给Delphi高版本添加类似Kotlin的for的功能

type
  //这是一个辅助类
  TForInHelper = record
  strict private
  type
    TEnumerator = class
    private
      FLowValue, FHighValue : Integer;
      FIndex: NativeInt;
      function GetCurrent: Integer;
    public
      constructor Create(ALowValue, AHighValue : Integer);
      function MoveNext: Boolean;
      procedure Reset;
      property Current: Integer read GetCurrent;
    end;

 var
    FLowValue, FHighValue : Integer;
 public
    function GetEnumerator(): TEnumerator;
    class function Create(l, h : Integer):TForInHelper;static;
  end;

{ TForInHelper.TEnumerator }

constructor TForInHelper.TEnumerator.Create(ALowValue, AHighValue: Integer);
begin
  FLowValue := ALowValue;
  FHighValue := AHighValue;
  FIndex := FLowValue - 1;  //先MoveNext，然后才GetCurrent，所以要先把Index比Low值小一个
end;

function TForInHelper.TEnumerator.GetCurrent: Integer;
begin
  Result := FIndex;
end;

function TForInHelper.TEnumerator.MoveNext: Boolean;
begin
  Result := False;
  if FIndex >= FHighValue then
    Exit;
  Inc(FIndex);
  Result := True;
end;

procedure TForInHelper.TEnumerator.Reset;
begin
  FIndex := FLowValue;
end;

{ TForInHelper }

class function TForInHelper.Create(l, h: Integer): TForInHelper;
begin
  Result.FLowValue := l;
  Result.FHighValue := h;
end;

function TForInHelper.GetEnumerator: TEnumerator;
begin
  Result := TEnumerator.Create(FLowValue, FHighValue);
end;

//ForInHelper
function FH(l, h : Integer): TForInHelper;
begin
  Result := TForInHelper.Create(l, h);
end;

  for var i in FH(0,100) do
  begin
    OutputDebugString(PChar(format('%d',[i])));

  end;