Xotcl May 2001

xotcl@alice.wu.ac.at

7 participants
11 discussions

aggregate objects with autoname
by Kristoffer Lawson 30 May '01

30 May '01

I'm proposing an object method "createAsChild", or something similar. The syntax would be: createAsChild <class> ?arg0 arg1 ...? This would basically be a convenience method to do the equivalent of creating an object as a child of another with the normal aggregation, plus using autoname. Ie the following two cases would be the same: set nm [MyClass autoname MyClass] MyClass ${ob}::$nm foo bar and $ob createAsChild MyClass foo bar Thus making it much easier to use aggregation with automatically created names. I'm not saying this is necessarily the best possible syntax for that: maybe it would be better to do "MyClass newAsChild $ob foo bar"? Anyway I only use autonaming myself for making instances of classes so this would be quite useful. Of course, with XOTcl I'm allowed the possibility of adding to the Object or Class objects myself which is fabulous. Just that it might be useful as a core element of the language. As a matter of interest, how many people here only use objects created with autoname? - ---------- = = ---------//--+ | / Kristoffer Lawson | www.fishpool.fi|.com +-> | setok(a)fishpool.com | - - --+------ |-- Fishpool Creations Ltd - / | +-------- = - - - = --------- /~setok/

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Almost working Garbage Collection
by Artur Trzewik 30 May '01

30 May '01

Hi TclJava was a good tip for implementing garbage collection in Xotcl. (Thanks Kristoffer Lawson) It overwrites the cmdType from native tcl. It is a little dirty and it can make problems by new tcl version, but I was implemented by SUN by tcl-gurus. The same think I have done by xotcl - references. and it works partially. (new snapshoot) http://www.xdobry.de/xotclref.tar.gz example Class A set a [A newReference] $a set a value set a {} the last procedure destroy the A object. Other examples works fine too. There are some problems. 1. It do not work by Classes with destroy method. I suppose it is the problem by reference counting by xotcl stack. I do not understand how it work. 2. The Garbage Collection procedures can be difficult made as Xotcl-extension. - The procedure doObjInitialization in not visible. At this time newReference do not accept any parameters. I am not so sure how I can implement the full object initialization with normal interface. - xotcl.c use internal GetObject procedure this convert string to XOTclObject. I think it should use Tc_Obj as parameter. The most usage of this procedure is GetObject(in, ObjStr(objv[1]) So. The procedure can check the type of Tcl_Obj directly and get XOTclObject from XOTclObjectType or my new (XOTclReferenceObjectType). And also increment the tcl_obj counter if it use the object local. Is there any internal Xotcl restrictions that makes xotclref impossible? ========================================= Artur Trzewik http://www.xdobry.de =========================================

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Debugger
by Rick Hedin 30 May '01

30 May '01

Hello all. I have been just using puts to debug my xotcl code. Is there a debugger that works? TclPro seems to have some problems with Xotcl, or I don't understand how to use TclPro. Regards, Rick Today's mighty oak is just yesterday's acorn that held its ground.

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xoTk
by Kristoffer Lawson 24 May '01

24 May '01

Did somebody have a package containing mappings of Tk commands to XOTcl objects? Or if not that than at least a document or ideas about the things I should take into account when designing Tk stuff with XOTcl? Maybe even a TclWiki page? Just so I don't go stumbling across the same problems others have already solved and thus waste time. - ---------- = = ---------//--+ | / Kristoffer Lawson | www.fishpool.fi|.com +-> | setok(a)fishpool.com | - - --+------ |-- Fishpool Creations Ltd - / | +-------- = - - - = --------- /~setok/

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Garbage Collection
by Artur Trzewik 22 May '01

22 May '01

Hi Thanks for good resource tip to Kristoffer Lawson. There are good publication at http://ftp.sage.usenix.org/events/tcl2k/duffin.html The Feather tcl extension seems to be very interesting. It is shame it was published only as Windows binary (Kann ein Mensch so tief sinken?) I have made first attempt to implement it and I have noticed one big Problem. source as Xotcl extension http://www.xdobry.de/xotclref.tar.gz (copy in xotcl/src and make -f XRMakefile) example Class A set a [A newReference] $a set var value by last line the tcl interpreter try to convert my new type to Tcl_ObjType tclCmdNameType by this operation the internal representation is freed. And so the object is deleted before I can use it as command There can be 2 solution on this problem 1. Special invoke of referenced objects invokeRef $a set var value it is probably also used by Feather extension. 2. Overwrite the interal pointers of Tcl_ObjType tclCmdNameType SetCmdNameFromAny see tcl sources generic/tclExecute.c it should not freed our new Tcl_ObjType XOTclReferenceObjectType So I give up. These two solution does not seems to be acceptable. Maybe futures version of tcl interpeters will offer more flexible type conversion solution. The new type should decide by itself how it can be converted to another type. ========================================= Artur Trzewik http://www.xdobry.de =========================================

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XOTcl 0.85 available
by Gustaf Neumann 22 May '01

22 May '01

Dear XOTcl community, here is the annoucement about the availability of XOTcl 0.85 It is mostly a bug-fix release. best regards -gustaf neumann, uwe zdun Announcing XOTcl 0.85. ********************** WHAT IS XOTCL? XOTcl is an object-oriented extension of Tcl that was derived from OTcl. In short, XOTcl tries to provide a highly flexible, reflective, component-based, and object-oriented environment. It integrates language support for high level concepts which are not found in other languages, with reasonable performance. It prevails the Tcl programming style and the dynamic/introspective nature of the language, rather than introducing other language's styles and rigidness (such as C++) into Tcl. RECENT CHANGES IN VERSION 0.85 The most important changes relative to 0.84 are: - improved documentation - various small fixes in Httpd to improve extensibility - parent namespaces of objects are checked for existence (could lead to crash in earlier versions) - optional arguments for ismetaclass and isclass - created object return absolute names - cleanup destroys aggregated children (e.g. recreate provides per default a "clean" object) - new and more orthogonal directory structure, using version number in directory name MORE INFO General information about XOTcl and its components can be found at http://www.xotcl.org Mailing list: http://wi.wu-wien.ac.at/mailman/listinfo/xotcl Best regards, Gustaf Neumann Uwe Zdun

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Garbage Collector in Xotcl
by Artur Trzewik 21 May '01

21 May '01

Hi The really problem of Xotcl is, it has no garbage collector. It means you must destroy your object yourself per destroy method. The garbage collector of such languages as Java, smalltalk, ruby work by tracking references to one object. if no reference point to object, this object is destroyed. This would not work by xotcl. Xotcl object are localized per name (string) and no reference. (And it is very flexible in most cases) It can by hardly changed. It is pity, if one consider that tcl has internal full garbage collector based on Tcl_Obj (structure) with references counter. This problem is no so dramatic if one use object aggregation. So the aggregated object is deleted automatically if parent object is to be destroyed. But is can be rather hard by using "short-live" object (for example by implementing special data structures in Xotcl). The solution of this problem can be to add new create method in Xotcl. To create object to use only as reference. It means object lives only so long if the reference exist. It will use internal standard tcl structures (as Tcl Stings, Integer, Arrays) example usage proc exampleScope {} { # create short-live Object for reference set ref [Object newReference] # using object $ref set var 11 # be exit the object referenced by variable ref # will be deleted automatically } The best think is one can choose to use garbage collector or not. >Object newReference will for example create one object and destroy it immediately. So in such case the old method >Object new should be used. Internal implementation. The main thing is to tread Xotcl objects in the same way as other tcl objects (Stings, Interger, Array) and use tcl garbage collector I thing there should be a wrapper Tcl_Obj (new Type) Here only the main idea static Tcl_ObjType XOTclReferenceObjectType = { "XOTclReferenceObject", (Tcl_FreeInternalRepProc *) ourNewDestroyMethod, (Tcl_DupInternalRepProc *) NULL, UpdateStringOfXOTclObject, SetXOTclObjectFromAny }; The newReference method must create such reference Tcl_Obj and return it as result. Of course newReference must be implemented in C in libxotcl.so. What do you think about it? I mean I can implement it but I am not sure how it would suite to another concepts or future plans. For example for xotcl objects created per newReference the destroy method make no sense. It can make also another problems that should be discused. ========================================= Artur Trzewik http://www.xdobry.de =========================================

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calledclass in a filter: what if the calledclass is/has a mixin?
by Catherine Letondal 14 May '01

14 May '01

Hi, I have a filter on Object which purpose is to register the called procs of every class in my application, for debugging purpose. The list of called procs is then displayed in a graphical component where it can be selected to be traced (http://www-alt.pasteur.fr/~letondal/biok/Images/tracegui.gif). I would like to have also mixin procs registered, but apparently, the calledclass in the filter, when called on the mixin, does not return the mixin class, but the actual called class. Is there a way to know that the mixin proc was called - in the filter scope I mean ? This filter is put on every class during a given period: Object instproc spyFilter args { set proc [self calledproc] set class [self calledclass] # debug is an Object doing debugging tasks and registering # trace/debug informations debug instvar calledprocs lappend calledprocs($class) $proc } Class UpdateMixin UpdateMixin instproc update args { ... } UpdateMixin filter actually displays spyFilter, but the filter does not "see" the UpdateMixin as the calledclass, but rather the class the mixin is associated with. Thanks for your help, -- Catherine Letondal -- Pasteur Institute Computing Center

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Fwd: [tcl_announce] II. European Tcl/Tk User Meeting
by Uwe Zdun 14 May '01

14 May '01

---------- Fwd ---------- Subject: [tcl_announce] II. European Tcl/Tk User Meeting Date: 10 May 2001 16:54:40 -0000 From: Carsten Zerbst <zerbst(a)tu-harburg.de> To: tcl_announce(a)yahoogroups.com The schedule for the II. European Tcl/Tk User Meeting is fixed now. With Andreas Kupries a prominent member of the community was found for the keynote speach about the actual state of the Tcl development and it's future. Andreas is not only well known for his work at the Tcl core but forms together with Jeffrey Hobbs the Tcl group of Active State. This years programm offers you a wide range of papers and tutorials, the schedule could be found here http://www.tu-harburg.de/skf/tcltk/time2001.html Registration is open, if you want to present your work in form of a poster contact me. Bye and see you in Hamburg, Carsten Zerbst -- Dipl. Ing. Carsten Zerbst | Come to the | 2. European Tcl Conference 2001 ! zerbst(a)tu-harburg.de | http://www.tu-harburg.de/~skfcz | http://www.tu-harburg.de/skf/tcltk [[Send Tcl/Tk announcements to tcl-announce(a)mitchell.org Send administrivia to tcl-announce-request(a)mitchell.org Announcements archived at http://www.egroups.com/list/tcl_announce/ The primary Tcl/Tk archive is ftp://ftp.neosoft.com/pub/tcl/ ]] Your use of Yahoo! Groups is subject to http://docs.yahoo.com/info/terms/ ------------------------------------------------------- -- Uwe Zdun Specification of Software Systems, University of Essen Phone: +49 201 81 00 332, Fax: +49 201 81 00 398 zdun(a)xotcl.org, uwe.zdun(a)uni-essen.de

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XotclIDE announce
by Artur Trzewik 10 May '01

10 May '01

Hallo There are new Version 0.15 of xotclIDE on my site http://www.xdobry/xotclIDE New futures: 1. databased control version system. All changes on the xotcl source are stored persistent to database on the fly. Also CompLoader to load applications from database. (Currently only mysql are tested) You can return to every development state in the past, manage editions and versions of components, classes, objects and methods 2. improved object inspector. To see and invoke mixins methods 3. simply configuration managment browser. To handle components sets and make a xotcl distributions of your applications 4. improved component modell (currently only better tcl packages) to handle dependiences 5. more documentation and simple application There can be many reasonable tools for xotclIDE. I thing xotclIDE should be rather a set of tools than one application. If you have any usefull tools for xotcl (tracker, profiler, optimizer, debugger) send them to me. Bug reports and suggestions are welcome Artur Trzewik

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Xotcl May 2001