January 2015 - Pharo-users - lists.pharo.org

Re: [Pharo-users] Notification on GC of an object?

by Ben Coman

what if the object stores a reference to itself? then you can access it from the shadow copy? On Thu, Jan 15, 2015 at 4:39 AM, Johan Fabry <jfabry(a)dcc.uchile.cl> wrote: > > Yes, in the end itâs not working out for me, sadly. I think itâs because > of that, but Iâm not sure as itâs complicated â¦ Iâll show you next week if > you want to know more. > > On Jan 14, 2015, at 16:14, Luc Fabresse <luc.fabresse(a)gmail.com> wrote: > > Hi Johan, > > Be careful, it is not the object that will execute the finalizing code but > a shallow copy of it. > It can lead to deep debugging session sometimes ;-) > > o := Object new. > WeakRegistry default add: o. "a shallow copy of o is registered" > o := nil. > Smalltalk garbageCollect. > "the shallow copy of o will receive the finalize message" > > Cheers, > > Luc > > 2015-01-14 19:13 GMT+01:00 Johan Fabry <jfabry(a)dcc.uchile.cl>: > >> >> Yes, adding it to the weak registry does the trick! Thank you Esteban for >> the pointer and Torsten for the magic line of code WeakRegistry default >> add: anObject. > > >> Being able to hook into the GC in this way is extremely cool, it saves me >> a lot of housekeeping work and I am very happy because of that ! >> >> > On Jan 13, 2015, at 17:35, Torsten Bergmann <astares(a)gmx.de> wrote: >> > >> > Esteban wrote: >> >> you also need to register the object for cleanup, in the WeakRegistry. >> >> (not on my machine, sorry I cannot put an example, but look around) >> > >> > It is simple and here is an example: >> > >> > >> > Create a class: >> > >> > Object subclass: #Bar >> > instanceVariableNames: 'id' >> > classVariableNames: '' >> > category: 'Foo' >> > >> > implemented an #initialize method >> > >> > initialize >> > super initialize. >> > id := UUID new. >> > Transcript show: 'Initialized ', id printString; cr >> > >> > and implemented a finalization method: >> > >> > finalize >> > >> > Transcript show: 'Finalized ', id printString; cr >> > >> > Now in the workspace I instantiate the object: >> > >> > |anObject| >> > Transcript open; clear. >> > anObject := Bar new. >> > Transcript flush. >> > WeakRegistry default add: anObject. >> > >> > and by forcing garbage collection in a second step I can >> > see that the finalization method is working: >> > >> > 3 timesRepeat: [ Smalltalk garbageCollect ]. >> > Transcript flush. >> > >> > >> > And I get the following output >> > >> > Initialized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 >> > Finalized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 >> > >> > If it doesnt work check your VM for updates. >> > >> > I'm using Pharo4.0 Latest update: #40442 on Windows with the following >> VM: >> > Win32 built on Sep 4 2014 01:13:32 Compiler: 4.6.2 VMMaker >> versionString https://github.com/pharo-project/pharo-vm.git >> > Commit: c7bc23dd6053d5f9934f7dd427537f76fc96eb32 Jenkins build #14851 >> > >> >> >> >> ---> Save our in-boxes! http://emailcharter.org <--- >> >> Johan Fabry - http://pleiad.cl/~jfabry >> PLEIAD lab - Computer Science Department (DCC) - University of Chile >> >> >> > > > > ---> Save our in-boxes! http://emailcharter.org <--- > > Johan Fabry - http://pleiad.cl/~jfabry > PLEIAD lab - Computer Science Department (DCC) - University of Chile > >

Jan. 14, 2015

Re: [Pharo-users] Notification on GC of an object?

by Johan Fabry

Yes, in the end itâs not working out for me, sadly. I think itâs because of that, but Iâm not sure as itâs complicated â¦ Iâll show you next week if you want to know more. > On Jan 14, 2015, at 16:14, Luc Fabresse <luc.fabresse(a)gmail.com> wrote: > > Hi Johan, > > Be careful, it is not the object that will execute the finalizing code but a shallow copy of it. > It can lead to deep debugging session sometimes ;-) > > o := Object new. > WeakRegistry default add: o. "a shallow copy of o is registered" > o := nil. > Smalltalk garbageCollect. > "the shallow copy of o will receive the finalize message" > > Cheers, > > Luc > > 2015-01-14 19:13 GMT+01:00 Johan Fabry <jfabry(a)dcc.uchile.cl <mailto:jfabry@dcc.uchile.cl>>: > > Yes, adding it to the weak registry does the trick! Thank you Esteban for the pointer and Torsten for the magic line of code WeakRegistry default add: anObject. > > Being able to hook into the GC in this way is extremely cool, it saves me a lot of housekeeping work and I am very happy because of that ! > > > On Jan 13, 2015, at 17:35, Torsten Bergmann <astares(a)gmx.de <mailto:astares@gmx.de>> wrote: > > > > Esteban wrote: > >> you also need to register the object for cleanup, in the WeakRegistry. > >> (not on my machine, sorry I cannot put an example, but look around) > > > > It is simple and here is an example: > > > > > > Create a class: > > > > Object subclass: #Bar > > instanceVariableNames: 'id' > > classVariableNames: '' > > category: 'Foo' > > > > implemented an #initialize method > > > > initialize > > super initialize. > > id := UUID new. > > Transcript show: 'Initialized ', id printString; cr > > > > and implemented a finalization method: > > > > finalize > > > > Transcript show: 'Finalized ', id printString; cr > > > > Now in the workspace I instantiate the object: > > > > |anObject| > > Transcript open; clear. > > anObject := Bar new. > > Transcript flush. > > WeakRegistry default add: anObject. > > > > and by forcing garbage collection in a second step I can > > see that the finalization method is working: > > > > 3 timesRepeat: [ Smalltalk garbageCollect ]. > > Transcript flush. > > > > > > And I get the following output > > > > Initialized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 > > Finalized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 > > > > If it doesnt work check your VM for updates. > > > > I'm using Pharo4.0 Latest update: #40442 on Windows with the following VM: > > Win32 built on Sep 4 2014 01:13:32 Compiler: 4.6.2 VMMaker versionString https://github.com/pharo-project/pharo-vm.git <https://github.com/pharo-project/pharo-vm.git> > > Commit: c7bc23dd6053d5f9934f7dd427537f76fc96eb32 Jenkins build #14851 > > > > > > ---> Save our in-boxes! http://emailcharter.org <http://emailcharter.org/> <--- > > Johan Fabry - http://pleiad.cl/~jfabry <http://pleiad.cl/~jfabry> > PLEIAD lab - Computer Science Department (DCC) - University of Chile > > > ---> Save our in-boxes! http://emailcharter.org <--- Johan Fabry - http://pleiad.cl/~jfabry PLEIAD lab - Computer Science Department (DCC) - University of Chile

Jan. 14, 2015

Re: [Pharo-users] Notification on GC of an object?

by Luc Fabresse

Hi Johan, Be careful, it is not the object that will execute the finalizing code but a shallow copy of it. It can lead to deep debugging session sometimes ;-) o := Object new. WeakRegistry default add: o. "a shallow copy of o is registered" o := nil. Smalltalk garbageCollect. "the shallow copy of o will receive the finalize message" Cheers, Luc 2015-01-14 19:13 GMT+01:00 Johan Fabry <jfabry(a)dcc.uchile.cl>: > > Yes, adding it to the weak registry does the trick! Thank you Esteban for > the pointer and Torsten for the magic line of code WeakRegistry default > add: anObject. > Being able to hook into the GC in this way is extremely cool, it saves me > a lot of housekeeping work and I am very happy because of that ! > > > On Jan 13, 2015, at 17:35, Torsten Bergmann <astares(a)gmx.de> wrote: > > > > Esteban wrote: > >> you also need to register the object for cleanup, in the WeakRegistry. > >> (not on my machine, sorry I cannot put an example, but look around) > > > > It is simple and here is an example: > > > > > > Create a class: > > > > Object subclass: #Bar > > instanceVariableNames: 'id' > > classVariableNames: '' > > category: 'Foo' > > > > implemented an #initialize method > > > > initialize > > super initialize. > > id := UUID new. > > Transcript show: 'Initialized ', id printString; cr > > > > and implemented a finalization method: > > > > finalize > > > > Transcript show: 'Finalized ', id printString; cr > > > > Now in the workspace I instantiate the object: > > > > |anObject| > > Transcript open; clear. > > anObject := Bar new. > > Transcript flush. > > WeakRegistry default add: anObject. > > > > and by forcing garbage collection in a second step I can > > see that the finalization method is working: > > > > 3 timesRepeat: [ Smalltalk garbageCollect ]. > > Transcript flush. > > > > > > And I get the following output > > > > Initialized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 > > Finalized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 > > > > If it doesnt work check your VM for updates. > > > > I'm using Pharo4.0 Latest update: #40442 on Windows with the following > VM: > > Win32 built on Sep 4 2014 01:13:32 Compiler: 4.6.2 VMMaker > versionString https://github.com/pharo-project/pharo-vm.git > > Commit: c7bc23dd6053d5f9934f7dd427537f76fc96eb32 Jenkins build #14851 > > > > > > ---> Save our in-boxes! http://emailcharter.org <--- > > Johan Fabry - http://pleiad.cl/~jfabry > PLEIAD lab - Computer Science Department (DCC) - University of Chile > > >

Jan. 14, 2015

Re: [Pharo-users] Notification on GC of an object?

by Johan Fabry

Yes, adding it to the weak registry does the trick! Thank you Esteban for the pointer and Torsten for the magic line of code WeakRegistry default add: anObject. Being able to hook into the GC in this way is extremely cool, it saves me a lot of housekeeping work and I am very happy because of that ! > On Jan 13, 2015, at 17:35, Torsten Bergmann <astares(a)gmx.de> wrote: > > Esteban wrote: >> you also need to register the object for cleanup, in the WeakRegistry. >> (not on my machine, sorry I cannot put an example, but look around) > > It is simple and here is an example: > > > Create a class: > > Object subclass: #Bar > instanceVariableNames: 'id' > classVariableNames: '' > category: 'Foo' > > implemented an #initialize method > > initialize > super initialize. > id := UUID new. > Transcript show: 'Initialized ', id printString; cr > > and implemented a finalization method: > > finalize > > Transcript show: 'Finalized ', id printString; cr > > Now in the workspace I instantiate the object: > > |anObject| > Transcript open; clear. > anObject := Bar new. > Transcript flush. > WeakRegistry default add: anObject. > > and by forcing garbage collection in a second step I can > see that the finalization method is working: > > 3 timesRepeat: [ Smalltalk garbageCollect ]. > Transcript flush. > > > And I get the following output > > Initialized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 > Finalized 4aa47ef1-0e4c-9a47-bddf-b406ee2042e4 > > If it doesnt work check your VM for updates. > > I'm using Pharo4.0 Latest update: #40442 on Windows with the following VM: > Win32 built on Sep 4 2014 01:13:32 Compiler: 4.6.2 VMMaker versionString https://github.com/pharo-project/pharo-vm.git > Commit: c7bc23dd6053d5f9934f7dd427537f76fc96eb32 Jenkins build #14851 > ---> Save our in-boxes! http://emailcharter.org <--- Johan Fabry - http://pleiad.cl/~jfabry PLEIAD lab - Computer Science Department (DCC) - University of Chile

Jan. 14, 2015

Re: [Pharo-users] Becoming proficient in Pharo

by Offray Vladimir Luna CÃ¡rdenas

Hi, I totally agree with what Martin says here. In my case I was interested in Smalltalk for long time, but the game tutorial didn't catch my attention. I planned several projects to learn, but none of them where easy to start with. It was not until the expansion of Moose from software analysis to data analysis and visualization and the idea of moldable tools that I found my way to learn the program by solving a small but non trivial problem (as Sergio suggested in this thread also). Now I'm making my interactive documentation platform for data narratives and visualization. I can start small and hopefully with this tool introduce newbies to the internals of Pharo/Smalltalk as we need them. It's a still buggie but useful tool for me. My way yo introduce others to this will be by workshops in our local hackerspace. We're documenting everything and creating non-English docs for Spanish speakers. We will share them when they're in better shape. Cheers, Offray El 13/01/15 a las 12:13, Martin BÃ¤hr escribiÃ³: > Excerpts from nacho's message of 2015-01-13 15:13:41 +0100: >> As I struggle, not without fun of course, to learn more about Pharo and its >> frameworks and idea came to my mind. >> We could put together some guidelines on how to become proficient in Pharo, >> and eventually come to be a power user and / or a developer. >> I read several of this recommendations on various list of other programming >> languages. >> Basically the idea is to have some sort of guide, with theoretical and >> practical stuff. >> For example: >> *Beginners.* >> *Intermediate* >> *Advanced* >> etc, etc, etc >> >> Like a road map to becoming a serious Pharo users and / or developer. I know > > one thing i noticed, is that such guides need to be topical. > as a web developer i am not interested in GUI stuff, and if i have to go > through tutorials that teach me how to build games than that's not very > motivating. > > fortunately there are several web tutorials out there, but not all of them > assume a pharo newbie, but expect me to learn pharo first (which brings me back > to the game tutorial) > > one advantage pharo has is that new users need to learn the IDE and smalltalk > at the same time. kind of like learning eclipse and java at the same time. i > could learn eclipse using another language i already know, and i could learn > java without using eclipse, but i can't really learn smalltalk without learning > the IDE at the same time. > > so a new-user tutorial needs to explain every step in the IDE while teaching > the language. > > a good example for a tutorial on the web-side is > http://zn.stfx.eu/zn/build-and-deploy-1st-webapp/ > > it does not assume any prior knowledge about pharo, yet it is sufficiently high > level that it will be interesting for an experienced developer (like me) > > even a person without programming experience will complete this tutorial > successfully. i just had two students go through this tutorial during google > code-in with more success than i had for other tutorials. > > one of them just started to learn programming, so throughout the tutorial he > didn't really understand all of what he was doing there, but understanding > comes from practice, and a few more tutorials and a good book or course on > programming basics, and he'll get it. > > another aspect where this tutorial shines is, that it not only covers coding, > but also deployment and packaging. the only thing missing is testing and > debugging. in other words it introduces me to the major aspects i'd need to > know to start building websites. > >> Just an idea, it will be collaborative. I volunteer to keep and maintain the >> list updated in a place where it will be available to anyone but of course >> can't contribute much besides doing that. > > as i am involved as mentor for code-in, semester of code and summer of code > programs with a few smalltalk projects, i'll likely have more opportunities to > test different approaches to get started, and hopefully will be able to provide > more input. > > greetings, martin. >

Jan. 14, 2015

Re: [Pharo-users] Becoming proficient in Pharo

by kilon alios

i am afraid not. But it will definitely be my next video tutorial ;) On Wed, Jan 14, 2015 at 4:18 PM, nacho <0800nacho(a)gmail.com> wrote: > Thanks! > Kilon, is this feature included in one of your amazing videos? > thanks > > > > > ----- > Nacho > Smalltalker apprentice. > Buenos Aires, Argentina. > -- > View this message in context: > http://forum.world.st/Becoming-proficient-in-Pharo-tp4799284p4799505.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >

Jan. 14, 2015

Re: [Pharo-users] Becoming proficient in Pharo

by Ben Coman

The other thing I like about Smalltalk debugger is from there being able to select code and spawn a sub-debugger, so later I can return to the original location and continue. On Wed, Jan 14, 2015 at 10:18 PM, nacho <0800nacho(a)gmail.com> wrote: > Thanks! > Kilon, is this feature included in one of your amazing videos? > thanks > > > > > ----- > Nacho > Smalltalker apprentice. > Buenos Aires, Argentina. > -- > View this message in context: > http://forum.world.st/Becoming-proficient-in-Pharo-tp4799284p4799505.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >

Jan. 14, 2015

Re: [Pharo-users] Becoming proficient in Pharo

by nacho

Thanks! Kilon, is this feature included in one of your amazing videos? thanks ----- Nacho Smalltalker apprentice. Buenos Aires, Argentina. -- View this message in context: http://forum.world.st/Becoming-proficient-in-Pharo-tp4799284p4799505.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

Jan. 14, 2015

Re: [Pharo-users] Becoming proficient in Pharo

by kilon alios

by using the message "self halt" inside any method. When it reaches this message it will stop execution and pop up the debugger, from there on its just a matter of using the debugger to inspect the variables and move execution one step at a time, the true power of smalltalk. This way you can see exactly what code is executed and how it affects the variables. Of course you can do this with other IDEs too but where it gets real interesting is that the smalltalk debugger allows you to change the code on the fly thus perform tests on the code to see how it behaves. On Wed, Jan 14, 2015 at 3:56 PM, nacho <0800nacho(a)gmail.com> wrote: > Ben, > How do you actually use the halt method? > I don't follow you. > Seems like an interesting thing to explore. > thanks > Nacho > > > > > ----- > Nacho > Smalltalker apprentice. > Buenos Aires, Argentina. > -- > View this message in context: > http://forum.world.st/Becoming-proficient-in-Pharo-tp4799284p4799495.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > >

Jan. 14, 2015

Re: [Pharo-users] Becoming proficient in Pharo

by Johan Fabry

The halt method is used to put a breakpoint in the code, popping up the debugger. Just write the following: self halt. and when this gets executed the debugger jumps into action. I am surprised this is not clear, I thought that all beginner documentation mentioned this. Can you tell me what documentation you used to learn the language? Now I am afraid that some students of mine donât know about this, while it is so incredibly useful â¦ > On Jan 14, 2015, at 10:56, nacho <0800nacho(a)gmail.com> wrote: > > Ben, > How do you actually use the halt method? > I don't follow you. > Seems like an interesting thing to explore. > thanks > Nacho > > > > > ----- > Nacho > Smalltalker apprentice. > Buenos Aires, Argentina. > -- > View this message in context: http://forum.world.st/Becoming-proficient-in-Pharo-tp4799284p4799495.html > Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com. > > ---> Save our in-boxes! http://emailcharter.org <--- Johan Fabry - http://pleiad.cl/~jfabry PLEIAD lab - Computer Science Department (DCC) - University of Chile

Jan. 14, 2015