Constants instead of string allocations for Ruby < 2.1

It costs a bit of code readability but avoids allocating
new string objects repeatedly.

lib/ransack/adapters/active_record/context.rb

@@ -79,7 +79,7 @@ module Ransack
           end
         end
 
-        if ::ActiveRecord::VERSION::STRING >= '4.1'.freeze
+        if ::ActiveRecord::VERSION::STRING >= Ransack::Constants::RAILS_4_1
 
           def join_associations
             raise NotImplementedError,
@@ -213,14 +213,14 @@ module Ransack
             join_dependency.alias_tracker.aliases[join.left.name.downcase] = 1
           end
 
-          if ::ActiveRecord::VERSION::STRING >= '4.1'.freeze
+          if ::ActiveRecord::VERSION::STRING >= Ransack::Constants::RAILS_4_1
             join_dependency
           else
             join_dependency.graft(*stashed_association_joins)
           end
         end
 
-        if ::ActiveRecord::VERSION::STRING >= '4.1'.freeze
+        if ::ActiveRecord::VERSION::STRING >= Ransack::Constants::RAILS_4_1
 
           def build_or_find_association(name, parent = @base, klass = nil)
             found_association = @join_dependency.join_root.children

lib/ransack/constants.rb

@@ -8,12 +8,19 @@ module Ransack
     AND                 = 'and'.freeze
     SORT                = 'sort'.freeze
     SORT_LINK           = 'sort_link'.freeze
+    CAP_SEARCH          = "Search".freeze
     SEARCH              = 'search'.freeze
+    SEARCHES            = 'searches'.freeze
     ATTRIBUTE           = 'attribute'.freeze
     COMBINATOR          = 'combinator'.freeze
     SPACE               = ' '.freeze
     COMMA_SPACE         = ', '.freeze
+    COLON_SPACE         = ': '.freeze
+    TWO_COLONS          = '::'.freeze
     UNDERSCORE          = '_'.freeze
+    LEFT_PARENTHESIS    = '('.freeze
+    Q                   = 'q'.freeze
+    I                   = 'i'.freeze
     NON_BREAKING_SPACE  = ' '.freeze
     EMPTY               = ''.freeze
 
@@ -34,11 +41,13 @@ module Ransack
     AREL_PREDICATES     = %w(
       eq not_eq matches does_not_match lt lteq gt gteq in not_in
     ).freeze
+    A_S_I               = %w(a s i).freeze
 
     EQ                  = 'eq'.freeze
     NOT_EQ              = 'not_eq'.freeze
     EQ_ANY              = 'eq_any'.freeze
     NOT_EQ_ALL          = 'not_eq_all'.freeze
 
+    RAILS_4_1           = '4.1'.freeze
   end
 end

lib/ransack/naming.rb

@@ -28,15 +28,15 @@ module Ransack
     alias_method :cache_key, :collection
 
     def initialize
-      super("Search".freeze)
-      @singular = "search".freeze
-      @plural = "searches".freeze
-      @element = "search".freeze
-      @human = "Search".freeze
+      super(Ransack::Constants::CAP_SEARCH)
+      @singular = Ransack::Constants::SEARCH
+      @plural = Ransack::Constants::SEARCHES
+      @element = Ransack::Constants::SEARCH
+      @human = Ransack::Constants::CAP_SEARCH
       @collection = "ransack/searches".freeze
       @partial_path = "#{@collection}/#{@element}".freeze
-      @param_key = "q".freeze
-      @route_key = "searches".freeze
+      @param_key = Ransack::Constants::Q
+      @route_key = Ransack::Constants::SEARCHES
       @i18n_key = :ransack
     end
   end
@@ -51,4 +51,4 @@ module Ransack
     end
   end
 
-end
+end

lib/ransack/search.rb

@@ -113,7 +113,7 @@ module Ransack
         ([:scope, @scope_args] if @scope_args.present?),
         [:base, base.inspect]
       ]
-      .compact.map { |d| d.join(': '.freeze) }
+      .compact.map { |d| d.join(Ransack::Constants::COLON_SPACE) }
       .join(Ransack::Constants::COMMA_SPACE)
 
       "Ransack::Search<#{details}>"
@@ -146,15 +146,24 @@ module Ransack
 
     def collapse_multiparameter_attributes!(attrs)
       attrs.keys.each do |k|
-        if k.include?('('.freeze)
+        if k.include?(Ransack::Constants::LEFT_PARENTHESIS)
           real_attribute, position = k.split(/\(|\)/)
-          cast = %w(a s i).freeze.include?(position.last) ? position.last : nil
+          cast =
+          if Ransack::Constants::A_S_I.include?(position.last)
+            position.last
+          else
+            nil
+          end
           position = position.to_i - 1
           value = attrs.delete(k)
           attrs[real_attribute] ||= []
           attrs[real_attribute][position] =
           if cast
-            value.blank? && cast == 'i'.freeze ? nil : value.send("to_#{cast}")
+            if value.blank? && cast == Ransack::Constants::I
+              nil
+            else
+              value.send("to_#{cast}")
+            end
           else
             value
           end

lib/ransack/visitor.rb

@@ -54,7 +54,9 @@ module Ransack
 
     DISPATCH = Hash.new do |hash, klass|
       hash[klass] = "visit_#{
-        klass.name.gsub('::'.freeze, Ransack::Constants::UNDERSCORE)
+        klass.name.gsub(
+          Ransack::Constants::TWO_COLONS, Ransack::Constants::UNDERSCORE
+          )
         }"
     end