Einheiten parsen

[Bjoerk]

Geht sehr gut. Danke Robert.

Delphi-Quellcode:

type
  TUnitBase = (fuKN, fuM);
  TUnitStyle = (usNone, usKNdivM3, usKNdivM2, usKNdivM, usKNM, usKN, usM3, usM2, usM);

  TUnits = class
  private
    FItems: array[usNone..usM, fuKN..fuM] of integer;
    function GetValues(Index: TUnitStyle): double;
    function GetAsString(Index: TUnitStyle): string;
  public
    property Values[Index: TUnitStyle]: double read GetValues;
    property AsString[Index: TUnitStyle]: string read GetAsString;
    function GetPlus(const A, B: TUnitStyle): TUnitStyle;
    function GetMinus(const A, B: TUnitStyle): TUnitStyle;
    function GetDiv(const A, B: TUnitStyle): TUnitStyle;
    function GetMult(const A, B: TUnitStyle): TUnitStyle;
    constructor Create;
  end;

var
  Form1: TForm1;

implementation

{$R *.dfm}

{ TUnits }

constructor TUnits.Create;
begin
  FItems[usNone, fuKN] := 0;
  FItems[usNone, fuM] := 0;

  FItems[usKNdivM3, fuKN] := 1;
  FItems[usKNdivM3, fuM] := -3;

  FItems[usKNdivM2, fuKN] := 1;
  FItems[usKNdivM2, fuM] := -2;

  FItems[usKNdivM, fuKN] := 1;
  FItems[usKNdivM, fuM] := -1;

  FItems[usKNM, fuKN] := 1;
  FItems[usKNM, fuM] := 1;

  FItems[usKN, fuKN] := 1;
  FItems[usKN, fuM] := 0;

  FItems[usM3, fuKN] := 0;
  FItems[usM3, fuM] := 3;

  FItems[usM2, fuKN] := 0;
  FItems[usM2, fuM] := 2;

  FItems[usM, fuKN] := 0;
  FItems[usM, fuM] := 1;
end;

function TUnits.GetValues(Index: TUnitStyle): double;
begin
  Result := IntPower(FItems[Index, fuKN], FItems[Index, fuM]);
end;

function TUnits.GetAsString(Index: TUnitStyle): string;
begin
  case Index of
    usKNdivM3:
      Result := 'kN/m3';
    usKNdivM2:
      Result := 'kN/m2';
    usKNdivM:
      Result := 'kN/m';
    usKNM:
      Result := 'kNm';
    usKN:
      Result := 'kN';
    usM3:
      Result := 'm3';
    usM2:
      Result := 'm2';
    usM:
      Result := 'm';
    else
      Result := '';
  end;
end;

function TUnits.GetPlus(const A, B: TUnitStyle): TUnitStyle;
begin
  if A = B then
    Result := A
  else
    Result := usNone;
end;

function TUnits.GetMinus(const A, B: TUnitStyle): TUnitStyle;
begin
  if A = B then
    Result := A
  else
    Result := usNone;
end;

function TUnits.GetMult(const A, B: TUnitStyle): TUnitStyle;
var
  I: TUnitStyle;
  KN, M: integer;
begin
  Result := usNone;
  KN := FItems[A, fuKN] + FItems[B, fuKN];
  M := FItems[A, fuM] + FItems[B, fuM];
  for I := Low(TUnitStyle) to High(TUnitStyle) do
    if (KN = FItems[I, fuKN]) and (M = FItems[I, fuM]) then
    begin
      Result := I;
      Break;
    end;
end;

function TUnits.GetDiv(const A, B: TUnitStyle): TUnitStyle;
var
  I: TUnitStyle;
  KN, M: integer;
begin
  Result := usNone;
  KN := FItems[A, fuKN] - FItems[B, fuKN];
  M := FItems[A, fuM] - FItems[B, fuM];
  for I := Low(TUnitStyle) to High(TUnitStyle) do
    if (KN = FItems[I, fuKN]) and (M = FItems[I, fuM]) then
    begin
      Result := I;
      Break;
    end;
end;

{ TForm1 }

procedure TForm1.Button1Click(Sender: TObject);
var
  Units: TUnits;
  A, B, C: TUnitStyle;
begin
  Units := TUnits.Create;
  try
    A := usM3;
    B := usKNdivM2;
    C := Units.GetMult(A, B);
    ShowMessage(Units.AsString[C]);
    A := usKN;
    B := usM;
    C := Units.GetDiv(A, B);
    ShowMessage(Units.AsString[C]);
  finally
    Units.Free;
  end;
end;