LIEU OF FILTER
-    // ( monadic return for lists is just lambda x -> [x] )
+  // ( monadic return for lists is just lambda x -> [x] )
-    return chain(
+  return chain(
-        rng(nFrom, nTo),
+    rng(nFrom, nTo),
-        function (x) {
+    function (x) {
-            return (
+      return (
-                function perfect(n) {
+        function perfect(n) {
-                    return chain(
+          return chain(
-                        rng(1, Math.floor(Math.sqrt(n))),
+            rng(1, Math.floor(Math.sqrt(n))),
-                        function (y) {
-                            return (n % y) === 0 && n > 1 ? [y, n / y] : [];
+            function (y) {
-                        }
+              return (n % y) === 0 && n > 1 ? [y, n / y] : [];
-                    ).reduce(function (a, x) {
+            }
-                        return a + x;
+          ).reduce(function (a, x) {
-                    }, 0) / 2 === n;
+            return a + x;
-                }
+          }, 0) / 2 === n;
-            )(x) ? [x] : [];
         }
-    );
+      )(x) ? [x] : [];
+    }
+  );
-    /******************************************************************/
+  /******************************************************************/
-    // Monadic bind (chain) for lists
+  // Monadic bind (chain) for lists
-    function chain(xs, f) {
+  function chain(xs, f) {
-        return [].concat.apply([], xs.map(f));
+    return [].concat.apply([], xs.map(f));
-    }
+  }
-    function rng(m, n) {
+  function rng(m, n) {
-        return Array.apply(null, Array(n - m + 1)).map(function (x, i) {
+    return Array.apply(null, Array(n - m + 1)).map(function (x, i) {
-            return m + i;
+      return m + i;
-        });
+    });
-    }
+  }
 })(1, 10000);</lang>