move attributes under contractor

as it is essential that attributes are in the same order for the json
to work

lib/ast/basic_expressions.rb

@@ -7,31 +7,40 @@ module Ast
     def initialize val
       @value = val
     end
+    def attributes
+      [:value]
+    end
     def inspect
       self.class.name + ".new(" + value.to_s+ ")"
     end
     def to_s
       value.to_s
     end
-    def attributes
-      [:value]
-    end
   end
 
   class TrueExpression < Expression
     def to_s
       "true"
     end
+  def attributes
+    []
+  end
   end
   class FalseExpression < Expression
     def to_s
       "false"
     end
+    def attributes
+      []
+    end
   end
   class NilExpression < Expression
     def to_s
       "nil"
     end
+    def attributes
+      []
+    end
   end
 
   class NameExpression < Expression
@@ -39,15 +48,15 @@ module Ast
     def initialize name
       @name = name.to_sym
     end
+    def attributes
+      [:name]
+    end
     def inspect
       "#{self.class.name}.new(#{name.inspect})"
     end
     def to_s
       name.to_s
     end
-    def attributes
-      [:name]
-    end
   end
 
   class VariableExpression < NameExpression
@@ -61,15 +70,15 @@ module Ast
     def initialize str
       @string = str
     end
+    def attributes
+      [:string]
+    end
     def inspect
       self.class.name + '.new("' + string + '")'
     end
     def to_s
       '"' + string.to_s + '"'
     end
-    def attributes
-      [:string]
-    end
   end
 
 end

lib/ast/call_site_expression.rb

@@ -9,6 +9,9 @@ module Ast
       @args = args
       @receiver =  receiver
     end
+    def attributes
+      [:name , :args , :receiver]
+    end
     
     def inspect
       self.class.name + ".new(" + name.inspect + ", ["+
@@ -17,8 +20,5 @@ module Ast
     def to_s
       "#{name}(" + args.join(",") + ")"
     end
-    def attributes
-      [:name , :args , :receiver]
-    end
   end
 end

lib/ast/compound_expressions.rb

@@ -2,27 +2,28 @@ module Ast
 
   class ArrayExpression < Expression
     attr_reader :values
+    def attributes
+      [:values]
+    end
     def initialize vals
       @values = vals
     end
     def inspect
       self.class.name + ".new(" + values.to_s+ ")"
     end
-    def attributes
-      [:values]
-    end
   end
+
   class AssociationExpression < Expression
     attr_reader :key , :value
     def initialize key , value
       @key , @value = key , value
     end
-    def inspect
-      self.class.name + ".new(" + key.inspect + " , " + value.inspect + ")"
-    end
     def attributes
       [:key , :value]
     end
+    def inspect
+      self.class.name + ".new(" + key.inspect + " , " + value.inspect + ")"
+    end
 
   end
   class HashExpression < ArrayExpression

lib/ast/expression_list.rb

@@ -14,5 +14,7 @@ module Ast
     def to_s
       expressions.collect(&:inspect).join("\n")
     end
+
+
   end
 end

lib/ast/if_expression.rb

@@ -4,12 +4,12 @@ module Ast
     def initialize cond, if_true, if_false
       @cond, @if_true, @if_false = cond, if_true, if_false
     end
+    def attributes
+      [:cond, :if_true, :if_false]
+    end
     def inspect
       self.class.name + ".new(" + cond.inspect + ", "+
         if_true.inspect +  ","  + if_false.inspect + " )"
     end
-    def attributes
-      [:cond, :if_true, :if_false]
-    end
   end
 end

lib/ast/module_expression.rb

@@ -7,15 +7,15 @@ module Ast
       @name = name.to_sym
       @expressions = expressions
     end
+    def attributes
+      [:name , :expressions]
+    end
     def inspect
       self.class.name + ".new(" + @name.inspect + " ," + @expressions.inspect + " )"
     end
     def to_s
       "module #{name}\n #{expressions}\nend\n"
     end
-    def attributes
-      [:name , :expressions]
-    end
   end
 
   class ClassExpression < ModuleExpression
@@ -24,6 +24,9 @@ module Ast
       super(name , expressions)
       @derived_from = derived
     end
+    def attributes
+      [:name , :derived_from , :expressions]
+    end
     def inspect
       self.class.name + ".new(" + @name.inspect + " ," +
                                 @derived_from.inspect + ", " + @expressions.inspect + " )"
@@ -34,8 +37,5 @@ module Ast
     def to_s
       s = "class #{name} < #{derived_from}\n #{expressions}\nend\n"
     end
-    def attributes
-      [:name , :derived_from , :expressions]
-    end
   end
 end