September 2012 - Pharo-dev - lists.pharo.org

Re: [Pharo-project] Webcam + barcode

by StÃ©phane Ducasse

On Sep 24, 2012, at 8:50 PM, Torsten Bergmann wrote: > Laurent wrote >> I've seen >> http://www.squeaksource.com/WebCamMorph.html but it doesn't seem to work >> on Pharo OneClick > > It uses the cross-platform webcam access from Scratch. > It worked for me some time ago with the plugins found > in the Scratch distro - even with Pharo (when it was > close to Squeak). > > Havent tested in a recent pharo image or Cog. > > Stef wrote >> Igor improved a lot the communication with Objective-C so we were thinking >that it would be fun to see how to use >> the webcam > > For the fun side yes - but Mac only. Yes but hacking Cocoa interactively can be a killer app :) > For serious cross platform > Pharo we should think about packaging the plugin with the VM, Yes Now we are all really working and busy. This is probably a good exercise for me to learn VM stuff. > the code is MIT: > > http://www.squeaksource.com/CameraPlugin.html > > Bye > T. > >

Sept. 24, 2012

Re: [Pharo-project] instVarNames vs instVarNamed:

by Mariano Martinez Peck

On Mon, Sep 24, 2012 at 8:24 PM, Guillermo Polito <guillermopolito(a)gmail.com > wrote: > > > Maybe rename #instVarNames to #myInstancesVariableNames? > > +1. I think something around this would clarify this scenario. Because for me Class is a normal object... > Guille > > On Mon, Sep 24, 2012 at 8:18 PM, Camillo Bruni <camillobruni(a)gmail.com>wrote: > >> On 2012-09-24, at 20:15, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> >> wrote: >> > On Sep 24, 2012, at 6:51 PM, Camillo Bruni wrote: >> >>>> Nautilus class instVarNames >> >>> -> #('maxSize' 'cachedLastClasses' 'groups') >> >>> >> >>> ok we get the instance variables >> >>> >> >>> Nautilus class instVarNamed: 'groups' >> >>> -> error >> >>> >> >>> For me that is wrong. I should not get an error, I should get the >> actual >> >>> variable. >> >>> I mean, why #instVarNames workds but #instVarNamed: doesn't? That is >> >>> inconsistent. >> > >> > to me mariano is right. if I can ask a class for a receiver a list of >> stuff I should be able to >> > send to the same receiver the value of the named elements. >> > this distinction is confusing (Normally I know what is metaclass >> programming) >> >> but with methods it's the very same, you get them no the class side, but >> you >> cannot do anything with them on the class. >> >> The problem is just that on a Class the instance side (of the Metaclass) >> and the >> class side collapse, so you have a double interface there. >> >> unless you have a strict and weird kind of separation of these two layers >> like in Java, you will always have a double set of methods there.. >> > > -- Mariano http://marianopeck.wordpress.com

Sept. 24, 2012

Re: [Pharo-project] Pharo and Namespaces

by Tudor Girba

Great. And what is the conclusion? :) Doru On Mon, Sep 24, 2012 at 5:57 PM, James Foster <Smalltalk(a)jgfoster.net> wrote: > Stef, > > Thanks for taking time at ESUG to listen and learn more about our namespace proposal. I believe that we have cleared up some of the misconceptions surrounding this complex topic. > > James > > On Jun 27, 2012, at 8:27 AM, StÃ©phane Ducasse wrote: > >> >> On Jun 27, 2012, at 4:44 PM, James Foster wrote: >> >>> Stef, >>> >>> I'm sorry to hear about your burnout and I understand that you are not prepared to seriously discuss the issues that others have raised. I hope when the issue is raised again (it does seem to come up every year or so!) we can correct some of the misunderstandings that exist. >> >> yes we are discussing regularly that topic and Camille is writing a master where all the points are discussed and summarized with pros and cons. >> Now for 20 we should finish all the open tracks we have. >> >> Stef >> >>> >>> Best wishes, >>> >>> James >>> >>> On Jun 27, 2012, at 12:08 AM, StÃ©phane Ducasse wrote: >>> >>>> James >>>> >>>> sorry but I'm at home stopped for 10 days because of a burnout (linked partly to pharo and the business I want to spawn for the community). >>>> We talked endlessly about namespaces and so far we lived happily without. Right now I will not talk about that. Read subsystem the paper of wirfs-brock >>>> if you want to see what I would prefer to have. But we need to have a scientific approach to evaluate. >>>> And yes I read the implementation two years ago. >>>> Finally did you see the list of topics that I mention? >>>> - do you want to help in any of them to make pharo better? >>>> because we have to get them first and I need all my energy for them. >>>> >>>> Stef >>>> >>>> >>>> On Jun 27, 2012, at 12:25 AM, James Foster wrote: >>>> >>>>> On Jun 26, 2012, at 12:51 PM, StÃ©phane Ducasse wrote: >>>>> >>>>>> On Jun 26, 2012, at 9:30 PM, James Foster wrote: >>>>>> >>>>>>> On Jun 26, 2012, at 11:19 AM, StÃ©phane Ducasse wrote: >>>>>>> >>>>>>>>>>> What happened to the project from GermÃ¡n Leiva >>>>>>>>>>> http://www.youtube.com/watch?v=n4I7fSVNX2A >>>>>>>>>> >>>>>>>>>> we do not want class level namespace because this is the mess >>>>>>>>> >>>>>>>>> As the sponsor for GermÃ¡n's project, I have some interest in this topic. StÃ©phane has said a couple times that it is wrong but has never taken time to explain his objections. >>>>>>>> >>>>>>>> We do not want to have class name resolution at the granularity of a class. >>>>>>> >>>>>>> And are you saying this because you think GermÃ¡n's implementation does this? >>>>>>> >>>>>>>> Why because it means that in the same package reading the code containing a class Foo could be a different one. >>>>>> >>>>>>>> Why because it means that in the same package, reading the code containing a class Foo could be a different one. >>>>>> ^^^^^ >>>>>> >>>>>> Class level namespace import means that in a given class, a method accessing the variable Foo may end up pointing to another class Foo in a class in the same package importing another namespace. >>>>> >>>>> I still don't understand the definition. What do you mean by "another class Foo in a class." How can a class be in a class? Is Foo defined in two packages? Is the method on the class Foo? Should the name be resolved to the Foo in the package containing the method or to another Foo? Perhaps it would help if you named the sample classes, packages, and methods. >>>>> >>>>> Are you saying that if the namespace is allowed to be defined (or refined) at any level other than the package, then it is lumped into the bucket called "class level namespace import"? >>>>> >>>>>>> I don't understand your example. I don't know what you mean by "package reading the code." Are you describing a package that defines classes Foo and Bar, and a method in a class Bar that references the Foo in the same package? Are you providing this example because you think GermÃ¡n's implementation does not support this use case? >>>>>> >>>>>> No >>>>>> I just say that changing binding of variables at the class level is not a good granularity. I do not want to have >>>>>> >>>>>> Object subclass: #NameOfSubclass >>>>>> instanceVariableNames: '' >>>>>> classVariableNames: '' >>>>>> poolDictionaries: '' >>>>>> category: 'Bob' >>>>>>>>> environment: >>>>> >>>>> Is it your impression that GermÃ¡n's implementation requires this? If so, on what do you base that understanding? Have you looked at the code? >>>>> >>>>>>>> I'm saying that since years. >>>>>>> >>>>>>> I agree you have been saying that GermÃ¡n's implementation isn't what you want. I just don't understand what you don't like about it. >>>>>> >>>>>> because this is a class level import. >>>>> >>>>> I still don't know what you mean by "class level import" or why you think GermÃ¡n's implementation fits your definition. >>>>> >>>>>>> Name resolution of all variables (including Globals, of which Classes are a subset) should be part of a method compile. At the time a method is compiled, an 'environment' should be provided to the compiler that indicates how global name resolution should occur. >>>>>> >>>>>> Usually this is the class of the method. >>>>> >>>>> By "Usually" do you mean in pre-namespace Pharo? That is, the class is one of the factors that the compiler considers in doing name lookup? Is the "usual" approach good? Would it still be a factor considered by the compiler in an environment namespace regime? >>>>> >>>>>>> This is a tools issue and it should be possible to specify the default namespace environment for the method, for a method category, for a class, for a class category, for a package, and for the system as a whole. >>>>>> >>>>>> no this is a question of language design. >>>>> >>>>> Do you consider packages to be part of the language? I have always thought that one of the nice things about Smalltalk is how little of the development environment is actually part of the language. Being able to augment things through tools rather than changing the language seems to me to be a feature, not a bug. >>>>> >>>>>>> In addition, within a particular method it should be possible to explicitly reference a particular namespace environment, whether through syntax (dot or double colons) >>>>>> >>>>>> No we do not want to have that. >>>>>> We want import to be specified at the border: i.e. during module import. Inside a module the world is flat and as a developer I do not want to know that this Point is from Core when that one is from MyCore. >>>>> >>>>> By "I do not want to know" do you mean "I do not want to be required to specify" or do you mean "I do not want anyone else to be able to find out"? If I want to know (say, to build tools), would that be okay? If I'm willing to let you remain ignorant of a global's source would you be willing to let me be enlightened? >>>>> >>>>>> If I want both, at the module import level I write >>>>>> >>>>>> Import: Point from: core as: CorePoint; >>>>>> import: Point from: dev as: DevPoint; >>>>> >>>>> What object implements #'import:from:as:'? >>>>> >>>>>>> or through message sends (e.g., a Dictionary's #'at:' method). I prefer not to add new syntax and favor GemStone's implementation over that of VisualWorks. >>>>>> >>>>>> I dislike them both. >>>>>> A module should provide a certain level of encapsulation, else naming convention is good enough. >>>>>> Because else having namespace does not prevent you to have to declare that WA is not a namespace somebody else should use. >>>>> >>>>> You say that you "do not want to" allow code "to explicitly reference a particular namespace." Do you mean that arbitrary code should not be able to see a global that is not explicitly imported at package load time and that code should never be able to explicitly look at and manipulate namespaces. Really? This seems to me to be very much contrary to the existing spirit of reflection and introspection in Smalltalk and would make tools much more limited. I suspect that this is not really what you mean. >>>>> >>>>> I believe that a package should be allowed to provide a default environment, but I don't see the need to make it mandatory or exclusive. I believe that a class should be allowed to override the default environment, but I don't think it should be required. >>>>> >>>>> If a class is allowed (but not required) to override the default (provided by the package/module, for example), does that make it a "class level import" (and wrong, in your view)? >>>>> >>>>> What I understand from your statements so far is that GermÃ¡n's approach allows too much flexibility (namespace can be specified not just at the package level but also at the class level and explicitly in code). You do not want to allow anyone to experiment with different levels of granularity. Is that it? >>>>> >>>>> Thanks for engaging in the discussion. >>>>> >>>>> James Foster >>>>> >>>>> >>>> >>>> >>>> >>> >>> >> >> >> > > -- www.tudorgirba.com "Every thing has its own flow"

Sept. 24, 2012

[Pharo-project] Sprint in November

by StÃ©phane Ducasse

Hi Pharoers we would like to organize a sprint in november and make it open to external people. So if you are interested coding with us. Please indicates your preferences. Stef > From: Marcus Denker <marcus.denker(a)inria.fr> > Subject: Doodle Sprint > Date: September 24, 2012 5:43:31 PM GMT+02:00 > To: StÃ©phane Ducasse <Stephane.Ducasse(a)inria.fr> > >> http://doodle.com/wsxdcxg3irzvn47v > -- > Marcus Denker -- http://marcusdenker.de >

Sept. 24, 2012

[Pharo-project] Webcam + barcode

by Torsten Bergmann

Laurent wrote >I've seen >http://www.squeaksource.com/WebCamMorph.html but it doesn't seem to work >on Pharo OneClick It uses the cross-platform webcam access from Scratch. It worked for me some time ago with the plugins found in the Scratch distro - even with Pharo (when it was close to Squeak). Havent tested in a recent pharo image or Cog. Stef wrote >Igor improved a lot the communication with Objective-C so we were thinking >that it would be fun to see how to use >the webcam For the fun side yes - but Mac only. For serious cross platform Pharo we should think about packaging the plugin with the VM, the code is MIT: http://www.squeaksource.com/CameraPlugin.html Bye T.

Sept. 24, 2012

Re: [Pharo-project] instVarNames vs instVarNamed:

by Guillermo Polito

On Mon, Sep 24, 2012 at 8:28 PM, Camillo Bruni <camillobruni(a)gmail.com>wrote: > On 2012-09-24, at 20:24, Guillermo Polito <guillermopolito(a)gmail.com> > wrote: > > What if we do it the other way? Add #variableNames to the instances :) > > in my opinion wrong :/, then you can start to replicate the whole > class-side > interface on the instance side... that's a never-ending circle. > > I'm not strongly against nor in favor for any of those approaches. > besides, that's yet another method on Object? :D > The problem is not the amount of methods per se but the packaging of most of them -which btw is much better than some years ago-, and the tools showing lots of info in such annoying way. > > > Nautilus new variableNames = Nautilus instVarNames. > > > > And them > > > > Nautilus new variableNames > > ==> #('announcer' 'browsedEnvironment' 'browsingHistory' 'plugins' > > 'selectedCategory' 'selectedClass' 'selectedGroup' 'selectedMethod' > > 'selectedPackage' 'showCategories' 'showComment' 'showGroups' > > 'showHierarchy' 'showInstance' 'showPackages' 'ui' 'uiClass') > > > > Nautilus new instVarNamed: 'announcer' > > > > ? > > > > Of course, that will happen/work at metaclass level too. > > > > Maybe rename #instVarNames to #myInstancesVariableNames? > > > > Guille > >

Sept. 24, 2012

Re: [Pharo-project] instVarNames vs instVarNamed:

by Camillo Bruni

On 2012-09-24, at 20:24, Guillermo Polito <guillermopolito(a)gmail.com> wrote: > What if we do it the other way? Add #variableNames to the instances :) in my opinion wrong :/, then you can start to replicate the whole class-side interface on the instance side... that's a never-ending circle. besides, that's yet another method on Object? :D > Nautilus new variableNames = Nautilus instVarNames. > > And them > > Nautilus new variableNames > ==> #('announcer' 'browsedEnvironment' 'browsingHistory' 'plugins' > 'selectedCategory' 'selectedClass' 'selectedGroup' 'selectedMethod' > 'selectedPackage' 'showCategories' 'showComment' 'showGroups' > 'showHierarchy' 'showInstance' 'showPackages' 'ui' 'uiClass') > > Nautilus new instVarNamed: 'announcer' > > ? > > Of course, that will happen/work at metaclass level too. > > Maybe rename #instVarNames to #myInstancesVariableNames? > > Guille

Sept. 24, 2012

Re: [Pharo-project] instVarNames vs instVarNamed:

by Guillermo Polito

What if we do it the other way? Add #variableNames to the instances :) Nautilus new variableNames = Nautilus instVarNames. And them Nautilus new variableNames ==> #('announcer' 'browsedEnvironment' 'browsingHistory' 'plugins' 'selectedCategory' 'selectedClass' 'selectedGroup' 'selectedMethod' 'selectedPackage' 'showCategories' 'showComment' 'showGroups' 'showHierarchy' 'showInstance' 'showPackages' 'ui' 'uiClass') Nautilus new instVarNamed: 'announcer' ? Of course, that will happen/work at metaclass level too. Maybe rename #instVarNames to #myInstancesVariableNames? Guille On Mon, Sep 24, 2012 at 8:18 PM, Camillo Bruni <camillobruni(a)gmail.com>wrote: > On 2012-09-24, at 20:15, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> > wrote: > > On Sep 24, 2012, at 6:51 PM, Camillo Bruni wrote: > >>>> Nautilus class instVarNames > >>> -> #('maxSize' 'cachedLastClasses' 'groups') > >>> > >>> ok we get the instance variables > >>> > >>> Nautilus class instVarNamed: 'groups' > >>> -> error > >>> > >>> For me that is wrong. I should not get an error, I should get the > actual > >>> variable. > >>> I mean, why #instVarNames workds but #instVarNamed: doesn't? That is > >>> inconsistent. > > > > to me mariano is right. if I can ask a class for a receiver a list of > stuff I should be able to > > send to the same receiver the value of the named elements. > > this distinction is confusing (Normally I know what is metaclass > programming) > > but with methods it's the very same, you get them no the class side, but > you > cannot do anything with them on the class. > > The problem is just that on a Class the instance side (of the Metaclass) > and the > class side collapse, so you have a double interface there. > > unless you have a strict and weird kind of separation of these two layers > like in Java, you will always have a double set of methods there.. >

Sept. 24, 2012

Re: [Pharo-project] instVarNames vs instVarNamed:

by Camillo Bruni

On 2012-09-24, at 20:15, StÃ©phane Ducasse <stephane.ducasse(a)inria.fr> wrote: > On Sep 24, 2012, at 6:51 PM, Camillo Bruni wrote: >>>> Nautilus class instVarNames >>> -> #('maxSize' 'cachedLastClasses' 'groups') >>> >>> ok we get the instance variables >>> >>> Nautilus class instVarNamed: 'groups' >>> -> error >>> >>> For me that is wrong. I should not get an error, I should get the actual >>> variable. >>> I mean, why #instVarNames workds but #instVarNamed: doesn't? That is >>> inconsistent. > > to me mariano is right. if I can ask a class for a receiver a list of stuff I should be able to > send to the same receiver the value of the named elements. > this distinction is confusing (Normally I know what is metaclass programming) but with methods it's the very same, you get them no the class side, but you cannot do anything with them on the class. The problem is just that on a Class the instance side (of the Metaclass) and the class side collapse, so you have a double interface there. unless you have a strict and weird kind of separation of these two layers like in Java, you will always have a double set of methods there..

Sept. 24, 2012

Re: [Pharo-project] Webcam + barcode

by StÃ©phane Ducasse

Laurent Igor improved a lot the communication with Objective-C so we were thinking that it would be fun to see how to use the webcam but now igor is heavily hacking vm and all the team is moving to a new building. So we were packing and we will unpack everything. Stef On Sep 24, 2012, at 6:51 PM, laurent laffont wrote: > Thanks Torsten. Ideally I would like a Morph-based one. I've seen http://www.squeaksource.com/WebCamMorph.html but it doesn't seem to work > on Pharo OneClick > > Laurent > > On Mon, Sep 24, 2012 at 6:02 PM, Torsten Bergmann <astares(a)gmx.de> wrote: > I remeber Seabreeze for Seaside had some > interface to webcam (using flash) and by using a > webservice to decode barcodes. > > You can see it in action in the second video at the bottom of > http://seabreeze.heeg.de/ > > A short description is here > http://seabreeze.heeg.de/files/SBWebsiteFiles/seaBreeze.pdf > > Maybe the barcode widget is available in the MIT licensed > open source distro (based on VisualWorks) > > Hope that helps! > > Bye > T. > >

Sept. 24, 2012