diff --git a/NEWS b/NEWS
index ab27497082..272b9ba475 100644
--- a/NEWS
+++ b/NEWS
@@ -20,6 +20,13 @@ with all sufficient information, see the ChangeLog file or Redmine
 
 === Core classes updates (outstanding ones only)
 
+* Array
+
+  * Aliased methods:
+
+    * Array#filter is a new alias for Array#select [Feature #13784]
+    * Array#filter! is a new alias for Array#select! [Feature #13784]
+
 * Binding
 
   * New methods:
@@ -40,6 +47,25 @@ with all sufficient information, see the ChangeLog file or Redmine
 
     * added Dir#each_child and Dir#children instance methods. [Feature #13969]
 
+* Enumerable
+
+  * Aliased methods:
+
+    * Enumerable#filter is a new alias for Enumerable#select [Feature #13784]
+
+* Enumerator::Lazy
+
+  * Aliased methods:
+
+    * Enumerator::Lazy#filter is a new alias for Enumerator::Lazy#select [Feature #13784]
+
+* Hash
+
+  * Aliased methods:
+
+    * Hash#filter is a new alias for Hash#select [Feature #13784]
+    * Hash#filter! is a new alias for Hash#select! [Feature #13784]
+
 * Kernel
 
   * Kernel.#system takes :exception option to raise an exception on
@@ -80,6 +106,12 @@ with all sufficient information, see the ChangeLog file or Redmine
 
     * Matrix#antisymmetric?
 
+* Set
+
+  * Aliased methods:
+
+    * Set#filter! is a new alias for Set#select! [Feature #13784]
+
 === Compatibility issues (excluding feature bug fixes)
 
 === Stdlib compatibility issues (excluding feature bug fixes)
diff --git a/array.c b/array.c
index f97447f7ea..1d536284d5 100644
--- a/array.c
+++ b/array.c
@@ -6298,6 +6298,8 @@ Init_Array(void)
     rb_define_method(rb_cArray, "map!", rb_ary_collect_bang, 0);
     rb_define_method(rb_cArray, "select", rb_ary_select, 0);
     rb_define_method(rb_cArray, "select!", rb_ary_select_bang, 0);
+    rb_define_method(rb_cArray, "filter", rb_ary_select, 0);
+    rb_define_method(rb_cArray, "filter!", rb_ary_select_bang, 0);
     rb_define_method(rb_cArray, "keep_if", rb_ary_keep_if, 0);
     rb_define_method(rb_cArray, "values_at", rb_ary_values_at, -1);
     rb_define_method(rb_cArray, "delete", rb_ary_delete, 1);
diff --git a/enum.c b/enum.c
index 0df4461430..b9b9ca7b7a 100644
--- a/enum.c
+++ b/enum.c
@@ -388,8 +388,10 @@ enum_size_over_p(VALUE obj, long n)
  *  call-seq:
  *     enum.find_all { |obj| block } -> array
  *     enum.select   { |obj| block } -> array
+ *     enum.filter   { |obj| block } -> array
  *     enum.find_all                 -> an_enumerator
  *     enum.select                   -> an_enumerator
+ *     enum.filter                   -> an_enumerator
  *
  *  Returns an array containing all elements of +enum+
  *  for which the given +block+ returns a true value.
@@ -401,6 +403,8 @@ enum_size_over_p(VALUE obj, long n)
  *
  *     [1,2,3,4,5].select { |num|  num.even?  }   #=> [2, 4]
  *
+ *     [:foo, :bar].filter { |x| x == :foo }   #=> [:foo]
+ *
  *  See also Enumerable#reject.
  */
 
@@ -3994,6 +3998,7 @@ Init_Enumerable(void)
     rb_define_method(rb_mEnumerable, "find_index", enum_find_index, -1);
     rb_define_method(rb_mEnumerable, "find_all", enum_find_all, 0);
     rb_define_method(rb_mEnumerable, "select", enum_find_all, 0);
+    rb_define_method(rb_mEnumerable, "filter", enum_find_all, 0);
     rb_define_method(rb_mEnumerable, "reject", enum_reject, 0);
     rb_define_method(rb_mEnumerable, "collect", enum_collect, 0);
     rb_define_method(rb_mEnumerable, "map", enum_collect, 0);
diff --git a/enumerator.c b/enumerator.c
index 0c2ce19502..ba470a4492 100644
--- a/enumerator.c
+++ b/enumerator.c
@@ -2377,6 +2377,7 @@ InitVM_Enumerator(void)
     rb_define_method(rb_cLazy, "collect_concat", lazy_flat_map, 0);
     rb_define_method(rb_cLazy, "select", lazy_select, 0);
     rb_define_method(rb_cLazy, "find_all", lazy_select, 0);
+    rb_define_method(rb_cLazy, "filter", lazy_select, 0);
     rb_define_method(rb_cLazy, "reject", lazy_reject, 0);
     rb_define_method(rb_cLazy, "grep", lazy_grep, 1);
     rb_define_method(rb_cLazy, "grep_v", lazy_grep_v, 1);
diff --git a/hash.c b/hash.c
index d2ca057e33..3a499872ad 100644
--- a/hash.c
+++ b/hash.c
@@ -4690,6 +4690,8 @@ Init_Hash(void)
     rb_define_method(rb_cHash, "keep_if", rb_hash_keep_if, 0);
     rb_define_method(rb_cHash, "select", rb_hash_select, 0);
     rb_define_method(rb_cHash, "select!", rb_hash_select_bang, 0);
+    rb_define_method(rb_cHash, "filter", rb_hash_select, 0);
+    rb_define_method(rb_cHash, "filter!", rb_hash_select_bang, 0);
     rb_define_method(rb_cHash, "reject", rb_hash_reject, 0);
     rb_define_method(rb_cHash, "reject!", rb_hash_reject_bang, 0);
     rb_define_method(rb_cHash, "slice", rb_hash_slice, -1);
@@ -4752,6 +4754,8 @@ Init_Hash(void)
     rb_define_singleton_method(envtbl, "reject!", env_reject_bang, 0);
     rb_define_singleton_method(envtbl, "select", env_select, 0);
     rb_define_singleton_method(envtbl, "select!", env_select_bang, 0);
+    rb_define_singleton_method(envtbl, "filter", env_select, 0);
+    rb_define_singleton_method(envtbl, "filter!", env_select_bang, 0);
     rb_define_singleton_method(envtbl, "shift", env_shift, 0);
     rb_define_singleton_method(envtbl, "invert", env_invert, 0);
     rb_define_singleton_method(envtbl, "replace", env_replace, 1);
diff --git a/lib/set.rb b/lib/set.rb
index 9642e74af4..e639636c97 100644
--- a/lib/set.rb
+++ b/lib/set.rb
@@ -424,6 +424,9 @@ class Set
     self if size != n
   end
 
+  # Equivalent to Set#select!
+  alias filter! select!
+
   # Merges the elements of the given enumerable object to the set and
   # returns self.
   def merge(enum)
diff --git a/spec/ruby/core/array/filter_spec.rb b/spec/ruby/core/array/filter_spec.rb
new file mode 100644
index 0000000000..d7c722e44c
--- /dev/null
+++ b/spec/ruby/core/array/filter_spec.rb
@@ -0,0 +1,14 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
+
+describe "Array#filter" do
+  it_behaves_like :array_select, :filter
+end
+
+describe "Array#filter!" do
+  it "returns nil if no changes were made in the array" do
+    [1, 2, 3].filter! { true }.should be_nil
+  end
+
+  it_behaves_like :keep_if, :filter!
+end
diff --git a/spec/ruby/core/array/select_spec.rb b/spec/ruby/core/array/select_spec.rb
index 8b83acaa5f..b7531c967d 100644
--- a/spec/ruby/core/array/select_spec.rb
+++ b/spec/ruby/core/array/select_spec.rb
@@ -1,30 +1,8 @@
 require File.expand_path('../../../spec_helper', __FILE__)
-require File.expand_path('../fixtures/classes', __FILE__)
-require File.expand_path('../shared/enumeratorize', __FILE__)
-require File.expand_path('../shared/keep_if', __FILE__)
-require File.expand_path('../../enumerable/shared/enumeratorized', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
 
 describe "Array#select" do
-  it_behaves_like :enumeratorize, :select
-  it_behaves_like :enumeratorized_with_origin_size, :select, [1,2,3]
-
-  it "returns a new array of elements for which block is true" do
-    [1, 3, 4, 5, 6, 9].select { |i| i % ((i + 1) / 2) == 0}.should == [1, 4, 6]
-  end
-
-  it "does not return subclass instance on Array subclasses" do
-    ArraySpecs::MyArray[1, 2, 3].select { true }.should be_an_instance_of(Array)
-  end
-
-  it "properly handles recursive arrays" do
-    empty = ArraySpecs.empty_recursive_array
-    empty.select { true }.should == empty
-    empty.select { false }.should == []
-
-    array = ArraySpecs.recursive_array
-    array.select { true }.should == [1, 'two', 3.0, array, array, array, array, array]
-    array.select { false }.should == []
-  end
+  it_behaves_like :array_select, :select
 end
 
 describe "Array#select!" do
diff --git a/spec/ruby/core/array/shared/select.rb b/spec/ruby/core/array/shared/select.rb
new file mode 100644
index 0000000000..e09231415d
--- /dev/null
+++ b/spec/ruby/core/array/shared/select.rb
@@ -0,0 +1,32 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../../fixtures/classes', __FILE__)
+require File.expand_path('../../shared/enumeratorize', __FILE__)
+require File.expand_path('../../shared/keep_if', __FILE__)
+require File.expand_path('../../../enumerable/shared/enumeratorized', __FILE__)
+
+describe :array_select, shared: true do
+  it_should_behave_like :enumeratorize
+
+  before :each do
+    @object = [1,2,3]
+  end
+  it_should_behave_like :enumeratorized_with_origin_size
+
+  it "returns a new array of elements for which block is true" do
+    [1, 3, 4, 5, 6, 9].send(@method) { |i| i % ((i + 1) / 2) == 0}.should == [1, 4, 6]
+  end
+
+  it "does not return subclass instance on Array subclasses" do
+    ArraySpecs::MyArray[1, 2, 3].send(@method) { true }.should be_an_instance_of(Array)
+  end
+
+  it "properly handles recursive arrays" do
+    empty = ArraySpecs.empty_recursive_array
+    empty.send(@method) { true }.should == empty
+    empty.send(@method) { false }.should == []
+
+    array = ArraySpecs.recursive_array
+    array.send(@method) { true }.should == [1, 'two', 3.0, array, array, array, array, array]
+    array.send(@method) { false }.should == []
+  end
+end
diff --git a/spec/ruby/core/enumerable/filter_spec.rb b/spec/ruby/core/enumerable/filter_spec.rb
new file mode 100644
index 0000000000..7f4bdd6d59
--- /dev/null
+++ b/spec/ruby/core/enumerable/filter_spec.rb
@@ -0,0 +1,7 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../fixtures/classes', __FILE__)
+require File.expand_path('../shared/find_all', __FILE__)
+
+describe "Enumerable#filter" do
+  it_behaves_like(:enumerable_find_all , :filter)
+end
diff --git a/spec/ruby/core/hash/filter_spec.rb b/spec/ruby/core/hash/filter_spec.rb
new file mode 100644
index 0000000000..46c7bea8e8
--- /dev/null
+++ b/spec/ruby/core/hash/filter_spec.rb
@@ -0,0 +1,10 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
+
+describe "Hash#filter" do
+  it_behaves_like :hash_select, :filter
+end
+
+describe "Hash#filter!" do
+  it_behaves_like :hash_select!, :filter!
+end
diff --git a/spec/ruby/core/hash/select_spec.rb b/spec/ruby/core/hash/select_spec.rb
index 9348cc4c39..f8d66d09fd 100644
--- a/spec/ruby/core/hash/select_spec.rb
+++ b/spec/ruby/core/hash/select_spec.rb
@@ -1,83 +1,10 @@
 require File.expand_path('../../../spec_helper', __FILE__)
-require File.expand_path('../fixtures/classes', __FILE__)
-require File.expand_path('../shared/iteration', __FILE__)
-require File.expand_path('../../enumerable/shared/enumeratorized', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
 
 describe "Hash#select" do
-  before :each do
-    @hsh = { 1 => 2, 3 => 4, 5 => 6 }
-    @empty = {}
-  end
-
-  it "yields two arguments: key and value" do
-    all_args = []
-    { 1 => 2, 3 => 4 }.select { |*args| all_args << args }
-    all_args.sort.should == [[1, 2], [3, 4]]
-  end
-
-  it "returns a Hash of entries for which block is true" do
-    a_pairs = { 'a' => 9, 'c' => 4, 'b' => 5, 'd' => 2 }.select { |k,v| v % 2 == 0 }
-    a_pairs.should be_an_instance_of(Hash)
-    a_pairs.sort.should == [['c', 4], ['d', 2]]
-  end
-
-  it "processes entries with the same order as reject" do
-    h = { a: 9, c: 4, b: 5, d: 2 }
-
-    select_pairs = []
-    reject_pairs = []
-    h.dup.select { |*pair| select_pairs << pair }
-    h.reject { |*pair| reject_pairs << pair }
-
-    select_pairs.should == reject_pairs
-  end
-
-  it "returns an Enumerator when called on a non-empty hash without a block" do
-    @hsh.select.should be_an_instance_of(Enumerator)
-  end
-
-  it "returns an Enumerator when called on an empty hash without a block" do
-    @empty.select.should be_an_instance_of(Enumerator)
-  end
-
-  it_behaves_like :hash_iteration_no_block, :select
-  it_behaves_like :enumeratorized_with_origin_size, :select, { 1 => 2, 3 => 4, 5 => 6 }
+  it_behaves_like :hash_select, :select
 end
 
 describe "Hash#select!" do
-  before :each do
-    @hsh = { 1 => 2, 3 => 4, 5 => 6 }
-    @empty = {}
-  end
-
-  it "is equivalent to keep_if if changes are made" do
-    h = { a: 2 }
-    h.select! { |k,v| v <= 1 }.should equal h
-
-    h = { 1 => 2, 3 => 4 }
-    all_args_select = []
-    h.dup.select! { |*args| all_args_select << args }
-    all_args_select.should == [[1, 2], [3, 4]]
-  end
-
-  it "removes all entries if the block is false" do
-    h = { a: 1, b: 2, c: 3 }
-    h.select! { |k,v| false }.should equal(h)
-    h.should == {}
-  end
-
-  it "returns nil if no changes were made" do
-    { a: 1 }.select! { |k,v| v <= 1 }.should == nil
-  end
-
-  it "raises a #{frozen_error_class} if called on an empty frozen instance" do
-    lambda { HashSpecs.empty_frozen_hash.select! { false } }.should raise_error(frozen_error_class)
-  end
-
-  it "raises a #{frozen_error_class} if called on a frozen instance that would not be modified" do
-    lambda { HashSpecs.frozen_hash.select! { true } }.should raise_error(frozen_error_class)
-  end
-
-  it_behaves_like :hash_iteration_no_block, :select!
-  it_behaves_like :enumeratorized_with_origin_size, :select!, { 1 => 2, 3 => 4, 5 => 6 }
+  it_behaves_like :hash_select!, :select!
 end
diff --git a/spec/ruby/core/hash/shared/select.rb b/spec/ruby/core/hash/shared/select.rb
new file mode 100644
index 0000000000..3ffd901cea
--- /dev/null
+++ b/spec/ruby/core/hash/shared/select.rb
@@ -0,0 +1,91 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../../fixtures/classes', __FILE__)
+require File.expand_path('../../shared/iteration', __FILE__)
+require File.expand_path('../../../enumerable/shared/enumeratorized', __FILE__)
+
+describe :hash_select, shared: true do
+  before :each do
+    @hsh = { 1 => 2, 3 => 4, 5 => 6 }
+    @empty = {}
+  end
+
+  it "yields two arguments: key and value" do
+    all_args = []
+    { 1 => 2, 3 => 4 }.send(@method) { |*args| all_args << args }
+    all_args.sort.should == [[1, 2], [3, 4]]
+  end
+
+  it "returns a Hash of entries for which block is true" do
+    a_pairs = { 'a' => 9, 'c' => 4, 'b' => 5, 'd' => 2 }.send(@method) { |k,v| v % 2 == 0 }
+    a_pairs.should be_an_instance_of(Hash)
+    a_pairs.sort.should == [['c', 4], ['d', 2]]
+  end
+
+  it "processes entries with the same order as reject" do
+    h = { a: 9, c: 4, b: 5, d: 2 }
+
+    select_pairs = []
+    reject_pairs = []
+    h.dup.send(@method) { |*pair| select_pairs << pair }
+    h.reject { |*pair| reject_pairs << pair }
+
+    select_pairs.should == reject_pairs
+  end
+
+  it "returns an Enumerator when called on a non-empty hash without a block" do
+    @hsh.send(@method).should be_an_instance_of(Enumerator)
+  end
+
+  it "returns an Enumerator when called on an empty hash without a block" do
+    @empty.send(@method).should be_an_instance_of(Enumerator)
+  end
+
+  it_should_behave_like :hash_iteration_no_block
+
+  before :each do
+    @object = { 1 => 2, 3 => 4, 5 => 6 }
+  end
+  it_should_behave_like :enumeratorized_with_origin_size
+end
+
+describe :hash_select!, shared: true do
+  before :each do
+    @hsh = { 1 => 2, 3 => 4, 5 => 6 }
+    @empty = {}
+  end
+
+  it "is equivalent to keep_if if changes are made" do
+    h = { a: 2 }
+    h.send(@method) { |k,v| v <= 1 }.should equal h
+
+    h = { 1 => 2, 3 => 4 }
+    all_args_select = []
+    h.dup.send(@method) { |*args| all_args_select << args }
+    all_args_select.should == [[1, 2], [3, 4]]
+  end
+
+  it "removes all entries if the block is false" do
+    h = { a: 1, b: 2, c: 3 }
+    h.send(@method) { |k,v| false }.should equal(h)
+    h.should == {}
+  end
+
+  it "returns nil if no changes were made" do
+    { a: 1 }.send(@method) { |k,v| v <= 1 }.should == nil
+  end
+
+  it "raises a #{frozen_error_class} if called on an empty frozen instance" do
+    lambda { HashSpecs.empty_frozen_hash.send(@method) { false } }.should raise_error(frozen_error_class)
+  end
+
+  it "raises a #{frozen_error_class} if called on a frozen instance that would not be modified" do
+    lambda { HashSpecs.frozen_hash.send(@method) { true } }.should raise_error(frozen_error_class)
+  end
+
+  it_should_behave_like :hash_iteration_no_block
+
+  before :each do
+    @object = { 1 => 2, 3 => 4, 5 => 6 }
+  end
+  it_should_behave_like :enumeratorized_with_origin_size
+end
diff --git a/spec/ruby/library/set/filter_spec.rb b/spec/ruby/library/set/filter_spec.rb
new file mode 100644
index 0000000000..3ac0c660b2
--- /dev/null
+++ b/spec/ruby/library/set/filter_spec.rb
@@ -0,0 +1,6 @@
+require File.expand_path('../../../spec_helper', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
+
+describe "Set#filter!" do
+  it_behaves_like :set_select_bang, :filter!
+end
diff --git a/spec/ruby/library/set/select_spec.rb b/spec/ruby/library/set/select_spec.rb
index 34274a7c46..433fbb4617 100644
--- a/spec/ruby/library/set/select_spec.rb
+++ b/spec/ruby/library/set/select_spec.rb
@@ -1,42 +1,6 @@
 require File.expand_path('../../../spec_helper', __FILE__)
-require 'set'
+require File.expand_path('../shared/select', __FILE__)
 
 describe "Set#select!" do
-  before :each do
-    @set = Set["one", "two", "three"]
-  end
-
-  it "yields every element of self" do
-    ret = []
-    @set.select! { |x| ret << x }
-    ret.sort.should == ["one", "two", "three"].sort
-  end
-
-  it "keeps every element from self for which the passed block returns true" do
-    @set.select! { |x| x.size != 3 }
-    @set.size.should eql(1)
-
-    @set.should_not include("one")
-    @set.should_not include("two")
-    @set.should include("three")
-  end
-
-  it "returns self when self was modified" do
-    @set.select! { false }.should equal(@set)
-  end
-
-  it "returns nil when self was not modified" do
-    @set.select! { true }.should be_nil
-  end
-
-  it "returns an Enumerator when passed no block" do
-    enum = @set.select!
-    enum.should be_an_instance_of(Enumerator)
-
-    enum.each { |x| x.size != 3 }
-
-    @set.should_not include("one")
-    @set.should_not include("two")
-    @set.should include("three")
-  end
+  it_behaves_like :set_select_bang, :select!
 end
diff --git a/spec/ruby/library/set/shared/select.rb b/spec/ruby/library/set/shared/select.rb
new file mode 100644
index 0000000000..c9f01b8a25
--- /dev/null
+++ b/spec/ruby/library/set/shared/select.rb
@@ -0,0 +1,42 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require 'set'
+
+describe :set_select_bang, shared: true do
+  before :each do
+    @set = Set["one", "two", "three"]
+  end
+
+  it "yields every element of self" do
+    ret = []
+    @set.send(@method) { |x| ret << x }
+    ret.sort.should == ["one", "two", "three"].sort
+  end
+
+  it "keeps every element from self for which the passed block returns true" do
+    @set.send(@method) { |x| x.size != 3 }
+    @set.size.should eql(1)
+
+    @set.should_not include("one")
+    @set.should_not include("two")
+    @set.should include("three")
+  end
+
+  it "returns self when self was modified" do
+    @set.send(@method) { false }.should equal(@set)
+  end
+
+  it "returns nil when self was not modified" do
+    @set.send(@method) { true }.should be_nil
+  end
+
+  it "returns an Enumerator when passed no block" do
+    enum = @set.send(@method)
+    enum.should be_an_instance_of(Enumerator)
+
+    enum.each { |x| x.size != 3 }
+
+    @set.should_not include("one")
+    @set.should_not include("two")
+    @set.should include("three")
+  end
+end
diff --git a/spec/ruby/library/set/sortedset/filter_spec.rb b/spec/ruby/library/set/sortedset/filter_spec.rb
new file mode 100644
index 0000000000..59e264ed84
--- /dev/null
+++ b/spec/ruby/library/set/sortedset/filter_spec.rb
@@ -0,0 +1,7 @@
+require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
+require 'set'
+
+describe "SortedSet#filter!" do
+  it_behaves_like :sorted_set_select_bang, :filter!
+end
diff --git a/spec/ruby/library/set/sortedset/select_spec.rb b/spec/ruby/library/set/sortedset/select_spec.rb
index 3ca748350a..b00525346c 100644
--- a/spec/ruby/library/set/sortedset/select_spec.rb
+++ b/spec/ruby/library/set/sortedset/select_spec.rb
@@ -1,35 +1,7 @@
 require File.expand_path('../../../../spec_helper', __FILE__)
+require File.expand_path('../shared/select', __FILE__)
 require 'set'
 
 describe "SortedSet#select!" do
-  before :each do
-    @set = SortedSet["one", "two", "three"]
-  end
-
-  it "yields each Object in self in sorted order" do
-    res = []
-    @set.select! { |x| res << x }
-    res.should == ["one", "two", "three"].sort
-  end
-
-  it "keeps every element from self for which the passed block returns true" do
-    @set.select! { |x| x.size != 3 }
-    @set.to_a.should == ["three"]
-  end
-
-  it "returns self when self was modified" do
-    @set.select! { false }.should equal(@set)
-  end
-
-  it "returns nil when self was not modified" do
-    @set.select! { true }.should be_nil
-  end
-
-  it "returns an Enumerator when passed no block" do
-    enum = @set.select!
-    enum.should be_an_instance_of(Enumerator)
-
-    enum.each { |x| x.size != 3 }
-    @set.to_a.should == ["three"]
-  end
+  it_behaves_like :sorted_set_select_bang, :select!
 end
diff --git a/spec/ruby/library/set/sortedset/shared/select.rb b/spec/ruby/library/set/sortedset/shared/select.rb
new file mode 100644
index 0000000000..d3ce4ed33a
--- /dev/null
+++ b/spec/ruby/library/set/sortedset/shared/select.rb
@@ -0,0 +1,35 @@
+require File.expand_path('../../../../../spec_helper', __FILE__)
+require 'set'
+
+describe :sorted_set_select_bang, shared: true do
+  before :each do
+    @set = SortedSet["one", "two", "three"]
+  end
+
+  it "yields each Object in self in sorted order" do
+    res = []
+    @set.send(@method) { |x| res << x }
+    res.should == ["one", "two", "three"].sort
+  end
+
+  it "keeps every element from self for which the passed block returns true" do
+    @set.send(@method) { |x| x.size != 3 }
+    @set.to_a.should == ["three"]
+  end
+
+  it "returns self when self was modified" do
+    @set.send(@method) { false }.should equal(@set)
+  end
+
+  it "returns nil when self was not modified" do
+    @set.send(@method) { true }.should be_nil
+  end
+
+  it "returns an Enumerator when passed no block" do
+    enum = @set.send(@method)
+    enum.should be_an_instance_of(Enumerator)
+
+    enum.each { |x| x.size != 3 }
+    @set.to_a.should == ["three"]
+  end
+end
diff --git a/test/ruby/test_array.rb b/test/ruby/test_array.rb
index 955121c0f0..39bf635079 100644
--- a/test/ruby/test_array.rb
+++ b/test/ruby/test_array.rb
@@ -170,6 +170,7 @@ class TestArray < Test::Unit::TestCase
   def test_find_all_0
     assert_respond_to([], :find_all)
     assert_respond_to([], :select)       # Alias
+    assert_respond_to([], :filter)       # Alias
     assert_equal([], [].find_all{ |obj| obj == "foo"})
 
     x = ["foo", "bar", "baz", "baz", 1, 2, 3, 3, 4]
@@ -2301,6 +2302,25 @@ class TestArray < Test::Unit::TestCase
     assert_equal(@cls[4, 5], a)
   end
 
+  def test_filter
+    assert_equal([0, 2], [0, 1, 2, 3].filter {|x| x % 2 == 0 })
+  end
+
+  # alias for select!
+  def test_filter!
+    a = @cls[ 1, 2, 3, 4, 5 ]
+    assert_equal(nil, a.filter! { true })
+    assert_equal(@cls[1, 2, 3, 4, 5], a)
+
+    a = @cls[ 1, 2, 3, 4, 5 ]
+    assert_equal(a, a.filter! { false })
+    assert_equal(@cls[], a)
+
+    a = @cls[ 1, 2, 3, 4, 5 ]
+    assert_equal(a, a.filter! { |i| i > 3 })
+    assert_equal(@cls[4, 5], a)
+  end
+
   def test_delete2
     a = [0] * 1024 + [1] + [0] * 1024
     a.delete(0)
diff --git a/test/ruby/test_enumerator.rb b/test/ruby/test_enumerator.rb
index 235dfbfc9b..86cab539ab 100644
--- a/test/ruby/test_enumerator.rb
+++ b/test/ruby/test_enumerator.rb
@@ -505,7 +505,7 @@ class TestEnumerator < Test::Unit::TestCase
   def test_size_for_enum_created_from_array
     arr = %w[hello world]
     %i[each each_with_index reverse_each sort_by! sort_by map map!
-      keep_if reject! reject select! select delete_if].each do |method|
+      keep_if reject! reject select! select filter! filter delete_if].each do |method|
       assert_equal arr.size, arr.send(method).size
     end
   end
@@ -522,7 +522,7 @@ class TestEnumerator < Test::Unit::TestCase
 
   def test_size_for_enum_created_from_hash
     h = {a: 1, b: 2, c: 3}
-    methods = %i[delete_if reject reject! select select! keep_if each each_key each_pair]
+    methods = %i[delete_if reject reject! select select! filter filter! keep_if each each_key each_pair]
     enums = methods.map {|method| h.send(method)}
     s = enums.group_by(&:size)
     assert_equal([3], s.keys, ->{s.reject!{|k| k==3}.inspect})
@@ -532,7 +532,7 @@ class TestEnumerator < Test::Unit::TestCase
   end
 
   def test_size_for_enum_created_from_env
-    %i[each_pair reject! delete_if select select! keep_if].each do |method|
+    %i[each_pair reject! delete_if select select! filter filter! keep_if].each do |method|
       assert_equal ENV.size, ENV.send(method).size
     end
   end
diff --git a/test/ruby/test_env.rb b/test/ruby/test_env.rb
index ffed94efa6..699f7db084 100644
--- a/test/ruby/test_env.rb
+++ b/test/ruby/test_env.rb
@@ -222,6 +222,18 @@ class TestEnv < Test::Unit::TestCase
     assert_nil(ENV.select! {|k, v| IGNORE_CASE ? k.upcase != "TEST" : k != "test" })
   end
 
+  def test_filter_bang
+    h1 = {}
+    ENV.each_pair {|k, v| h1[k] = v }
+    ENV["test"] = "foo"
+    ENV.filter! {|k, v| IGNORE_CASE ? k.upcase != "TEST" : k != "test" }
+    h2 = {}
+    ENV.each_pair {|k, v| h2[k] = v }
+    assert_equal(h1, h2)
+
+    assert_nil(ENV.filter! {|k, v| IGNORE_CASE ? k.upcase != "TEST" : k != "test" })
+  end
+
   def test_keep_if
     h1 = {}
     ENV.each_pair {|k, v| h1[k] = v }
@@ -254,6 +266,21 @@ class TestEnv < Test::Unit::TestCase
     end
   end
 
+  def test_filter
+    ENV["test"] = "foo"
+    h = ENV.filter {|k| IGNORE_CASE ? k.upcase == "TEST" : k == "test" }
+    assert_equal(1, h.size)
+    k = h.keys.first
+    v = h.values.first
+    if IGNORE_CASE
+      assert_equal("TEST", k.upcase)
+      assert_equal("FOO", v.upcase)
+    else
+      assert_equal("test", k)
+      assert_equal("foo", v)
+    end
+  end
+
   def test_clear
     ENV.clear
     assert_equal(0, ENV.size)
diff --git a/test/ruby/test_hash.rb b/test/ruby/test_hash.rb
index 55e46584b4..088178defa 100644
--- a/test/ruby/test_hash.rb
+++ b/test/ruby/test_hash.rb
@@ -1017,6 +1017,44 @@ class TestHash < Test::Unit::TestCase
     assert_equal({}, {}.slice)
   end
 
+  def test_filter
+    assert_equal({3=>4,5=>6}, @cls[1=>2,3=>4,5=>6].filter {|k, v| k + v >= 7 })
+
+    base = @cls[ 1 => 'one', '2' => false, true => 'true', 'cat' => 99 ]
+    h1   = @cls[ '2' => false, 'cat' => 99 ]
+    h2   = @cls[ 1 => 'one', true => 'true' ]
+    h3   = @cls[ 1 => 'one', true => 'true', 'cat' => 99 ]
+
+    h = base.dup
+    assert_equal(h, h.filter { true })
+    assert_equal(@cls[], h.filter { false })
+
+    h = base.dup
+    assert_equal(h1, h.filter {|k,v| k.instance_of?(String) })
+
+    assert_equal(h2, h.filter {|k,v| v.instance_of?(String) })
+
+    assert_equal(h3, h.filter {|k,v| v })
+    assert_equal(base, h)
+
+    h.instance_variable_set(:@foo, :foo)
+    h.default = 42
+    h.taint
+    h = h.filter {true}
+    assert_instance_of(Hash, h)
+    assert_not_predicate(h, :tainted?)
+    assert_nil(h.default)
+    assert_not_send([h, :instance_variable_defined?, :@foo])
+  end
+
+  def test_filter!
+    h = @cls[1=>2,3=>4,5=>6]
+    assert_equal(h, h.filter! {|k, v| k + v >= 7 })
+    assert_equal({3=>4,5=>6}, h)
+    h = @cls[1=>2,3=>4,5=>6]
+    assert_equal(nil, h.filter!{true})
+  end
+
   def test_clear2
     assert_equal({}, @cls[1=>2,3=>4,5=>6].clear)
     h = @cls[1=>2,3=>4,5=>6]
diff --git a/test/test_set.rb b/test/test_set.rb
index 4c6730d141..b20920e63e 100644
--- a/test/test_set.rb
+++ b/test/test_set.rb
@@ -545,6 +545,24 @@ class TC_Set < Test::Unit::TestCase
     assert_equal(Set.new(1..10), set)
   end
 
+  def test_filter!
+    set = Set.new(1..10)
+    ret = set.filter! { |i| i <= 10 }
+    assert_equal(nil, ret)
+    assert_equal(Set.new(1..10), set)
+
+    set = Set.new(1..10)
+    ret = set.filter! { |i| i % 3 != 0 }
+    assert_same(set, ret)
+    assert_equal(Set[1,2,4,5,7,8,10], set)
+
+    set = Set.new(1..10)
+    enum = set.filter!
+    assert_equal(set.size, enum.size)
+    assert_equal(nil, enum.each { |i| i <= 10 })
+    assert_equal(Set.new(1..10), set)
+  end
+
   def test_merge
     set = Set[1,2,3]