October 2017 - Pharo-users - lists.pharo.org

FileReference#entries caching?

by Steven R. Baker

Heya folks, I'm loading some PNG icons from disk, and I'm noticing some weirdness with FileReference#entries. When I inspect: '/home/srbaker/Projects/FocusFrog/icons' asFileReference entries it gives me an Array of size one, containing the refernce to the only file there. Then I delete the file, the same thing gives an array of size zero. But then when I fill the directory with a bunch of icons (240, to be exact), and inspect that line again I get zero. Eventually it gets the right answer. Is it cached or something? How do I guarantee that I'm *definitely* getting the current state of the directory on disk? Should I not even be using FileReference for this? Thanks! -Steven

Oct. 7, 2017

What does RMoD stand for?

by horrido

It is bizarre. Nowhere on the web can I find any reference to what INRIA's *RMoD* acronym stands for. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Oct. 7, 2017

Fun with UI Avatars

by Sven Van Caekenberghe

I came across https://ui-avatars.com, a web service that creates avatar images based on some parameters. >From Pharo, the shortest invocation would be something like ZnEasy getPng: 'https://ui-avatars.com/api?name=Albert+Einstein&size=128&background=0D8ABC&…'. Making use of the full builder interface of ZnClient that would look more like ZnClient new https; host: 'ui-avatars.com'; addPath: #api; queryAt: #name put: 'Albert Einstein'; queryAt: #size put: 128; queryAt: #color put: 'FFF'; queryAt: #background put: '0D8ABC'; queryAt: #rounded put: true; accept: ZnMimeType imagePng; enforceHttpSuccess: true; enforceAcceptContentType: true; contentReader: [ :entity | ImageReadWriter formFromStream: entity readStream ]; beOneShot; get. Anyway, it is cool to have an environment that makes this kind of experimentation so much fun. It is probably easy to implement this avatar image generation directly in Pharo ... Sven

Oct. 7, 2017

Re: [Pharo-users] Behold Pharo: The Modern Smalltalk

by horrido

> My point is that indeed you can do with EASE live coding in a numerous languages, at least to my experience. I have tried only Python and C/C++. Until I came upon this thread, I never knew you could do live coding in Python and C/C++. And I was a professional C/C++ programmer for over 15 years! It is certainly a well-kept secret. I have found very little information on the web about doing live coding in these languages (in fact, none). This leads me to believe that the vast majority of Python and C/C++ developers don't know about, or don't do, live coding. Whether it's "easy" is rather subjective. I suspect it's not as easy nor as convenient as in Pharo. If it were, then live coding ought to be much more prevalent in the Python and C/C++ communities. After all, what developer doesn't want to improve their productivity or increase their velocity of development? The key differentiator here, I think, is that live coding is baked into Pharo/Smalltalk, thus making it natural to use. It is not natural for Python and C/C++ programmers. It would be difficult to convince the IT industry to adopt live coding en masse. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Oct. 7, 2017

Re: [Pharo-users] Deploying on Linux with LibC version < 2.15

by Dimitris Chloupis

Why use a special Pharo VM when you can use LibC via UFFI from inside the image ? UFFI even offers partial wrapper to LibC. We prefer afterall to move things outside the VM and inside the image as much as we can to offers us a greater deal of flexibility. On Sat, Oct 7, 2017 at 12:45 PM Cyril Ferlicot D. <cyril.ferlicot(a)gmail.com> wrote: > Le 05/10/2017 Ã 15:46, Holger Freyther a Ã©crit : > > > > Hi! > > > > > > for a brief moment you really scared me. I thought you referred to > RedHat Linux 6 which was released in 1999 but you are referring to Red Hat > Enterprise Linux (RHEL). > > > > As it turns out we have "latest" (as soon as a commit is made to > pharo-vm.git) and hand curated "stable" (hand created source tarballs, > rebuilt from a git commit of opensmalltalk-vm) for RHEL6 and CentOS 6. > > > > CentOS 6.x: > > > > # Add the repo > > $ yum-config-manager --add-repo > http://download.opensuse.org/repositories/devel:/languages:/pharo:/latest/C… > > > > OR (for stable): > > > > > http://download.opensuse.org/repositories/devel:/languages:/pharo:/latest/C… > > > > # Install 32bit packages (with X11 dependency for *-ui or not) > > > > $ yum install pharo6-32-ui.i686 or pharo6-32.i386 > > > > # Install 64bit packages > > > > $ yum install pharo6-64-ui.x86_64 pharo6-64.x86_64 > > > > > > Hi, > > Maybe the instructions for CentOS and RHEL could be added to the linux > download page of pharo.org? > > > -- > Cyril Ferlicot > https://ferlicot.fr > > http://www.synectique.eu > 2 rue Jacques PrÃ©vert 01, > 59650 Villeneuve d'ascq France > >

Oct. 7, 2017

Re: [Pharo-users] Equals and HashCode Builder

by Noury Gmail

Hi, I have developed few years ago a trait-based solution to make it easy to deal with equality. By default, instances of the same class with equal IVs are equal + have the same hash code. You can customize the list of IVs to compare, which is handy in case of IVs that store cache values. All you have to do is to use the TEquality in your class. The code + tests are here http://smalltalkhub.com/#!/~CAR/ReusableBricks/packages/Equals This is part of the "ReusableBricks" repo that gather packages we're using it in different projects in my team. And it works fine. I'd love to have this integrated in Pharo. Note : I no longer receive mailing-lists emails, because I can't handle all the traffic. We can continue the conversation on Discord Noury > > > On 06 Oct 2017, at 18:31, Stephane Ducasse <stepharo.self(a)gmail.com> wrote: > > Contact noury because I do not remember. > But having a little builder is also nice. > > On Fri, Oct 6, 2017 at 4:15 PM, Vitor Medina Cruz <vitormcruz(a)gmail.com> wrote: >> Stephane >> >> "Vitor why don't you take it as a small project to propose a solution for >> Pharo." >> >> I will try :) I like the idea of using a Trait. >> >> >> Em 6 de out de 2017 05:01, "Stephane Ducasse" <stepharo.self(a)gmail.com> >> escreveu: >> >> Here is what I extracted from older emails >> >> From David Allouche in Pharo-dev to see if >> The ==hash== method is used in Pharo to separate objects in >> bucket-based data structures. >> >> >> !! Property >> >> It must have one required property which is required data integrity: >> >> !!!! A. >> Objects that are equal according to ==\=== must have equal hashes. >> >> >> It should have two desirable properties that are required to support >> the algorithmic assumptions of bucket-based data structures: >> >> !!!! B. >> Objects that are not equal should have different hashes. Ideally, the >> probability of hash collision should by 1/N where N is the size of >> hash value space. >> >> !!!! C. The hash values should spread as much as possible over their >> value space. For example: ProtoObject>>#identityHash. >> >> >> >> >> How these two desirable properties can be implemented depends on the >> actual distribution of the values used to compute the hash. >> >> An object can safely use XOR hashing if its instance variables are all >> different objects that already provide a hash method with these two >> properties. >> >> @@todo check following sentence because the use of singleton is obscure >> >> For example, an object whose behaviour is defined by several of >> singleton delegates of different classes that do not override >> Object>>#hash. >> >> But if the instance variables are not guaranteed to have those >> properties, it is necessary to more thoroughly "mix the bits". For >> example the method ==hash== of ==SequenceableCollection== illustrates >> this point. >> >> >> [[[ >> SequenceableCollection >> hash >> | hash | >> hash := self species hash. >> 1 to: self size do: [:i | hash := (hash + (self at: i) hash) hashMultiply]. >> ^ hash >> ]]] >> >> >> The mixing of the bits is done by the combination of addition and >> ==hashMultiply==. The value of ==species hash== does not need to be >> processed by ==hashMultiply==, because it is probably computed by the >> method =identityHash== of ==ProtoObject==, and that already provides >> property C. >> >> !!! When we should not use XOR >> >> ==LayoutFrame== is a particularly good example of a data structure >> that should not use XOR hashing. Its instance variables provide none >> of the required properties: >> >> - ==SmallInteger>>hash== is just ==^self==. >> - In addition, common ==LayoutFrame== instances tend to use pairs of >> identical values in their instance variables. Like ==0@0 corner: >> 1@1==, or ==Margin fromNumber: 10==. >> >> A good hash function for LayoutFrame needs to: >> >> - Get hashes for each instance variable that provides properties A and B. >> - Combine them in a way that is order-sensitive (to maintain property >> B) and that does some extra mixing (to provide property C). >> >> Now, we can assume that common values for the instance variables will >> be instances of ==SmallInteger==, ==Float==, or ==Fraction==. >> >> You can see in ==Fraction>>hash==, that a comment mentions the >> assumption that the fraction is already reduced, that is what makes it >> acceptable to use bitXor. >> >> The hash of ==SmallInteger== does provide properties A and B, but not >> property C. The hash of ==Float== is harder to understand, but tests >> show that it provides distinct values for 0.5, 0.25 and 0.125. So it >> hopefully provides B for the range of values of interest to >> ==LayoutFrame==. >> >> Another class that has similar hashing constraints to ==LayoutFrame== >> is ==Point==. Its ==hash== method is: >> >> [[[ >> Point >> hash >> "Hash is reimplemented because = is implemented." >> ^(x hash hashMultiply + y hash) hashMultiply >> ]]] >> >> It does not include species in the computation, which is less than >> ideal because it favours collisions with objects of different species >> that have a similar content and a the same hash algorithm. >> >> Finally, it is probably not necessary or useful to use the accessors >> to get to the instance variables. >> >> So a good implementation for LayoutFrame is >> >> [[[ >> LayoutFrame >> hash >> | hash | >> hash := self species hash >> hash := (hash + leftFraction hash) hashMultiply >> hash := (hash + leftOffset hash) hashMultiply >> hash := (hash + topFraction hash) hashMultiply >> hash := (hash + topOffset hash) hashMultiply >> hash := (hash + rightFraction hash) hashMultiply >> hash := (hash + rightOffset hash) hashMultiply >> hash := (hash + bottomFraction hash) hashMultiply >> hash := (hash + bottomOffset hash) hashMultiply >> ^ hash >> ]]] >> >> On Fri, Oct 6, 2017 at 9:59 AM, Stephane Ducasse >> <stepharo.self(a)gmail.com> wrote: >>> Noury also proposed a trait to avoid to systematically have to implement >>> hash. >>> Vitor why don't you take it as a small project to propose a solution for >>> Pharo. >>> >>> On Thu, Oct 5, 2017 at 6:34 PM, Vitor Medina Cruz <vitormcruz(a)gmail.com> >>> wrote: >>>> Yes, canEqual implementation also make #= be commutative. >>>> >>>> On Tue, Oct 3, 2017 at 11:11 AM, Denis Kudriashov <dionisiydk(a)gmail.com> >>>> wrote: >>>>> >>>>> >>>>> 2017-10-02 17:30 GMT+02:00 Denis Kudriashov <dionisiydk(a)gmail.com>: >>>>>> >>>>>> >>>>>> 2017-10-02 17:13 GMT+02:00 Vitor Medina Cruz <vitormcruz(a)gmail.com>: >>>>>>> >>>>>>> I am sorry, not species, but #isKindOf istead of #= to compare >>>>>>> classes. >>>>>> >>>>>> >>>>>> It is bad idea. #= should be transitive. >>>>> >>>>> >>>>> Oh, I used wrong word, shame on me :). I tried to say commutative. >>>>> >>>>>> >>>>>> How you will generate it with isKindOf: logic? You need to know common >>>>>> parent. >>>>>> >>>>>> Also I not remember cases where I was needed two instances of different >>>>>> classes to be equal. >>>>>> And I can imaging the problems which it will lead to. >>>>>> >>>>>>> >>>>>>> >>>>>>> On Mon, Oct 2, 2017 at 11:57 AM, Denis Kudriashov >>>>>>> <dionisiydk(a)gmail.com> >>>>>>> wrote: >>>>>>>> >>>>>>>> >>>>>>>> 2017-10-02 16:37 GMT+02:00 Sean P. DeNigris <sean(a)clipperadams.com>: >>>>>>>>> >>>>>>>>> >>>>>>>>> Two questions/comments about the generated code: >>>>>>>>> 1. #= >>>>>>>>> ... >>>>>>>>> self class = anObject class "should compare #species >>>>>>>>> instead?" >>>>>>>>> ifFalse: [ ^ false ]. >>>>>>>>> ... >>>>>>>>> Typically, I've seen #species instead of #class in the guard >>>>>>>>> statement. >>>>>>>>> Should we change it to that? >>>>>>>> >>>>>>>> >>>>>>>> I doubt that it is important for domain classes. Because I never saw >>>>>>>> the user of #species which is not a kind of Collection. And for >>>>>>>> collections >>>>>>>> this refactoring is not valid anyway. >>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> 2. #hash >>>>>>>>> ^ var1 hash bitXor: (var2 hash bitXor: var3 hash) >>>>>>>>> Is this implementation always safe? It's what I usually hand roll >>>>>>>>> based on >>>>>>>>> what I've seen, but Andres Valloud wrote a whole (large) book on >>>>>>>>> hashing, so >>>>>>>>> I've always wondered if I was missing somethingâ¦ >>>>>>>>> >>>>>>>>> >>>>>>>>> >>>>>>>>> ----- >>>>>>>>> Cheers, >>>>>>>>> Sean >>>>>>>>> -- >>>>>>>>> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>>>>>>>> >>>>>>>> >>>>>>> >>>>>> >>>>> >>>> >> >>

Oct. 7, 2017

Re: [Pharo-users] [Ann] PharoLauncher v1.0.1 released!

by Christophe Demarey

Hi Nicolai, > Le 7 oct. 2017 Ã 09:38, Nicolai Hess <nicolaihess(a)gmail.com> a Ã©crit : > > Just starting pharolauncher on windows still does not work (if you put it into the default "program" folder). > On start, it tries to create a local direcitory "pharo-local" and does not have the permission to do so. > You need to start it with admin-rights. A Pharo image needs write permission in the image folder to store image sessions (epicea) as well as other image data (package cache, play-cache, changes file, etc.) Maybe we should disable Epicea and it could work in a read only environment? For now, either you can start it with admin rights or you install Pharo Launcher in a user folder. Regards, Christophe

Oct. 7, 2017

Re: [Pharo-users] Deploying on Linux with LibC version < 2.15

by Cyril Ferlicot D.

Le 05/10/2017 Ã 15:46, Holger Freyther a Ã©critÂ : > > Hi! > > > for a brief moment you really scared me. I thought you referred to RedHat Linux 6 which was released in 1999 but you are referring to Red Hat Enterprise Linux (RHEL). > > As it turns out we have "latest" (as soon as a commit is made to pharo-vm.git) and hand curated "stable" (hand created source tarballs, rebuilt from a git commit of opensmalltalk-vm) for RHEL6 and CentOS 6. > > CentOS 6.x: > > # Add the repo > $ yum-config-manager --add-repo http://download.opensuse.org/repositories/devel:/languages:/pharo:/latest/C… > > OR (for stable): > > http://download.opensuse.org/repositories/devel:/languages:/pharo:/latest/C… > > # Install 32bit packages (with X11 dependency for *-ui or not) > > $ yum install pharo6-32-ui.i686 or pharo6-32.i386 > > # Install 64bit packages > > $ yum install pharo6-64-ui.x86_64 pharo6-64.x86_64 > > Hi, Maybe the instructions for CentOS and RHEL could be added to the linux download page of pharo.org? -- Cyril Ferlicot https://ferlicot.fr http://www.synectique.eu 2 rue Jacques PrÃ©vert 01, 59650 Villeneuve d'ascq France

Oct. 7, 2017

Re: [Pharo-users] using mocketry to mock subcall

by Denis Kudriashov

Hi Peter. You should stub instance instead of class: s := Something new. s stub askFor... 7 Ð¾ÐºÑ. 2017 Ð³. 9:18 Ð¿Ð¾Ð»ÑÐ·Ð¾Ð²Ð°ÑÐµÐ»Ñ "Peter UhnÃ¡k" <i.uhnak(a)gmail.com> Ð½Ð°Ð¿Ð¸ÑÐ°Ð»: > Hi, > > maybe I am missing something fundamental, because this seems like an > obvious scenario > > I have a class Something with two methods > > Something>>askForName > ^ UIManager default request: 'Name' > > Something>>name > ^ self askForName , ' suffix' > > Now I want to mock out askForName, so I can run it automatically in > tests... > > I've tried just stubbing it... > > SomethingTest>>testRenameStub > Something stub askForName willReturn: 'new'. > Something new name should be: 'new suffix' > > however it still opens the window to ask for the name, so the original > method is being called. > > Right now I have to stub it with metalinks, which doesn't play well with > some tools (hapao) > > SomethingTest>>testRenameMeta > | link newName | > link := MetaLink new > metaObject: [ 'new' ]; > control: #instead. > (Something >> #askForName) ast link: link. > [ newName := Something new name ] > ensure: [ link uninstall ]. > self assert: newName equals: 'new suffix' > > Thanks, > Peter > >

Oct. 7, 2017

Re: [Pharo-users] Behold Pharo: The Modern Smalltalk

by Dimitris Chloupis

The dicussion is about Pharo's live coding and OOP compared to other languages. IF you look at all my threads you will see I ALWAYS mention Python , Blender , Unreal for relevant topics. I do not remember hi jackig a thread with random remarks just for the shake of mentioning those things. Plus 99% of the times I mention Python is about Atlas , my library for using Python libraries from inside Pharo. Atlas is a "trojan horse" for Pharo to invade Python projects. Also I have been very clear that I consider C++ an abomination syntax wise and Python weaker than Smalltalk, language wise.Mainly because of Smalltalk's minimal syntax and of course offering live coding outside the box with no special setup from the coder. My point is that indeed you can do with EASE live coding in a numerous languages, at least to my experience. I have tried only Python and C/C++. Is it as easy or as flexible as Pharo ? I do not know because live coding as you know is about workflow and we dont code all the same way. For example I was never comfortable with coding solely from inside Pharo debugger as some of you are doing. I am more a Class Browser guy and I rarely use Workspace/Playground/REPL as well. My questions were sincere even though I was sarcastic because I always want to learn more about live coding and things I do not know about OOP. My sarcasm was an effort to be funny not to be rude. I am also certain that many experienced coders coming from other language will ask the same questions as well. What Pharo can give me OO wise that I cannot get in my X language ? What exactly is live coding for Pharo ? Is doing X things in that Y language live coding or is it something else ? What's the real purpose of message passing ? How it benefits me compared to just using method calls ? I am suprised that there has not been an article about live coding workflows. I think it could greatly benefit Pharo to demostrate its uniqueness. People prefer to be shown that something is better than being told. Most people also not bother at all coming to the mailing list and ask questions, they will ignore things they dont understand and carry on. So its not important to say that Pharo special but why Pharo is special and after 5 year I feel will still struggle in this area, not because of the fault of the community but because live coding and OOP can be an extremely wide field that you can easily get lost into. We have also to be fair with othe programming languages, respect them, to the degree they deserve our respect and not exaggerate our claims because that harms Pharo reputation. On Sat, Oct 7, 2017 at 11:50 AM Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > Your contribution to Pharo are much appreciated. And indeed you did not > directly say anything negative. > > But you have to agree that you often discuss about Python, C++, Blender, > ... in mailing lists that are not for that purpose. You are absolutely free > to do whatever you want and to give your opinions freely, but this is not > the right place. > > > On 7 Oct 2017, at 10:42, Dimitris Chloupis <kilon.alios(a)gmail.com> > wrote: > > > > I agree, ignore that crazy dude that he is all talk and non sense > excluding the fact the original article uses a graphic he made with love > for Pharo and with over 5 years of active contribution to Pharo > documentation and libraries. OR the fact that he said nothing negative > about Pharo in this thread. > > > > Or the fact that he said that is enternal greatful for Pharo introducing > him to the art and fun of live coding. What's more negative than that , > right ? > > > > On Sat, Oct 7, 2017 at 11:14 AM Stephane Ducasse < > stepharo.self(a)gmail.com> wrote: > > Hi sven > > > > Do the same than me, trash this thread and let us focus on making Pharo > better. > > This is far better productive and energy positive. > > > > Stef > > > > On Sat, Oct 7, 2017 at 12:16 AM, Sven Van Caekenberghe <sven(a)stfx.eu> > wrote: > > > Yes, you are right: Pharo/Smalltalk is more or less the same as > Ruby/Python/C/C++ in terms of power & flexibility of OOP and in live coding. > > > > > > Come on. > > > > > >> On 6 Oct 2017, at 23:18, Dimitris Chloupis <kilon.alios(a)gmail.com> > wrote: > > >> > > >> Wise not to mention Ruby and Python and Pick the worst of the worst > in OOP. Because frankly the competition for Pharo against those two > behemoths can be quite brutal in the flexibility and power of OOP. > > >> > > >> And no , these language can do live coding with ease. I know because > I currently code live coding style with Python for an app I am making. Sure > it wont provide you with a live system out of the box, but put in 10 lines > of code and you already ready to go with hardcore live coding. At least > Python , Ruby being practically a rip off of Smalltalk language may need > even less. > > >> > > >> iPython which by the way is by far the most popular Python tool is > the real deal, a full blow live coding enviroment. > > >> > > >> To my suprise its not even hard to do live coding with C/C++ > including using image format. To my shock live coding is actually supported > by both the OS and the hardware. Hardware has its own exception system , OS > has an image flie format called "memory mapped files" used for DLLs and a > lot of essential functionality. > > >> > > >> For some weird reason however its well hidden and not that much > utilised by coders. They really love long compile times, dont ask me why. > > >> > > >> But yeah C++ even though it has come a long way with its template > system, its still the king of ugly. That sytax, oh the horrors of that > syntax..... yiaks !!! > > >> > > >> I am so enternal greatful that Pharo introduced me to live coding and > opened my eyes to universe of fun and productivity. I cannot imagine coding > an other way ever again. > > >> > > >> I really hope that we take this further though. > > >> > > >> On Wed, Oct 4, 2017 at 1:31 PM horrido <horrido.hobbies(a)gmail.com> > wrote: > > >> Behold Pharo: The Modern Smalltalk > > >> < > https://medium.com/smalltalk-talk/behold-pharo-the-modern-smalltalk-38e132c… > > > > >> > > >> If you would like to suggest some edits, I'm all ears. Anything to > improve > > >> the impact of the article. > > >> > > >> Thanks. > > >> > > >> > > >> > > >> -- > > >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > > >> > > > > > > > > > > >

Oct. 7, 2017