anchor.diff:  AUTO: "AUTO"i
   PATH: /([a-z0-9_]*\.*\/|[a-z_]+[.\/])[a-z0-9_\/\.]+/i
   NAME: /[a-z_][a-z0-9_]*/i
  +NULL: "NULL"i
   
   SIGNED_FLOAT: ["-"|"+"] FLOAT
   SIGNED_INT: ["-"|"+"] INT
  
positive.code: attr: attr_name (value | NAME)+
  
  attr_name: NAME | composite_type
  ?value: string | int | float | expression | not_expression | attr_bind | path | regexp | runtime_var | list | bare_string2
  
  int: SIGNED_INT
  int_pair: int int
  
negative.code: 
  %ignore COMMENT
  %ignore CCOMMENT
  %ignore WS
  