帮我看看这段代码

unit persrec;

interface
uses Classes, dialogs, sysutils;

type
TPersonRec = packed record //声明一个TPersonRec记录
FirstName: String[20];
LastName: String[20];
MI: String[1];
BirthDay: TDateTime;
Age: Integer;
end;

//创建一个TFileStream派生类TPersonRec
//TRecordStream从TFileStream派生而来，为TPersonRec进行文件的输入/输出
TRecordStream = class(TFileStream);
private
function GetNumRecs: Longint;
function GetCurRec: Longint;
procedure SetCurRec(RecNo: Longint);
protected
function GetRecSize: Longint;virtual;
public
function SeekRec(RecNo: Longint; Origin: Word): Longint;
function WriteRec(const Rec): Longint;
function AppendRec(const Rec): Longint;
function ReadRec(var Rec): Longint;
procedure First;
procedure Last;
procedure NextRec;
procedure PreviousRec;
property NumRecs: Longint read GetNumRecs;
//NumRecs显示了文件流中的记录数
property CurRec: Longint read GetCurRec write SetCurRec;
//CurRec反映了文件流中的当前记录
end;

implementation

function TRecordStream. 为什么我在这打点出不来我在上面声明的那些内容呢？？？