refactor promise, geneerators, global object

1-js/06-advanced-functions/13-generators/01-pseudo-random-generator/solution.md

@@ -0,0 +1,38 @@
+```js run demo
+function* pseudoRandom(seed) {
+  let value = seed;
+
+  while(true) {
+    value = value * 16807 % 2147483647
+    yield value;
+  }
+
+};
+
+let generator = pseudoRandom(1);
+
+alert(generator.next().value); // 16807
+alert(generator.next().value); // 282475249
+alert(generator.next().value); // 1622650073
+```
+
+Please note, the same can be done with a regular function, like this:
+
+```js run
+function pseudoRandom(seed) {
+  let value = seed;
+
+  return function() {
+    value = value * 16807 % 2147483647;
+    return value;
+  }
+}
+
+let generator = pseudoRandom(1);
+
+alert(generator()); // 16807
+alert(generator()); // 282475249
+alert(generator()); // 1622650073
+```
+
+That's fine for this context. But then we loose ability to iterate with `for..of` and to use generator composition, that may be useful elsewhere.