updating nodes and depth first visitor

8 files changed, 89 insertions, 51 deletions

diff --git a/lib/arel/nodes/delete_statement.rb b/lib/arel/nodes/delete_statement.rb
index 610d69e460..3bac8225ec 100644
--- a/lib/arel/nodes/delete_statement.rb
+++ b/lib/arel/nodes/delete_statement.rb
@@ -1,16 +1,18 @@
 module Arel
   module Nodes
-    class DeleteStatement
-      attr_accessor :relation, :wheres
+    class DeleteStatement < Arel::Nodes::Binary
+      alias :relation :left
+      alias :relation= :left=
+      alias :wheres :right
+      alias :wheres= :right=
 
-      def initialize
-        @from   = nil
-        @wheres = []
+      def initialize relation = nil, wheres = []
+        super
       end
 
       def initialize_copy other
         super
-        @wheres = @wheres.clone
+        @right = @right.clone
       end
     end
   end
diff --git a/lib/arel/nodes/lock.rb b/lib/arel/nodes/lock.rb
index 3c7a72273f..e5fb258e26 100644
--- a/lib/arel/nodes/lock.rb
+++ b/lib/arel/nodes/lock.rb
@@ -1,6 +1,6 @@
 module Arel
   module Nodes
-    class Lock
+    class Lock < Arel::Nodes::Node
     end
   end
 end
diff --git a/lib/arel/nodes/not.rb b/lib/arel/nodes/not.rb
index d463ae9d08..de138435bb 100644
--- a/lib/arel/nodes/not.rb
+++ b/lib/arel/nodes/not.rb
@@ -1,11 +1,6 @@
 module Arel
   module Nodes
-    class Not < Arel::Nodes::Node
-      attr_reader :expr
-
-      def initialize expr
-        @expr = expr
-      end
+    class Not < Arel::Nodes::Unary
     end
   end
 end
diff --git a/lib/arel/nodes/on.rb b/lib/arel/nodes/on.rb
index 4cc76b70db..953d64f9f1 100644
--- a/lib/arel/nodes/on.rb
+++ b/lib/arel/nodes/on.rb
@@ -1,11 +1,6 @@
 module Arel
   module Nodes
-    class On
-      attr_accessor :expr
-
-      def initialize expr
-        @expr = expr
-      end
+    class On < Arel::Nodes::Unary
     end
   end
 end
diff --git a/lib/arel/nodes/table_alias.rb b/lib/arel/nodes/table_alias.rb
index 60da7b19f3..723b025883 100644
--- a/lib/arel/nodes/table_alias.rb
+++ b/lib/arel/nodes/table_alias.rb
@@ -1,14 +1,10 @@
 module Arel
   module Nodes
-    class TableAlias
-      attr_reader :name, :relation
+    class TableAlias < Arel::Nodes::Binary
+      alias :name :left
+      alias :relation :right
       alias :table_alias :name
 
-      def initialize name, relation
-        @name     = name
-        @relation = relation
-      end
-
       def [] name
         Attribute.new self, name
       end
diff --git a/lib/arel/nodes/unqualified_column.rb b/lib/arel/nodes/unqualified_column.rb
index 9882cb08e2..f7ba653c11 100644
--- a/lib/arel/nodes/unqualified_column.rb
+++ b/lib/arel/nodes/unqualified_column.rb
@@ -1,18 +1,15 @@
 module Arel
   module Nodes
-    class UnqualifiedColumn
-      attr_accessor :attribute
-
-      def initialize attribute
-        @attribute = attribute
-      end
+    class UnqualifiedColumn < Arel::Nodes::Unary
+      alias :attribute :expr
+      alias :attribute= :expr=
 
       def column
-        @attribute.column
+        @expr.column
       end
 
       def name
-        @attribute.name
+        @expr.name
       end
     end
   end
diff --git a/lib/arel/nodes/values.rb b/lib/arel/nodes/values.rb
index 4c7ca76360..814e843dab 100644
--- a/lib/arel/nodes/values.rb
+++ b/lib/arel/nodes/values.rb
@@ -1,11 +1,13 @@
 module Arel
   module Nodes
-    class Values
-      attr_accessor :expressions, :columns
+    class Values < Arel::Nodes::Binary
+      alias :expressions :left
+      alias :expressions= :left=
+      alias :columns :right
+      alias :columns= :right=
 
       def initialize exprs, columns = []
-        @expressions = exprs
-        @columns = columns
+        super
       end
     end
   end
diff --git a/lib/arel/visitors/depth_first.rb b/lib/arel/visitors/depth_first.rb
index d6d3984ce2..3d34ff139e 100644
--- a/lib/arel/visitors/depth_first.rb
+++ b/lib/arel/visitors/depth_first.rb
@@ -7,14 +7,55 @@ module Arel
 
       private
 
+      def unary o
+        visit o.expr
+        @block.call o
+      end
+      alias :visit_Arel_Nodes_Group             :unary
+      alias :visit_Arel_Nodes_Grouping          :unary
+      alias :visit_Arel_Nodes_Having            :unary
+      alias :visit_Arel_Nodes_Not               :unary
+      alias :visit_Arel_Nodes_Offset            :unary
+      alias :visit_Arel_Nodes_On                :unary
+      alias :visit_Arel_Nodes_UnqualifiedColumn :unary
+
+      def function o
+        visit o.expressions
+        visit o.alias
+        @block.call o
+      end
+      alias :visit_Arel_Nodes_Avg    :function
+      alias :visit_Arel_Nodes_Exists :function
+      alias :visit_Arel_Nodes_Max    :function
+      alias :visit_Arel_Nodes_Min    :function
+      alias :visit_Arel_Nodes_Sum    :function
+
+      def visit_Arel_Nodes_Count o
+        visit o.expressions
+        visit o.alias
+        visit o.distinct
+        @block.call o
+      end
+
+      def join o
+        visit o.left
+        visit o.right
+        visit o.constraint
+        @block.call o
+      end
+      alias :visit_Arel_Nodes_InnerJoin :join
+      alias :visit_Arel_Nodes_OuterJoin :join
+
       def binary o
         visit o.left
         visit o.right
         @block.call o
       end
       alias :visit_Arel_Nodes_And                :binary
+      alias :visit_Arel_Nodes_As                 :binary
       alias :visit_Arel_Nodes_Assignment         :binary
       alias :visit_Arel_Nodes_Between            :binary
+      alias :visit_Arel_Nodes_DeleteStatement    :binary
       alias :visit_Arel_Nodes_DoesNotMatch       :binary
       alias :visit_Arel_Nodes_Equality           :binary
       alias :visit_Arel_Nodes_GreaterThan        :binary
@@ -26,6 +67,10 @@ module Arel
       alias :visit_Arel_Nodes_NotEqual           :binary
       alias :visit_Arel_Nodes_NotIn              :binary
       alias :visit_Arel_Nodes_Or                 :binary
+      alias :visit_Arel_Nodes_Ordering           :binary
+      alias :visit_Arel_Nodes_StringJoin         :binary
+      alias :visit_Arel_Nodes_TableAlias         :binary
+      alias :visit_Arel_Nodes_Values             :binary
 
       def visit_Arel_Attribute o
         visit o.relation
@@ -38,6 +83,7 @@ module Arel
       alias :visit_Arel_Attributes_Time :visit_Arel_Attribute
       alias :visit_Arel_Attributes_Boolean :visit_Arel_Attribute
       alias :visit_Arel_Attributes_Attribute :visit_Arel_Attribute
+      alias :visit_Arel_Attributes_Decimal :visit_Arel_Attribute
 
       def visit_Arel_Table o
         visit o.name
@@ -47,19 +93,24 @@ module Arel
       def terminal o
         @block.call o
       end
-      alias :visit_Arel_Nodes_SqlLiteral :terminal
-      alias :visit_Arel_SqlLiteral       :terminal
-      alias :visit_BigDecimal            :terminal
-      alias :visit_Date                  :terminal
-      alias :visit_DateTime              :terminal
-      alias :visit_FalseClass            :terminal
-      alias :visit_Fixnum                :terminal
-      alias :visit_Float                 :terminal
-      alias :visit_NilClass              :terminal
-      alias :visit_String                :terminal
-      alias :visit_Symbol                :terminal
-      alias :visit_Time                  :terminal
-      alias :visit_TrueClass             :terminal
+      alias :visit_ActiveSupport_Multibyte_Chars :terminal
+      alias :visit_ActiveSupport_StringInquirer  :terminal
+      alias :visit_Arel_Nodes_Lock               :terminal
+      alias :visit_Arel_Nodes_SqlLiteral         :terminal
+      alias :visit_Arel_SqlLiteral               :terminal
+      alias :visit_BigDecimal                    :terminal
+      alias :visit_Bignum                        :terminal
+      alias :visit_Class                         :terminal
+      alias :visit_Date                          :terminal
+      alias :visit_DateTime                      :terminal
+      alias :visit_FalseClass                    :terminal
+      alias :visit_Fixnum                        :terminal
+      alias :visit_Float                         :terminal
+      alias :visit_NilClass                      :terminal
+      alias :visit_String                        :terminal
+      alias :visit_Symbol                        :terminal
+      alias :visit_Time                          :terminal
+      alias :visit_TrueClass                     :terminal
 
       def visit_Arel_Nodes_InsertStatement o
         visit o.relation