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

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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HTTP Header field handling in Zinc
by Udo Schneider July 27, 2013

July 27, 2013

All, Is there a supported way to change the capitalization of HTTP header fields in Zinc? I'm currently running into problems with a websocketpp (https://github.com/zaphoyd/websocketpp) based backend which expects a specifically capitalized Sec-WebSocket-* header field. E.g. Sec-WebSocket-* works, Sec-Websocket-* does not. As far as as I can see Zinc nicely capitalizes HTTP header fields. E.g. even if you provide "Sec-WebSocket-Key" the actual transmitted header is "Sec-Websocket-Key". I know that HTTP specified that header fields are case-insensitive. So problem is clearly on the websocketpp side. I just want to know if I can somehow instruct Zinc to not touch the capitalization to make working with non-compliant backends easier. Thanks, Udo

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GitHub
by phil＠highoctane.be July 27, 2013

July 27, 2013

What exactly is https://github.com/pharo-project about ? It is to test the Monticello Git integration? Give visibility to Pharo? I also see Pharo-VM. Is this the reference repository for the VM? (which used to on Gitorious for the OSX code I know about). Thanks. Phil

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[Smalltalks 2013] --- Invitation
by Andres Valloud July 26, 2013

July 26, 2013

The FundaciÃ³n Argentina de Smalltalk (FAST, http://www.fast.org.ar) invites you to the 7th International Conference on Smalltalk Technologies (Smalltalks), to be held from October 30th through November 1st at the Universidad TecnolÃ³gica Nacional, Facultad Regional Rosario, located in Rosario, Argentina. Everyone, including teachers, students, researchers, developers and entrepreneurs, are welcome as speakers or attendees. Registration is free and now open at http://www.fast.org.ar/smalltalks2013. This year we are accepting donations from participants to help fund the conference's costs. Please see the Donate section at FAST's website, http://www.fast.org.ar/smalltalks2013/donate. Contributions are greatly appreciated, and can be received both in pesos for local attendees, as well as via Paypal for those coming from abroad. Donors will receive a set of thank you gifts as well as the conference's shirt. The goal of the Conference is to strengthen the bonds between the Argentine and the international Smalltalk community through the exchange of works, experiences and anecdotes connected with this technology and related matters. As in the previous editions, renowned members of the international Smalltalk community will visit us, and like last year we will have a Research Session with publications reviewed by an international committee. Also, the traditional Industry Track will be available for those who prefer a more practical environment. You can submit papers or talks now through our website at http://www.fast.org.ar/smalltalks2013/technical-session The Industry Track's submission deadline is October 7th. For more information about related events, such as a Pharo Sprint or talks and presentations around the dates of the conference, please visit http://www.fast.org.ar/smalltalks2013/events We will update related event information as we get closer to the conference, so please check for updates. As in previous years, we will have a social dinner during the conference. If you are planning to attend, please reply to this email with a subject of "[Social Dinner]" and indicate how many people will be coming in your party. We will have a variety of dishes available for everyone. If you have special needs other than vegetarian dishes, please let us know. For any additional questions please contact us at info(a)fast.org.ar. See you there!

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Units package
by phil＠highoctane.be July 26, 2013

July 26, 2013

In my application, I need to work with units (which I have to integrate in Seaside-Magritte 3). So, I looked around and after a while found http://www.smalltalkhub.com/#!/~MarcusDenker/Units Tests are green on 2.0 and it looks like it will do what I need. Pretty cool package, worth a chapter somewhere. Is there any doc on this except the code itself? Phil

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Your vm is too oldâ¦.
by Norbert Hartl July 25, 2013

July 25, 2013

As I cannot work with the pharo VM right now I'm back to use Eliots Cog. But If I open a more recent image it complains about my vm being to old. What does it really check in order to complain? Some just version string/number parsing? Is it always sever? Norbert

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