Freeze strings in array constants and begin moving

from using global constants to frozen strings (cc @avit).

It's not pretty, but it's faster and better for understanding the code
without having to look up what the special constants represent.

From the discussion in #530:

"Things are evolving, but with Ruby 2.2 here is my current
understanding:

- I believe you are correct that the strings inside the array could
benefit from freezing, in hot spots.

- Freezing a string may now be faster than looking up a frozen string
constant.

So, it might make sense now in Ransack master and upcoming releases, to
optimize for Ruby 2.2+ and stop using frozen constants, and replace
them with frozen strings or symbols."

Closes #530.

lib/ransack/adapters/active_record/3.0/compat.rb

@@ -138,16 +138,16 @@ def visit_Arel_Nodes_NamedFunction o
         "#{
           o.name
           }(#{
-          o.distinct ? Ransack::Constants::DISTINCT : Ransack::Constants::EMPTY
+          o.distinct ? Ransack::Constants::DISTINCT : ''.freeze
           }#{
-          o.expressions.map { |x| visit x }.join(Ransack::Constants::COMMA_SPACE)
+          o.expressions.map { |x| visit x }.join(', '.freeze)
           })#{
-          o.alias ? " AS #{visit o.alias}" : Ransack::Constants::EMPTY
+          o.alias ? " AS #{visit o.alias}" : ''.freeze
           }"
       end
 
       def visit_Arel_Nodes_And o
-        o.children.map { |x| visit x }.join(Ransack::Constants::SPACED_AND)
+        o.children.map { |x| visit x }.join(' AND '.freeze)
       end
 
       def visit_Arel_Nodes_Not o
@@ -164,7 +164,7 @@ def visit_Arel_Nodes_Values o
             quote(value, attr && column_for(attr))
           end
         }
-        .join(Ransack::Constants::COMMA_SPACE)
+        .join(', '.freeze)
         })"
       end
     end

lib/ransack/constants.rb

@@ -1,19 +1,10 @@
 module Ransack
   module Constants
-    ASC                 = 'asc'.freeze
-    DESC                = 'desc'.freeze
-    ASC_DESC            = [ASC, DESC].freeze
-
     ASC_ARROW           = '▲'.freeze
     DESC_ARROW          = '▼'.freeze
 
     OR                  = 'or'.freeze
     AND                 = 'and'.freeze
-    SPACED_AND          = ' AND '.freeze
-
-    SORT                = 'sort'.freeze
-    SORT_LINK           = 'sort_link'.freeze
-    SORT_DIRECTION      = 'sort_direction'.freeze
 
     CAP_SEARCH          = 'Search'.freeze
     SEARCH              = 'search'.freeze
@@ -23,17 +14,12 @@ module Constants
     ATTRIBUTES          = 'attributes'.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
     DOT_ASTERIX         = '.*'.freeze
-    EMPTY               = ''.freeze
 
     STRING_JOIN         = 'string_join'.freeze
     ASSOCIATION_JOIN    = 'association_join'.freeze
@@ -44,14 +30,17 @@ module Constants
     FALSE_VALUES = [false, 0, '0', 'f', 'F', 'false', 'FALSE'].to_set
     BOOLEAN_VALUES = (TRUE_VALUES + FALSE_VALUES).freeze
 
-    S_SORTS             = %w(s sorts).freeze
-    AND_OR              = %w(and or).freeze
-    IN_NOT_IN           = %w(in not_in).freeze
-    SUFFIXES            = %w(_any _all).freeze
-    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
+    AND_OR              = ['and'.freeze, 'or'.freeze].freeze
+    IN_NOT_IN           = ['in'.freeze, 'not_in'.freeze].freeze
+    SUFFIXES            = ['_any'.freeze, '_all'.freeze].freeze
+    AREL_PREDICATES     = [
+      'eq'.freeze, 'not_eq'.freeze,
+      'matches'.freeze, 'does_not_match'.freeze,
+      'lt'.freeze, 'lteq'.freeze,
+      'gt'.freeze, 'gteq'.freeze,
+      'in'.freeze, 'not_in'.freeze
+      ].freeze
+    A_S_I               = ['a'.freeze, 's'.freeze, 'i'.freeze].freeze
 
     EQ                  = 'eq'.freeze
     NOT_EQ              = 'not_eq'.freeze

lib/ransack/context.rb

@@ -17,9 +17,12 @@ def for_object(object, options = {})
       end
 
       def for(object, options = {})
-        context = Class === object ?
-          for_class(object, options) :
-          for_object(object, options)
+        context =
+          if Class === object
+            for_class(object, options)
+          else
+            for_object(object, options)
+          end
         context or raise ArgumentError,
           "Don't know what context to use for #{object}"
       end
@@ -59,7 +62,7 @@ def bind(object, str)
     end
 
     def traverse(str, base = @base)
-      str ||= Constants::EMPTY
+      str ||= ''.freeze
 
       if (segments = str.split(/_/)).size > 0
         remainder = []
@@ -68,13 +71,12 @@ def traverse(str, base = @base)
           # Strip the _of_Model_type text from the association name, but hold
           # onto it in klass, for use as the next base
           assoc, klass = unpolymorphize_association(
-            segments.join(Constants::UNDERSCORE)
+            segments.join('_'.freeze)
             )
           if found_assoc = get_association(assoc, base)
             base = traverse(
-              remainder.join(
-                Constants::UNDERSCORE), klass || found_assoc.klass
-                )
+              remainder.join('_'.freeze), klass || found_assoc.klass
+              )
           end
 
           remainder.unshift segments.pop
@@ -88,7 +90,7 @@ def traverse(str, base = @base)
 
     def association_path(str, base = @base)
       base = klassify(base)
-      str ||= Constants::EMPTY
+      str ||= ''.freeze
       path = []
       segments = str.split(/_/)
       association_parts = []
@@ -131,15 +133,15 @@ def ransackable_scope?(str, klass)
       klass.ransackable_scopes(auth_object).any? { |s| s.to_s == str }
     end
 
-    def searchable_attributes(str = Constants::EMPTY)
+    def searchable_attributes(str = ''.freeze)
       traverse(str).ransackable_attributes(auth_object)
     end
 
-    def sortable_attributes(str = Constants::EMPTY)
+    def sortable_attributes(str = ''.freeze)
       traverse(str).ransortable_attributes(auth_object)
     end
 
-    def searchable_associations(str = Constants::EMPTY)
+    def searchable_associations(str = ''.freeze)
       traverse(str).ransackable_associations(auth_object)
     end
   end

lib/ransack/helpers/form_builder.rb

@@ -15,8 +15,7 @@ def value(object)
 RANSACK_FORM_BUILDER = 'RANSACK_FORM_BUILDER'.freeze
 
 require 'simple_form' if
-  (ENV[RANSACK_FORM_BUILDER] || Ransack::Constants::EMPTY)
-  .match('SimpleForm'.freeze)
+  (ENV[RANSACK_FORM_BUILDER] || ''.freeze).match('SimpleForm'.freeze)
 
 module Ransack
   module Helpers
@@ -47,7 +46,7 @@ def attribute_select(options = nil, html_options = nil, action = nil)
         raise ArgumentError, formbuilder_error_message(
           "#{action}_select") unless object.respond_to?(:context)
         options[:include_blank] = true unless options.has_key?(:include_blank)
-        bases = [Constants::EMPTY] + association_array(options[:associations])
+        bases = [''.freeze].freeze + association_array(options[:associations])
         if bases.size > 1
           collection = attribute_collection_for_bases(action, bases)
           object.name ||= default if can_use_default?(
@@ -66,13 +65,13 @@ def attribute_select(options = nil, html_options = nil, action = nil)
       def sort_direction_select(options = {}, html_options = {})
         unless object.respond_to?(:context)
           raise ArgumentError,
-          formbuilder_error_message(Constants::SORT_DIRECTION)
+          formbuilder_error_message('sort_direction'.freeze)
         end
         template_collection_select(:dir, sort_array, options, html_options)
       end
 
       def sort_select(options = {}, html_options = {})
-        attribute_select(options, html_options, Constants::SORT) +
+        attribute_select(options, html_options, 'sort'.freeze) +
         sort_direction_select(options, html_options)
       end
 
@@ -135,7 +134,7 @@ def predicate_select(options = {}, html_options = {})
           else
             only = Array.wrap(only).map(&:to_s)
             keys = keys.select {
-              |k| only.include? k.sub(/_(any|all)$/, Constants::EMPTY)
+              |k| only.include? k.sub(/_(any|all)$/, ''.freeze)
             }
           end
         end

lib/ransack/helpers/form_helper.rb

@@ -93,7 +93,7 @@ def initialize(search, attribute, args, params)
         def name
           [ERB::Util.h(@label_text), order_indicator]
           .compact
-          .join(Constants::NON_BREAKING_SPACE)
+          .join(' '.freeze)
           .html_safe
         end
 
@@ -106,8 +106,8 @@ def url_options
         def html_options(args)
           html_options = extract_options_and_mutate_args!(args)
           html_options.merge(
-            class: [[Constants::SORT_LINK, @current_dir], html_options[:class]]
-                   .compact.join(Constants::SPACE)
+            class: [['sort_link'.freeze, @current_dir], html_options[:class]]
+                   .compact.join(' '.freeze)
           )
         end
 
@@ -159,7 +159,7 @@ def detect_previous_sort_direction_and_invert_it(attr_name)
             if sort_dir = existing_sort_direction(attr_name)
               direction_text(sort_dir)
             else
-              default_sort_order(attr_name) || Constants::ASC
+              default_sort_order(attr_name) || 'asc'.freeze
             end
           end
 
@@ -179,17 +179,17 @@ def order_indicator
           end
 
           def no_sort_direction_specified?(dir = @current_dir)
-            !Constants::ASC_DESC.include?(dir)
+            !['asc'.freeze, 'desc'.freeze].freeze.include?(dir)
           end
 
           def direction_arrow
-            return Constants::DESC_ARROW if @current_dir == Constants::DESC
+            return Constants::DESC_ARROW if @current_dir == 'desc'.freeze
             Constants::ASC_ARROW
           end
 
           def direction_text(dir)
-            return Constants::ASC if dir == Constants::DESC
-            Constants::DESC
+            return 'asc'.freeze if dir == 'desc'.freeze
+            'desc'.freeze
           end
       end
     end

lib/ransack/nodes/condition.rb

@@ -224,7 +224,7 @@ def inspect
         ]
         .reject { |e| e[1].blank? }
         .map { |v| "#{v[0]}: #{v[1]}" }
-        .join(Constants::COMMA_SPACE)
+        .join(', '.freeze)
         "Condition <#{data}>"
       end
 

lib/ransack/nodes/grouping.rb

@@ -68,7 +68,7 @@ def values
       def respond_to?(method_id)
         super or begin
           method_name = method_id.to_s
-          writer = method_name.sub!(/\=$/, Constants::EMPTY)
+          writer = method_name.sub!(/\=$/, ''.freeze)
           attribute_method?(method_name) ? true : false
         end
       end
@@ -114,7 +114,7 @@ def groupings=(groupings)
 
       def method_missing(method_id, *args)
         method_name = method_id.to_s
-        writer = method_name.sub!(/\=$/, Constants::EMPTY)
+        writer = method_name.sub!(/\=$/, ''.freeze)
         if attribute_method?(method_name)
           if writer
             write_attribute(method_name, *args)
@@ -169,7 +169,7 @@ def inspect
         ]
         .reject { |e| e[1].blank? }
         .map { |v| "#{v[0]}: #{v[1]}" }
-        .join(Constants::COMMA_SPACE)
+        .join(', '.freeze)
         "Grouping <#{data}>"
       end
 

lib/ransack/nodes/sort.rb

@@ -38,10 +38,10 @@ def name=(name)
       def dir=(dir)
         dir = dir.downcase if dir
         @dir =
-          if Constants::ASC_DESC.include?(dir)
+          if ['asc'.freeze, 'desc'.freeze].freeze.include?(dir)
             dir
           else
-            Constants::ASC
+            'asc'.freeze
           end
       end
 

lib/ransack/predicate.rb

@@ -10,7 +10,7 @@ def names
       end
 
       def names_by_decreasing_length
-        names.sort { |a,b| b.length <=> a.length }
+        names.sort { |a, b| b.length <=> a.length }
       end
 
       def named(name)
@@ -19,7 +19,7 @@ def named(name)
 
       def detect_and_strip_from_string!(str)
         if p = detect_from_string(str)
-          str.sub! /_#{p}$/, Constants::EMPTY
+          str.sub! /_#{p}$/, ''.freeze
           p
         end
       end

lib/ransack/search.rb

@@ -37,7 +37,7 @@ def result(opts = {})
 
     def build(params)
       collapse_multiparameter_attributes!(params).each do |key, value|
-        if Constants::S_SORTS.include?(key)
+        if ['s'.freeze, 'sorts'.freeze].freeze.include?(key)
           send("#{key}=", value)
         elsif base.attribute_method?(key)
           base.send("#{key}=", value)
@@ -92,7 +92,7 @@ def new_sort(opts = {})
 
     def method_missing(method_id, *args)
       method_name = method_id.to_s
-      getter_name = method_name.sub(/=$/, Constants::EMPTY)
+      getter_name = method_name.sub(/=$/, ''.freeze)
       if base.attribute_method?(getter_name)
         base.send(method_id, *args)
       elsif @context.ransackable_scope?(getter_name, @context.object)
@@ -113,8 +113,8 @@ def inspect
         [:base, base.inspect]
       ]
       .compact
-      .map { |d| d.join(Constants::COLON_SPACE) }
-      .join(Constants::COMMA_SPACE)
+      .map { |d| d.join(': '.freeze) }
+      .join(', '.freeze)
 
       "Ransack::Search<#{details}>"
     end

lib/ransack/translate.rb

@@ -25,7 +25,7 @@ def self.attribute(key, options = {})
         |x| x.respond_to?(:model_name)
       }
       predicate = Predicate.detect_from_string(original_name)
-      attributes_str = original_name.sub(/_#{predicate}$/, Constants::EMPTY)
+      attributes_str = original_name.sub(/_#{predicate}$/, ''.freeze)
       attribute_names = attributes_str.split(/_and_|_or_/)
       combinator = attributes_str.match(/_and_/) ? :and : :or
       defaults = base_ancestors.map do |klass|
@@ -74,7 +74,7 @@ def self.association(key, options = {})
     def self.attribute_name(context, name, include_associations = nil)
       @context, @name = context, name
       @assoc_path = context.association_path(name)
-      @attr_name = @name.sub(/^#{@assoc_path}_/, Constants::EMPTY)
+      @attr_name = @name.sub(/^#{@assoc_path}_/, ''.freeze)
       associated_class = @context.traverse(@assoc_path) if @assoc_path.present?
       @include_associated = include_associations && associated_class