July 2013 - Pharo-users - lists.pharo.org

About validation
by StÃ©phane Ducasse March 11, 2018

March 11, 2018

Hi I read the chapter on validation of the mentoring course book of andres valloud. http://www.lulu.com/fr/fr/shop/andres-valloud/a-mentoring-course-on-smallta… And I love this extension of SUnit. I loved the idea when I saw it for the first time at Lugano (presentation of Leandro Caniglia). I encourage everybody to read it. Now does anybody implemented in Pharo the SUnit extension? I would like to play with it and eventually write a chapter on it for the next book. The idea is so good. Stef

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Re: [Pharo-users] Slot questions
by Paul Davidowitz June 2, 2015

June 2, 2015

To Camillo Bruni: I'm not using any slot image (I only looked over the paper). According to the Pharo book, 'pvt' should be implemented in the mainstream image. To Marcus Denker: There are actually several methods in the image with the 'pvt' prefix. Please update the doc (Pharo book) to remove talking about 'pvt'. It would have saved me a little headache :)

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funny idea Symbol vs. Selector
by stephane ducasse May 14, 2015

May 14, 2015

Hi guys I'm thinking aloud... I was wondering if we could not take advantage of a new class: Selector. MethodDict would only contain selectors and not symbols. I remember that I talked about that with hernan. Stef

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How do I save contents of Workspace into a collection?
by Frank Church Jan. 31, 2015

Jan. 31, 2015

Hi guys, My images are gathering a number of Workspaces whose contents I don't want to delete. I want to create a collection of Workspace contents along this defintion: Description Date Category Content (the actual text in the Workspace). In the final version I would like to be able to select a workspace and simply click a button or a menu item and get a dialog where I can enter the Description, Category and Date with the Workspace contents automatically captured into a text box. Copying and pasting the contents would be okay to start with. Filing it out would be another aspect later. What kind of array would best suited to the task? There is quite a number of them depicted here: http://www.jmcsweeney.co.uk/computing/m206/collections_intro.php What could be the best way to go about it? For those who are curious I am experimenting with the original ideas of Smalltalk where a computer user would do everything in Smalltalk workspace/desktop. I am intrigued by the possibility and somehow it seems eminently doable. -- Frank Church ======================= http://devblog.brahmancreations.com

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Slots
by Thomas Worthington May 19, 2014

May 19, 2014

I notice that "Slots" are slated for addition in Pharo 3.0. Is there anywhere I can see which model of "slots" is being suggested? I'm not sure that slots, in the sense of Javascript, are a good idea generally and, in the broader context, I'm very unhappy with the idea of messing with Smalltalk's generally clean syntax by adding new language features. Could the desired effects be achieved by subclassing Behavour or somesuch high-level approach? -- Thomas Worthington

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Postmark email library
by Francois Stephany Aug. 31, 2013

Aug. 31, 2013

Hi guys, I've made a simple wrapper around the Postmark API. It lets you send emails without dealing with a SMTP server. You can read about it here: http://developer.postmarkapp.com/developer-libs.html http://developer.postmarkapp.com/developer-build.html and there: http://articles.tulipemoutarde.be/send-email-from-pharo-with-postmark It's pretty simple and naive implementation but it gets the job done. I'll add email attachements when I will need it. Francois

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Ph.D. Student Position on Dynamic Reflective Language Integration with FPGAs for Robotic Applications
by jannik.laval Aug. 21, 2013

Aug. 21, 2013

Dear Smalltalkers, We are searching for a PhD Student. Following you will find the proposal. Best regards, ====== Location: Mines de Douai and ENSTA Brest (France) Advisor and contacts: Noury Bouraqadi, Luc Fabresse, Jannik Laval (car(a)mines-douai.fr, website: http://car.mines-douai.fr/) LoÃ¯c Lagadec (loic.lagadec(a)ensta-bretagne.fr) Profile: the candidate must hold a recent Master of Science degree in Computer Science or Software Engineering and must have solid skills in dynamic reflective language and OOP. Description of the work: The goal of this PhD is to study Smalltalk integration with FPGAs for robotic applications. This integration will enable us get the best from both worlds. Developers are provided with a high-level dynamic reflective language (Smalltalk) for building and debugging their applications. Still, we can have high performances by projecting part of the programs into FPGAs. These reconfigurable hardware chips can achieve performance faster than C programs, while consuming much less energy. The work to do can decompose into the following tasks: -Build reference robotic applications fully in Pharo Smalltalk using actual robots (see http://car.mines-douai.fr/robots/) -Analyze these applications to identify critical parts to project on FPGAs to significantly increase performances (speed, energy) -Do the actual projection to FPGA and evaluate performances of the transformed applications -Generalize the approach and define a methodology for turning Smalltalk code into FPGA -Propose a solution to automate the methodology The Ph.D student will receive a grant which net amount is approximately 1420 euros per month for 3 years (36 months). He will be co-supervised by LoÃ¯c Lagadec from the ENSTA-Bretagne (Lab-STICC, Brest) and Jannik Laval, Luc Fabresse and Noury Bouraqadi from Ecole des Mines de Douai (CAR, http://car.mines-douai.fr/) The first 18th month will be spent in Douai (Lille area), while the last half of the PhD will be spent in Brest. However, during the full 3 years, there will be a strong interaction with co-supervisers from both labs. Bibliography: -A Robust Layered Control System For A Mobile Robot. R. Brooks. IEEE Journal of Robotics and Automation. Vol. 2. Num 1. March, 1985. -RCS: A Cognitive Architecture for Intelligent MultiAgent Systems. J.S. Albus and A. J. Barbera. Proceedings of the 5th IFAC/EURON Symposium on Intelligent Autonomous Vehicles (IAV 2004). Lisbon, Portugal, 2004. -Handbook of Robotics. Bruno Siciliano and Oussama Khatib editors. Springer. 2008. -Multi-Level Simulation of Heterogeneous Reconfigurable Platforms. D. Picard and L. Lagadec. International Journal of Reconfigurable Computing. 2012. -High-level synthesis for FPGAs: From Prototyping to Deployment. Jason cong and stephen neuendorffer and juanjo noguera and kees vissers and zhiru zhang. IEEE Transactions on Computer-aided design of integrated circuits and systems. Vol. 30. Num 4. April, 2011. -The MOLEN Polymorphic Processor. S. Vassiliadis and S. Wong and G. Gaydadjiev and K. Bertels and G. Kuzmanov and E. Moscu Panainte. IEEE Transactions on Computers. 2004. _______________________________________________________ Jannik LAVAL Enseignant-Chercheur TÃ©l. : 03 27 71 26 32 Mines Douai 941 rue Charles Bourseul BP 10838 59508 Douai Cedex _______________________________________________________

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Voyage: Circular references
by Bernat Romagosa Aug. 14, 2013

Aug. 14, 2013

Hi! I'm having an issue I don't recall having had about half a year ago when trying out Voyage. In my schema, a *User* has an *instVar* referencing all the *Center*s he belongs to, and a *Center* has an *instVar* referencing all of its *User*s, so when the Voyage serializer tries to serialize a user (or a center), it goes into an infinite loop trying to find the end of the reference chain and the image clogs. I remember saving the exact same schema a while ago without a problem, is there something new I should know about? BTW, I'm using the #bleedingEdge version, with Magritte3 and all. Thanks! :) -- Bernat Romagosa.

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Git filetree workflow
by joerick Aug. 12, 2013

Aug. 12, 2013

I work on a project that uses smalltalk as a part of a larger system. We version control most of the code (Objective-C, mainly) using Git. Currently the repo has a build script under version control which specifies the monticello package versions to fetch for a given commit. This works okay, and keeps everything in step, but the change histories are in two places (Git and monticello) which is undesirable, and branching/merging is difficult. I'm looking at using filetree (https://github.com/dalehenrich/filetree) to store the smalltalk source in the git repo. I was wondering what the workflow is within the image. Is there an easy way to keep the code on the filesystem in sync with the code in the image? At the moment it seems that there will be a lot of loading/saving in the monticello browser whenever I change code either using git or within the image. For example, do I have to save code out to the filesystem using the Monticello browser, and then inspect the diffs in git? -- View this message in context: http://forum.world.st/Git-filetree-workflow-tp4701465.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

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Pharo 2.0 with Seaside + DBXTalk + GlorpDBX + Magritte 3 + TWBS is getting slower and slower
by phil＠highoctane.be Aug. 4, 2013

Aug. 4, 2013

Hello, I've been loading all of those packages in order to build a full web stack development image. Everything now loads fine and kind of works but... The image is really slowing down and the size is getting very large. Here is the current one: 332580684 29 jul 10:50 Pharo-DripfeedIt-Magritte3-OpenDBX_20130729_1050.image 300+ megs... I've been doing some development in there and started looking for why this was getting so large and slow. I did a SpaceTally print analysis and imported the results in a spreadsheet. Look at the top consumers, especially the Semaphore thing. It is way beyond whatever was expected. There is something wrong there. There must be a leak of Points, MorphExtensions and I can't just figure out why there are so many Floats. I've been running test suites for some of the packages (e.g. OpenDBX and Glorp) and this may be the result. This image is kind of what one doing web dev would end up with. But then, it is very hard to get rid of that unwanted space. I am trying to build a system I can start using for business projects and feel concerned about that memory growth very seriously. Any pointers (I chased some already but here, there are way too many entries); Thx Phil

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Storing test data in methods
by Norbert Hartl Aug. 2, 2013

Aug. 2, 2013

I try to untangle my modules. I have a parser that creates a model and a tool that uses that model. For testing it is convenient to just generate the model and work with it. But this way I introduce dependencies which always pulls everything in. In order to untangle I would need a way to easily serialize the runtime model into methods or something similar. Anything that can be transported via monticello is ok. I just don't want to have dependencies to present of external files. That would just change the problem but not solving it. Any ideas? Norbert

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[DOC] Building and deploying your first web app with Pharo
by Sven Van Caekenberghe Aug. 1, 2013

Aug. 1, 2013

Hi, I wrote a new tutorial, "Building and deploying your first web app with Pharo - Understanding HTTP fundamentals through Zinc HTTP Components". By chronologically following the development process, you will see a small web app growing from something trivial to the final result. Finally, we will save our source code in a repository and deploy for real in the cloud. http://zn.stfx.eu/zn/build-and-deploy-1st-webapp Pharo 2.0/3.0 features such as Nautilus, SmalltalkHub, Metacello Configurations, Zeroconf Scripts and of course Zinc HTTP Components are used while highlighting traditional strengths such as incremental, live & interactive development in a rich environment. Enjoy, Sven PS: Feedback is welcome, the source document lives here https://github.com/svenvc/zinc/blob/master/build-and-deploy-1st-webapp/buil… - pull requests appreciated. -- Sven Van Caekenberghe Proudly supporting Pharo http://pharo.org http://association.pharo.org http://consortium.pharo.org

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Packages ... group view example
by Geert Claes Aug. 1, 2013

Aug. 1, 2013

I know I have seen it somewhere but I can't seem to find it. Can someone point me to an example where the packages are parsed by the "-"? e.g. Dsplayed as: v AST v Core > Matching > Nodes > Parser > Pattern > Tokens > Visitors > Interpreter > Tests Instead of: AST-Core AST-Core-Matching AST-Core-Nodes AST-Core-Parser AST-Core-Pattern AST-Core-Tokens AST-Core-Visitors AST-Interpreter-Core AST-Interpreter-Extension AST-Interpreter-Test AST-Tests-Core Thanks! -- View this message in context: http://forum.world.st/Packages-group-view-example-tp4701657.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

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Pharo performance
by Chris Aug. 1, 2013

Aug. 1, 2013

I've been getting a little concerned with certain aspects of performance recently. Just a couple of examples off the top of my head were trying to do a printString on 200000 floats which takes over 3 seconds. If I do the same in Python it is only 0.25 seconds. Similarly reading 65000 points from a database with the PostgresV2 driver was about 800m/s and only 40 with psycopg. I'd have to try it again but am pretty sure going native was faster than OpenDBX as well. I appreciate Pharo is never going to be able to compete with the static-typed heavyweight languages but would hope we can get performance at least comparable to other dynamic languages :) Is it just that some method implementations are in need of some TLC; more things moved on top of C libraries and primitives and so forth rather than anything with the VM itself? Cheers Chris

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Large images reasons [WAS] Re: Pharo 2.0 with Seaside + DBXTalk + GlorpDBX + Magritte 3 + TWBS is getting slower and slower
by Mariano Martinez Peck Aug. 1, 2013

Aug. 1, 2013

OK, this was was my experiment.... Image fresh with all my app and dependencies loades: 30MB After using it for some days/weeks: 160MB. SpaceTally new printSpaceAnalysis showed: Class code space # instances inst space percent inst average size ByteString 2785 413144 116244078 69.90 281.36 Array 3712 181772 8466668 5.10 46.58 ByteArray 8574 1319 8186802 4.90 6206.82 Bitmap 3653 303 6656340 4.00 21968.12 CompiledMethod 22467 90554 5685374 3.40 62.78 After executing ImageCleaner cleanUpForRelease: 36MB Then...I searched which part of #cleanUpForRelease: was making the difference, and it was: Smalltalk cleanUp: true except: #() confirming: false. So now it was time to know WHICH class did the diference, so I modified #cleanUp: aggressive except: exclusions confirming: aBool in these lines: "Run the cleanup code" classes do:[:aClass| Transcript show: 'Image size before cleaning ', aClass name, ' : ', Smalltalk imagePath asFileReference size asString. aClass cleanUp: aggressive. 3 timesRepeat: [Smalltalk garbageCollect]. Smalltalk snapshot: true andQuit: false. Transcript show: 'Image size after cleaning ', aClass name, ' : ', Smalltalk imagePath asFileReference size asString. ] displayingProgress: [:aClass| 'Cleaning up in ', aClass name]. I then opened a Transcript, and evaluated Smalltalk cleanUp: true except: #() confirming: false. I went to prepare Mate, and when I come back, the result was, of course: "Image size after cleaning MCFileBasedRepository : 39744008" That clean up ends up doing: flushAllCaches self allSubInstancesDo: [:ea | ea flushCache] So it sends #flushCache to all instances of MCHttpRepository and MCFileBasedRepository. Now what I wanted to see if it there was a particular repo that could take most of the space (like package-cache). And indeed, it was...I modified #flushCaches to: flushAllCaches | file | file := 'repos.txt' asFileReference writeStream text. self allSubInstancesDo: [:each | file nextPutAll: 'Image size before cleaning ', each printString, ' : ', Smalltalk imagePath asFileReference size asString; cr. each flushCache. 3 timesRepeat: [Smalltalk garbageCollect]. Smalltalk snapshot: true andQuit: false. file nextPutAll: 'Image size after cleaning ', each printString, ' : ', Smalltalk imagePath asFileReference size asString;cr. ]. file flush; close. And then I looked in the 'repos.txt' file. My package cache repo cleaned 60 MB. Glorp cleaned 35MB. Seaside30 cleaned 10MB. So...cleaning cache of just 3 repos frees approx 100MB. The question is....can we flush the cache safely? If they are called "cache", then I guess yes, we can. Thoughts? Thanks, On Wed, Jul 31, 2013 at 10:48 AM, Mariano Martinez Peck < marianopeck(a)gmail.com> wrote: > Guys, I have images also with seaside, magritte, glorp, postgresV2, etc > and it is also around 200MB. > I will try to do some research today and let you know. > > Cheers, > > > On Tue, Jul 30, 2013 at 8:55 AM, Marcus Denker <marcus.denker(a)inria.fr>wrote: > >> >> On Jul 30, 2013, at 1:49 PM, "phil(a)highoctane.be" <phil(a)highoctane.be> >> wrote: >> >> > the changes file contained passwords and I replaced the text. So >> offsets may be wrong due to that. >> > >> Yes, the first thing I wanted to do is to recompile everything. Does not >> work. >> >> > Memorymonitor is not doing fanct stuff. It just counts instances. >> > >> Yes, but maybe it holds on to these instances? >> >> Marcus >> >> >> > > > -- > Mariano > http://marianopeck.wordpress.com > -- Mariano http://marianopeck.wordpress.com

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RFB on 2.0 + linux - semaphore primitive failed
by Paul DeBruicker July 31, 2013

July 31, 2013

Hi - In Pharo2 do I need to stop and start the RFB server? I 've been getting a primitive #signal in Semaphore failed error after the image starts. I'm using this version of RFB RFB-MarianoMartinezPeck.41 Thanks Paul

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[ANN] Pharo 2 Summer released
by Esteban Lorenzano July 31, 2013

July 31, 2013

The Pharo Team is happy to announce the Pharo 2 Summer release, the regular half of the year bugfix edition. For this version, we incorporated really few changes since 2.0 was a really successful release. Anyway, we managed to sneak in a couple of minor additions: - Integrated ProfStef - Updated Configurations Browser Also, we integrated 42 bugfixes, 20 of them backported from 3. 0 alpha. As always, Summer edition can be downloaded at: http://www.pharo-project.org/pharo-download We want to thank to all members of the community for their help and support and specially to all who submitted the reports, fixed the bugs and tested them. The Pharo Team List complete of bugfixes and backports: =============================== Fixed: -------- 7345 DNU with Glamour: PaginatedMorphTreeMorph>>setSelectedMorph: https://code.google.com/p/pharo/issues/detail?id=7345 10014 World menu > System > Switch User serves no purpose https://pharo.fogbugz.com/f/cases/10014/World-menu-System-Switch-User-serve… 10004 SmalltalkImage current reportCPUandRAM > DNU https://pharo.fogbugz.com/f/cases/10004/SmalltalkImage-current-reportCPUand… 10017 ProtocolCLient do not propagate the erros from the server https://pharo.fogbugz.com/f/cases/10017 7627 FileReference>>deleteAll follows symlinks https://pharo.fogbugz.com/f/cases/7627 10027 Failing Test: FileReferenceTest>>#testDeleteAl https://pharo.fogbugz.com/f/cases/10027 10123 Bug in warning in CriticBrowser https://pharo.fogbugz.com/f/cases/10123 10196 Change shortcuts default settings of 2.0 to the traditional ones https://pharo.fogbugz.com/f/cases/10196 10195 Replace ugly Keymappings API on:do: https://pharo.fogbugz.com/f/cases/10195 10200 Date instances dayOfWeek wrong https://pharo.fogbugz.com/f/cases/10200 10109 MNU : SmalltalkEditor>>browseItHere: https://pharo.fogbugz.com/f/cases/10109 10394 Duplicated instance #model in NewList (already defined in MorphicModel) https://pharo.fogbugz.com/f/cases/10394 10336 Port 2.0: Document difference between TextModel and TextInputFieldModel https://pharo.fogbugz.com/f/cases/10336 10653 Some Jenkins images show a stdout is closed error https://pharo.fogbugz.com/f/cases/10653 10653 Some Jenkins images show a stdout is closed error https://pharo.fogbugz.com/f/cases/10653 10415 Integrate 2.0: 10411 flush after nextChunkPut: https://pharo.fogbugz.com/f/cases/10415 10888 Backport 2.0: Compound Extension Methods Unpackaged https://pharo.fogbugz.com/f/cases/10888/Backport-2-0-Compound-Extension-Met… 10730 Fix for stack serialization with Fuel https://pharo.fogbugz.com/f/cases/10730/Fix-for-stack-serialization-with-Fu… 10946 HistoryCollection package is empty https://pharo.fogbugz.com/f/cases/10946 11101 fileOutMethod:on: uncategorized in 2.0 https://pharo.fogbugz.com/f/cases/11101 11179 Config browser buttons broken due to missing method https://pharo.fogbugz.com/f/cases/11179 10860 option click on list in TestRunner and others: freeze system https://pharo.fogbugz.com/f/cases/10860 Backported: ---------------- 10194 Backport to 2.0: special objects array recreation crash https://pharo.fogbugz.com/f/cases/10194 10185 Backport 2.0: 10173 ClassBuilder cannot safely modify a class why using it https://pharo.fogbugz.com/f/cases/10185 10174 Backport 2.0 Issue 10162: multiple selection of methods in method pane ... https://pharo.fogbugz.com/f/cases/10174 10249 Backport 2.0: Red Light when all test are green https://pharo.fogbugz.com/f/cases/10249 10230 backport 2.0: 10229 Fix sender of #copyWithTempsFromMethodNode: https://pharo.fogbugz.com/f/cases/10230 10179 backport 2.0: 10038 Wrong deprecated message https://pharo.fogbugz.com/f/cases/10179 10260 backport 2.0: 10258 DivideByZero in SystemProgressMorph https://pharo.fogbugz.com/f/cases/10260 10406 backport 2.0: 5819 Implement a way to get the user directories based on the current OS https://pharo.fogbugz.com/f/cases/10406 10396 backport 2.0 10395 DNU SmallInteger>>#add: when loading metacello configuration https://pharo.fogbugz.com/f/cases/10396 10387 backport 2.0: 10102 SocketStream>>next: should not signal ConncetionClosed https://pharo.fogbugz.com/f/cases/10387 10311 Backport 2.0: 10228 Fix tab key for autocompletion https://pharo.fogbugz.com/f/cases/10311 10537 Backport 2.0: StartupPreferences interferes with zeroconf pharo binary https://pharo.fogbugz.com/f/cases/10537 10938 backport 2.0 : an MCOrganizationDefinition should only remove empty categories during unload https://pharo.fogbugz.com/f/cases/10938 10909 Backport Pharo2.0: Prepare isHeadless for new VMs with double dash -- arguments https://pharo.fogbugz.com/f/cases/10909 10994 Backport 2.0: Delays do not work properly directly on image startup https://pharo.fogbugz.com/f/cases/10994/Backport-2-0-Delays-do-not-work-pro… 10931 Backport 2.0: Filing out extension package in Nautilus produces empty file https://pharo.fogbugz.com/f/cases/10931 10978 Backport 20: ZipArchive utf8 handling https://pharo.fogbugz.com/f/cases/10978 11125 backport 2.0: 10859 Monticello freezing the image https://pharo.fogbugz.com/f/cases/11125 10569 Backport 2.0: Better Interrruptionche https://pharo.fogbugz.com/f/cases/10569 10940 Backport 2.0: 10925 Use caching in Gofer https://pharo.fogbugz.com/f/cases/10940 11252 backport 2.0: have SliceMaker use fogbugz https://pharo.fogbugz.com/f/cases/11252

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Garbage collector & Memory Profiling
by Alejandro Infante July 31, 2013

July 31, 2013

Hello, We are currently working on memory profiling and we are having troubles to detect when an object is garbage collected. Any ideas? Thanks for the help, Alejandro Infante

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[ann] a snappier snapshotcello
by Tudor Girba July 30, 2013

July 30, 2013

Hi, A new version of Snapshotcello is now reachable from your Pharo 2.0 image. Besides snapshotting the current version, you now get the possibility of: - marking the new version as stable, - committing the configuration package, and - pushing the package to the official Pharo repository. Here is an example: Snapshotcello new configurationClass: ConfigurationOfSnapshotcello; sourceVersion: #development; targetVersion: '1.4-snapshot'; snapshot; makeStableFor: #'pharo2.x'; commit; pushToPharo20Repository A more detailed description can be found here: http://www.tudorgirba.com/blog/snappier-snapshotcello We can certainly improve this, and it would be great to have a similar mechanism integrated into Metacello. But, in the meantime, I find myself for the first time literally one do-it away from distributing projects that are developed without much constraints. Cheers, Doru -- www.tudorgirba.com "Every thing has its own flow"

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Little tutorial on customizing zero conf scripts
by Guillermo Polito July 30, 2013

July 30, 2013

Hey guys! inspired by the work of Camillo and Andrei customizing the ZeroConf scripts for moose, I did the same for my phd project and wrote a little tiny shy tutorial about it. http://playingwithobjects.wordpress.com/2013/07/30/customizing-zeroconf-scr… Hope it's helpful for somebody :) Guille

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Bug in Date>>readFrom:pattern: ? Pharo2.0
by Sabine KnÃ¶fel July 30, 2013

July 30, 2013

Hi, Date readFrom: '4.2.13' readStream pattern: 'd.m.yy' Does not return 4.2.2013 but 4.2.0013 The comment is saying "A year given using only two decimals is considered to be >2000" So, the comment is not ok or this is a bug? Sabine -- View this message in context: http://forum.world.st/Bug-in-Date-readFrom-pattern-Pharo2-0-tp4700427.html Sent from the Pharo Smalltalk Users mailing list archive at Nabble.com.

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Re: [Pharo-users] Pharo performance
by Mariano Martinez Peck July 29, 2013

July 29, 2013

I forward Nico's answer because he is not in the mailing list. On Mon, Jul 29, 2013 at 6:12 PM, Nicolas Cellier < nicolas.cellier.aka.nice(a)gmail.com> wrote: > First thing, printing a Float correctly is a difficult task. > > Let's remind the requirements for a decimal printString: > 1) every two different Float shall have a different printString > representation > 2) the printString should be re-interpreted as the same Float > 3) the printString should be the shortest decimal that would be > re-interpreted as the same Float > > Requirement 2) is stronger than 1), and 3) is stronger than 2). > For a REPL, we at least want 2) > > If we restrict to requirement 2) then we can simply use printf with 17 > decimal digits to accelerate printString. > But then we must expect 0.1 to be printed '0.10000000000000001' or > something like that, an awfull thing for a REPL > > Requirement 3) is stronger than 2) and it nicely gives 0.1 printString -> > '0.1' > This is what Python Java Scheme and maybe some other languages do. > > Squeak/Pharo did implement 3) for long by using the algorithm of Scheme, > absPrintExactlyOn:base: > It is a relatively easy naive implementation using LargeInteger arithmetic. > But it did not use it by default, which made Squeak/Pharo not even > respecting requirement 1) > So all I did was to make this algorithm the default choice (and maybe > correct some edge cases, can't remember). > > But LargeInteger arithmetic is relatively slow (compared to SmallInteger / > Float arithmetic). > So I have done plenty of things to try and (marginally) accelerate > printString. > But allmost all should already be integrated in Pharo. > > My last experiments consisted in rewriting some LargeInteger primitives to > use 32 bits digits instead of 8 bits digits. > This work is mostly ready. I personnally exclusively work with such > modified VM. > Only ImageSegment support on BigEndian VM is lacking, but this should > hardly be a problem for Pharo. > It has not been integrated, but again the acceleration of Float > printString is marginal. > > Maybe it could be accelerated with a primitive, but this will be a tough > task. > > In presence of identified bottleneck, the questions are: > a) can we use a binary format ? > b) can we use another exact representation (like hexadecimal printString > of float bits for example, or C printf %a format...) > c) can we use a degraded solution 2) (printf with 17 decimals) > d) can we afford an inexact representation not satisfying 1)-2)-3) > To me, it depends mostly on usage. a) and b) are not for human end-user > for example, but is a human going to grok Giga-Floats ? > a) and b) might be solutions for serialization, but it mostly depend on > the other end. > It must be an application specific decision > > Maybe a support for solution b) and c) could help. > > Nicolas > > > 2013/7/29 Mariano Martinez Peck <marianopeck(a)gmail.com> > >> I remember Nicolas Cieller did something about improving performance of >> Float printing. >> Not sure what is the state yet.... >> >> >> >> >> On Mon, Jul 29, 2013 at 4:50 PM, Chris <cpmbailey(a)btinternet.com> wrote: >> >>> I often use the profiler :) >>> >>> The float printString is all fairly evenly split which is why I mention >>> about whether another implementation may be required. I'll always raise >>> anything much more obvious that I see! >>> >>> Hi Chris, >>> >>> My recommendation in this case is always do not spend a single second >>> trying to figure out what is the bottleneck by yourself. First thing ever >>> to do, is to run a profiler. You can do that very easily in Pharo. >>> >>> TimeProfiler spyOn: [ Transcript show: 'do something for real here to >>> benchmark'. >>> Object allSubclasses. ] >>> >>> replace the closure for what you want to benchmark. >>> >>> Then, share with us if you have interesting finds.... >>> >>> Cheers, >>> >>> >>> >>> On Mon, Jul 29, 2013 at 3:52 PM, Chris <cpmbailey(a)btinternet.com> wrote: >>> >>>> I've been getting a little concerned with certain aspects of >>>> performance recently. Just a couple of examples off the top of my head were >>>> trying to do a printString on 200000 floats which takes over 3 seconds. If >>>> I do the same in Python it is only 0.25 seconds. Similarly reading 65000 >>>> points from a database with the PostgresV2 driver was about 800m/s and only >>>> 40 with psycopg. I'd have to try it again but am pretty sure going native >>>> was faster than OpenDBX as well. I appreciate Pharo is never going to be >>>> able to compete with the static-typed heavyweight languages but would hope >>>> we can get performance at least comparable to other dynamic languages :) Is >>>> it just that some method implementations are in need of some TLC; more >>>> things moved on top of C libraries and primitives and so forth rather than >>>> anything with the VM itself? >>>> >>>> Cheers >>>> Chris >>>> >>>> >>> >>> >>> -- >>> Mariano >>> http://marianopeck.wordpress.com >>> >>> >>> >> >> >> -- >> Mariano >> http://marianopeck.wordpress.com >> > > -- Mariano http://marianopeck.wordpress.com

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[Voyage] Using OID as a domain object identifier
by Esteban A. Maringolo July 29, 2013

July 29, 2013

Hi all, Is it a good practice to use the OID value (anInteger) as an "external" identifier of your domain object? Let's suppose I have a collection of "People", as I save them in the collection, it will automatically create OIDs for them. But let's suppose I want to map that person to a RESTful URI, would it be "legal" to use its OID as part of the URI? E.g. mydomain.com/people/123456790 where 123456790 is the OID value. I like OID/UUIDs, and I don't want to duplicate that logic in my app. Regards, Esteban A. Maringolo

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Unix Domain Sockets
by Pierce Ng July 28, 2013

July 28, 2013

Hello, I want to share that I wrote a blog post on using Unix domain sockets in Pharo. http://samadhiweb.com/blog/2013.07.27.unixdomainsockets.html The NetNameResolver bits can be made more Smalltalk-ish. Also, I'll be looking into the minor changes needed to support SocketStream as well. Maybe this is the wrong list to ask, but how do I contribute this to Pharo? Cheers. -- Pierce Ng http://samadhiweb.com/blog/

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Fun with symbols
by jannik.laval July 28, 2013

July 28, 2013

Hi guys, Something I did not know and I would like to share: what is the result of "#a < #9" ? DNU ! When I expected to compare two symbols, in fact "#9 class" returns SmallInteger. So if I want to compare two symbols, I have to do "#a < #'9' ". Kind of small fun things ! Cheers, Jannik

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