5 files changed, 40 insertions, 14 deletions
diff --git a/activesupport/CHANGELOG b/activesupport/CHANGELOG
index acf9788285..59e59e37ba 100644
--- a/activesupport/CHANGELOG
+++ b/activesupport/CHANGELOG
@@ -1,5 +1,7 @@
 *SVN*
 
+* Added Array#to_sentence that'll turn ['one', 'two', 'three'] into "one, two, and three" #2157 [m.stienstra@fngtps.com]
+
 * Added Kernel#silence_warnings to turn off warnings temporarily for the passed block
 
 * Added String#starts_with? and String#ends_with? #2118 [thijs@vandervossen.net]
diff --git a/activesupport/lib/active_support/core_ext/array.rb b/activesupport/lib/active_support/core_ext/array.rb
index 83eef79b38..ddf2a369c1 100644
--- a/activesupport/lib/active_support/core_ext/array.rb
+++ b/activesupport/lib/active_support/core_ext/array.rb
@@ -1,5 +1,5 @@
-require File.dirname(__FILE__) + '/array/to_param'
+require File.dirname(__FILE__) + '/array/conversions'
 
 class Array #:nodoc:
-  include ActiveSupport::CoreExtensions::Array::ToParam
+  include ActiveSupport::CoreExtensions::Array::Conversions
 end
diff --git a/activesupport/lib/active_support/core_ext/array/conversions.rb b/activesupport/lib/active_support/core_ext/array/conversions.rb
new file mode 100644
index 0000000000..19220da2b1
--- /dev/null
+++ b/activesupport/lib/active_support/core_ext/array/conversions.rb
@@ -0,0 +1,22 @@
+module ActiveSupport #:nodoc:
+  module CoreExtensions #:nodoc:
+    module Array #:nodoc:
+      # Enables to conversion of Arrays to human readable lists. ['one', 'two', 'three'] => "one, two, and three"
+      module Conversions
+        # Converts the array to comma-seperated sentence where the last element is joined by the connector word (default is 'and').
+        def to_sentence(connector = 'and')
+          if length > 1
+            "#{self[0...-1].join(', ')}, #{connector} #{self[-1]}"
+          elsif length == 1
+            self[0]
+          end
+        end
+
+        # When an array is given to url_for, it is converted to a slash separated string.
+        def to_param
+          join '/'
+        end
+      end
+    end
+  end
+end
diff --git a/activesupport/lib/active_support/core_ext/array/to_param.rb b/activesupport/lib/active_support/core_ext/array/to_param.rb
deleted file mode 100644
index 85e91e6b1a..0000000000
--- a/activesupport/lib/active_support/core_ext/array/to_param.rb
+++ /dev/null
@@ -1,12 +0,0 @@
-module ActiveSupport #:nodoc:
-  module CoreExtensions #:nodoc:
-    module Array #:nodoc:
-      module ToParam #:nodoc:
-        # When an array is given to url_for, it is converted to a slash separated string.
-        def to_param
-          join '/'
-        end
-      end
-    end
-  end
-end
diff --git a/activesupport/test/core_ext/array_ext_test.rb b/activesupport/test/core_ext/array_ext_test.rb
index 3b16c8d2b3..2ee86c8af9 100644
--- a/activesupport/test/core_ext/array_ext_test.rb
+++ b/activesupport/test/core_ext/array_ext_test.rb
@@ -12,3 +12,17 @@ class ArrayExtToParamTests < Test::Unit::TestCase
     assert_equal '10/20', [10, 20].to_param
   end
 end
+
+class ArrayExtConversionTests < Test::Unit::TestCase
+  def test_plain_array_to_sentence
+    assert_equal "one, two, and three", ['one', 'two', 'three'].to_sentence
+  end
+  
+  def test_to_sentence_with_connector
+    assert_equal "one, two, and also three", ['one', 'two', 'three'].to_sentence('and also')
+  end
+  
+  def test_one_element
+    assert_equal "one", ['one'].to_sentence
+  end
+end