94
  function Get_Word (Data : Data_Type) return String is
  begin
     return Data.Word;
  end;
•
  function Equivalent (Word : String; Data : Data_Type)
    return Boolean is
  begin
     return Word = Data.Word; -- compare key to key-part
  end;
•
  package Word_Keys is new Data_Sets.Generic_Keys
    (String,
     Get_Word,
     Ada.Strings.Hash,
     Equivalent);