Alias Set#=== to #include?

* set.rb (Set#===): Added via [Feature #13801] by davidarnold.

Closes #1673.

git-svn-id: svn+ssh://ci.ruby-lang.org/ruby/trunk@59966 b2dd03c8-39d4-4d8f-98ff-823fe69b080e

5 files changed, 49 insertions, 0 deletions

diff --git a/NEWS b/NEWS
index 717ae69b65..940491ae39 100644
--- a/NEWS
+++ b/NEWS
@@ -149,6 +149,7 @@ with all sufficient information, see the ChangeLog file or Redmine
 
 * Set
   * Add Set#to_s as alias to #inspect [Feature #13676]
+  * Add Set#=== as alias to #inspect [Feature #13801]
 
 * WEBrick
 
diff --git a/lib/set.rb b/lib/set.rb
index bfa37d4dc0..009721381b 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -475,6 +475,23 @@ class Set
     @hash.eql?(o.instance_variable_get(:@hash))
   end
 
+  # Returns true if obj is a member of the set, and false otherwise.
+  #
+  # Used in case statements:
+  #
+  #   case :apple
+  #   when Set[:potato, :carrot] then 'vegetable'
+  #   when Set[:apple, :banana]  then 'fruit'
+  #   end
+  #   #=> "fruit"
+  #
+  # Or by itself:
+  #
+  #   Set[1, 2, 3] === 2 #=> true
+  #   Set[1, 2, 3] === 4 #=> false
+  #
+  alias === include?
+
   # Classifies the set by the return value of the given block and
   # returns a hash of {value => set of elements} pairs.  The block is
   # called once for each element of the set, passing the element as
diff --git a/spec/rubyspec/library/set/case_equality_spec.rb b/spec/rubyspec/library/set/case_equality_spec.rb
new file mode 100644
index 0000000000..ca1e900557
--- /dev/null
+++ b/spec/rubyspec/library/set/case_equality_spec.rb
@@ -0,0 +1,7 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../shared/include', __FILE__)
+require 'set'
+
+describe "Set#===" do
+  it_behaves_like :set_include, :===
+end
diff --git a/spec/rubyspec/library/set/sortedset/case_equality_spec.rb b/spec/rubyspec/library/set/sortedset/case_equality_spec.rb
new file mode 100644
index 0000000000..f5ff2c91fe
--- /dev/null
+++ b/spec/rubyspec/library/set/sortedset/case_equality_spec.rb
@@ -0,0 +1,7 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../shared/include', __FILE__)
+require 'set'
+
+describe "SortedSet#===" do
+  it_behaves_like :sorted_set_include, :===
+end
diff --git a/test/test_set.rb b/test/test_set.rb
index aaf3bfe3b8..daae12723d 100644
--- a/test/test_set.rb
+++ b/test/test_set.rb
@@ -200,6 +200,23 @@ class TC_Set < Test::Unit::TestCase
     assert_equal(false, set.include?(true))
   end
 
+  def test_eqq
+    set = Set[1,2,3]
+
+    assert_equal(true, set === 1)
+    assert_equal(true, set === 2)
+    assert_equal(true, set === 3)
+    assert_equal(false, set === 0)
+    assert_equal(false, set === nil)
+
+    set = Set["1",nil,"2",nil,"0","1",false]
+    assert_equal(true, set === nil)
+    assert_equal(true, set === false)
+    assert_equal(true, set === "1")
+    assert_equal(false, set === 0)
+    assert_equal(false, set === true)
+  end
+
   def test_superset?
     set = Set[1,2,3]