From 44cb2c1855f81135a2b38ecb3ff8a3928bc65274 Mon Sep 17 00:00:00 2001
From: John Lin <johnlin@exosite.com>
Date: Sat, 23 Mar 2019 13:39:46 +0800
Subject: [PATCH] add float part

---
 lib/autodiff/numeric.rb | 6 ++++++
 test/autodiff_test.rb   | 4 ++++
 2 files changed, 10 insertions(+)

diff --git a/lib/autodiff/numeric.rb b/lib/autodiff/numeric.rb
index f961468..1cc2c62 100644
--- a/lib/autodiff/numeric.rb
+++ b/lib/autodiff/numeric.rb
@@ -17,3 +17,9 @@ class Integer
   dual_op(:+)
   dual_op(:-)
 end
+
+class Float
+  extend DualNumConvertible
+  dual_op(:+)
+  dual_op(:-)
+end
diff --git a/test/autodiff_test.rb b/test/autodiff_test.rb
index b5917cc..a20431d 100644
--- a/test/autodiff_test.rb
+++ b/test/autodiff_test.rb
@@ -21,6 +21,10 @@ def test_gradient_can_do_1_minus_x
     assert_equal -1, Autodiff.gradient(0) { |x| 1 - x }
   end
 
+  def test_gradient_can_do_1_point_5_minus_x
+    assert_equal -1, Autodiff.gradient(0) { |x| 1.5 - x }
+  end
+
   def test_gradient_can_handle_x_square
     assert_equal 2, Autodiff.gradient(1) { |x| x*x}
   end