anchor.diff:      ;
   
   memberDeclaration
  -    : 'assign' memberName block
  +    : 'object' memberName objectDefinition
  +    -> ^(OBJECT_DECL memberName objectDefinition)
  +    | 'assign' memberName block
       -> ^(ATTRIBUTE_SETTER memberName block)
       | 'void' memberName methodParameters voidMethodDefinition
       -> ^(METHOD_DECL 'void' memberName methodParameters voidMethodDefinition?)
  
positive.code:     EXPR;
      EXPR_LIST;
      EXPR_STMT;
      FINALLY_BLOCK;
      FORMAL_PARAMETER;
      FORMAL_PARAMETER_LIST;
      IF_FALSE;
  
negative.code:     SWITCH_STMT;
      SWITCH_EXPR;
      SWITCH_CASE_LIST;
      TYPE_CONSTRAINT_LIST;
      TYPE;
      TYPE_CONSTRAINT;
  