2 files changed, 30 insertions, 15 deletions

diff --git a/activesupport/lib/active_support/inflector/inflections.rb b/activesupport/lib/active_support/inflector/inflections.rb
index c9e50a9462..091692e5a4 100644
--- a/activesupport/lib/active_support/inflector/inflections.rb
+++ b/activesupport/lib/active_support/inflector/inflections.rb
@@ -1,13 +1,15 @@
 require 'active_support/core_ext/array/prepend_and_append'
+require 'active_support/i18n'
 
 module ActiveSupport
   module Inflector
     extend self
 
     # A singleton instance of this class is yielded by Inflector.inflections, which can then be used to specify additional
-    # inflection rules.
+    # inflection rules. If passed an optional locale, rules for other languages can be specified. The default locale is
+    # <tt>:en</tt>. Only rules for English are provided.
     #
-    #   ActiveSupport::Inflector.inflections do |inflect|
+    #   ActiveSupport::Inflector.inflections(:en) do |inflect|
     #     inflect.plural /^(ox)$/i, '\1\2en'
     #     inflect.singular /^(ox)en/i, '\1'
     #
@@ -20,8 +22,9 @@ module ActiveSupport
     # pluralization and singularization rules that is runs. This guarantees that your rules run before any of the rules that may
     # already have been loaded.
     class Inflections
-      def self.instance
-        @__instance__ ||= new
+      def self.instance(locale = :en)
+        @__instance__ ||= Hash.new { |h, k| h[k] = new }
+        @__instance__[locale]
       end
 
       attr_reader :plurals, :singulars, :uncountables, :humans, :acronyms, :acronym_regex
@@ -160,16 +163,18 @@ module ActiveSupport
     end
 
     # Yields a singleton instance of Inflector::Inflections so you can specify additional
-    # inflector rules.
+    # inflector rules. If passed an optional locale, rules for other languages can be specified.
+    # If not specified, defaults to <tt>:en</tt>. Only rules for English are provided.
+    # 
     #
-    #   ActiveSupport::Inflector.inflections do |inflect|
+    #   ActiveSupport::Inflector.inflections(:en) do |inflect|
     #     inflect.uncountable "rails"
     #   end
-    def inflections
+    def inflections(locale = :en)
       if block_given?
-        yield Inflections.instance
+        yield Inflections.instance(locale)
       else
-        Inflections.instance
+        Inflections.instance(locale)
       end
     end
   end
diff --git a/activesupport/lib/active_support/inflector/methods.rb b/activesupport/lib/active_support/inflector/methods.rb
index c14a43de0d..44214d16fa 100644
--- a/activesupport/lib/active_support/inflector/methods.rb
+++ b/activesupport/lib/active_support/inflector/methods.rb
@@ -10,31 +10,41 @@ module ActiveSupport
   #
   # The Rails core team has stated patches for the inflections library will not be accepted
   # in order to avoid breaking legacy applications which may be relying on errant inflections.
-  # If you discover an incorrect inflection and require it for your application, you'll need
-  # to correct it yourself (explained below).
+  # If you discover an incorrect inflection and require it for your application or wish to
+  # define rules for languages other than English, please correct or add them yourself (explained below).
   module Inflector
     extend self
 
     # Returns the plural form of the word in the string.
     #
+    # If passed an optional +locale+ parameter, the word will be
+    # pluralized using rules defined for that language. By default,
+    # this parameter is set to <tt>:en</tt>.
+    #
     #   "post".pluralize             # => "posts"
     #   "octopus".pluralize          # => "octopi"
     #   "sheep".pluralize            # => "sheep"
     #   "words".pluralize            # => "words"
     #   "CamelOctopus".pluralize     # => "CamelOctopi"
-    def pluralize(word)
-      apply_inflections(word, inflections.plurals)
+    #   "ley".pluralize(:es)         # => "leyes"
+    def pluralize(word, locale = :en)
+      apply_inflections(word, inflections(locale).plurals)
     end
 
     # The reverse of +pluralize+, returns the singular form of a word in a string.
     #
+    # If passed an optional +locale+ parameter, the word will be
+    # pluralized using rules defined for that language. By default,
+    # this parameter is set to <tt>:en</tt>.
+    #
     #   "posts".singularize            # => "post"
     #   "octopi".singularize           # => "octopus"
     #   "sheep".singularize            # => "sheep"
     #   "word".singularize             # => "word"
     #   "CamelOctopi".singularize      # => "CamelOctopus"
-    def singularize(word)
-      apply_inflections(word, inflections.singulars)
+    #   "leyes".singularize(:es)       # => "ley"
+    def singularize(word, locale = :en)
+      apply_inflections(word, inflections(locale).singulars)
     end
 
     # By default, +camelize+ converts strings to UpperCamelCase. If the argument to +camelize+