fix issue 29: move sequence functions from lazy_seqs to seq_utils

2 files changed, 32 insertions, 41 deletions

diff --git a/src/clojure/contrib/lazy_seqs.clj b/src/clojure/contrib/lazy_seqs.clj
index 9b40af26..1806cca2 100644
--- a/src/clojure/contrib/lazy_seqs.clj
+++ b/src/clojure/contrib/lazy_seqs.clj
@@ -21,17 +21,8 @@
 ;;
 ;;  == Lazy sequence functions ==
 ;;
-;;  rotations - returns a lazy seq of all the rotations of a seq
-;;
-;;  partition-all - like built-in partition, but does not throw away
-;;                  the last partition if it is too short 
-;;
-;;  (permutations and combinations used to be here, but have
-;;  been moved to combinatorics.clj)
-;;
-;;  random-permutation - from Jason Wolfe
-;;
-;;  random-element - from Jason Wolfe
+;;  (rotations, partition-all, shuffle, rand-elt  moved to seq_utils.clj)
+;;  (permutations and combinations moved to combinatorics.clj)
 ;;
 ;;  [1] http://www.cs.hmc.edu/~oneill/papers/Sieve-JFP.pdf
 ;;  [2] http://clj-me.blogspot.com/2008/06/primes.html
@@ -63,32 +54,3 @@
 (defvar powers-of-2
   (lazy-cons 1 (map #(bit-shift-left % 1) powers-of-2))
   "A lazy sequence of all the powers of 2")
-
-(defn rotations
-  "Returns a lazy seq of all rotations of a seq"
-  [x]
-  (if (seq x)
-    (map
-     (fn [n _]
-       (lazy-cat (drop n x) (take n x)))
-     (iterate inc 0) x)
-    (list nil)))
-
-(defn partition-all 
-  "Lazily break s into chunks of length n (or less, for the
-  final chunk)."
-  [n s]
-  (when (seq s)
-    (lazy-cons (take n s)
-               (partition-all n (drop n s)))))
-
-(defn random-permutation
-  "Return a random permutation of coll"
-  [coll]
-  (let [l (java.util.ArrayList. coll)]
-    (java.util.Collections/shuffle l)
-    (seq l)))
-
-(defn random-element [s]
-  "Return a random element of this seq"
-  (nth s (rand-int (count s))))
diff --git a/src/clojure/contrib/seq_utils.clj b/src/clojure/contrib/seq_utils.clj
index c559cb1b..36a8e07d 100644
--- a/src/clojure/contrib/seq_utils.clj
+++ b/src/clojure/contrib/seq_utils.clj
@@ -121,4 +121,33 @@
      (rec-cons self (first coll) (map f self (rest coll)))
      (cons (f) nil)))
   ([f init coll]
-   (rec-cons self init (map f self coll))))
\ No newline at end of file
+   (rec-cons self init (map f self coll))))
+
+(defn rotations
+  "Returns a lazy seq of all rotations of a seq"
+  [x]
+  (if (seq x)
+    (map
+     (fn [n _]
+       (lazy-cat (drop n x) (take n x)))
+     (iterate inc 0) x)
+    (list nil)))
+
+(defn partition-all 
+  "Lazily break s into chunks of length n (or less, for the
+  final chunk)."
+  [n s]
+  (when (seq s)
+    (lazy-cons (take n s)
+               (partition-all n (drop n s)))))
+
+(defn shuffle
+  "Return a random permutation of coll"
+  [coll]
+  (let [l (java.util.ArrayList. coll)]
+    (java.util.Collections/shuffle l)
+    (seq l)))
+
+(defn rand-elt [s]
+  "Return a random element of this seq"
+  (nth s (rand-int (count s))))