anchor.diff:  //This one is fully general
   assignable 
       : (functorStart) => functor
  -    | enumeration
       | expression
       ;
   
   //This one is for use as a functor body
  -simpleAssignable 
  -    : (functorStart) => functor
  -    | enumeration	
  -    | simpleExpression
  -    ;
   
   functorStart
       : 'functor' | formalParameterStart
  
positive.code: primary
      : base selector*
      ;
  
  base 
      : '#'? regularType
      |'#'? memberName
      | literal
      | parExpression
      //| enumeration
      | 'this' 
      | 'super' 
      | 'null'
      | 'none'
      | inlineClassDeclaration
      ;
  
  enumeration
  
negative.code:     ;
  
  setter
      : 'assign' memberName block
      ;
      
  voidMethod 
  