anchor.diff:      | TIMELITERAL
       | REGEXPLITERAL
       | stringLiteral
  -    | typeLiteral
       ;   
  -
  -//FIXME: member literals are a problem!
  -//FIXME: type parameters 
  -typeLiteral
  -    : '#' typeName //'#' type
  -    ;
   
   stringLiteral
       : SIMPLESTRINGLITERAL
  
positive.code:     ;
  
  base 
      : typeName
      | memberName
      | literal
      | parExpression
      //| enumeration
  
negative.code:     ;
  
  regularType
      : typeName ( (typeParameterStart) => typeParameters )?
      ;
  
  functorType
  