Versionsnummern vergleichen?

[PaddyL]

Seltsam, ähnliches Problem kam vor kurzer Zeit in einem anderen Forum auf, wo ich folgende Delphi Lösung vorstellte:

Delphi-Quellcode:

program Project1;

{$APPTYPE CONSOLE}
{$DEFINE DEBUG}

uses
  SysUtils, Classes;

type
  TCVSResult = (csEqual, csFirst, csSecond);
  TStrArray = array of string;

function Explode(Border, S: string): TStrArray;
var
  S2: string;
  I: Integer;
  a: TStrArray;
begin
  I  := 0;
  S2 := S + Border;
  repeat
    SetLength(A, Length(A) + 1);
    a[I] := Copy(S2, 0, Pos(Border, S2) - 1);
    Delete(S2, 1, Length(a[I] + Border));
    Inc(I);
  until S2 = '';
  Result := a;
end;

function StringReplaceCharacters(Str: String): String;
var
  I: Integer;
begin
  Str := StringReplace(Str, ' ', '', [rfIgnoreCase]);
  Str := StringReplace(Str, 'alpha', '.-26', [rfIgnoreCase]);
  Str := StringReplace(Str, 'beta',  '.-25', [rfIgnoreCase]);
  for I := 0 to 19 do
    Str := StringReplace(Str, 'RC' + IntToStr(I), '.-' + IntToStr(20 - I),
                         [rfIgnoreCase]);
  for I := 0 to 25 do
    Str := StringReplace(Str, Chr(Ord('a') + I), '.-' + IntToStr(26 - I + 20),
                         [rfIgnoreCase]);
  Result := Str;
end;

function CompareVersionStrings(Str1, Str2: String): TCVSResult;
var
  S1, S2: String;
  Stl: array[0..1] of TStrArray;
  I: Integer;
  X: Integer;
begin
  {$IFDEF DEBUG}
    WriteLn('Debug: comparing' + Str1 + ' vs ' + Str2);
  {$ENDIF}
  Result := csEqual;
  S1 := StringReplaceCharacters(Str1);
  S2 := StringReplaceCharacters(Str2);

  if S1 = S2 then
    Exit;

  Stl[0] := Explode('.', S1);
  Stl[1] := Explode('.', S2);

  I := 0;
  if Length(Stl[0]) > Length(Stl[1]) then
  begin
    X := 1;
    Result := csFirst;
  end
  else if Length(Stl[0]) < Length(Stl[1]) then
  begin
    X := 0;
    Result := csSecond;
  end;

  for I := 0 to Length(Stl[X]) -1 do
  begin
    {$IFDEF DEBUG}
      WriteLn('Debug: '+Stl[0][I]+' vs '+Stl[1][I]);
    {$ENDIF}
    if StrToInt(Stl[0][I]) > StrToInt(Stl[1][I]) then
    begin
      Result := csFirst;
      Exit;
    end
    else if StrToInt(Stl[0][I]) < StrToInt(Stl[1][I]) then
    begin
      Result := csSecond;
      Exit;
    end;
  end;
end;

begin
  case CompareVersionStrings('1.0RC1', '1.0a') of
    csFirst: WriteLn('First one');
    csSecond: WriteLn('Second one');
    csEqual: WriteLn('Equal Strings');
  end;
  ReadLn;
end.

Die Aufgabenstellung hier war allerdings bei Strings wie:

Code:

1a
1b
1RC1
1RC2
1.1
1.1.1
1.1.2
1.2
1.2fix
1.2fix2
2a
...

den neusten Finden zu können.