Refactor choose and weighted

lib/random/random.js

@@ -144,43 +144,35 @@ class random {
       throw new TypeError(`random.choose() received non-array type: (${list})`)
     }
 
-    let total = 0
-    for (let i = 0; i < list.length; i++) {
-      total += list[i][0]
-    }
-
-    let n = random.number(total)
-    for (let i = 0; i < list.length; i++) {
-      if (n < list[i][0]) {
-        if (flat === true) {
-          return list[i][1]
-        } else {
-          return random.pick([list[i][1]])
-        }
-      }
-      n = n - list[i][0]
+    const expanded = []
+    list.forEach(([weight, value]) => {
+      while (weight--) {
+        expanded.push(value)
       }
+    })
 
     if (flat) {
-      return list[0][1]
+      return random.item(expanded)
     }
 
-    return random.pick([list[0][1]])
+    return random.pick(expanded)
   }
 
   /**
-   * More memory-hungry but hopefully faster than random.choose$flat.
-   * @param {*} wa
+   * Return a flattened list of weighted values
+   * [{w: 1, v: 'foo'}, {w: 1, v: 'bar'}]
+   * @param {Array} list
+   * @param {Array}
    */
-  static weighted (wa) {
-    let a = []
-    for (let i = 0; i < wa.length; ++i) {
-      for (let j = 0; j < wa[i].w; ++j) {
-        a.push(wa[i].v)
-      }
+  static weighted (list) {
+    const expanded = []
+    list.forEach((item) => {
+      while (item.w--) {
+        expanded.push(item.v)
       }
+    })
 
-    return a
+    return expanded
   }
 
   static use (obj) {