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[Pharo-project] #hasBindingThatBeginsWith:, Shout, E/OCompletion (fwd)
by Levente Uzonyi Oct. 9, 2010

Oct. 9, 2010

I accidentally sent this to the pharo-users list... ---------- Forwarded message ---------- Date: Fri, 8 Oct 2010 23:14:02 +0200 (CEST) From: Levente Uzonyi <leves(a)elte.hu> To: squeak-dev(a)lists.squeakfoundation.org, pharo-users(a)lists.gforge.inria.fr Subject: #hasBindingThatBeginsWith:, Shout, E/OCompletion Hi folks, there's a method called #hasBindingThatBeginsWith: which seems to be used only by Shout. If that's true, then it would be better to add it to the Shout/ShoutCore package if possible. Also this method is responsible for the slowdown of Shout's parser when there are undefined variables in the code. Actually only SystemDictionary >> #hasBindingsThatBeginsWith: is responsible for the slowdown which uses Dictionary's implementation which checks all keys. There's already an issue on Pharo's tracker (with some useful, but with some wrong info too): http://code.google.com/p/pharo/issues/detail?id=1452 . The slowdown affects E/OCompletion more, because those invoke Shout's parser after every keystroke, while Shout uses a background process for parsing. I propose two possible solutions here: 1) Add the following method (+2-3 other, see below): SystemDictionary >> hasBindingThatBeginsWith: aString | className | aString isEmpty ifTrue: [ ^false ]. (self class fastBindingPrefixSearch and: [ aString first isLowercase ]) ifTrue: [ ^false ]. className := self classNames findBinary: [ :element | (element beginsWith: aString) ifTrue: [ 0 ] ifFalse: [ aString < element ifTrue: [ -1 ] ifFalse: [ 1 ] ] ] ifNone: nil. className ifNotNil: [ ^true ]. ^super hasBindingThatBeginsWith: aString How does it work? There are two optimizations. The first checks if the argument's first letter is lowercase. If it's a lowercase letter, then it returns false instead of checking the dictionary. This is the most common case when you're typing methods with undefined local/instance variables. Since this optimization breaks Shout's highlighting when the argument is a prefix of a global that begins with a lowercase letter, there's a boolean preference/setting that enables/disables this optimization (SystemDictionary class >> #fastBindingPrefixSearch). The other optimization uses binary search on SystemDictionary's cached class names, which is a SortedCollection with all the classnames in the system. This helps when you're typing the name of an existing class. Since Shout uses a background process, this is mostly useful for E/OCompletion. When none of these optimizations are usable, the method simply falls back to scanning all keys. Pros: - very simple addition - covers the most common cases Cons: - it doesn't work for all cases - it breaks Shout highlighting a bit 2) Add a new instance variable to SystemDictionary to hold the name of non-class globals, use binary search on both sorted collections: SystemDictionary >> hasBindingThatBeginsWith: aString | name searchBlock | searchBlock := [ :element | (element beginsWith: aString) ifTrue: [ 0 ] ifFalse: [ aString < element ifTrue: [ -1 ] ifFalse: [ 1 ] ] ]. name := self classNames findBinary: searchBlock ifNone: nil. name ifNotNil: [ ^true ]. name := self nonClassNames findBinary: searchBlock ifNone: nil. ^name notNil (for the rest see System-ul.384 in the Inbox for Squeak and http://leves.web.elte.hu/squeak/SystemDictionary.ul.1.cs for Pharo) How does it work? It's just two binary search, one on the class names and one on the non-clas names. This covers all globals (except those which are not in memory (Squeak only)). Pros: - covers all cases with good performance - the new cache can be used to speed up other methods (like #allTraits) Cons: - modifies SystemDictionary I'd go with the second solution. What do you think? Cheers, Levente

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Re: [Pharo-project] XTream was Re: Ocean (was Re: Less plugins, more Smalltalk code!)
by mkobetic＠gmail.com Oct. 8, 2010

Oct. 8, 2010

"Nicolas Cellier"<nicolas.cellier.aka.nice(a)gmail.com> wrote: > More example than the site http://code.google.com/p/xtreams/ ? If so, I'm interested. Not more, but different. For example I'm quite fond of the Morse code decoding example: ('. ... ..- --. -... .- .-. -.-. . .-.. --- -. .- -- -- -..- ' reading transforming: [ :in :out || node beep | node := MorseTree. [ beep := in get. beep = Character space ] whileFalse: [ node := beep = $. ifTrue: [ node at: 3 ] ifFalse: [ node at: 2 ] ]. out put: node first ] ) rest Where MorseTree is (http://en.wikipedia.org/wiki/File:Morse_code_tree3.png) encoded as nested three element arrays: #($ ($T ($M ($O) ($G ($Q) ($Z))) ($N ($K ($Y) ($C)) ($D ($X) ($B)))) ($E ($A ($W ($J) ($P)) ($R () ($L))) ($I ($U () ($F)) ($S ($V) ($H))))) Anyway, I'll send you the PDF directly. > Yes, that makes sense, what I call the Xtreme approach... Less confusion. > However it would be wonderfull to get feedback from average programmer > about this on real application. Not sure what you meant. > Maybe this will be a matter of adding one missing convenient message or two... Yes we can certainly add a package that implements most (maybe all) of the classic API as an extension. But I'd rather keep the Core clean and minimal. This way you have the choice of both. > Of course the best option is to share. Though I don't think Xtream was > developped with portability as main goal, it's not sure it has so many > external dependencies. Yes, we didn't spend much time thinking about portability so far. We rewrote the whole thing bottom up several times trying to get the design right, so we didn't want to be distracted by other concerns. That doesn't mean that we can't focus on that now assuming we're reasonably happy with current design. I don't think there are particular dependencies that are critical to make Xtreams work in general. As long as we can preserve the efficiency, we can certainly make necessary changes. That said, I think we'll just have dialect specific versions of some of the packages. Hopefully Xtreams-Core can be fully portable. Xtreams-Terminals are likely going to be dialect specific. Xtreams-Transforms could probably be portable if we move the VW specific encoding stuff elsewhere. Maybe it can just go into Xtreams-Xtras. It was nice to have the encodings with the core transforms but until we have portable encoders we can just maintain those in dialect specific packages. Something like that. > Is there a tool to identify the dependency on classes outside the package in VW ? Yes there is a tab in the browser that autocomputes prerequisites and a menu option that gives you depenedents if you want the other direction. > We know in advance a few concerning the system, File & Sockets, DLLCC, compression... Yes, I would expect each dialect to have it's own implementation of most of the terminal streams. It might be possible to share some of those, e.g. collection or buffer streams, but given that different dialects have different ways to deal with them efficiently, we may want to have dialect specific implementations anyway. Ultimately, it's fine if different dialects support different set of terminals. There will probably be some that we want everywhere, but maybe it would be great to be able to stream over some Morphs in Squeak or something such. If that's useful, there's no reason not to do it because VW doesn't have Morphic. Anyway, the point is not all the code has to be portable, we can try to share as much as is feasible and have dialect specific implementation of the rest. So at least initially, I'd focus on getting a portable Core and Transforms, with dialect specific Terminals, and we can think about stuff in Xtras later. > Then, there is the question of using Exception handling or not. In > Squeak, this isn't going to be a matter of compatibility (though the > difference might be subtle), rather a matter of efficiency. > However, Incomplete is a corner stone of Xtream implementation if I > understand correctly... > Squeak is not using EndOfStream > http://bugs.squeak.org/view.php?id=6755 and some of the efficiency > reasons are there > http://lists.squeakfoundation.org/pipermail/squeak-dev/2007-November/122434… > > On the other hand, the endOfStreamAction of Squeak_Xtream is pleasant > at first, but hard to handle across wrappers. I don't yet have an > answer whether it scales on a more complete xtream library or not > (thinking of blocking streams...). Yes, this one is tricky. Exceptions cost something in VW as well, so you need to be reasonably prudent with them. As Michael mentioned we've made some serious adjustments in Xtreams earlier this year to avoid triggering Incomplete internally if we could get by without it. See http://www.cincomsmalltalk.com/userblogs/mls/blogView?entry=3445952077 http://www.cincomsmalltalk.com/userblogs/mls/blogView?entry=3448891140 But I think your original argument that in common case the exception should not be triggered frequently is valid. Certainly if you write a micro-benchmark which stacks the odds the other way it will show, but as they say micro-benchmarks are not applications. At the same time consider the cost of not using an exception. Exception allows me to write my algorithm without worrying about the end of stream if I wrap the whole thing in a handler. And the handler is normally located in the right place to handle the end of stream. Without the exception you'll have to add end checks to every single read call of the algorithm. I'm not talking about runtime cost here, I'm talking code complexity. And I don't see how an "end of stream block" makes this much better. The exception allows me to get out of the main body of the algorithm at any of its points, and if the handler exits, the main block gets unwound cleanly. How do I do that with a block that I set on the stream instance? You'd have to carefully structure the code so that the algorithm body is in a method of its own and then there's a dedicated wrapper method around that so that the block can use a side-ways return to exit the method. That is some pretty hideous boiler-plate code, if you ask me.f So, I'm not saying that exception costs are negligible, but there are often ways to minimize them in specific scenarios, often via well designed APIs and patterns (and proper internal implementation). As Michael's posts above show, we were able to match and beat the speed of regular streams in the example without sacrificing the API. At the same time Squeak is getting faster, so I'm not at all convinced that the slow-down factor always does and always will trump the other costs. In fact I feel that it's more often than not the other way around, that the slow down can be made sufficiently small so that it does pay off in terms of code complexity. Maybe some things will always want a stream that doesn't trigger exceptions, but that doesn't mean most things are better off that way. That's just my opinion. Anyway, so far we've been doing quite well in terms of performance without sacrificing exceptions. I'd say let's see if we can keep that track record on Squeak as well. If we find out that it's just not good enough in general case, maybe we'll re-evaluate then. But at this point I'm not convinced that we need to drop the exception to keep Xtreams reasonably usable. Martin

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Re: [Pharo-project] [vwnc] XTream was Re: Ocean (was Re: Less plugins, more Smalltalk code!)
by Nicolas Cellier Oct. 8, 2010

Oct. 8, 2010

Resent, reply to all... 2010/10/9 Michael Lucas-Smith <michael.lucassmith(a)gmail.com>: >> >> Hehe, I've got the feeling to surf on your hard work with low investment ;) >> Xtream ideas should definitly continue to attract. J'espÃ¨re que la >> mayonnaise va prendre. >> Of course the best option is to share. Though I don't think Xtream was >> developped with portability as main goal, it's not sure it has so many >> external dependencies. >> Is there a tool to identify the dependency on classes outside the >> package in VW ? >> We know in advance a few concerning the system, File & Sockets, DLLCC, >> compression... >> With good package delimitation, that can be worked out. > > We divided the Xtreams packages up with this in mind. The Core should be portable, the Terminals are not -- they must be implemented for each platform because they're the ones that use the platform specific objects. > I'm browsing VW right now, at first sight there are not so many uncompatibilities in core, should be solved easily Incomplete>>#raise could be added (#signal in Squeak) #copyEmpty: could be an extension #isFixedArgument not existing in Squeak (external heap notion exists though) Lack of namespace in Squeak shall force use of a prefix (XT ?). Some terminals are generic and should port easily too: BlockClosure/Buffer/Collection For File, assuming they are non blocking, we can arrange a quick hack. For transforms, the StreamEncoder does not exist in Squeak (better not use existing Multilingual, a rewrite will be cleaner). >> The problem with Squeak is that we don't have a good File library (non >> blocking). The good point with Xtream is that we don't need that many >> primitives. >> And last good point is the huge effort you made to coverage tests... >> That should ease porting. > > It's okay if not all terminals and transformation are supported on every platform. We could create a capabilities grid for the different ports to show what can and can't be done. > >> >> Then, there is the question of using Exception handling or not. In >> Squeak, this isn't going to be a matter of compatibility (though the >> difference might be subtle), rather a matter of efficiency. >> However, Incomplete is a corner stone of Xtream implementation if I >> understand correctly... >> Squeak is not using EndOfStream >> http://bugs.squeak.org/view.php?id=6755 and some of the efficiency >> reasons are there >> http://lists.squeakfoundation.org/pipermail/squeak-dev/2007-November/122434… > > Even in VisualWorks Exceptions are expensive. We went to great lengths to make sure the exception mechanism did not fire constantly. We spent several agonizing weeks studying the effects of our implementation on garbage generation and efficiency until we finally arrived at the design we have now. The biggest problems were with substreaming which we eventually solved. > > Michael The simplest thing is just to port a few classes then bench... That's worth a try. Nicolas

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Re: [Pharo-project] XTream was Re: Re: Ocean (was Re: Less plugins, more Smalltalk code!)
by StÃ©phane Ducasse Oct. 8, 2010

Oct. 8, 2010

pay attention that there are two xtreams package frameworks from what I understand one presented at esug and one developed by nicolas Stef On Oct 7, 2010, at 4:58 PM, Sven Van Caekenberghe wrote: > > On 06 Oct 2010, at 08:48, Nicolas Cellier wrote: > >> See also hijacked http://www.squeaksource.com/XTream.html borrowing >> some of the ideas, but somehow less extreme. >> Most packages should now load in Pharo. > > Hi Nicolas, > > I have been looking at the ESUG 2010 slides & google code project pages of xstreams and I must say that I like this very much. > > Your code on SS does indeed load in Pharo 1.1. 8 tests fail out of 37 with errors that I think are probably fixable. I am browsing it now. > > Now my question is, first, do you have some write up somewhere explaining what you did and why, and second, what is the current state of your project and what are your future plans/goals ? > > Thx, > > Sven > > > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

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[Pharo-project] Error: subscript is out of bounds: 2
by HernÃ¡n Morales Durand Oct. 8, 2010

Oct. 8, 2010

Hi all, When I evaluate Compiler compile: '|' in an old version like PharoCore1.1ALPHA #11106 brings a Syntax Error window with the message " |Argument name expected -> " Now in Pharo1.2a #12186 or Pharo1.1rc2 #11400 I get a Debugger with the message "Error: subscript is out of bounds: 2". This happens in latest Squeak too. Apparently the parser is catching the exception but the #notify:at: method is not reading the source contents in a proper way when creating the SyntaxErrorNotification. Is this a known bug? -- HernÃ¡n Morales Information Technology Manager, Institute of Veterinary Genetics. National Scientific and Technical Research Council (CONICET). La Plata (1900), Buenos Aires, Argentina. Telephone: +54 (0221) 421-1799. Internal: 422 Fax: 425-7980 or 421-1799.

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Re: [Pharo-project] Cmd-t in OB?
by StÃ©phane Ducasse Oct. 8, 2010

Oct. 8, 2010

The problem is that with gofer only this is tedious to maintain multiple versions of something. Can somebody take care of the ConfigurationOfOB? Stef > I don't know, I do not maintain them. > > I just realize that people often report bugs that have been fixed a > long time ago. > > I suggest that you always load the latest code using the following script: > > "Refactoring" > Gofer new > squeaksource: 'rb'; > package: 'AST-Core'; > package: 'AST-Semantic'; > package: 'Refactoring-Core'; > package: 'Refactoring-Changes'; > package: 'Refactoring-Critics'; > package: 'Refactoring-Environment'; > package: 'Refactoring-Spelling'; > load. > ! > "OmniBrowser" > Gofer new > renggli: 'omnibrowser'; > package: 'OmniBrowser'; > package: 'OB-Standard'; > package: 'OB-Morphic'; > package: 'OB-Shout'; > package: 'OB-Refactory'; > package: 'OB-Regex'; > package: 'OB-SUnitIntegration'; > load. > ! > "Tools" > Gofer new > renggli: 'unsorted'; > package: 'Shout'; > package: 'ShoutWorkspace'; > package: 'RoelTyper'; > package: 'ECompletion'; > package: 'ECompletionOmniBrowser'; > load. > ! > "Select Tools" > SystemBrowser default: (Smalltalk at: #OBSystemBrowserAdaptor). > > Lukas > > On 8 October 2010 15:09, Alexandre Bergel <alexandre(a)bergel.eu> wrote: >> I did a "ConfigurationOfOmnibrowser project lastVersion load" >> Apparently ConfigurationOfOmnibrowser is not maintained... >> >> Cheers, >> Alexandre >> >> >> On 8 Oct 2010, at 09:03, Lukas Renggli wrote: >> >>> Update, this has been fixed half a year ago :-) >>> >>> Lukas >>> >>> On 8 October 2010 14:58, Alexandre Bergel <alexandre(a)bergel.eu> wrote: >>>> hi! >>>> >>>> When I press cmd-t in an ob browser in the class category pane, I get a window titled "Selected Command". I would expect executing the test of the class category. >>>> >>>> I tried to find out where the "Selected Command" command is defined with: >>>> OBCommand allSubclasses select: [:c | c new keystroke = $t ] >>>> => an OrderedCollection(OBCmdRunTests) >>>> >>>> But apparently only running the test is associated to Cmd-t. >>>> Isn't that convenient to be able to run the test from a class category? >>>> >>>> Cheers, >>>> alexandre >>>> -- >>>> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >>>> Alexandre Bergel http://www.bergel.eu >>>> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >>>> >>>> >>>> >>>> >>>> >>>> >>>> _______________________________________________ >>>> Pharo-project mailing list >>>> Pharo-project(a)lists.gforge.inria.fr >>>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >>>> >>> >>> >>> >>> -- >>> Lukas Renggli >>> www.lukas-renggli.ch >>> >>> _______________________________________________ >>> Pharo-project mailing list >>> Pharo-project(a)lists.gforge.inria.fr >>> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> >> -- >> _,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;: >> Alexandre Bergel http://www.bergel.eu >> ^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;._,.;:~^~:;. >> >> >> >> >> >> >> _______________________________________________ >> Pharo-project mailing list >> Pharo-project(a)lists.gforge.inria.fr >> http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project >> > > > > -- > Lukas Renggli > www.lukas-renggli.ch > > _______________________________________________ > Pharo-project mailing list > Pharo-project(a)lists.gforge.inria.fr > http://lists.gforge.inria.fr/cgi-bin/mailman/listinfo/pharo-project

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Re: [Pharo-project] 12186 image quit problem
by Marcus Denker Oct. 8, 2010

Oct. 8, 2010

On Oct 8, 2010, at 12:39 PM, Pavel Krivanek wrote: > Hi Marcus, > > is that really all what happened between 12172 and 12186? > > update12186 > Issue 3071: fixing timestamp tests > Issue 3068: Non portable SmalltalkImage>>platformName deprecationWarning > Issue 3063: removing explain > Issue 3039: There should not be any configuration on Core > > It doesn't explain the problems with VM versions and in 12186 I cannot build the PharoKernel (it hangs without error in unload phase) > No, we loaded: Issue 3002: A new finalization code ready for integration in Pharo http://code.google.com/p/pharo/issues/detail?id=3002 -- Marcus Denker -- http://www.marcusdenker.de INRIA Lille -- Nord Europe. Team RMoD.

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[Pharo-project] Seaside and KomHttpServer in Pharo 1.2
by Torsten Bergmann Oct. 8, 2010

Oct. 8, 2010

Hi Dale, again I typically use my MetaSource application to see if one can bootstrap a full seaside app in Pharo using Metacello: -------------------------------------------------------------------------- Gofer new squeaksource: 'MetaSource'; package: 'ConfigurationOfMetaSource'; load. ((Smalltalk at: #ConfigurationOfMetaSource) project version: '1.4') load -------------------------------------------------------------------------- Works well in "Pharo 1.1." but not in "PharoCore 1.2": In Pharo 1.2 some methods are deprecated and Seaside 3.0 still uses ConfigurationOfKomHttpServer 1.3 instead of the newer 1.5. So the question is: is it planned to use the newer KomHttpServer packages in the near future for Seaside 3.0 so I can switch to Pharo 1.2 early? Or is this planned when Pharo 1.2 is mature and released. Thx Torsten -- GMX DSL Doppel-Flat ab 19,99 €/mtl.! Jetzt auch mit gratis Notebook-Flat! http://portal.gmx.net/de/go/dsl

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[Pharo-project] UUID and Cog?
by Philippe Marschall Oct. 8, 2010

Oct. 8, 2010

Hi Does anybody know whether UUIDs are supposed to work on Cog on Linux? I got the latest prebuilt Cog from [1] and UUID new crashes my VM with a seg fault on a Monticello commit. I believe it was working before I updated some Linux packages. [1] http://www.mirandabanda.org/files/Cog/VM/VM.r2316/ Cheers Philippe

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Re: [Pharo-project] WebBrowser
by Marcus Denker Oct. 8, 2010

Oct. 8, 2010

On Oct 7, 2010, at 10:49 PM, Alexander LazareviÄ wrote: > 2010/10/7 Torsten Bergmann <astares(a)gmx.de>: >> Dont know why this specific subclass was removed since >> other subclasses of AppRegistry are still in the image >> (like MailSender, SoundService, ...) >> >> Was it by accident or if not what is the idea here. > > It got nuked with > > Name: System-Applications-StephaneDucasse.18 > Author: StephaneDucasse > Time: 11 July 2010, 6:52:54 pm > UUID: 7eb6ce52-4ac4-4523-b44f-eaf822506c76 > Ancestors: System-Applications-StephaneDucasse.14 > > - Issue 2664: empty classes: WebBrowser, SketchMorph, > PasteUpMorphTest, NameOfSubclass, MethodTempsNode > I think I removed it because I removed the code for browsing... with the idea that I am sure nobody needs Scamper these days. But I forgot the external webBrowser stuff. The nice thing is: we can put things back, easily. I think it's better to remove and put back than to never change anything because someone might need it. Marcus -- Marcus Denker -- http://www.marcusdenker.de INRIA Lille -- Nord Europe. Team RMoD.

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