text: #ifndef _NL_VISITABLE_TYPES_H_
  #define _NL_VISITABLE_TYPES_H_
  
  class Expr;
  class Unary;
  class Binary;
  class Grouping;
  class StrLiteral;
  class NumLiteral;
  class BoolLiteral;
  class Variable;
  class Assignment;
  class Logical;
  class Call;
  class Get;
  class Set;
  class GetIndex;
  class SetIndex;
  class This;
  class SentinelExpr;
  
  class Stmt;
  class ExprStmt;
  class BlockStmt;
  class PrintStmt;
  class VarStmt;
  class ClassStmt;
  class IfStmt;
  class WhileStmt;
  class FuncStmt;
  class ReturnStmt;
  
  #endif // _NL_VISITABLE_TYPES_H_
  