* array.c (rb_ary_shuffle_bang, rb_ary_sample): add optional

  argument random.  [ruby-dev:41923] [EXPERIMENTAL]

* random.c (rb_random_{int32,real,bytes}): fallback to normal
  method invocation.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@29083 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 33 insertions, 12 deletions

diff --git a/array.c b/array.c
index d047565022..172a653aa2 100644
--- a/array.c
+++ b/array.c
@@ -3730,22 +3730,30 @@ rb_ary_flatten(int argc, VALUE *argv, VALUE ary)
     return result;
 }
 
-#define RAND_UPTO(max) (long)(rb_genrand_real()*(max))
+#define OPTHASH_GIVEN_P(opts) \
+    (argc > 0 && !NIL_P(opts = rb_check_hash_type(argv[argc-1])) && (--argc, 1))
+static VALUE sym_random;
+
+#define RAND_UPTO(max) (long)(rb_random_real(randgen)*(max))
 
 /*
  *  call-seq:
- *     ary.shuffle!        -> ary
+ *     ary.shuffle!              -> ary
+ *     ary.shuffle!(random: rng) -> ary
  *
  *  Shuffles elements in +self+ in place.
+ *  If +rng+ is given, it will be used as the random number generator.
  */
 
-
 static VALUE
-rb_ary_shuffle_bang(VALUE ary)
+rb_ary_shuffle_bang(int argc, VALUE *argv, VALUE ary)
 {
-    VALUE *ptr;
+    VALUE *ptr, opts, randgen = Qnil;
     long i = RARRAY_LEN(ary);
 
+    if (OPTHASH_GIVEN_P(opts)) {
+	randgen = rb_hash_lookup2(opts, sym_random, randgen);
+    }
     rb_ary_modify(ary);
     ptr = RARRAY_PTR(ary);
     while (i) {
@@ -3760,27 +3768,34 @@ rb_ary_shuffle_bang(VALUE ary)
 
 /*
  *  call-seq:
- *     ary.shuffle -> new_ary
+ *     ary.shuffle              -> new_ary
+ *     ary.shuffle(random: rng) -> new_ary
  *
  *  Returns a new array with elements of this array shuffled.
  *
  *     a = [ 1, 2, 3 ]           #=> [1, 2, 3]
  *     a.shuffle                 #=> [2, 3, 1]
+ *
+ *  If +rng+ is given, it will be used as the random number generator.
+ *
+ *     a.shuffle(Random.new(1))  #=> [1, 3, 2]
  */
 
 static VALUE
-rb_ary_shuffle(VALUE ary)
+rb_ary_shuffle(int argc, VALUE *argv, VALUE ary)
 {
     ary = rb_ary_dup(ary);
-    rb_ary_shuffle_bang(ary);
+    rb_ary_shuffle_bang(argc, argv, ary);
     return ary;
 }
 
 
 /*
  *  call-seq:
- *     ary.sample        -> obj
- *     ary.sample(n)     -> new_ary
+ *     ary.sample                  -> obj
+ *     ary.sample(random: rng)     -> obj
+ *     ary.sample(n)               -> new_ary
+ *     ary.sample(n, random: rng)  -> new_ary
  *
  *  Choose a random element or +n+ random elements from the array. The elements
  *  are chosen by using random and unique indices into the array in order to
@@ -3788,6 +3803,7 @@ rb_ary_shuffle(VALUE ary)
  *  contained duplicate elements. If the array is empty the first form returns
  *  <code>nil</code> and the second form returns an empty array.
  *
+ *  If +rng+ is given, it will be used as the random number generator.
  */
 
 
@@ -3795,9 +3811,13 @@ static VALUE
 rb_ary_sample(int argc, VALUE *argv, VALUE ary)
 {
     VALUE nv, result, *ptr;
+    VALUE opts, randgen = Qnil;
     long n, len, i, j, k, idx[10];
 
     len = RARRAY_LEN(ary);
+    if (OPTHASH_GIVEN_P(opts)) {
+	randgen = rb_hash_lookup2(opts, sym_random, randgen);
+    }
     if (argc == 0) {
 	if (len == 0) return Qnil;
 	i = len == 1 ? 0 : RAND_UPTO(len);
@@ -4595,8 +4615,8 @@ Init_Array(void)
     rb_define_method(rb_cArray, "flatten", rb_ary_flatten, -1);
     rb_define_method(rb_cArray, "flatten!", rb_ary_flatten_bang, -1);
     rb_define_method(rb_cArray, "count", rb_ary_count, -1);
-    rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, 0);
-    rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, 0);
+    rb_define_method(rb_cArray, "shuffle!", rb_ary_shuffle_bang, -1);
+    rb_define_method(rb_cArray, "shuffle", rb_ary_shuffle, -1);
     rb_define_method(rb_cArray, "sample", rb_ary_sample, -1);
     rb_define_method(rb_cArray, "cycle", rb_ary_cycle, -1);
     rb_define_method(rb_cArray, "permutation", rb_ary_permutation, -1);
@@ -4611,4 +4631,5 @@ Init_Array(void)
     rb_define_method(rb_cArray, "drop_while", rb_ary_drop_while, 0);
 
     id_cmp = rb_intern("<=>");
+    sym_random = ID2SYM(rb_intern("random"));
 }