anchor.diff:      |   PRINT '(' expression ')'
       |   DEBUG '(' expression ')'
       |   TRACE '(' expression ')'
  +    |   func
  +    |   call
       |   expression '.' Identifier
       |   expression '[' expression ']'
  -    |   func
  -    |   call
       |   expression ('++' | '--')
       |   ('+'|'-'|'++'|'--') expression
       |   ('~'|'!') expression
  
positive.code:     ;
  
  inline
      :   '{' statement (';' statement)* '}'
      ;
  
  statements
  
negative.code: 
  StringLiteral
      :   '"' StringCharacters? '"'
      ;
  
  fragment
  