Re: [fpc-pascal] Oberon-0
On 4/19/2023 7:46 PM, Adriaan van Os via fpc-pascal wrote: Ralf Quint via fpc-pascal wrote: What does Oberon and Forth have to do with the FreePascal compiler? 1. Niklaus Wirth 2. Strong resemblance between Oberon and Pascal 3. An early version of his book Compiler Construction used Pascal rather than Oberon Well, still, neither one of those IMHO is a valid reason as to why this is discussed on a Free Pascal mailing list, beside possibly on fpc-other, as suggested. Ralf ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Is there a Pos() function for TBytes?
function PosInBytes(const Pattern: byte; Target: TBytes): integer; Let's use IndexByte standard procedure here? Maybe also in the 1st overloaded code too? Alex ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Is there a Pos() function for TBytes?
On Thu, 20 Apr 2023 08:40:48 +0200 (CEST), Michael Van Canneyt via fpc-pascal wrote: >> I found this page: >> https://www.freepascal.org/docs-html/rtl/system/copy.html >> >> Here there is also reference to the other functions for strings: >> Delete (string and dyn array) >> Copy(string and dyn array) >> Insert (string and dyn array but limited to 255 elements, why?) >> Pos (string only..) >> >> They describe what can be done with strings and in some cases dynamic arrays >> (like TBytes?), but for Pos() there is only string... >> >> And Insert seems to have a limit of 255 elements, why? >> >> What I need is a Pos(token) for TBytes where the token can be a single or >> multiple bytes in size (just like for strings). >> >> Is there such a thing? > >Not that I am aware of, but I think it would be a welcome addition to one of >the RTL units. I've been in need of such a function on multiple occasions, >and had to resort to custom code each time. > FWIW, I threw together two overloaded Pos functions for a TBytes container like this (except I didn't name them Pos in order not to interfere with the RTL): function PosInBytes(const Pattern, Target: TBytes): integer; overload; function PosInBytes(const Pattern: byte; const Target: TBytes): integer; overload; implementation function PosInBytes(const Pattern, Target: TBytes): integer; var i, j, res: integer; begin Result := -1; for i := 0 to Length(Target) - 1 - Length(Pattern) do begin if Target[i] = Pattern[0] then //First byte of pattern found begin res := i; for j := 1 to Length(Pattern)-1 do begin if Target[i+j] <> Pattern[j] then begin res := -1; break; end; end; if res >= 0 then break; end; end; Result := res; end; function PosInBytes(const Pattern: byte; Target: TBytes): integer; var i: integer; begin Result := -1; for i := 0 to Length(Target) - 1 do begin if Target[i] = Pattern then begin Result := i; break; end; end; end; -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Is there a Pos() function for TBytes?
On Thu, 20 Apr 2023, Bo Berglund via fpc-pascal wrote: I am transferring data via serial comm and they wind up inside a TBytes dyn array. Now I want to easily find a certain pattern of bytes inside that array, but how? I have a cludge that does not feel right but works and I want to get it replaced by the "correct" way of doing it. So what I have done so far is the following kind of thing using an AnsiString to supply the Pos() functionality: var bData: TBytes; sData: AnsiString; p: integer; begin GetSerialData(bData); //Load the array with incoming data SetLength(sData, Length(bData); //Prepare string to receive data Move(bData[0], sData[1], Length(bData)); //Copy all data p := Pos(pattern, sData); ... I'd rather use some built-in function that is *not* using intermediate strings but can operate on the TBytes array directly. I found this page: https://www.freepascal.org/docs-html/rtl/system/copy.html Here there is also reference to the other functions for strings: Delete (string and dyn array) Copy(string and dyn array) Insert (string and dyn array but limited to 255 elements, why?) Pos (string only..) They describe what can be done with strings and in some cases dynamic arrays (like TBytes?), but for Pos() there is only string... And Insert seems to have a limit of 255 elements, why? What I need is a Pos(token) for TBytes where the token can be a single or multiple bytes in size (just like for strings). Is there such a thing? Not that I am aware of, but I think it would be a welcome addition to one of the RTL units. I've been in need of such a function on multiple occasions, and had to resort to custom code each time. Michael. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] Is there a Pos() function for TBytes?
I am transferring data via serial comm and they wind up inside a TBytes dyn array. Now I want to easily find a certain pattern of bytes inside that array, but how? I have a cludge that does not feel right but works and I want to get it replaced by the "correct" way of doing it. So what I have done so far is the following kind of thing using an AnsiString to supply the Pos() functionality: var bData: TBytes; sData: AnsiString; p: integer; begin GetSerialData(bData); //Load the array with incoming data SetLength(sData, Length(bData); //Prepare string to receive data Move(bData[0], sData[1], Length(bData)); //Copy all data p := Pos(pattern, sData); ... I'd rather use some built-in function that is *not* using intermediate strings but can operate on the TBytes array directly. I found this page: https://www.freepascal.org/docs-html/rtl/system/copy.html Here there is also reference to the other functions for strings: Delete (string and dyn array) Copy(string and dyn array) Insert (string and dyn array but limited to 255 elements, why?) Pos (string only..) They describe what can be done with strings and in some cases dynamic arrays (like TBytes?), but for Pos() there is only string... And Insert seems to have a limit of 255 elements, why? What I need is a Pos(token) for TBytes where the token can be a single or multiple bytes in size (just like for strings). Is there such a thing? -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org https://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
