* enum.c (enum_slice_when): New method: Enumerable#slice_when.

  (slicewhen_i): New function.
  (slicewhen_ii): New function.

* enumerator.c (InitVM_Enumerator): New method:
  Enumerator::Lazy#slice_when.

  [ruby-core:62499] [Feature #9826]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@47652 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

2 files changed, 56 insertions, 0 deletions

diff --git a/test/ruby/test_enum.rb b/test/ruby/test_enum.rb
index d6795e49dd..edd389b071 100644
--- a/test/ruby/test_enum.rb
+++ b/test/ruby/test_enum.rb
@@ -574,6 +574,61 @@ class TestEnumerable < Test::Unit::TestCase
     assert_equal([["foo", ""], ["bar"]], e.to_a)
   end
 
+  def test_slice_when_0
+    e = [].slice_when {|a, b| flunk "should not be called" }
+    assert_equal([], e.to_a)
+  end
+
+  def test_slice_when_1
+    e = [1].slice_when {|a, b| flunk "should not be called" }
+    assert_equal([[1]], e.to_a)
+  end
+
+  def test_slice_when_2
+    e = [1,2].slice_when {|a,b|
+      assert_equal(1, a)
+      assert_equal(2, b)
+      true
+    }
+    assert_equal([[1], [2]], e.to_a)
+
+    e = [1,2].slice_when {|a,b|
+      assert_equal(1, a)
+      assert_equal(2, b)
+      false
+    }
+    assert_equal([[1, 2]], e.to_a)
+  end
+
+  def test_slice_when_3
+    block_invocations = [
+      lambda {|a, b|
+        assert_equal(1, a)
+        assert_equal(2, b)
+        true
+      },
+      lambda {|a, b|
+        assert_equal(2, a)
+        assert_equal(3, b)
+        false
+      }
+    ]
+    e = [1,2,3].slice_when {|a,b|
+      block_invocations.shift.call(a, b)
+    }
+    assert_equal([[1], [2, 3]], e.to_a)
+    assert_equal([], block_invocations)
+  end
+
+  def test_slice_when_noblock
+    assert_raise(ArgumentError) { [].slice_when }
+  end
+
+  def test_slice_when_contiguously_increasing_integers
+    e = [1,4,9,10,11,12,15,16,19,20,21].slice_when {|i, j| i+1 != j }
+    assert_equal([[1], [4], [9,10,11,12], [15,16], [19,20,21]], e.to_a)
+  end
+
   def test_detect
     @obj = ('a'..'z')
     assert_equal('c', @obj.detect {|x| x == 'c' })
diff --git a/test/ruby/test_lazy_enumerator.rb b/test/ruby/test_lazy_enumerator.rb
index 549d0f104e..7bf9903ddc 100644
--- a/test/ruby/test_lazy_enumerator.rb
+++ b/test/ruby/test_lazy_enumerator.rb
@@ -481,6 +481,7 @@ EOS
       assert_equal Enumerator::Lazy, [].lazy.send(method, *arg).class, bug7507
     end
     assert_equal Enumerator::Lazy, [].lazy.chunk{}.class, bug7507
+    assert_equal Enumerator::Lazy, [].lazy.slice_when{}.class, bug7507
   end
 
   def test_no_warnings