fixing offset bug

found by tests that overwrite the attribute

lib/parfait/indexed.rb

@@ -140,6 +140,7 @@ module Parfait
 
     module Methods
       def offset( offset  )
+        offset += 1 # for the attribute we add (indexed_length)
 
         define_method  :get_offset do
           offset

lib/parfait/layout.rb

@@ -25,7 +25,7 @@ module Parfait
     attribute :object_class
 
     include Indexed
-    self.offset(2)
+    self.offset(1)
 
     def initialize( object_class )
       super()
@@ -47,7 +47,7 @@ module Parfait
       self.get_length
     end
 
-    def object_instance_names
+    def instance_names
       names = List.new
       each do |item|
         names.push item
@@ -55,20 +55,14 @@ module Parfait
       names
     end
 
-    def object_instance_length
+    def instance_length
       self.get_length
     end
 
-    alias :list_index :index_of
-    # private inheritance is something to think off, we don't really want the list api exported
-    def index_of name
-      raise "should not rely on layout internal structure, use variable_index"
-    end
-
     # index of the variable when using internal_object_get
     # (internal_object_get is 1 based and 1 is always the layout)
     def variable_index name
-      has = list_index(name)
+      has = index_of(name)
       return nil unless has
       raise "internal error #{name}:#{has}" if has < 1
       has

test/parfait/test_list.rb

@@ -33,6 +33,15 @@ class TestList < MiniTest::Test
     assert_equal 1 , layout.variable_index(:layout)
   end
 
+  def test_length0
+    assert_equal 0 , @list.get_length
+    assert_equal nil , @list.indexed_length
+  end
+  def test_length1
+    @list.push :one
+    assert_equal 1 , @list.get_length
+    assert_equal 1 , @list.indexed_length
+  end
   def test_list_inspect
     @list.set(1,1)
     assert_equal "1" , @list.inspect
@@ -54,7 +63,7 @@ class TestList < MiniTest::Test
   end
   def test_one_set1
     assert_equal 2 , @list.set(1,2)
-    assert_equal 1 , @list.internal_object_get(1)
+    assert_equal 1 , @list.internal_object_get(2)
   end
   def test_set1_len
     @list.set(1,1)