lib/chrono/fields/month.rb in chrono-0.1.0 vs lib/chrono/fields/month.rb in chrono-0.2.0

@@ -1,8 +1,35 @@
 module Chrono
   module Fields
     class Month < Base
+      TABLE = {
+        'jan' => '1',
+        'feb' => '2',
+        'mar' => '3',
+        'apr' => '4',
+        'may' => '5',
+        'jun' => '6',
+        'jul' => '7',
+        'aug' => '8',
+        'sep' => '9',
+        'oct' => '10',
+        'nov' => '11',
+        'dec' => '12',
+      }
+      REGEXP = %r<\A(?<step>(?:\*|(?:(?<atom>\d+||jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec)(?:-\g<atom>)?))(?:/\d+)?)(?:,\g<step>)*\z>ix
+
+      def initialize(source)
+        unless REGEXP =~ source
+          raise InvalidField.new('Unparsable field', source)
+        end
+        @source = source
+      end
+
       private
+
+      def interpolated
+        super.downcase.gsub(/jan|feb|mar|apr|may|jun|jul|aug|sep|oct|nov|dec/, TABLE)
+      end
 
       def range
         1..12
       end
     end