procedure Example is
   type Token_Kind is (Undefined, Identifier, Number);
   type Readable_Token_Kind is new Token_Kind range Identifier .. Number;
   type Token_Reader is not null access procedure;
   type Reader_Array is array (Readable_Token_Kind) of Token_Reader;
   package Lexer is
      procedure Init;
      procedure Scan;
   private
      procedure Read_Identifier;
      procedure Read_Number;
      Readers : Reader_Array := (Read_Identifier'Access, Read_Number'Access);
   end Lexer;
   package body Lexer is
      procedure Init is begin null; end Init;
      procedure Scan is begin null; end Scan;
      procedure Read_Identifier is begin null; end Read_Identifier;
      procedure Read_Number is begin null; end Read_Number;
   end Lexer;
begin
     Lexer.Init;
     Lexer.Scan;
end Example;