- Pharo-users - lists.pharo.org

Re: [Pharo-users] What does RMoD stand for?

by Rene Paul Mages (ramix)

Le 07/10/2017 Ã 12:59, horrido a Ã©critÂ : > It is bizarre. Nowhere on the web can I find any reference to what INRIA's > *RMoD* acronym stands for. Please try this request : https://tinyurl.com/INRIA-Rmod -- Amicalement. Rene Paul Mages ( GnuPG_key 1024D/2CC455D9 ) http://www.linux-azur.org/ramix http://blog.pharo.fr http://nosoftwarepatents.wikidot.com

Oct. 7, 2017

Embeddable Smalltalk (was: Re: Behold Pharo: The Modern Smalltalk)

by Herby VojÄÃk

Ben Coman wrote: > Nice article. I like the way you've structured it and pushed the > "updated" angle. > > I feel a bit too strong a claim is laid on Pharo producing the CogVM. > Much of the Cog + Spur + 64bit VM work was originally done for Squeak > with Pharo riding the coat-tails of that work. Lately Pharo community > has been involved in improving VM with hotspot optimisation with Sista > and moving towards making Pharo embeddable.. (@Clement, is "hotspot Hi, this made me curious. I always had the problem with Amber (and, all the rest of Smalltalks in similar vein) that it is hard to use to one-off scripting, as it presumes existence of the not really small class library (objects, classes, collections, etc.). This disadvantaged it IMO in the field of "can I just embed it here and script it with a few lines?" scenarios. Did you (the Pharo community that is "moving towards making Pharo embeddable") find some way to work this around? > cheers -ben Herby

Oct. 7, 2017

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