extract city class for #city_parts

lib/indirizzo/address.rb

@@ -241,16 +241,7 @@ def remove_noise_words(strings)
     end
 
     def city_parts
-      strings = []
-      @city.map do |string|
-        tokens = string.split(" ")
-        strings |= (0...tokens.length).to_a.reverse.map {|i|
-                   (i...tokens.length).map {|j| tokens[i..j].join(" ")}}.flatten
-      end
-      # Don't return strings that consist solely of abbreviations.
-      # NOTE: Is this a micro-optimization that has edge cases that will break?
-      # Answer: Yes, it breaks on "Prairie"
-      strings.reject { |s| Std_Abbr.key?(s) }.uniq
+      City.city_parts(@city)
     end
 
     def city= (strings)

lib/indirizzo/city.rb

@@ -0,0 +1,17 @@
+module Indirizzo
+  class City
+    def self.city_parts(city)
+      strings = []
+      city.map do |string|
+        tokens = string.split(" ")
+        strings |= (0...tokens.length).to_a.reverse.map do |i|
+                   (i...tokens.length).map {|j| tokens[i..j].join(" ")}
+        end.flatten
+      end
+      # Don't return strings that consist solely of abbreviations.
+      # NOTE: Is this a micro-optimization that has edge cases that will break?
+      # Answer: Yes, it breaks on "Prairie"
+      strings.reject { |s| Std_Abbr.key?(s) }.uniq
+    end
+  end
+end