anchor.diff:  unionStyleEnumCase : enumCaseName tupleType? ;
   enumName : identifier  ;
   enumCaseName : identifier  ;
  -rawValueStyleEnum : enumName genericParameterClause? ':' typeIdentifier '{' rawValueStyleEnumMembers?'}'  ;
  +rawValueStyleEnum : enumName genericParameterClause? typeInheritanceClause? '{' rawValueStyleEnumMembers?'}'  ;
   rawValueStyleEnumMembers : rawValueStyleEnumMember rawValueStyleEnumMembers? ;
   rawValueStyleEnumMember : declaration | rawValueStyleEnumCaseClause  ;
   rawValueStyleEnumCaseClause : attributes? 'case' rawValueStyleEnumCaseList  ;
   rawValueStyleEnumCaseList : rawValueStyleEnumCase | rawValueStyleEnumCase ',' rawValueStyleEnumCaseList  ;
   rawValueStyleEnumCase : enumCaseName rawValueAssignment? ;
  -rawValueAssignment : AssignmentOperator literal  ;
  +rawValueAssignment : '=' literal  ;
   
   // GRAMMAR OF A STRUCTURE DECLARATION
   
  -structDeclaration : attributes? 'struct' structName genericParameterClause? typeInheritanceClause? structBody  ;
  +structDeclaration : attributes? accessLevelModifier? 'struct' structName genericParameterClause? typeInheritanceClause? structBody  ;
   structName : identifier  ;
   structBody : '{' declarations?'}'  ;
   
   // GRAMMAR OF A CLASS DECLARATION
   
  -classDeclaration : attributes? 'class' className genericParameterClause? typeInheritanceClause? classBody  ;
  +classDeclaration : attributes? accessLevelModifier? 'class' className genericParameterClause? typeInheritanceClause? classBody  ;
   className : identifier ;
   classBody : '{' declarations? '}'  ;
   
   // GRAMMAR OF A PROTOCOL DECLARATION
   
  -protocolDeclaration : attributes? 'protocol' protocolName typeInheritanceClause? protocolBody  ;
  +protocolDeclaration : attributes? accessLevelModifier? 'protocol' protocolName typeInheritanceClause? protocolBody  ;
   protocolName : identifier  ;
   protocolBody : '{' protocolMemberDeclarations?'}'  ;
   protocolMemberDeclaration : protocolPropertyDeclaration ';'?
  
positive.code:  | continueStatement
   | fallthroughStatement
   | returnStatement
   ;
  
  // GRAMMAR OF A BREAK STATEMENT
  
negative.code: // GRAMMAR OF A STATEMENT
  
  statement
   : declaration ';'?
   | loopStatement ';'?
   | branchStatement ';'?
   | labeledStatement
   | controlTransferStatement ';'?
   | deferStatement ';' ?
   | doStatement ':'?
   | expression ';'?
   ;
  
  statements : statement+ ;
  