DimsaMathParser/uParserValue.pas at master · dimsa/DimsaMathParser · GitHub

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unit uParserValue;

interface

type

 TValue = class
  strict private
    FText: String;
    FBoundLeft, FBoundRight: Integer;
  protected
    procedure SetText(const Value: String); virtual;
   { function PosFromRight(const ASubStr, AStr: string;
      AOffset: Integer = 0): Integer;
    function PosFromLeft(const ASubStr, AStr: string;
      AOffset: Integer = 1): Integer;}
    // Äåëàåò êàêóþ-òî ÷àñòü òåêñòà çíà÷åíèåì
//    function AddValue(const AText: String; const ALeft, ARight: Integer): TValue;
  public
    // Ãðàíèöû â êîòîòîðûõ íàõîäÿòñÿ ïîëîæåíèÿ ïîäñòðîêè çíà÷åíèÿ â ðîäèòåëå
    property Text: String read FText write SetText; // Îðèãèíàëüíûé òåêñò âûðàæåíèÿ
    property BoundLeft: Integer read FBoundLeft write FBoundLeft;
    property BoundRight: Integer read FBoundRight write FBoundRight;
    function Value: Double; virtual; abstract;
    constructor Create; virtual;
    destructor Destroy; override;
  end;

  TValues = class of TValue;

implementation

constructor TValue.Create;
begin
  inherited;

end;

destructor TValue.Destroy;
begin

  inherited;
end;

procedure TValue.SetText(const Value: String);
begin
  FText := Value;
//  FExpression := StringReplace(FText, ' ', '',[rfReplaceAll]);
end;
// Ðàáîòàåò òàê æå êàê Pos, íî â ñëó÷àå,åñëè óêàçàí îôôñåò 0, âûäàåò ðåçóëüòàò
{function TValue.PosFromLeft(const ASubStr, AStr: string;
  AOffset: Integer = 1): Integer;
var
  vStrLen, vSubStrLen: Integer;
  vStrI, vSubStrI: Integer; // Ñ÷åò÷èêè
begin
  vStrLen := Length(AStr);
  vSubStrLen := Length(ASubStr);

  for vStrI := AOffset to vStrLen - vSubStrLen do
  begin
    for vSubStrI := 1 to vSubStrLen do
    begin
      // Åñëè íå ñîâïàäàåò, òî ïðîïóñêàåì èòåðàöèþ
      if (AStr[vStrI + vSubStrI - vSubStrLen] <> ASubStr[vSubStrI]) then
        Break;
      // Åñëè íàòêíóëîñü íà ãðàíèöó, òî ïðîïóñêàåì èòåðàöèþ
    //  if Self.IsBound(vStrI + vSubStrI - vSubStrLen) then
      //  Break;
      // Åñëè íîâîå çíà÷åíèå è âñ¸ îê, òî âûõîäèì ñî çíà÷åíèåì ïîçèöèè
      if vSubStrI = 1 then
          Exit(vStrI - vSubStrLen + 1);
    end;
  end;

  Result := 0;
end; }

// Âûäàåò òå æå çíà÷åíèÿ, ÷òî è Pos, íî èùåò îò îôôñåòà âêëþ÷èòåëüíî âëåâî
// Ïåðâûé ñèìâîë òàê æå èìååò çíà÷åíè 1, à ïîñëåäíèé Length(s);
// Åñëè îôôñåò áîëüøå äëèíû, âñå íîðì, ò.ê. ñòðèíã êàê-òî êîíòðîëëèðóåò âñ¸
{function TValue.PosFromRight(const ASubStr, AStr: string;
  AOffset: Integer = 0): Integer;
var
  vStrLen, vSubStrLen: Integer;
  vStrI, vSubStrI: Integer; // Ñ÷åò÷èêè
begin
  vStrLen := Length(AStr);
  vSubStrLen := Length(ASubStr);
  if AOffset = 0 then
    AOffset := vStrLen;

  for vStrI := AOffset downto vSubStrLen do
  begin
    for vSubStrI := vSubStrLen downto 1 do
    begin
      // Åñëè íå ñîâïàäàåò, òî ïðîïóñêàåì èòåðàöèþ
      if (AStr[vStrI + vSubStrI - vSubStrLen] <> ASubStr[vSubStrI]) then
        Break;
      // Åñëè íàòêíóëîñü íà ãðàíèöó, òî ïðîïóñêàåì èòåðàöèþ
     // if Self.IsBound(vStrI + vSubStrI - vSubStrLen) then
    //    Break;
      // Åñëè íîâîå çíà÷åíèå è âñ¸ îê, òî âûõîäèì ñî çíà÷åíèåì ïîçèöèè
      if vSubStrI = 1 then
          Exit(vStrI - vSubStrLen + 1);
    end;
  end;

  Result := 0;
end; }

end.