refactoring where, fixing subselect

lib/arel/delete_manager.rb

@@ -3,6 +3,7 @@ module Arel
     def initialize engine
       super
       @ast = Nodes::DeleteStatement.new
+      @ctx = @ast
     end
 
     def from relation
@@ -10,11 +11,6 @@ module Arel
       self
     end
 
-    def where expression
-      @ast.wheres << expression
-      self
-    end
-
     def wheres= list
       @ast.wheres = list
     end

lib/arel/predications.rb

@@ -31,7 +31,7 @@ module Arel
     def in other
       case other
       when Arel::SelectManager
-        Arel::Nodes::In.new(self, other)
+        Arel::Nodes::In.new(self, other.ast)
       when Range
         if other.exclude_end?
           left  = Nodes::GreaterThanOrEqual.new(self, other.begin)
@@ -56,7 +56,7 @@ module Arel
     def not_in other
       case other
       when Arel::SelectManager
-        Arel::Nodes::NotIn.new(self, other)
+        Arel::Nodes::NotIn.new(self, other.ast)
       when Range
         if other.exclude_end?
           left  = Nodes::LessThan.new(self, other.begin)

lib/arel/select_manager.rb

@@ -107,11 +107,6 @@ module Arel
       self
     end
 
-    def where expr
-      @ctx.wheres << expr
-      self
-    end
-
     def order *expr
       # FIXME: We SHOULD NOT be converting these to SqlLiteral automatically
       @ast.orders.concat expr.map { |x|

lib/arel/tree_manager.rb

@@ -9,6 +9,7 @@ module Arel
     def initialize engine
       @engine  = engine
       @visitor = Visitors.visitor_for @engine
+      @ctx     = nil
     end
 
     def to_dot
@@ -23,5 +24,13 @@ module Arel
       super
       @ast = @ast.clone
     end
+
+    def where expr
+      if Arel::TreeManager === expr
+        expr = expr.ast
+      end
+      @ctx.wheres << expr
+      self
+    end
   end
 end

lib/arel/update_manager.rb

@@ -3,6 +3,7 @@ module Arel
     def initialize engine
       super
       @ast = Nodes::UpdateStatement.new
+      @ctx = @ast
     end
 
     def take limit

lib/arel/visitors/to_sql.rb

@@ -72,10 +72,6 @@ module Arel
         }.join ', '})"
       end
 
-      def visit_Arel_SelectManager o
-        o.to_sql
-      end
-
       def visit_Arel_Nodes_SelectStatement o
         [
           o.cores.map { |x| visit_Arel_Nodes_SelectCore x }.join,