2 files changed, 12 insertions, 2 deletions
diff --git a/activesupport/lib/active_support/number_helper.rb b/activesupport/lib/active_support/number_helper.rb
index 38a9ce361d..5ab0f0a7ea 100644
--- a/activesupport/lib/active_support/number_helper.rb
+++ b/activesupport/lib/active_support/number_helper.rb
@@ -135,6 +135,9 @@ module ActiveSupport
     #   to ",").
     # * <tt>:separator</tt> - Sets the separator between the
     #   fractional and integer digits (defaults to ".").
+    # * <tt>:delimiter_pattern</tt> - Sets a custom regular expression used for
+    #   for deriving, the placement of delimiter. Helpful when using currency
+    #   formats like INR.
     #
     # ==== Examples
     #
@@ -147,6 +150,8 @@ module ActiveSupport
     #   number_to_delimited(12345678.05, locale: :fr)    # => 12 345 678,05
     #   number_to_delimited('112a')                      # => 112a
     #   number_to_delimited(98765432.98, delimiter: ' ', separator: ',')
+    #   number_helper.number_to_delimited("123456.78",
+    #   delimiter_pattern: /(\d+?)(?=(\d\d)+(\d)(?!\d))/)  # => 1,23,456.78
     #   # => 98 765 432,98
     def number_to_delimited(number, options = {})
       NumberToDelimitedConverter.convert(number, options)
diff --git a/activesupport/lib/active_support/number_helper/number_to_delimited_converter.rb b/activesupport/lib/active_support/number_helper/number_to_delimited_converter.rb
index d85cc086d7..45ae8f1a93 100644
--- a/activesupport/lib/active_support/number_helper/number_to_delimited_converter.rb
+++ b/activesupport/lib/active_support/number_helper/number_to_delimited_converter.rb
@@ -3,7 +3,7 @@ module ActiveSupport
     class NumberToDelimitedConverter < NumberConverter #:nodoc:
       self.validate_float = true
 
-      DELIMITED_REGEX = /(\d)(?=(\d\d\d)+(?!\d))/
+      DEFAULT_DELIMITER_REGEX = /(\d)(?=(\d\d\d)+(?!\d))/
 
       def convert
         parts.join(options[:separator])
@@ -13,11 +13,16 @@ module ActiveSupport
 
         def parts
           left, right = number.to_s.split('.')
-          left.gsub!(DELIMITED_REGEX) do |digit_to_delimit|
+          left.gsub!(delimiter_pattern) do |digit_to_delimit|
             "#{digit_to_delimit}#{options[:delimiter]}"
           end
           [left, right].compact
         end
+
+        def delimiter_pattern
+          options.fetch(:delimiter_pattern, DEFAULT_DELIMITER_REGEX)
+        end
+
     end
   end
 end