Both functions are functioning properly. thank
Στις 28-02-2006, ημέρα Τρι, και ώρα 17:48 +0100, ο/η Mattias Gaertner
έγραψε:
> On Tue, 28 Feb 2006 18:08:34 +0200
> "Panagiotis Sidiropoulos" <[EMAIL PROTECTED]> wrote:
>
> > For anyone interest on a UTF8Pos function, here is one as suggested by
> > Vincent and Mattias:
> >
> > // Find position into a utf string
> > function UTF8Pos( cSearcFor, cSearchInto: UTF8String ): integer;
> > var
> > nPos: integer;
> >
> > begin
> > nPos := pos( cSearcFor, cSearchInto );
> > if nPos > 0 then Result := UTF8Length( copy( cSearchInto, 1, nPos
> > - 1 ) )
> >
> > else Result := 0;
> > end;
>
> Better use PChar for speed.
> I added the following two function to LCLProc:
>
> function UTF8Pos(const SearchForText, SearchInText: string): integer;
> // returns the character index, where the SearchForText starts in
> SearchInText
> var
> p: LongInt;
> begin
> p:=System.Pos(SearchForText,SearchInText);
> if p>0 then
> Result:=UTF8Length(PChar(SearchInText),p-1)+1
> else
> Result:=0;
> end;
>
> function UTF8Copy(const s: string; StartCharIndex, CharCount: integer):
> string;
> // returns substring
> var
> StartBytePos: PChar;
> EndBytePos: PChar;
> MaxBytes: PtrInt;
> begin
> StartBytePos:=UTF8CharStart(PChar(s),length(s),StartCharIndex-1);
> if StartBytePos=nil then
> Result:=''
> else begin
> MaxBytes:=PtrInt(PChar(s)+length(s)-StartBytePos);
> EndBytePos:=UTF8CharStart(StartBytePos,MaxBytes,CharCount);
> if EndBytePos=nil then
> Result:=copy(s,StartBytePos-PChar(s)+1,MaxBytes)
> else
> Result:=copy(s,StartBytePos-PChar(s)+1,EndBytePos-StartBytePos);
> end;
> end;
>
>
> Mattias
>
>
>
> >
> > Now, I'm trying to write a UTF8Copy function to return a specific
> > ammount of characters (not bytes) from a string. Here is what I've done
> > till now. It does not work correctly. Do you think I'm in the right path
> > or is there any other, smarter, way to do this?
> >
> > // Get a utf character at a specific position
> > function UTF8Copy( cCopyFrom: UTF8String; nFromPosition, nNoOfChars:
> > integer ): UTF8String;
> > var
> > i,
> > nUTF8Len,
> > nByteLen,
> > nStart: integer;
> >
> > begin
> > Result := '';
> > nUTF8Len := UTF8Length( cCopyFrom );
> > if nFromPosition > nUTF8Len then exit;
> >
> > nByteLen := Length( cCopyFrom );
> > nStart := 0;
> > for i := 1 to nByteLen do begin
> >
> > if UTF8Length( copy( cCopyFrom, 1, i ) ) = nFromPosition then
> > nStart := i + 1;
> > if ( nStart > 0 ) and
> > ( UTF8Length( copy( cCopyFrom, nStart, i ) ) = nNoOfChars )
> > then break;
> >
> > end;
>
> maybe better:
>
> var
> pCopyFrom
> pCopyFrom:=UTF8CharStart(PChar(cCopyFrom),length(cCopyFrom),nFromPosition-1
> );
> if
>
>
> > Result := copy( cCopyFrom, nStart, i );
> > end;
> >
> > Panagiotis
> >
> > -----Original Message-----
> > From: Mattias Gaertner [mailto:[EMAIL PROTECTED]
> > Sent: Tuesday, February 28, 2006 12:24 PM
> > To: [email protected]
> > Subject: Re: [lazarus] String functions on non latin text
> >
> >
> > On Tue, 28 Feb 2006 09:57:09 +0200
> > "Panagiotis Sidiropoulos" <[EMAIL PROTECTED]> wrote:
> >
> > > >so if there is something wrong with the sample I thought it should
> > > >be gtk2 and the only problem I found was the position returned
> > > >mismatched visually the substring
> > >
> > > I tried to find a relation between results but there is no any kind of
> >
> > > pattern, for example, for the first character give 1, the second 3 and
> >
> > > 21st give 41. Visually mismatch is the problem, I need to rearrange
> > > characters for indexing reasons and can't trace what character is what
> >
> > > into convertion table.
> >
> > Jesus is right.
> > UTF8 is a multi byte character encoding. This means a character has a
> > size varying between 1 to 4. To get the character position use:
> >
> > BytePos:=System.Pos(search,text);
> > if BytePos>0 then
> > CharPos:=UTF8Length(Pchar(text),BytePos-1)
> > else
> > CharPos:=0;
> >
> >
> > Mattias
> >
> >
> > >
> > > I will try to update Lazarus and FPC, just to be sure.
> > >
> > > Panagiotis
> > >
> > > -----Original Message-----
> > > From: Jesus Reyes [mailto:[EMAIL PROTECTED]
> > > Sent: Tuesday, February 28, 2006 8:30 AM
> > > To: [email protected]
> > > Subject: Re: [lazarus] String functions on non latin text
> > >
> > >
> > >
> > > ----- Original Message -----
> > > From: "Mattias Gaertner" <[EMAIL PROTECTED]>
> > > To: <[email protected]>
> > > Sent: Monday, February 27, 2006 2:45 PM
> > > Subject: Re: [lazarus] String functions on non latin text
> > >
> > >
> > > > On Mon, 27 Feb 2006 13:41:13 -0600 (CST)
> > > > Jesus Reyes <[EMAIL PROTECTED]> wrote:
> > > >
> > > > >
> > > > > --- Panagiotis Sidiropoulos <[EMAIL PROTECTED]> escribió:
> > > > >
> > > > > > Please download sample project at:
> > > > > > - www.magentadb.gr/ftp/pos-sample.zip
> > > > > >
> > > > > > Panagiotis
> > > > > >
> > > > >
> > > > > result := Pos(UTF8Decode(SubStr), UTF8Decode(Str));
> > > > >
> > > > > seems to work, I think Pos(UTF8String,UTF8String) is yet to be
> > > > > implemented.
> > > >
> > > > It does not need to be implemented. One nice feature of UTF8 is,
> > > > that
> > > > you can find out the start of an UTF8 character without parsing the
> > > > whole string. A simple substring search works with UTF8 and is
> > > > unambiguous.
> > >
> > > I guess it would depend on the need for the pos function return value,
> >
> > > if some feedback should be made to the user about the position the
> > > substring matched then current pos functions doesn't not return a
> > > visually right position, I mean
> > > counting characters form left to right, the correct position should
> > be
> > > 21 not 41.
> > >
> > > If the value is to be user with other string functions then the return
> >
> > > value is right.
> > >
> > > if the function is ever implemented I think it should be for something
> >
> > > like
> > > pos(UTFString,UTFString) where UTFString should represent any UTF
> > > Encoding in use. Unlikely? maybe :D
> > >
> > > > On the other hand: UTF8Decode will fail on some character sets, not
> > > > fitting into 2byte characters.
> > >
> > > it seems to have support for at least 3 byte chars. I didn't test
> > > tho..
> > >
> > > >
> > > > My guess, why a simple Pos does not work for Panagiotis, is a either
> >
> > > > a
> > >
> > > > FPC bug or a gtk1 bug with greek characters.
> > > >
> > >
> > > I compiled the test first for gtk1 and results looked right to me, so
> > > if there is something wrong with the sample I thought it should be
> > > gtk2 and the only problem I found was the position returned mismatched
> >
> > > visually the substring
> > >
> > > >
> > > > Mattias
> > > >
> > >
> > > Jesus Reyes A.
> > >
> > > __________________________________________________
> > > Correo Yahoo!
> > > Espacio para todos tus mensajes, antivirus y antispam ¡gratis!
> > > Regístrate ya - http://correo.yahoo.com.mx/
> > >
> > > _________________________________________________________________
> > > To unsubscribe: mail [EMAIL PROTECTED] with
> > > "unsubscribe" as the Subject
> > > archives at http://www.lazarus.freepascal.org/mailarchives
> > >
> > > _________________________________________________________________
> > > To unsubscribe: mail [EMAIL PROTECTED] with
> > > "unsubscribe" as the Subject
> > > archives at http://www.lazarus.freepascal.org/mailarchives
> >
> > _________________________________________________________________
> > To unsubscribe: mail [EMAIL PROTECTED] with
> > "unsubscribe" as the Subject
> > archives at http://www.lazarus.freepascal.org/mailarchives
> >
> > _________________________________________________________________
> > To unsubscribe: mail [EMAIL PROTECTED] with
> > "unsubscribe" as the Subject
> > archives at http://www.lazarus.freepascal.org/mailarchives
>
> _________________________________________________________________
> To unsubscribe: mail [EMAIL PROTECTED] with
> "unsubscribe" as the Subject
> archives at http://www.lazarus.freepascal.org/mailarchives
>
_________________________________________________________________
To unsubscribe: mail [EMAIL PROTECTED] with
"unsubscribe" as the Subject
archives at http://www.lazarus.freepascal.org/mailarchives
