September 2009 - Pharo-dev - lists.pharo.org

Re: [Pharo-project] The better debugger support by extending an Object protocol

by Igor Stasenko

2009/9/7 Henrik Johansen <henrik.s.johansen(a)veloxit.no>: > Well, if the goal is to be able to differentiate between two objects who > should behave similar in all cases except when you print them while > debugging, I can't really think of any better ways :) > > Playing the devil's advocate, here's two things to consider: > - Some people will likely expect *all* proxies to behave like that in a > debugger, enforcing consistent use may be hard. > - Some (other) people will likely see debugPrintOn:, and figure it's > cool to use it for any object they want additional info about at a > glance in a debugger. (not saying that is necessarily a bad thing) > > Maybe a good way to clarify its intended usage would be implementing > debugPrintOn: in a Â ProxyTrait? > This also ensures a consistent manner for how proxies are distinguished > from the real. (assuming of course, the implementation for different > proxies you were thinking of follows a constant pattern) > I'm not focusing this protocol to be used by a proxies only, and as you mentioned above, this message could be useful in other cases, when developer would like to see more detailed info (or formatted differently) while debugging. > Personally, I found inspecting the field to see the actual class of the > object to be of negligible overhead in situations where knowing whether > it's a proxy or a "real" object is really important. > So for me, this change falls in the category "not useful enough that I'd > spend time coding it myself, but useful enough that I'd use it if > available" :) > Yeah, sum up the extra time you spent (and will spend) for making additional 'lookup' and compare this to the time of developing the extra method + refactoring debugging tools to use new message. And btw, the actual class of object could be determined by sending a #class message to it. But it is happens that in Squeak VM the #class message send implemented as a hack and it avoids the regular lookup semantics and reading the class slot of object directly. In different smalltalks this could not be the case, and btw i strongly pushing the idea, of getting rid such 'optimizations' like #class, #== and other. Because this prevents us from having a truly transparent proxies. VM is free to cheat, but it should never get caught cheating :) > Cheers, > Henry > > Igor Stasenko skrev: >> 2009/9/7 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: >> >>> good idea! >>> We will add that in pharo if you open a bug item ticket. >>> Stef >>> >>> >> >> I could add it easily. But first we should make a good expertise, if >> this change is worth doing. >> Because for Object it means a trivial addition of a method, but for >> Debugger/Inspector and other tools >> this could mean a major refactoring and tracing all calls to printing >> methods in order to make sure >> that all of them using new message(s). This could be a big amount of work :) >> >> >>> On Sep 7, 2009, at 5:02 PM, Igor Stasenko wrote: >>> >>> >>>> Hello guys, >>>> i'd like to discuss with you an idea of having a specific methods in >>>> Object class for a better and more clever behavior when debugging. >>>> >>>> For those of you who are using different kinds of proxies, the main >>>> problem with them that you should override the #printOn: >>>> or #printString methods in order to behave them similar to what >>>> original(proxied) object should be, >>>> but from other side, especially for debugging purposes, this incurs a >>>> major inconvenience, because you often need to differentiate between >>>> the real object and object proxy while debugging. Because if proxy >>>> behaves similar to proxied object while printing, you can't really >>>> make a difference when looking at it. >>>> >>>> So, i thought that a nice solution would be to extend an Object >>>> protocol especially for debugging purposes by adding >>>> #debugPrintOn: >>>> method >>>> and change the debugger to use this message, instead of #printOn: for >>>> displaying objects in inspector panels. >>>> >>>> Here is the default implementation of >>>> >>>> Object>>debugPrintOn: aStream >>>> Â ^ self printOn: aStream >>>> >>>> And, as you may guess, now the proxy could choose to behave >>>> differently depending on context. >>>> >>>> P.S. Maybe i'm missing a point, and there are already the existing >>>> good practices how to get around this.. if so, then please tell me. >>>> >>>> -- >>>> Best regards, >>>> Igor Stasenko AKA sig. >>>> >>>> _______________________________________________ >>>> Pharo-project mailing list >>>> Pharo-project(a)lists.gforge.inria.fr >>>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>>> >>> _______________________________________________ >>> Pharo-project mailing list >>> Pharo-project(a)lists.gforge.inria.fr >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>> >>> >> >> >> >> > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project -- Best regards, Igor Stasenko AKA sig.

Sept. 7, 2009

Re: [Pharo-project] The better debugger support by extending an Object protocol

by Igor Stasenko

2009/9/7 Peter Hugosson-Miller <oldmanlink(a)gmail.com>: > On 7 sep 2009, at 17.02, Igor Stasenko <siguctua(a)gmail.com> wrote: > >> Hello guys, >> i'd like to discuss with you an idea of having a specific methods in >> Object class for a better and more clever behavior when debugging. >> >> For those of you who are using different kinds of proxies, the main >> problem with them that you should override the #printOn: >> or #printString methods in order to behave them similar to what >> original(proxied) object should be, >> but from other side, especially for debugging purposes, this incurs a >> major inconvenience, because you often need to differentiate between >> the real object and object proxy while debugging. Because if proxy >> behaves similar to proxied object while printing, you can't really >> make a difference when looking at it. >> >> So, i thought that a nice solution would be to extend an Object >> protocol especially for debugging purposes by adding >> #debugPrintOn: >> method >> and change the debugger to use this message, instead of #printOn: for >> displaying objects in inspector panels. >> >> Here is the default implementation of >> >> Object>>debugPrintOn: aStream >> Â ^ self printOn: aStream >> >> And, as you may guess, now the proxy could choose to behave >> differently depending on context. >> >> P.S. Maybe i'm missing a point, and there are already the existing >> good practices how to get around this.. if so, then please tell me. >> >> -- >> Best regards, >> Igor Stasenko AKA sig. >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > Just one thing: maybe the default implementation could wrap that call > to #printOn: in an exception handler, in case one is in the process of > debugging a #printOn: method. The exception could just swallow all > errors and return a String like 'Receiver cannot be printed' or similar. > AFAIK, debugger already having a work-arounds for this, so if #printOn: throws an exception it displays a reddish string , "object can't be printed, try debug object printString" or similar. What is interesting about that, that at some point, the source of such errors could be that an object which you trying to print is not fully initialized because developer do not expected the usage of #printString at early stages of object initialization, but this often happens in Debugger when you evaluating the code step-by-step. This just another case, where separate #debugPrintOn: could be useful. But i don't want to make it too clever in the Object, as you proposing, instead, i think it should be plain stupid and act as an entry point, while one who overriding this message could make sure that #debugPrintOn: never throws an exception... But still, this doesn't means that debugger should not care about such things by itself. > -- > Cheers, > Peter > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > -- Best regards, Igor Stasenko AKA sig.

Sept. 7, 2009

Re: [Pharo-project] problem with running Pharo under Solaris 10 9/05

by Mariano Martinez Peck

Hi, for Pharo you need a closure enable VM. You can try from here: http://www.squeakvm.org/unix/ the version Squeak-3.10-6 Or try http://gforge.inria.fr/frs/download.php/22745/pharo-vm-0.15.2d-linux.zip Best, Mariano On Mon, Sep 7, 2009 at 12:51 PM, Ivaylo Ganchev < ivaylo.ganchev(a)univ-paris8.fr> wrote: > Squeak works fine under solaris 10, I managed to compile one with some > struggle. Now a teacher at our department wants to have pharo, because > she feels better with it. I was suggested by her to ask a for assistance > at the mailing list. > > Regards, > Ivaylo > > StÃ©phane Ducasse wrote: > > first you should try squeak to run on solaris because there was a > > release on the new squeak vm. > > Then solaris this is 10 years I do not touch one :) > > > > Stef > > > > On Sep 7, 2009, at 3:58 PM, ivaylo.ganchev(a)univ-paris8.fr wrote: > > > > > >> Hello. > >> > >> I can't manage to run the virtual machine under solaris 10. I have > >> permanently the following output: > >> > >> -bash: ./squeak: Invalid argument > >> > >> Here is the output when I try to run the image with the vm of squeak: > >> > >> iconv_open: Invalid argument > >> This interpreter (vers. 6502) cannot read image file (vers. > >> 1746468864). > >> Press CR to quit... > >> > >> Could someone provide me with a solution or with instructions to > >> compile a > >> vm for Solaris 10? The makefile is somewhat obscure with plenty of > >> includes at /home/bryce/squeak/exupery without knowing whatś in > >> there. > >> > >> Help would be much appreciated. > >> > >> Thanks in advance, > >> Ivaylo > >> > >> > >> _______________________________________________ > >> Pharo-project mailing list > >> Pharo-project(a)lists.gforge.inria.fr > >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > >> > > > > > > _______________________________________________ > > Pharo-project mailing list > > Pharo-project(a)lists.gforge.inria.fr > > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >

Sept. 7, 2009

Re: [Pharo-project] The better debugger support by extending an Object protocol

by Henrik Johansen

Well, if the goal is to be able to differentiate between two objects who should behave similar in all cases except when you print them while debugging, I can't really think of any better ways :) Playing the devil's advocate, here's two things to consider: - Some people will likely expect *all* proxies to behave like that in a debugger, enforcing consistent use may be hard. - Some (other) people will likely see debugPrintOn:, and figure it's cool to use it for any object they want additional info about at a glance in a debugger. (not saying that is necessarily a bad thing) Maybe a good way to clarify its intended usage would be implementing debugPrintOn: in a ProxyTrait? This also ensures a consistent manner for how proxies are distinguished from the real. (assuming of course, the implementation for different proxies you were thinking of follows a constant pattern) Personally, I found inspecting the field to see the actual class of the object to be of negligible overhead in situations where knowing whether it's a proxy or a "real" object is really important. So for me, this change falls in the category "not useful enough that I'd spend time coding it myself, but useful enough that I'd use it if available" :) Cheers, Henry Igor Stasenko skrev: > 2009/9/7 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > >> good idea! >> We will add that in pharo if you open a bug item ticket. >> Stef >> >> > > I could add it easily. But first we should make a good expertise, if > this change is worth doing. > Because for Object it means a trivial addition of a method, but for > Debugger/Inspector and other tools > this could mean a major refactoring and tracing all calls to printing > methods in order to make sure > that all of them using new message(s). This could be a big amount of work :) > > >> On Sep 7, 2009, at 5:02 PM, Igor Stasenko wrote: >> >> >>> Hello guys, >>> i'd like to discuss with you an idea of having a specific methods in >>> Object class for a better and more clever behavior when debugging. >>> >>> For those of you who are using different kinds of proxies, the main >>> problem with them that you should override the #printOn: >>> or #printString methods in order to behave them similar to what >>> original(proxied) object should be, >>> but from other side, especially for debugging purposes, this incurs a >>> major inconvenience, because you often need to differentiate between >>> the real object and object proxy while debugging. Because if proxy >>> behaves similar to proxied object while printing, you can't really >>> make a difference when looking at it. >>> >>> So, i thought that a nice solution would be to extend an Object >>> protocol especially for debugging purposes by adding >>> #debugPrintOn: >>> method >>> and change the debugger to use this message, instead of #printOn: for >>> displaying objects in inspector panels. >>> >>> Here is the default implementation of >>> >>> Object>>debugPrintOn: aStream >>> ^ self printOn: aStream >>> >>> And, as you may guess, now the proxy could choose to behave >>> differently depending on context. >>> >>> P.S. Maybe i'm missing a point, and there are already the existing >>> good practices how to get around this.. if so, then please tell me. >>> >>> -- >>> Best regards, >>> Igor Stasenko AKA sig. >>> >>> _______________________________________________ >>> Pharo-project mailing list >>> Pharo-project(a)lists.gforge.inria.fr >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> >> > > > >

Sept. 7, 2009

Re: [Pharo-project] dnu - isScarySelector not found

by Damien Cassou

Hi Carlos, could you please explain all the steps to reproduce and tell us exactly what image you are using. 2009/9/4 Carlos Crosetti <carlos(a)mostar.com.ar>: > Hi, > > On any existing subclass of Object, I add a class method, I add > "testSelector" > > Got MNU Metaclass(class) dnu isScarySelector > OBMethodDefinition>>confirmMethod: > > What is wrong? > > Regards, Carlos > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > -- Damien Cassou http://damiencassou.seasidehosting.st "Lambdas are relegated to relative obscurity until Java makes them popular by not having them." James Iry

Sept. 7, 2009

Re: [Pharo-project] Using Pharo from the command-line

by Igor Stasenko

The problem with command-line arguments as a file names, like: cat myfile.foo is that the location of myfile.foo is determined by using a search path , usually provided in environment PATH var of a shell. I worked in a different unix shells, and some of them, do not adding/using the ./ into the search path by default, which means that cat myfile.foo will end up with 'file not found' message, while cat ./myfile.foo will work fine. i think that squeak should follow the shell semantics and do not try to automatically expand the pure file name, like foo.bar into something like: ./foo.bar, or ~/foo.bar 2009/9/2 John M McIntosh <johnmci(a)smalltalkconsulting.com>: > I think Â here you are trying to get to test.sq > > I only adjust the incoming image name in the VM looking for ~ for > example, and resolving usage of ./ and ../ > > The additional command line items are then passed to the image > unchanged, so it sees only 'test.sq' Â as the path name. > You would have to check the smalltalk code at the point where it gets > the command line parm and decide if it's 'test.sq' should that really > be './test.sq' > You might also try putting './test.sq' on the command line and see if > that works. > > > On 2-Sep-09, at 9:23 AM, StÃ©phane Ducasse wrote: > >>>> >>> The full path requirement should be considered a bug from my >>> perspective. >> >> mine too and I thought that john fixed that. >> So did you try without? > > -- > = > = > = > ======================================================================== > John M. McIntosh <johnmci(a)smalltalkconsulting.com> Â Twitter: > squeaker68882 > Corporate Smalltalk Consulting Ltd. Â http://www.smalltalkconsulting.com > = > = > = > ======================================================================== > > > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > -- Best regards, Igor Stasenko AKA sig.

Sept. 7, 2009

Re: [Pharo-project] problem with running Pharo under Solaris 10 9/05

by Ivaylo Ganchev

Squeak works fine under solaris 10, I managed to compile one with some struggle. Now a teacher at our department wants to have pharo, because she feels better with it. I was suggested by her to ask a for assistance at the mailing list. Regards, Ivaylo StÃ©phane Ducasse wrote: > first you should try squeak to run on solaris because there was a > release on the new squeak vm. > Then solaris this is 10 years I do not touch one :) > > Stef > > On Sep 7, 2009, at 3:58 PM, ivaylo.ganchev(a)univ-paris8.fr wrote: > > >> Hello. >> >> I can't manage to run the virtual machine under solaris 10. I have >> permanently the following output: >> >> -bash: ./squeak: Invalid argument >> >> Here is the output when I try to run the image with the vm of squeak: >> >> iconv_open: Invalid argument >> This interpreter (vers. 6502) cannot read image file (vers. >> 1746468864). >> Press CR to quit... >> >> Could someone provide me with a solution or with instructions to >> compile a >> vm for Solaris 10? The makefile is somewhat obscure with plenty of >> includes at /home/bryce/squeak/exupery without knowing whatś in >> there. >> >> Help would be much appreciated. >> >> Thanks in advance, >> Ivaylo >> >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > >

Sept. 7, 2009

Re: [Pharo-project] The better debugger support by extending an Object protocol

by Peter Hugosson-Miller

On 7 sep 2009, at 17.02, Igor Stasenko <siguctua(a)gmail.com> wrote: > Hello guys, > i'd like to discuss with you an idea of having a specific methods in > Object class for a better and more clever behavior when debugging. > > For those of you who are using different kinds of proxies, the main > problem with them that you should override the #printOn: > or #printString methods in order to behave them similar to what > original(proxied) object should be, > but from other side, especially for debugging purposes, this incurs a > major inconvenience, because you often need to differentiate between > the real object and object proxy while debugging. Because if proxy > behaves similar to proxied object while printing, you can't really > make a difference when looking at it. > > So, i thought that a nice solution would be to extend an Object > protocol especially for debugging purposes by adding > #debugPrintOn: > method > and change the debugger to use this message, instead of #printOn: for > displaying objects in inspector panels. > > Here is the default implementation of > > Object>>debugPrintOn: aStream > ^ self printOn: aStream > > And, as you may guess, now the proxy could choose to behave > differently depending on context. > > P.S. Maybe i'm missing a point, and there are already the existing > good practices how to get around this.. if so, then please tell me. > > -- > Best regards, > Igor Stasenko AKA sig. > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project Just one thing: maybe the default implementation could wrap that call to #printOn: in an exception handler, in case one is in the process of debugging a #printOn: method. The exception could just swallow all errors and return a String like 'Receiver cannot be printed' or similar. -- Cheers, Peter

Sept. 7, 2009

Re: [Pharo-project] Closure review

by Damien Cassou

Hi Michael, On Wed, Sep 2, 2009 at 10:50 PM, Michael Roberts<mike(a)mjr104.co.uk> wrote: > can someone point me to any of the following > 2) a definitive squeak (or other) image with closures integrated. Did > Elliot publish a closure image? Pharo has closures for a long time now: http://pharo-project.org/pharo-download -- Damien Cassou http://damiencassou.seasidehosting.st "Lambdas are relegated to relative obscurity until Java makes them popular by not having them." James Iry

Sept. 7, 2009

Re: [Pharo-project] The better debugger support by extending an Object protocol

by Igor Stasenko

2009/9/7 StÃ©phane Ducasse <stephane.ducasse(a)inria.fr>: > good idea! > We will add that in pharo if you open a bug item ticket. > Stef > I could add it easily. But first we should make a good expertise, if this change is worth doing. Because for Object it means a trivial addition of a method, but for Debugger/Inspector and other tools this could mean a major refactoring and tracing all calls to printing methods in order to make sure that all of them using new message(s). This could be a big amount of work :) > On Sep 7, 2009, at 5:02 PM, Igor Stasenko wrote: > >> Hello guys, >> i'd like to discuss with you an idea of having a specific methods in >> Object class for a better and more clever behavior when debugging. >> >> For those of you who are using different kinds of proxies, the main >> problem with them that you should override the #printOn: >> or #printString methods in order to behave them similar to what >> original(proxied) object should be, >> but from other side, especially for debugging purposes, this incurs a >> major inconvenience, because you often need to differentiate between >> the real object and object proxy while debugging. Because if proxy >> behaves similar to proxied object while printing, you can't really >> make a difference when looking at it. >> >> So, i thought that a nice solution would be to extend an Object >> protocol especially for debugging purposes by adding >> #debugPrintOn: >> method >> and change the debugger to use this message, instead of #printOn: for >> displaying objects in inspector panels. >> >> Here is the default implementation of >> >> Object>>debugPrintOn: aStream >> Â ^ self printOn: aStream >> >> And, as you may guess, now the proxy could choose to behave >> differently depending on context. >> >> P.S. Maybe i'm missing a point, and there are already the existing >> good practices how to get around this.. if so, then please tell me. >> >> -- >> Best regards, >> Igor Stasenko AKA sig. >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project > -- Best regards, Igor Stasenko AKA sig.

Sept. 7, 2009