paweld/lazarus
1
0
Fork 0
mirror of https://gitlab.com/freepascal.org/lazarus/lazarus.git synced 2025-04-18 05:49:30 +02:00
Code Issues Packages Projects Releases Wiki Activity

LazUtils: New implementation of UTF8StringReplace. Issue #41291.

Browse Source
This commit is contained in:
Juha 2024-12-28 16:30:20 +02:00
parent 602fb83512
commit 4c1a98b6fa
1 changed files with 40 additions and 83 deletions
Show Stats Download Patch File Download Diff File Expand all files Collapse all files

123
components/lazutils/lazutf8.pas
View File

@ -134,7 +134,7 @@ function UTF8UpperCaseFast(const AText: String): String;
function UTF8LowerCaseFast(const AText: String): String;
function UTF8SwapCase(const AInStr: string; const ALanguage: string=''): string;
// Capitalize the first letters of every word
// Capitalize the first letter of every word
function UTF8ProperCase(const AInStr: string; const WordDelims: TSysCharSet): string;
function FindInvalidUTF8Codepoint(p: PChar; Count: PtrInt; StopOnNonUTF8: Boolean = true): PtrInt;
function FindInvalidUTF8Character(p: PChar; Count: PtrInt; StopOnNonUTF8: Boolean = true): PtrInt; deprecated 'Use FindInvalidUTF8Codepoint instead.';
@ -1210,96 +1210,53 @@ end;
function UTF8StringReplace(const S, OldPattern, NewPattern: String;
Flags: TReplaceFlags; out Count: Integer; const ALanguage: string=''): String;
// same algorithm as fpc's StringReplace, but using UTF8LowerCase
// for case insensitive search
var
Srch, OldP: string;
P, PrevP, PatLength, NewPatLength, Cnt: Integer;
c, d: PChar;
SrcS, OldPtrn, TempS: string;
PSrc, POrig: PChar;
CharLen, OldPatLen: Integer;
OkToReplace: Boolean;
begin
Srch := S;
OldP := OldPattern;
Count := 0;
PatLength:=Length(OldPattern);
if PatLength=0 then
if OldPattern='' then
Exit(S);
if rfIgnoreCase in Flags then
begin
Result:=S;
Exit;
end;
if (rfIgnoreCase in Flags) then
begin
Srch := UTF8LowerCase(Srch,ALanguage);
OldP := UTF8LowerCase(OldP,ALanguage);
end;
PatLength := Length(OldP);
if (Length(NewPattern) = PatLength) then
begin //length will not change
Result := S;
P := 1;
repeat
P := Pos(OldP,Srch,P);
if (P > 0) then
begin
Inc(Count);
Move(NewPattern[1],Result[P],PatLength*SizeOf(Char));
if not (rfReplaceAll in Flags) then Exit;
Inc(P,PatLength);
end;
until (P = 0);
SrcS := UTF8LowerCase(S,ALanguage);
OldPtrn := UTF8LowerCase(OldPattern,ALanguage);
end
else
else begin
SrcS := S;
OldPtrn := OldPattern;
end;
OldPatLen := Length(OldPtrn);
PSrc := PChar(SrcS);
POrig := PChar(S);
Result := '';
OkToReplace := True;
while PSrc < PChar(SrcS) + Length(SrcS) do
begin
//Different pattern length -> Result length will change
//To avoid creating a lot of temporary strings, we count how many
//replacements we're going to make.
P := 1;
repeat
P:=Pos(OldP,Srch,P);
if (P > 0) then
begin
Inc(P,PatLength);
Inc(Count);
if not (rfReplaceAll in Flags) then Break;
end;
until (P = 0);
if (Count = 0) then
if OkToReplace and (CompareByte(PSrc^, OldPtrn[1], OldPatLen) = 0) then
begin
Result:=S;
Exit;
// Found: Replace with NewPattern and move forward
Inc(Count);
Result := Result + NewPattern;
Inc(PSrc, OldPatLen); // Skip the found string
// Move forward also in original string.
Inc(POrig, Length(OldPattern));
if not (rfReplaceAll in Flags) then
OkToReplace := False; // Replace only once.
end
else begin
// Move forward in possibly lowercased string
CharLen := UTF8CodepointSize(PSrc);
Inc(PSrc, CharLen); // Next Codepoint
// Copy a codepoint from original string and move forward
CharLen := UTF8CodepointSize(POrig);
SetLength(TempS{%H-}, CharLen);
System.Move(POrig^, TempS[1], CharLen);
Result := Result + TempS; // Copy one codepoint from original string
Inc(POrig, CharLen); // Next Codepoint
end;
NewPatLength := Length(NewPattern);
SetLength(Result, Length(S) + Count*(NewPatLength - PatLength));
P := 1;
PrevP := 0;
c := PChar(Result);
d := PChar(S);
repeat
P:=Pos(OldP, Srch, P);
if (P > 0) then
begin
Cnt := P - PrevP - 1;
if (Cnt > 0) then
begin
Move(d^, c^, Cnt*SizeOf(Char));
Inc(c,Cnt);
Inc(d,Cnt);
end;
if (NewPatLength > 0) then
begin
Move(NewPattern[1], c^, NewPatLength*SizeOf(Char));
Inc(c,NewPatLength);
end;
Inc(P,PatLength);
Inc(d,PatLength);
PrevP:=P-1;
if not (rfReplaceAll in Flags) then Break;
end;
until (P = 0);
Cnt := Length(S) - PrevP;
if (Cnt > 0) then
Move(d^, c^, Cnt*SizeOf(Char));
end;
end;