implement attr setter correctly

part of #25
still need to do for list and attr_reader

test/ruby/test_class_statement.rb

@@ -81,19 +81,44 @@ module Ruby
       input = "class Tryout < Base;attr :page ;end"
       @vool = compile( input ).to_vool
     end
+    def getter
+      @vool.body.statements.first
+    end
+    def setter
+      @vool.body.statements.last
+    end
     def test_class
       assert_equal Vool::ClassStatement , @vool.class
     end
     def test_body
       assert_equal Vool::Statements , @vool.body.class
     end
-    def test_compile_class_name
-      assert_equal :Tryout , @vool.name
+    def test_getter
+      assert_equal Vool::MethodStatement , getter.class
     end
-    def test_compile_class_super
-      assert_equal :Base , @vool.super_class_name
+    def test_getter_return
+      assert_equal Vool::ReturnStatement , getter.body.class
+    end
+    def test_getter_name
+      assert_equal :page , getter.name
+    end
+    def test_setter
+      assert_equal Vool::MethodStatement , setter.class
+    end
+    def test_setter_assign
+      assert_equal Vool::Statements , setter.body.class
+      assert_equal Vool::IvarAssignment , setter.body.first.class
+    end
+    def test_setter_return
+      assert_equal Vool::Statements , setter.body.class
+      assert_equal Vool::ReturnStatement , setter.body.last.class
+    end
+    def test_setter_name
+      assert_equal :page= , setter.name
+    end
+    def test_setter_args
+      assert_equal [:val] , setter.args
     end
-
   end
 
 end