* configure.in: Check nextafter() availability.

* include/ruby/missing.h (nextafter): New optional declaration.

* missing/nextafter.c: New file.

* numeric.c: Float#next_float and Float#prev_float implemented.

   [ruby-core:62562] [Feature #9834]



git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@45982 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

1 files changed, 35 insertions, 0 deletions

diff --git a/test/ruby/test_float.rb b/test/ruby/test_float.rb
index 3ee0a23a63..ed8f2992ed 100644
--- a/test/ruby/test_float.rb
+++ b/test/ruby/test_float.rb
@@ -619,4 +619,39 @@ class TestFloat < Test::Unit::TestCase
     assert_in_epsilon(10.0, ("1."+"1"*300000).to_f*9)
     end;
   end
+
+  def test_next_float
+    smallest = 0.0.next_float
+    assert_equal(-Float::MAX, (-Float::INFINITY).next_float)
+    assert_operator(-Float::MAX, :<, (-Float::MAX).next_float)
+    assert_equal(Float::EPSILON/2, (-1.0).next_float + 1.0)
+    assert_operator(0.0, :<, smallest)
+    assert_operator([0.0, smallest], :include?, smallest/2)
+    assert_equal(Float::EPSILON, 1.0.next_float - 1.0)
+    assert_equal(Float::INFINITY, Float::MAX.next_float)
+    assert_equal(Float::INFINITY, Float::INFINITY.next_float)
+    assert(Float::NAN.next_float.nan?)
+  end
+
+  def test_prev_float
+    smallest = 0.0.next_float
+    assert_equal(-Float::INFINITY, (-Float::INFINITY).prev_float)
+    assert_equal(-Float::INFINITY, (-Float::MAX).prev_float)
+    assert_equal(-Float::EPSILON, (-1.0).prev_float + 1.0)
+    assert_equal(-smallest, 0.0.prev_float)
+    assert_operator([0.0, 0.0.prev_float], :include?, 0.0.prev_float/2)
+    assert_equal(-Float::EPSILON/2, 1.0.prev_float - 1.0)
+    assert_operator(Float::MAX, :>, Float::MAX.prev_float)
+    assert_equal(Float::MAX, Float::INFINITY.prev_float)
+    assert(Float::NAN.prev_float.nan?)
+  end
+
+  def test_next_prev_float_zero
+    z = 0.0.next_float.prev_float
+    assert_equal(0.0, z)
+    assert_equal(Float::INFINITY, 1.0/z)
+    z = 0.0.prev_float.next_float
+    assert_equal(0.0, z)
+    assert_equal(-Float::INFINITY, 1.0/z)
+  end
 end