anchor.diff:  anonymousFunction
       : 'fun'
       (NL* type NL* '.')?
  -    NL* functionValueParameters
  +    NL* parametersWithOptionalType
       (NL* ':' NL* type)?
       (NL* typeConstraints)?
       (NL* functionBody)?
  
positive.code:     ;
  
  superExpression
      : 'super' ('<' NL* type NL* '>')? ('@' simpleIdentifier)?
      | SUPER_AT
      ;
  
  
negative.code:     ;
  
  functionValueParameter
      : parameterModifiers? parameter (NL* '=' NL* expression)?
      ;
  
  functionDeclaration
  