anchor.diff:   */
   grammar WebIDL;
   
  -// Note: Replaced keywords: const, default, enum, interface, null.
  +/* Note: appended underscore to keywords for CPP compat:
  +    const, default, enum, namespace, null
  +    see github.com/antlr/grammars-v4/issues/2099 for more info
  +*/
   // Note: Added "wrapper" rule webIDL with EOF token.
   
   webIDL
  
positive.code: 
  definition
  	: callbackOrInterfaceOrMixin
  	| namespace
  	| partial
  	| dictionary
  	| enum_
  
negative.code: 	: 'setlike' '<' typeWithExtendedAttributes '>' ';'
  ;
  
  namespace_
      : 'namespace' IDENTIFIER_WEBIDL '{' namespaceMembers '}' ';'
  ;
  
  