Rename seq abstraction to iterator. Add random functions.

examples/3sum.dst

@@ -2,7 +2,7 @@
  "Solve the 3SUM problem O(n^2) time."
  [s]
  (def tab @{})
- (def solutions [])
+ (def solutions @{})
  (def len (length s))
  (for [k 0 len]
   (put tab (get s k) k))
@@ -10,5 +10,5 @@
   (for [j 0 len]
    (def k (get tab (- 0 (get s i) (get s j))))
    (when (and k (not= k i) (not= k j) (not= i j))
-    (array-push solutions [i j k]))))
- solutions)
+    (put solutions {i true j true k true} true))))
+ (iter2array (map (fn [x] (iter2array (keys x))) (keys solutions))))

examples/frequencies.dst

@@ -4,8 +4,7 @@
  "Get the number of occurences of each value in a sequence."
  [s]
  (let [freqs @{}
-       fop (fn [x] 
-         (let [n (get freqs x)]
-          (put freqs x (if n (+ 1 n) 1))))
-       _ (domap fop s)]
+       _ (foreach s (fn [x] 
+          (let [n (get freqs x)]
+           (put freqs x (if n (+ 1 n) 1)))))]
   freqs))