Added comments about memoization

DmnChzl · DmnChzl · commit 0589fc19e0d1 · 2021-10-05T10:37:14.000+02:00
diff --git a/Cache/Memoize.js b/Cache/Memoize.js
@@ -1,21 +1,40 @@
 /**
  * Memoize
- * @param {Function} fn
- * @returns
+ *
+ * From [Wikipedia](https://en.wikipedia.org/wiki/Memoization),
+ * memoization is an optimization technique
+ * used primarily to speed up computer programs,
+ * by storing the results of expensive function calls
+ * and returning the cached result when the same inputs occur again
+ *
+ * This function is a first class objects,
+ * which lets us use it as [Higher-Order Function](https://eloquentjavascript.net/05_higher_order.html)
+ * and return another function
+ *
+ * @param {Function} func Original function
+ * @returns {Function} Memoized function
  */
 export const memoize = (func) => {
-  // Initializing new cache
+  // Initialization of a slot to store the function result
   const cache = {}
 
   return (...args) => {
+    // Retrieving the first argument of the function
     const [arg] = args
 
+    /**
+     * Checks if the argument is already present in the cache,
+     * then return the associated value / result
+     */
     if (arg in cache) {
-      // Reading cache by argument
       return cache[arg]
     }
 
-    // Updating cache by argument
+    /**
+     * If the argument is not yet present in the cache,
+     * execute original function and save its value / result in cache,
+     * finally return it
+     */
     const result = func(arg)
     cache[arg] = result
     return result
