fix word implementation and tests

much better, though wasteful implementation
breaks a few tests, but ploughing on first

lib/parfait/word.rb

@@ -7,20 +7,32 @@ module Parfait
   #
   # Words are constant, maybe like js strings, ruby symbols
   # Words are short, but may have spaces
+
+  # big TODO , this has NO encoding, a char takes a machine word. Go fix.
   class Word < Object
     # initialize with length. For now we try to keep all non-parfait (including String) out
     # Virtual provides methods to create Parfait objects from ruby
-    def initialize length
-      super
-      set_length( length , 32 )
+    def initialize len
+      super()
+      raise "Must init with int, not #{len.class}" unless len.kind_of? Fixnum
+      raise "Must init with positive, not #{len}" if len < 0
+      set_length( len - 1, 32 ) unless len == 0
     end
 
+    def length()
+      obj_len = internal_object_length
+      return obj_len
+    end
+
+    def empty?
+      return self.length == 0
+    end
 
     def set_length(len , fill_char)
       return if len < 0
       counter = self.length()
-      return if len >= counter
-      internal_object_grow( ( len + 1 ) / 2)
+      return if counter >= len
+      internal_object_grow( len )
       while( counter < len)
         set_char( counter , fill_char)
         counter = counter + 1
@@ -28,36 +40,25 @@ module Parfait
     end
 
     def set_char at , char
-      raise "char out of range #{char}" if (char < 0) or (char > 65000)
+      raise "char not fixnum #{char}" unless char.kind_of? Fixnum
       index = range_correct_index(at)
-      was = internal_object_get(index / 2 )
-      if index % 2
-        char = (char << 16) + (was & 0xFFFF)
-      else
-        char = char + (was & 0xFFFF0000)
-      end
-      internal_object_set( index / 2 , char )
+      internal_object_set( index  , char )
     end
 
     def get_char at
       index = range_correct_index(at)
-      whole = internal_object_get(index / 2 )
-      if index % 2
-        char = whole >> 16
-      else
-        char = whole & 0xFFFF
-      end
-      return char
+      return internal_object_get(index)
     end
 
     def range_correct_index at
       index = at
       index = self.length + at if at < 0
-      raise "index out of range #{at}" if index < 0
+      raise "index out of bounds #{at} > #{self.length}" if (index < 0) or (index > self.length)
       return index
     end
 
     def == other
+      return false if other.class != self.class
       return false if other.length != self.length
       len = self.length
       while len
@@ -66,7 +67,7 @@ module Parfait
       end
       return true
     end
-    
+
     def result= value
       raise "called"
       class_for(MoveInstruction).new(value , self , :opcode => :mov)