more correct syntax and AI instructions

docs/library/random.md

@@ -48,7 +48,7 @@ var random = use('random')
 var coin_flip = random.random() < 0.5
 
 // Random element from array
-function pick(arr) {
+var pick = function(arr) {
   return arr[random.random_whole(length(arr))]
 }
 
@@ -56,11 +56,14 @@ var colors = ["red", "green", "blue"]
 var color = pick(colors)
 
 // Shuffle array
-function shuffle(arr) {
+var shuffle = function(arr) {
   var result = array(arr)  // copy
-  for (var i = length(result) - 1; i > 0; i--) {
-    var j = random.random_whole(i + 1)
-    var temp = result[i]
+  var i = length(result) - 1
+  var j = 0
+  var temp = null
+  for (i = length(result) - 1; i > 0; i--) {
+    j = random.random_whole(i + 1)
+    temp = result[i]
     result[i] = result[j]
     result[j] = temp
   }
@@ -68,8 +71,8 @@ function shuffle(arr) {
 }
 
 // Random in range
-function random_range(min, max) {
-  return min + random.random() * (max - min)
+var random_range = function(lo, hi) {
+  return lo + random.random() * (hi - lo)
 }
 
 var x = random_range(-10, 10)  // -10 to 10