anchor.diff:      ;
       
   cases 
  -    : ('case' 'null' block)? ('case' '(' caseCondition ')' block)+ ('else' block)?
  +    : ('case' '(' caseCondition ')' block)+ ('else' block)?
       ;
       
   caseCondition
  
positive.code:     ;
  
  namedArguments
      : '{' ((namedArgument ';') => namedArgument ';')* varargArguments? '}'
      ;
  
  varargArguments
  
negative.code:     ;
        
  namedArgument
      : parameterName specifier ';'
      ;
      
  parameterName
  