[+10 Puan] String Manipülasyon İşlemleri

[Tuğrul HELVACI]

Ben de değişik bir kaç metod yazdım. Onları paylaşayım:

function GetData(const ASource : String; const AStart, ALen : Integer) : String;
var
 ASize,
 AIndex : Integer;
begin
 ASize := ALen;
 AIndex:= AStart;

 if ASource.IsEmpty then
   Exit('');

 if ASize <= 0 then
   Exit('');

 if ASize > ASource.Length then
   ASize := ASource.Length;

 if not AIndex in [1..ASize] then
   AIndex := 1;

 SetLength(Result, ASize);

 Move(ASource[AIndex], Pointer(Result)^, ASize * SizeOf(Char));
end;

function FromRight(const ASource : String; const ALen : Integer) : String;
begin
 Result := GetData(ASource, (ASource.Length - ALen) + 1, ALen);
end;

function FromLeft(const ASource : String; const ALen : Integer) : String;
begin
 Result := GetData(ASource, 1, ALen);
end;

function FromRightEx(const ASource : String; const ALen : Integer) : String;
var
 PCurrent,
 PEnd,
 PTarget : PChar;
begin
 SetLength(Result, ALen);

 PCurrent  := @ASource[(ASource.Length - ALen) + 1];
 PEnd      := @ASource[ASource.Length];
 PTarget   := @Result[1];

 while PCurrent <= PEnd do
 begin
   PTarget^ := PCurrent^;

   Inc(PCurrent);
   Inc(PTarget);
 end;
end;

function FromLeftEx(const ASource : String; const ALen : Integer) : String;
var
 PCurrent,
 PEnd,
 PTarget : PChar;
begin
 SetLength(Result, ALen);

 PCurrent  := @ASource[1];
 PEnd      := @ASource[ALen];
 PTarget   := @Result[1];

 while PCurrent <= PEnd do
 begin
   PTarget^ := PCurrent^;

   Inc(PCurrent);
   Inc(PTarget);
 end;
end;

GetData metodunda bazı güvenlik kontrolleri koydum, diğerlerine de ekleyip eklememek tamamen sizin tasarrufunuz.