[fpc-pascal] How to declare function with untyped array parameter
Hi, is there way how to declare function, which will accept as parameter any array type ? (this parameter I need forward to System.Length() only ) Just like Length() function. Now I fall into problem with generics , where I have in one unit generic object, which has Length property (or Length function) This function internally calls System.Length(A) But when I specialize such generic in another unit, I give "Compilation aborted" (FPC 2.6.4) Culprit is prefix "System.". When I omit prefix "System." then I give another error: Wrong number of parameters specified for call to "Length" (compiler is probably recognizing "Length" of object ) Example: - 1st unit: generic GT = object private var FArray: array of T; Fx, Fy: integer; function GetLength: integer; public type TElement = T; PElement = ^T; constructor Init; overload; constructor Init(x,y: integer); overload; property Length: integer read GetLength; end; function T2DArray.GetLength: integer; begin Result := System.Length(FArray); // <-- HERE prefix System is causing "Compilation aborted" in FPC 2.6.4 end; - 2nd unit: T2DIntArray = object(specialize GT) end; - Is there any workaround ? Thanks L. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
On Wed, 25 May 2016 21:59:21 +0100, Graeme Geldenhuys wrote: >On 2016-05-25 15:58, Paul Breneman wrote: >> so >> if you can figure out what part to use it should work good in Delphi and >> FPC. > >I can confirm Abbrevia worked well for a Delphi/FPC project I worked on >a couple years ago. I also don't recall it being difficult to use. > OK, I will see if I can work with it without installing the complete package. Maybe I can just figure out the needed units and go with these. If so I will post the result here (I mean which units were needed for a minimum file write). -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
On 2016-05-25 15:58, Paul Breneman wrote: > so > if you can figure out what part to use it should work good in Delphi and > FPC. I can confirm Abbrevia worked well for a Delphi/FPC project I worked on a couple years ago. I also don't recall it being difficult to use. Regards, Graeme -- fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal http://fpgui.sourceforge.net/ My public PGP key: http://tinyurl.com/graeme-pgp ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
On 05/25/2016 09:56 AM, Bo Berglund wrote: On Wed, 25 May 2016 08:21:54 -0500, Paul Breneman wrote: You've probably considered Abbrevia: http://wiki.lazarus.freepascal.org/FreePascalArchivePackage Yes, I got that as a suggestion over at the Embarcadero forum... But when I downloaded it from Sourceforge it turned out to be really massive, some 700+ files and basically overwhelming. I would like something simple, preferably built-in like TZipFile in later versions of Delphi. Or paszlib in FPC... But I also would like to have it work both in Delphi and FPC/Lazarus. Yes, it may be large as it does a *lot* of things. I know that people invested a *lot* of work in improving it after it went open source, so if you can figure out what part to use it should work good in Delphi and FPC. Regards, Paul www.ControlPascal.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
On Wed, 25 May 2016 08:21:54 -0500, Paul Breneman wrote: >You've probably considered Abbrevia: >http://wiki.lazarus.freepascal.org/FreePascalArchivePackage > Yes, I got that as a suggestion over at the Embarcadero forum... But when I downloaded it from Sourceforge it turned out to be really massive, some 700+ files and basically overwhelming. I would like something simple, preferably built-in like TZipFile in later versions of Delphi. Or paszlib in FPC... But I also would like to have it work both in Delphi and FPC/Lazarus. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
Michael Van Canneyt wrote on Wed, 25 May 2016: On Wed, 25 May 2016, Jonas Maebe wrote: Sven Barth wrote on Wed, 25 May 2016: An method pointer is always automatically constructed by the compiler consisting of the address of the method (here IFPReportFilter.RenderReport) and the instance that method belongs to (in this case the FReportFilter), so this will indeed work without problems. The question however is whether it is guaranteed to keep working and isn't merely the use of an implementation detail... It works by design. I can't think of a reason why it would stop working. What is the self in case of an interface that is not in a FPC program ? In all cases we pass the unadjusted interface pointer. Such an interface pointer is always a pointer to an interface VMT pointer/address. The interface method is required to be able to reconstitute the interface's self pointer (the start of the instance that implements this interface) from that. In both FPC and in regular COM, that generally happens by some kind of stub code that is created for every interface method implemented by a class, which subtracts the offset of the interface's VMT in that specific class' instance layout from the passed self pointere. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
On 2016-05-25 13:31, Sven Barth wrote: > that contains the pointer to the method as well as what is going to be > loaded as "Self" (the data part Michael mentioned) Thanks for explaining it Sven. Regards, Graeme ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
On 2016-05-25 13:32, Jonas Maebe wrote: > It works by design. Excellent, thanks for confirming that. Regards, Graeme ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
On Wed, 25 May 2016, Jonas Maebe wrote: Sven Barth wrote on Wed, 25 May 2016: An method pointer is always automatically constructed by the compiler consisting of the address of the method (here IFPReportFilter.RenderReport) and the instance that method belongs to (in this case the FReportFilter), so this will indeed work without problems. The question however is whether it is guaranteed to keep working and isn't merely the use of an implementation detail... It works by design. I can't think of a reason why it would stop working. What is the self in case of an interface that is not in a FPC program ? Michael. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
On 05/25/2016 03:00 AM, Bo Berglund wrote: I have a project that is targeting both Linux (on Raspberry Pi) and Windows. It started in Delphi 2007 and is a command line utility. It needs to use some zip compression of binary files, which must be readable both by the programs and the standard tools (WinZip etc). I am going to finish the code in Delphi 2007 and then move the files over to FPC on the RPi and compile there. So I need a zipper that can be used in both ends and since D2007 does not come with one built in but FPC does (paszlib), I figured I could copy the src dir from FPC over to Delphi and use that to compress my files. Question before I start: Does this work or must I add a number of conditionals or such in the code to make it work? Also: which files are needed? It looks like the paszlib src dir has a subdir too with most of the files, is this necessary? You've probably considered Abbrevia: http://wiki.lazarus.freepascal.org/FreePascalArchivePackage Regards, Paul www.ControlPascal.com ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
Sven Barth wrote on Wed, 25 May 2016: An method pointer is always automatically constructed by the compiler consisting of the address of the method (here IFPReportFilter.RenderReport) and the instance that method belongs to (in this case the FReportFilter), so this will indeed work without problems. The question however is whether it is guaranteed to keep working and isn't merely the use of an implementation detail... It works by design. I can't think of a reason why it would stop working. Jonas ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
Am 25.05.2016 13:54 schrieb "Graeme Geldenhuys" < mailingli...@geldenhuys.co.uk>: > > On 2016-05-25 12:18, Michael Van Canneyt wrote: > > I am not sure this is safe to do, since an event handler exists of 2 > > pointers: data and method. As far as I know, an interface does not have a > > data pointer. > > I don't fully understand your statement about 2 pointers? An event > handler is simply a procedure of a object. When an event is triggered, > that simply means the procedure is called and parameters are passed to it. A "procedure of object" is in fact a TMethod record (yes that type exists) that contains the pointer to the method as well as what is going to be loaded as "Self" (the data part Michael mentioned), because without that you wouldn't know which instance this method belongs to (all instances of a class share the same code after all). Regards, Sven ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
Am 25.05.2016 13:18 schrieb "Michael Van Canneyt" : > > > > On Wed, 25 May 2016, Graeme Geldenhuys wrote: > >> Hi, >> >> Can I safely assign a method from an Interface reference to an event >> handler. The code below works, but I'm not sure if it is safe to do so, >> and allowed. >> >> == >> TTestApp = class(TObject) >> private >>rpt: TFPReportReport; >>FReportFilter: IFPReportFilter; // can hold any export filter >> ... >> >> constructor TTestApp.Create; >> begin >> rpt := TFPReportReport.Create(nil); >> rpt.Author := 'Graeme Geldenhuys'; >> rpt.Title := 'FPReport Demo 4 - Frames and Fonts'; >> >> FReportFilter := TFPReportExportPDF.Create; // PDF output >> //FReportFilter := TFPReportExportAggPas.Create; // PNG output >> rpt.OnRenderReport := @FReportFilter.RenderReport; >> ... >> end; > > > I am not sure this is safe to do, since an event handler exists of 2 > pointers: data and method. As far as I know, an interface does not have a > data pointer. An method pointer is always automatically constructed by the compiler consisting of the address of the method (here IFPReportFilter.RenderReport) and the instance that method belongs to (in this case the FReportFilter), so this will indeed work without problems. The question however is whether it is guaranteed to keep working and isn't merely the use of an implementation detail... Regards, Sven ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
On Wed, 25 May 2016 12:59:34 +0200 (CEST), mar...@stack.nl (Marco van de Voort) wrote: >I would look for a ZIP codebase based on top of the zlib stream >(TCompressionstream) interfaces. > >These exist both in Delphi and FPC. I checked in the D2007 help and it did show the TCompressionstream class so it does exist in my Delph version. Next is trying to find a zipper based on that, I guess... When I google the first hit points to paszlib, so I am in a circle here. Paszlib wiki doc pages state that paszlib is used for TCompressionstream... http://wiki.lazarus.freepascal.org/paszlib (second line) >If you don't need the archiving aspect (multiple files into one), and only >the compression, consider using gzip instead of ZIP, since it opens with >fairly general tools like winzip, and TCompressionStream is enough. Well, the system I am working on collects data from a measuring instrument and saves the binary data (a memory image from the instrument) onto several types of bin files. Then it also converts the data to corresponding ASCII text files. Finally it is all stuffed into a single zipfile for transmission. SoI need multiple files into one just like WinZip provides. Except done in my code. -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
On 2016-05-25 12:18, Michael Van Canneyt wrote: > I am not sure this is safe to do, since an event handler exists of 2 > pointers: data and method. As far as I know, an interface does not have a > data pointer. I don't fully understand your statement about 2 pointers? An event handler is simply a procedure of a object. When an event is triggered, that simply means the procedure is called and parameters are passed to it. So that explains why my code worked - I'm simply calling a method of that interface. This all works as long as the interface reference stays in scope of course - which it is in my case Regards, Graeme -- fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal http://fpgui.sourceforge.net/ My public PGP key: http://tinyurl.com/graeme-pgp ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Assigning Interface method to event handler
On Wed, 25 May 2016, Graeme Geldenhuys wrote: Hi, Can I safely assign a method from an Interface reference to an event handler. The code below works, but I'm not sure if it is safe to do so, and allowed. == TTestApp = class(TObject) private rpt: TFPReportReport; FReportFilter: IFPReportFilter; // can hold any export filter ... constructor TTestApp.Create; begin rpt := TFPReportReport.Create(nil); rpt.Author := 'Graeme Geldenhuys'; rpt.Title := 'FPReport Demo 4 - Frames and Fonts'; FReportFilter := TFPReportExportPDF.Create; // PDF output //FReportFilter := TFPReportExportAggPas.Create; // PNG output rpt.OnRenderReport := @FReportFilter.RenderReport; ... end; I am not sure this is safe to do, since an event handler exists of 2 pointers: data and method. As far as I know, an interface does not have a data pointer. Michael. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
Re: [fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
In our previous episode, Bo Berglund said: > over to FPC on the RPi and compile there. > So I need a zipper that can be used in both ends and since D2007 does > not come with one built in but FPC does (paszlib), I figured I could > copy the src dir from FPC over to Delphi and use that to compress my > files. paszlib was originally a TP/D1 package that was afaik somewhat adapted to 32-bit delphi too. FPC integrated this package about 15 years, and compatibility with other compilers is not guaranteed. The units are compiled in FPC mode, not even in TP or Delphi mode. > Also: which files are needed? It looks like the paszlib src dir has a > subdir too with most of the files, is this necessary? I would look for a ZIP codebase based on top of the zlib stream (TCompressionstream) interfaces. These exist both in Delphi and FPC. If you don't need the archiving aspect (multiple files into one), and only the compression, consider using gzip instead of ZIP, since it opens with fairly general tools like winzip, and TCompressionStream is enough. ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] Assigning Interface method to event handler
Hi, Can I safely assign a method from an Interface reference to an event handler. The code below works, but I'm not sure if it is safe to do so, and allowed. == TTestApp = class(TObject) private rpt: TFPReportReport; FReportFilter: IFPReportFilter; // can hold any export filter ... constructor TTestApp.Create; begin rpt := TFPReportReport.Create(nil); rpt.Author := 'Graeme Geldenhuys'; rpt.Title := 'FPReport Demo 4 - Frames and Fonts'; FReportFilter := TFPReportExportPDF.Create; // PDF output //FReportFilter := TFPReportExportAggPas.Create; // PNG output rpt.OnRenderReport := @FReportFilter.RenderReport; ... end; destructor TTestApp.Destroy; begin rpt.Free; FReportFilter := nil; inherited Destroy; end; == Regards, Graeme -- fpGUI Toolkit - a cross-platform GUI toolkit using Free Pascal http://fpgui.sourceforge.net/ My public PGP key: http://tinyurl.com/graeme-pgp ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
[fpc-pascal] Using paszlib from fpc 3.0 with fpc and delphi 2007?
I have a project that is targeting both Linux (on Raspberry Pi) and Windows. It started in Delphi 2007 and is a command line utility. It needs to use some zip compression of binary files, which must be readable both by the programs and the standard tools (WinZip etc). I am going to finish the code in Delphi 2007 and then move the files over to FPC on the RPi and compile there. So I need a zipper that can be used in both ends and since D2007 does not come with one built in but FPC does (paszlib), I figured I could copy the src dir from FPC over to Delphi and use that to compress my files. Question before I start: Does this work or must I add a number of conditionals or such in the code to make it work? Also: which files are needed? It looks like the paszlib src dir has a subdir too with most of the files, is this necessary? -- Bo Berglund Developer in Sweden ___ fpc-pascal maillist - fpc-pascal@lists.freepascal.org http://lists.freepascal.org/cgi-bin/mailman/listinfo/fpc-pascal
