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

[Modeling with Pharo] How to model a simple human interaction.
by sergio ruiz June 10, 2017

June 10, 2017

Hey all.. I got my first paying gig that i am able to use pharo with, and i am on the last leg before calling it complete. Hereâs what I need to do.. This application accepts SMS text messages. It allows the user to send images via MMS and place an order to a print house for those images.. Â it then compiles the order, and submits it to the order processing system and makes the prints. The last thing I need to zero in on is handling the interaction. Believe it or not, I have never modeled such an interaction. The interaction goes: - user sends images{s) - bot says âthanksâ and asks if there are more - user types âdoneâ or sends more - on âdoneâ bot asks for print size - bot says âthanksâ and the interaction is done. order is processed. my first inclination is to use a state machine, progressing through order each time the user enters âdoneâ..Â does this sound reasonable, or is there a better model/design pattern for this interaction? Thanks! ---- peace, sergio photographer, journalist, visionary Public Key:Â http://bit.ly/29z9fG0 #BitMessageÂ BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV http://www.Village-Buzz.com http://www.ThoseOptimizeGuys.com http://www.coffee-black.com http://www.painlessfrugality.com http://www.twitter.com/sergio_101 http://www.facebook.com/sergio101

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using UFFI in non-crashing way
by Peter Uhnak May 7, 2017

May 7, 2017

Hi, is it possible to use UFFI and avoid crashing the image when the called code segfaults? In other words, can I somehow wrap the call and throw in-image Exception/Error on failure instead of the whole thing crashing? Or is the only way to do that have the called thing running as a separate app (e.g. via OSSubProcess) and communicate via pipes or sockets? Thanks, Peter

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Re: [Pharo-users] type checking in Smalltalk
by Dimitris Chloupis April 25, 2017

April 25, 2017

On Thu, Mar 30, 2017 at 5:04 PM Marc Hanisch via Pharo-users < pharo-users(a)lists.pharo.org> wrote: > Hello, > > I have a question which is more related to software engineering than to > Pharo, but I hope that someone can give me an useful hint ;-) > > > Thanks for any advice :-) > Marc > There are three schools of thought Static programming , Dynamic programming and Hybrid Programming *School of Static Programming * The school of Static Programming which has been originating from compiled languages (turn code from source code to machine code before execution) it follows a static approach to the code. This means everything is clearly predefined, planned ahead and follows strict rules. *Pros: * 1) because compilers have specific code that its intentions are clear its much easier for them to optimize performance, hence code tends to run much faster eg C code tends to be 100s to 1000s times faster than Python code 2) Certain bugs can be captured at compile time which makes code safer to deploy to client. The compiler usually can capture such bugs and display relevant warning and errors again because the compiler is more strict to what goes in and what gets out. *Cons:* 1) Changing code on the fly, while the code runs can be notorious hard to do because of these restrictions. This means it does not work well with coders that love to experiment and try new ideas on the fly. 2) Finding bugs also can be harder because of these restrictions, the coder cannot easily change code on the fly on execution and generally the programming language is much less forgiving not only when coding but also when trying to inspect code and debug it. 3) Overall design can be quite ugly in the shake of increased performance and safety and that may affect the design of code as well *School of Dynamic Programming* The school of Dynamic Programming originates from interpreted languages , though modern implementations have compilers that compile source code to byte code and an interpreter that converts byte code to machine code on execution. There is no need for planning ahead in dynamic coding, instead dynamic coding works on the basis of abstractions and its proud to be the father and mother of OOP. OOP is an abstraction based , dynamic coding workflow that dominates dynamic language and even modern statically compiled languages. *Pros:* 1) Code can change on the fly making coding much easier and beginner friendly 2) No need to plan ahead 3) more dynamic workflow also when debugging code that allows to interact and communicate with code real time *Cons:* 1) Performance is sacrificed, thats not obvious for code that executes at once but for code that repeats thousands to millions of times the slow downs depending on the implementation of the language can be anywhere between 10s of times to 1000s of times slower that a static language 2) Using the wrong data / object will not be easily reported beforehand and at times it can be hard to detect such problems. Other bugs can also be hard to be detected even under the use of helping tools that examine and evaluate code because of the generic nature of the code. *Hybrid Programming* Even though static languages give us static programming outside the box and dynamic languages give us dynamic programming outside the box, modern implementation allow for repetitively easily to mix these two workflows. Its also possible for the coder to implement his/her own features with a language. For example C language does not support OOP outside the box, but OOP implementations for C do exist most popular being GObjects used by the GTK+ library C++ and Java although statically typed languages support also more dynamic types through the use of templates and generics Dynamic languages also can come with a variety of tools that perform checks during runtime or even compile time. Also test driven development is very popular for performing this task allowing the coder to create code , launch with a single command thousands of tests and make sure his code passes even more strict guidelines than an average compiler for a statically compiled language. The catch however is that in both cases there are compromises, sub standard implementations and plain weird behavior. *Summary:* *There is no right and wrong, whether we talk about types or other features whether you will follow the dynamic school or the static school is up to you and you preferences.* Both approaches have pros and cons and both will make you waste time while coding. The future however looks more bright and promising for the dynamic school with the rise of AI. Compilers and developer tools in the future may be smarter not only detecting errors and common bugs but actually analyzing coder intentions and even coding philosophies. AI is already used for code analysis but its still on early stage but is none the less our very close future. Funny irony: The most popular scenario for future technology is quantum computing. Hardware by nature is "static" , you have to design it before hand and make sure it works almost perfectly before selling it. This is reflected to the basis of digital architecture where the smaller unit is bit which is always a number and always either 1 or 0. But with quantum computing the bit can inherit quantum properties and be both 1 and 0 at the same time. This will allow in the future for more flexible design of "dynamic" hardware allowing for hardware to also deal with abstractions directly.

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Adding our local hackerspace to Pharo Teachers page
by Offray Vladimir Luna CÃ¡rdenas April 7, 2017

April 7, 2017

Hi :-), We're teaching/learning Pharo in a consistent fashion in our local hackerspace, HackBo in BogotÃ¡, Colombia. Could you please add this line to the Pharo Teachers page: HackBo, Hackerspace en BogotÃ¡, Colombia. http://hackbo.co/ Thanks, Offray

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PetitParser question parsing HTML meta tags
by PAUL DEBRUICKER April 5, 2017

April 5, 2017

This is kind of a "I'm tired of thinking about this and not making much progress for the amount of time I'm putting in question" but here it is: I'm trying to parse descriptions from HTML meta elements. I can't use Soup because there isn't a working GemStone port. I've got it to work with the structure: <meta name="description" content="my description"> and <meta name="Description" content="my description"> but I'm running into instances of: <meta http-equiv="description" content="my description"> and <meta http-equiv="Description" content="my description"> and am having trouble adapting my parsing code (such as it is). The parsing code that addresses the first two cases is: parseHtmlPageForDescription: htmlString | startParser endParser ppStream descParser result text lower str doubleQuoteIndex | lower := 'escription' asParser. startParser := '<meta name=' asParser , #'any' asParser , #'any' asParser. endParser := '>' asParser. ppStream := htmlString readStream asPetitStream. descParser := ((#'any' asParser starLazy: startParser , lower) , (#'any' asParser starLazy: endParser)) ==> #'second'. result := descParser parse: ppStream. text := (result inject: (WriteStream on: String new) into: [ :stream :char | stream nextPut: char. stream ]) contents trimBoth. str := text copyFrom: (text findString: 'content=') + 9 to: text size. doubleQuoteIndex := 8 - ((str last: 7) indexOf: $"). ^ str copyFrom: 1 to: str size - doubleQuoteIndex I can't figure out how to change the startParser parser to accept the second idiom. And maybe there's a better approach altogether. Anyway. If anyone has any ideas on different approaches I'd appreciate learning them. Thanks for giving it some thought Paul

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Smacc debugger
by Stephane Ducasse April 1, 2017

April 1, 2017

Hi where can I load the Smacc gt extension and debugger extensions? Stef

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Morphic component to display images/pictures
by Peter Uhnak April 1, 2017

April 1, 2017

Hi, do we have a Morphic/Brick/whatever component for displaying pictures/images in Pharo? The "best" I found was GTInspector extension on PNG files, which provides scrollbars, however I would like to also have: 1) zooming with mousewheel (now it scrolls vertically) 2) dragging the image around to scroll both vertically and horizontally (now I have to use manually the scrollbars) 3) ideally also buttons like "show 1:1 size", "show fit to window" Do we have something like that? Thanks, Peter

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Voyage, DateAndTime and UTC
by Hilaire April 1, 2017

April 1, 2017

Hi, As far as I see when I store a DateAndTime with local time, "2017-03-31T17:10:46.137086+02:00", then I fetch it back, I got an UTC DateAndTime "2017-03-31T15:10:46.137086+00:00". Am I doing something wrong or do I need to use a mongo description to correct that. But wait, even so, I will not know what was the initial local time. How do you usually deal such issue? Thanks Hilaire -- Dr. Geo http://drgeo.eu

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diff'ing with metacello
by Siemen Baader March 31, 2017

March 31, 2017

Hi all, is there a tool to diff two Metacello versions with different baselines? I tried MetacelloBrowser ( http://www.squeaksource.com/@6xz1bzmNF75EduBA/vZ263dVA) but it does not install on Pharo 5.0. I need it to see what has changed when I install a new release of PharoJS and to bisect in search for regressions. thanks, Siemen

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Re: [Pharo-users] New chapter for new book
by Stephane Ducasse March 31, 2017

March 31, 2017

Marc the full book is available at: https://ci.inria.fr/pharo-contribution/view/Books/job/LearningObjectOriente… On Fri, Mar 31, 2017 at 4:05 PM, Marc Hanisch via Pharo-users < pharo-users(a)lists.pharo.org> wrote: > > > ---------- Forwarded message ---------- > From: Marc Hanisch <marc.hanisch(a)googlemail.com> > To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> > Cc: > Bcc: > Date: Fri, 31 Mar 2017 16:05:11 +0200 > Subject: Re: [Pharo-users] New chapter for new book > Wow, thats amazing! > > Thank you Stephane! > > 2017-03-31 15:51 GMT+02:00 Stephane Ducasse <stepharo.self(a)gmail.com>: > >> Hi >> >> I attached a new chapter for my forthcoming book. >> >> Stef >> >> > >

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