plurals.rb: frozen variables; added explicit 'zero' for :zero_one_few…

…_may_other, added :pl pluralization (#111); added README.md

lib/locales/README.md

@@ -0,0 +1,15 @@
+# Pagy locales
+
+### Please, submit your translation!
+
+If you are using pagy with some language missing from the dictionary files, please, submit your translation!
+
+The `pagy.info.single_page`, `pagy.info.item_name` and `pagy.items` keys of the yaml file are pluralized according to the plural rules of the language.
+
+If you are going to submit a dictionary, please check wether the pluralization type of your language exists in the [plurals.rb](https://github.com/ddnexus/pagy/blob/master/lib/locales/plurals.rb) file. If it is missing, please, report it. Thanks.
+
+### Useful Links
+
+* [Pagy I18n Documentation](https://ddnexus.github.io/pagy/api/frontend#i18n)
+* [i18n extra](https://ddnexus.github.io/pagy/extra/i18n)
+

lib/locales/plurals.rb

@@ -3,24 +3,36 @@
 # frozen_string_literal: true
 
 # utility variables
-zero_one   = ['zero', 'one']
-from2to4   = (2..4)
-from5to9   = (5..9)
-from11to14 = (11..14)
-from12to14 = (12..14)
+zero_one   = ['zero', 'one'].freeze
+from2to4   = (2..4).freeze
+from5to9   = (5..9).freeze
+from11to14 = (11..14).freeze
+from12to14 = (12..14).freeze
 
 # Plurals
 # A plural proc returns a plural type string based on the passed count
 # Each plural proc may apply to one or more languages below
 plurals = {
-  zero_one_other:     -> (count) {zero_one[count] || 'other'},
-  one_few_many_other: -> (count) do
+  zero_one_other: -> (count) {zero_one[count] || 'other'},
+
+  zero_one_few_many_other: -> (count) do
     mod10, mod100 = count % 10, count % 100
-    if    mod10 == 1 && mod100 != 11                                        ; 'one'
+    if count == 0                                                           ; 'zero'
+    elsif mod10 == 1 && mod100 != 11                                        ; 'one'
     elsif from2to4.cover?(mod10) && !from12to14.cover?(mod100)              ; 'few'
     elsif mod10 == 0 || from5to9.cover?(mod10) || from11to14.cover?(mod100) ; 'many'
     else                                                                      'other'
     end
+  end,
+
+  pl: -> (count) do
+    mod10, mod100 = count % 10, count % 100
+    if count == 0                                                                       ; 'zero'
+    elsif count == 1                                                                    ; 'one'
+    elsif from2to4.cover?(mod10) && !from12to14.cover?(mod100)                          ; 'few'
+    elsif [0, 1].include?(mod10) || from5to9.cover?(mod10) || from12to14.cover?(mod100) ; 'many'
+    else                                                                                  'other'
+    end
   end
 }
 
@@ -30,7 +42,8 @@
 # is the :zero_one_other plural (used for English)
 Hash.new(plurals[:zero_one_other]).tap do |languages|
   languages['en'] = plurals[:zero_one_other]
-  languages['ru'] = plurals[:one_few_many_other]
+  languages['ru'] = plurals[:zero_one_few_many_other]
+  languages['pl'] = plurals[:pl]
 end
 
 # PR for other languages and plurals are very welcome. Thanks!