unit SimpleParser;

interface

uses
  Classes,
  Parser;

type
  TParserState = procedure( AChar : Char ) of object;

  TSimpleParser = class( TInterfacedObject, IParser )
  private
    FBuffer : string;
    FTokens : TStrings;
    procedure StartState( AChar : Char );
    procedure TokenState( AChar : Char );
  public
    constructor Create;
    destructor Destroy; override;

    function Parse( const AString : string ) : TArray<string>;
  end;

implementation

// unit-globale Variable und ich kann threadsafe vergessen
var
  FState : TParserState;

{ TSimpleParser }

constructor TSimpleParser.Create;
begin
  inherited;
  FTokens := TStringList.Create;
end;

destructor TSimpleParser.Destroy;
begin
  FTokens.Free;
  inherited;
end;

function TSimpleParser.Parse( const AString : string ) : TArray<string>;
var
  LIdx : Integer;
begin
  FTokens.Clear;
  FState := StartState;
  for LIdx := 1 to Length( AString ) do
  begin
    FState( AString[LIdx] );
  end;
  Result := FTokens.ToStringArray;
end;

procedure TSimpleParser.StartState( AChar : Char );
begin
  case AChar of
    ' ' :
      ;
    ',' :
      ;
  else
    FState := TokenState;
    FState(AChar);
  end;
end;

procedure TSimpleParser.TokenState( AChar : Char );
begin
  case AChar of
    ',' :
      begin
        FTokens.Add( FBuffer );
        FBuffer := '';
        FState := StartState;
      end;
  else
    FBuffer := FBuffer + AChar;
  end;
end;

end.