//------------------ File Singers.pas ------------------
unit Singers;

interface

uses
  SysUtils ;

type
  TAbstractSinger = class
  private
    FLine: String ;
    FCanSing: boolean ;
    function GetLine: String ; virtual ;
    procedure SetLine(aLine: String) ; virtual ;
  public
    property CanSing: boolean read FCanSing write FCanSing ;
    property Line: String read GetLine write SetLine ;
    function Sing: String ; virtual ; abstract ;
  end ;

  TBottlesSinger = class(TAbstractSinger)
  private
    FCounter: integer ;
    function EvalS: String ;
    procedure SetCounter(aValue: integer) ;
    procedure PrepareLine ;
    property Counter: integer read FCounter write SetCounter;
  public
    constructor Create ;
    function Sing: String ; override ;
  end ;

const
  CRLF: String = '' + #13#10 ;

implementation

{ TAbstractSinger }

function TAbstractSinger