* array.c (rb_ary_permutation): implementation contributed from

  David Flanagan.  [ruby-core:12344]

* array.c (rb_ary_combination): RDoc update to clarify.  a patch
  from David Flanagan.  [ruby-core:12344]

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@13590 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 16 insertions, 8 deletions

diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 9ab3168d73..2e9c6fca57 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -1177,14 +1177,6 @@ class TestArray < Test::Unit::TestCase
     assert_equal(@cls[1,2], @cls[1, 2] | @cls[1, 2])
   end
 
-# def test_permutation
-#    assert_equal(@cls[[]], @cls[1,2,3].permutation(0).to_a)
-#    assert_equal(@cls[[1],[2],[3]], @cls[1,2,3].permutation(1).to_a)
-#    assert_equal(@cls[[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]], @cls[1,2,3].permutation(2).to_a)
-#    assert_equal(@cls[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]], @cls[1,2,3].permutation(3).to_a)
-#    assert_equal(@cls[], @cls[1,2,3].permutation(4).to_a)
-#  end
-
  def test_combination
     assert_equal(@cls[[]], @cls[1,2,3,4].combination(0).to_a)
     assert_equal(@cls[[1],[2],[3],[4]], @cls[1,2,3,4].combination(1).to_a)
@@ -1199,4 +1191,20 @@ class TestArray < Test::Unit::TestCase
                  @cls[1,2,3].product([4,5]))
     assert_equal(@cls[[1,1],[1,2],[2,1],[2,2]], @cls[1,2].product([1,2]))
   end
+
+  def test_permutation
+    a = @cls[1,2,3]
+    assert_equal(@cls[[]], a.permutation(0).to_a)
+    assert_equal(@cls[[1],[2],[3]], a.permutation(1).to_a.sort)
+    assert_equal(@cls[[1,2],[1,3],[2,1],[2,3],[3,1],[3,2]],
+                 a.permutation(2).to_a.sort)
+    assert_equal(@cls[[1,2,3],[1,3,2],[2,1,3],[2,3,1],[3,1,2],[3,2,1]],
+                 a.permutation(3).sort.to_a)
+    assert_equal(@cls[], a.permutation(4).to_a)
+    assert_equal(@cls[], a.permutation(-1).to_a)
+    assert_equal("abcde".each_char.to_a.permutation(5).sort,
+                 "edcba".each_char.to_a.permutation(5).sort)
+    assert_equal(@cls[].permutation(0).to_a, @cls[[]])
+
+  end
 end