function TAssEditor.DoSpacesToTab(const Str: string): string;

var

  nIndex, nLen, nTmpLen, nNeedSpaceCount : integer;

  TmpStr : string;

begin

  Result := ＇＇;

  nLen := Length(Str);

  nIndex := 1;

  while nIndex <= nLen do

  begin

    if Str[nIndex] = CHAR_SPACE then

    begin

      nNeedSpaceCount := FTabSize - (Length(ExpandStr(Result)) mod FTabSize);

      TmpStr := GetStringWhile(Str, [CHAR_SPACE], nIndex);

      nTmpLen := Length(TmpStr);

      if nTmpLen = 0 then

        Result := Result + Str[nIndex]

      else if nTmpLen = nNeedSpaceCount then

        Result := Result + CHAR_TAB

      else if nTmpLen > nNeedSpaceCount then

      begin

        Result := Result + CHAR_TAB;

        Delete(TmpStr, 1, nNeedSpaceCount);

        Dec(nIndex, Length(TmpStr));

      end

      else

        Result := Result + TmpStr;

    end

    else

    begin

      Result := Result + Str[nIndex];

      Inc(nIndex);

    end;

  end;

end;