StringList Buchstaben verbieten?

[Blup]

Das ist doch mal eine Möglichkeit einen Enumerator zu verwenden:

Delphi-Quellcode:

type
  TNumericEnumerator = record
    constructor Create(AList: TStrings);
  private
    FIndex: Integer;
    FList: TStrings;
    function Accept(const AItem: string): Boolean; inline;
    function GetCurrent: string; inline;
  public
    function MoveNext: Boolean; inline;
    property Current: string read GetCurrent;
    function GetEnumerator: TNumericEnumerator;
  end;

{ TNumericEnumerator }

function TNumericEnumerator.Accept(const AItem: string): Boolean;
const
  NUMBERS = ['0'..'9'];
var
  i: Integer;
begin  
  for i := 1 to Length(AItem) do
  begin
    if not (AItem[i] in NUMBERS) then
    begin
      Result := False;
      Exit;
    end;
  end;
  Result := True;
end;

constructor TNumericEnumerator.Create(AList: TStrings);
begin
  FList := AList;
end;

function TNumericEnumerator.GetCurrent: string;
begin
  Result := FList[FIndex];
end;

function TNumericEnumerator.GetEnumerator: TNumericEnumerator;
begin
  Result := Self;
end;

function TNumericEnumerator.MoveNext: Boolean;
var
  i: Integer;
begin
  for i := FIndex + 1 to FList.Count - 1 do
  begin
    if Accept(FList[i]) then
    begin
      FIndex := i;
      Result := True;
      Exit; // ==>
    end;
  end;
  Result := False;
end;

{ Anwendung}

procedure TuWas(AList: TStrings);
var
  s: string;
begin
  for s in TNumericEnumerator.Create(AList) do
    TuWasMitNumeric(s);
end;