February 2019 - Pharo-users

Re: [Pharo-users] How to write out simple Json?

by Sven Van Caekenberghe

STONJSON toString: { #id->1. #name->'tim' } asDictionary. JSON cannot deal with Associations by themselves. > On 28 Feb 2019, at 14:05, Tim Mackinnon <tim(a)testit.works> wrote: > > I am stumped about how to write out some simple json (for a config file). I didn't think I need Neo, and STONJSON would be fine but it seems like creating items like: > > { 'id'-> self id. 'name' -> self name } > > gives an error about the association. I think you have to do: { ('id'-> self id) asDictionary. ('name' -> self name) asDictionary } everywhereâ¦. > > But when I switch over to NeoJsonWriter it also complains about Assocations too. I just want a simple output like: > { "id" : 12, "name" : "timâ } > > I thought it was simple to do this? Am I missing something obvious. > > Tim

Feb. 28, 2019

How to write out simple Json?

by Tim Mackinnon

I am stumped about how to write out some simple json (for a config file). I didn't think I need Neo, and STONJSON would be fine but it seems like creating items like: { 'id'-> self id. 'name' -> self name } gives an error about the association. I think you have to do: { ('id'-> self id) asDictionary. ('name' -> self name) asDictionary } everywhereâ¦. But when I switch over to NeoJsonWriter it also complains about Assocations too. I just want a simple output like: { "id" : 12, "name" : "timâ } I thought it was simple to do this? Am I missing something obvious. Tim

Feb. 28, 2019

Re: [Pharo-users] Interval form: x to: y when x > y - or how to count down...

by Tim Mackinnon

Hi Richard - but why would you expect 1 to: 0 to give you an empty sequence? If I inspect â0 to: 1â I see: 1 -> 0 2 -> 1 So I would expect â1 to: 0â to see: 1 -> 1 2 -> 0. I asked for a sequence going from 1 down to 0 (in my mind). Knowing about all the by: -1 stuff seems very Câish. Of course, I get that maybe it will break peoples existing code (and maybe that would be why it never gets changed) - but it still feels very strange. Or am I missing something? Tim > On 28 Feb 2019, at 12:38, Richard O'Keefe <raoknz(a)gmail.com> wrote: > > Of the couple of hundred programming languages I have > used, there is precisely one that does what you expect > (the S programming language, as implemented in R). > And it is a major pain in the posterior with no upside > that I can discern. > > Suppose I want a sequence of n consecutive integers > beginning with 1. In Smalltalk, (1 to: n) does the > job. In R, 1:n *almost* does the job. But what > happens when n = 0? Smalltalk gives me the right > answer: an empty sequence. R gives me (1,0). That > means that *every* *flaming* *time* I write > for (i in 1:n) {...} > I have to take special care to ensure that n is not > 0, sometimes even having to whack in an extra > if (n > 0) for (i in 1:n) {...} > > Trawling through my Smalltalk code, I find that about > 6.8% of my counted loops are by: -1, > 0.7% of them are by: a negative number other than -1, > 2.5% of them are by: a positive number other than 1, > 90 % are just to:do: with no by: > Inspecting some of the 90% showed that many of them > would go catastrophically wrong if 1 to: 0 do: > performed its body > > On Sat, 23 Feb 2019 at 03:58, Tim Mackinnon <tim(a)testit.works> wrote: > I've just been caught out with Intervals - why can't you do: > 5 to: 1 do: [ :i | Transcript show: i printString] (eg a negative interval)? > > if you want to iterate down a series of numbers do you really have to do: > 5 to: 1 by: -1 do: [â¦ > > I always assumed that if x > y the step was automatically -1 (but its not). > > I asked on Discord - and someone pointed out that if you use variables it could be ambiguous - but is it really? I donât know if other smalltalks do it this way (I vaguely recall Dolphin going down, but not sure). > > Either way the Interval comment should mention this - and Iâll correct it when I get the wisdom of the crowd here. > > Tim

Feb. 28, 2019

Re: [Pharo-users] Interval form: x to: y when x > y - or how to count down...

by Richard O'Keefe

Of the couple of hundred programming languages I have used, there is precisely one that does what you expect (the S programming language, as implemented in R). And it is a major pain in the posterior with no upside that I can discern. Suppose I want a sequence of n consecutive integers beginning with 1. In Smalltalk, (1 to: n) does the job. In R, 1:n *almost* does the job. But what happens when n = 0? Smalltalk gives me the right answer: an empty sequence. R gives me (1,0). That means that *every* *flaming* *time* I write for (i in 1:n) {...} I have to take special care to ensure that n is not 0, sometimes even having to whack in an extra if (n > 0) for (i in 1:n) {...} Trawling through my Smalltalk code, I find that about 6.8% of my counted loops are by: -1, 0.7% of them are by: a negative number other than -1, 2.5% of them are by: a positive number other than 1, 90 % are just to:do: with no by: Inspecting some of the 90% showed that many of them would go catastrophically wrong if 1 to: 0 do: performed its body On Sat, 23 Feb 2019 at 03:58, Tim Mackinnon <tim(a)testit.works> wrote: > I've just been caught out with Intervals - why can't you do: > 5 to: 1 do: [ :i | Transcript show: i printString] (eg a negative > interval)? > > if you want to iterate down a series of numbers do you really have to do: > 5 to: 1 by: -1 do: [â¦ > > I always assumed that if x > y the step was automatically -1 (but its not). > > I asked on Discord - and someone pointed out that if you use variables it > could be ambiguous - but is it really? I donât know if other smalltalks do > it this way (I vaguely recall Dolphin going down, but not sure). > > Either way the Interval comment should mention this - and Iâll correct it > when I get the wisdom of the crowd here. > > Tim >

Feb. 28, 2019

Re: [Pharo-users] Mac OS X test [ smaller image ]

by CÃ©drick BÃ©ler

I will try to help you there Hilaire too. > Le 27 fÃ©vr. 2019 Ã 17:57, Hilaire <hilaire(a)drgeo.eu> a Ã©crit : > > Hi, > > I have a build script too to build the drgeo bundle from scratch [1], I > will take a look yours to add up. > > In the mean time I built a new mac os bundle with your info.plist. > > I tested it on a mac, but without privilege to move it to the > Applications location. After downloading it to the Desktop folder, I can > experiment: > > 1. Double click on the app does not work Same for me. > 2. From a shell, "Desktop/DrGeo.app/Contents/MacOS/Pharo" starts DrGeo > fine, without error, locale is correctly detected Yes it works but I have this message in the terminal: > 3. Double click again on the app starts it this time, but I got a funny > error message: "error with stdout does not exist, force recursive > file creation, filename Â« stdout" > No it doesnât for me. I have a message saying that the archive is corruptedâ¦ > Can someone with privilege to the Application location, test this new > DrGeo bundle[2]? THANKS ! > > I own you free meals for the help. > > [1] > https://bazaar.launchpad.net/~drgeo-developers/drgeo/trunk/view/head:/build… > > [2] https://www.dropbox.com/s/gbey77opzpw143a/DrGeo-mac-19.03a.zip?dl=0 <https://www.dropbox.com/s/gbey77opzpw143a/DrGeo-mac-19.03a.zip?dl=0> I will try to build it from your script. Cheers, CÃ©drick > > > Le 26/02/2019 Ã 21:09, Christophe Demarey a Ã©crit : >> Basically, it is where you design the UI part of the app. In our case, it is just the menu of the main app. >> >>> I noted the Info.plist is a lot shorter in PharoLauncher compared to the >>> Mac OSX VM zip archive one, though. >>> >>> Any reason? >> I removed useless entries like associations files type / icons >> >> Also, what I pointed is to build a dmg used to deliver the app. >> Building of the application is done through a shell script: https://github.com/pharo-project/pharo-build-scripts/blob/master/build-plat… >> >> you could use it to package your image / vm / ressources in an app bundle. >> >> >> >> > -- > Dr. Geo > http://drgeo.eu > > >

Feb. 28, 2019

Re: [Pharo-users] Why is #findString: in accessing?

by Richard O'Keefe

On Thu, 28 Feb 2019 at 18:59, Richard Sargent < richard.sargent(a)gemtalksystems.com> wrote: > > It's not you would be doing anything new. VA Smalltalk has been doing that > for more and a quarter of a century. > I have Squeak, Pharo, ST/X, GST, VW, VAST, Dolphin, and even Strongtalk. I found the development UI of VAST hard to use for several reasons. It is useful to know which package a method belongs to sometimes, but not having semantic categories is a pain.

Feb. 28, 2019

Re: [Pharo-users] Repeateble URLs - REST?

by Sven Van Caekenberghe

I fully agree with everything Torsten said, but I would like to add a couple of points. It is very easy to add a couple of readable/shareable URL to a classic Seaside app. Here is a simple example: https://audio359.eu/ss/audio359-store?showSKU=sku0101 This jumps right into a web store written in Seaside/Bootstrap (this is #initialRequest: handling special arguments). People also overestimate their need to scale: you can get very far with a classic Seaside app, you just have to know what you are doing. The chance that you will have 1000s or even 100s of (concurrent) users is very small - in B2B even less so. Also, perfect horizontal linear scaling of http web apps does not exist in practice (unless for very simple applications). 9 times out of 10, your users will have to log in, will have preferences/settings, unfinished data structures (shopping cart, ..), and more. All this constitutes your session state. This state must be shared between all workers, which is the big problem. And your web app workers will most probably need to access some shared database as well, which can be a bottleneck as well. You can quite easily scale Seaside using session affinity: your load balancer sends each request from the same client back to the same worker, where its state lives. Hence no need for complex session sharing. When a worker crashes, the client has to log in again and connect to a new worker. You can augment this with minimal session sharing (for example in memcached), so that at least the login and maybe some other essential information is preserved. I have a couple of responsive mobile web apps written with classic Seaside/Bootstrap that perform very well, IMHO. The trick is to make you app fast and do as little work as possible on each interaction. Client side, javascript based web apps are way more complicated, IMO. > On 28 Feb 2019, at 10:04, Torsten Bergmann <astares(a)gmx.de> wrote: > > Hi sergio, > > I like that http://www.bagelconcertfinder.com uses Seaside and also my Twitter Bootstrap Library. > > Seaside by default works with stateful (web) components - making it easy to develop - but possibly hard to scale to be the next Twitter, Amazon, ... ;) > > Seaside usually renders the page on the server and sends the HTML to the client similar to other "old style" web frameworks like JSF who work with server > side rendering. But Seaside also supports building a stateless REST interface using the "Seaside-REST" package [1]. > > Statelessness can help in scaling an APIs to millions of concurrent users - that's why REST is so popular these days. Another reason > is that within a web browser you can do more and more work locally - so it is often appropriate to use a client side framework and talk > to a (REST) API on the server. > > Also a REST interface could open up your application functionality not only to users but also to other software for public consumption or > composing different application functionality into a common usable service. > > One style you can provide it to use the same URL as your HTML interface - so depending on the mime type requested in the REQUEST HEADER > for a GET the > > <SERVER URL>/zipcode/44805 > > could provide either HTML (for a browser) or a JSON (for consumption via an application). This might make sense for data driven pages with > a clear boundary on the data provided and often for data that could be fetched without any authentication or other. > > Often it is better to provide a specific API on a different URL - as this allows to provide authentication to your service and a workflow like style (login on the API, > get or put some data on the server or trigger functionality). Also you can version your exposed API if required. > > Basically you can use whatever backend technology to build your service and expose it via such a REST API. If you use Pharo and want to > provide a "stateless" server interface you can start as many images as you like and scale out with a load balancer in front. > > If you want to have an easy way to do REST with Pharo (without any Seaside magic) then check out the docu and the example on my Tealigh GitHub project on [2]. > Tealight is a lightweight project on top of Teapot to experiment and quickly build a REST interface using pragmas on methods. It is simple to use and > you can build an interface in a few minutes only with the help of Zinc and Teapot/Tealight. > > Also data is usually exchanged using JSON - so Svens NeoJSON for Pharo [3] is something to look at. > > If you work with stateless sessions then often you require a token exchange, so not every call requires a second authentication. This is usually done > using JSON Web Tokens (JWT) and there is a Pharo project for that as well [4]. > > Hope this helps a little bit moving forward. > > Regards > Torsten (aka "astares") > > [1] http://book.seaside.st/book/advanced/restful > [2] https://github.com/astares/Tealight > [3] https://github.com/svenvc/NeoJSON > [4] https://github.com/noha/JSONWebToken > > > Gesendet: Montag, 25. Februar 2019 um 19:12 Uhr > Von: "sergio ruiz" <sergio.rrd(a)gmail.com> > An: "Any question about pharo is welcome" <pharo-users(a)lists.pharo.org> > Betreff: [Pharo-users] Repeateble URLs - REST? > Hi, all.. > > I am looking to have a repeatable url so users can save them and share them.. something like: > > www.bagelconcertfinder.com/zipcode/44805 > > and in my next project, Iâll be doing something like a CMS where you would get: > > /blog_entries/this-is-the-path > > I am thinking of using REST to flesh out the paths.. > > does this seem reasonable? > > ---- > peace, > sergio > photographer, journalist, visionary > > Public Key: http://bit.ly/29z9fG0 > #BitMessage BM-NBaswViL21xqgg9STRJjaJaUoyiNe2dV > http://www.codeandmusic.com > http://www.twitter.com/sergio_101 > http://www.facebook.com/sergio101

Feb. 28, 2019

Re: [Pharo-users] Repeateble URLs - REST?

by Torsten Bergmann

Feb. 28, 2019

Running Pharo under Ubuntu (Windows Subsystem for Linux)

by Christopher Fuhrman

Thanks to Cyril who told me it was possible, I got Pharo 7 Unix running under the Ubuntu 18 that's part of Windows Subsystem for Linux (WSL) in Windows 10. It's not a VM VirtualBox. I documented the install steps on my new blog that uses Jekyll and github pages, which actually took longer to set up than the Pharo under WSL :) The Mesa install step on the blog might be useful for documenting how to get Pharo 7 to work in Ubuntu 18? https://fuhrmanator.github.io/Pharo-in-WSL/

Feb. 28, 2019

Re: [Pharo-users] Why is #findString: in accessing?

by Richard Sargent

On Wed, Feb 27, 2019, 21:50 K K Subbu <kksubbu.ml(a)gmail.com> wrote: > > > On 28/02/19 5:23 AM, Richard O'Keefe wrote: > > > It is surprisingly hard to keep categories consistent. If there is > > a way to say "here I am browsing method M in category G of class C, > > is there an ancestor of C that puts the selector of M in a different > > category?" I would love to know it. (Adding such a code critic to > > my Smalltalk is on the TODO list.) > > > Richard, > > There is Browser>>#categorizeAllUncategorizedMethods that works this way > in Squeak but for uncategorized methods. > > But then, a tag-set would be more useful than just single > categorization. It doesn't matter how accurate a category is, there will > always be someone who will find an equally justifiable reason for > putting a method into a different category ;-). > Or you could model it correctly. Formally define how packages extend classes and allow an arbitrary number of categories for any method. It's not you would be doing anything new. VA Smalltalk has been doing that for more and a quarter of a century. > Is it possible to have a pragma or dummy method (say tags:) to list tags > that could be extracted to facilitate searches? It should not have any > runtime impact. > > Regards .. Subbu > >

Feb. 28, 2019