December 2019 - Pharo-users

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by Ben Coman

On Wed, 18 Dec 2019 at 16:12, Steve Davies <steve(a)connection-telecom.com> wrote: > Hi, > > I'm having yet another go to get to grips with Pharo. > > My project is for home automation. It seems in principle a great match > since object inside Smalltalk are obviously a great match for physical > objects being controlled. > > I started at the Pharo Wiki on Github "Setting up a new project". > > I'm a career programmer but I'm nearly 60 and sadly I can't absorb > information like I used to be able to, and I'm just finding Pharo so > overwhelming - I feel like a maintenance programmer trying to find a way > into a million lines of code when you don't understand the principles of > organisation and the conventions of the developers. > Consider the analogy would be someone wanting to write Hello World as a newcomer in C and having the source code for the Eclipse IDE in front of them and feeling like they have to understand all of that source code before writing Hello World. Just because because the code for the whole Pharo IDE system is front of you doesn't mean you should feel need to understand it all at once, or even ever. But I remember a similar initial jarring of my workflow before developing a constructive-ignorance mindset. Is there no way to have some sort of "progressive revelation" of the > insides of Pharo? Just documentation on most classes, examples of how to > use the class, without the implementation being exposed initially? > The books and MOOC are probably the best for this https://pharo.org/documentation For something a bit more goal oriented, try Exercism... https://exercism.io/tracks/pharo-smalltalk The stuff I need to look into for my project is mixed in with 1000s of > classes that I (hopefully) can ignore for now - but there seems to be no > way to hide away all the irrelevant stuff. > > Traditionally if I was trying to get to grips with a large unfamiliar code > base I would use grep to search, skim through source files getting a sense > of it. With the browser in Pharo I feel like I'm looking through a > keyhole. No doubt this is just unfamiliarity and I just need to learn the > tools better. > A few things I find useful are: * In the class definition, select a variable the right-click-it > Code Search > References to it * In the Browser, select a class, right-click-it > Class Refs to find some unit tests using it, then debug-into those tests. * Make heavy use of Senders and Implementors to find examples of how things are used. * Add "self haltOnce" into methods so you can observe the call stack of how they are used. Note: "self halt" can be dangerous in system methods you're not familiar with, in case that method is used by the UI loop. haltOnce effectively stops the current UI loop and spawn a new UI loop to keep working. Personally I find it easier to understand the Pharo libraries by watching them run in a debugger than perusing static code. I'm looking forward to trying out the new object-centric-debugging... https://www.youtube.com/watch?v=uDYJIm54yE4 Please read this as a request for help as to how to get a finger hold and > how to shake this feeling of drinking from the firehose? It's not intended > as a complaint. > Cool. It does read that way. Happy to help you settle in. cheers -ben >

Dec. 18, 2019

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by Ben Coman

On Wed, 18 Dec 2019 at 23:05, ponyatov <dponyatov(a)gmail.com> wrote: > I'm speaking about 20K SRAM computers and Java-only services. FFI and VMs > do > not matter here. > Ahh, got it. Pharo's never going squeeze down to a 20K device, but I think its feasible for our StackInterpreter VM to be ported to the ESP32 microprocessor (https://www.sparkfun.com/products/13907) Oh if I had the time... And these devices get more powerful and cheaper every year. Maybe we will get there. cheers -ben

Dec. 18, 2019

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by ponyatov

I'm speaking about 20K SRAM computers and Java-only services. FFI and VMs do not matter here. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Dec. 18, 2019

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by Ben Coman

On Wed, 18 Dec 2019 at 20:06, ponyatov <dponyatov(a)gmail.com> wrote: > Hello, colleague. > > I'm also working in the same domain, primarily on the target of adapting > the > Actor model (async distributed messaging) for IoT systems in a wide: from > deeply embedded nodes to top-level north-side cloud cervices. > > I like Pharo as a workstation system and IDE, but I'm not looking Pharo as > a > self-hosted platform for my needs. The problem is all IoT infrastructure it > tightly bound with low-level C for nodes and Java for top-side. There are > dozens and hundreds of existing projects, firmware source codes, platforms, > etc which I must integrate with as is. > > As you know, Smalltalk is well known as bad in interaction with other > existing projects, Historically that was true, but Pharoers saw interaction with the outside as a gap they had to close and third party libraries are not hard to use via FFI.. Here is one small example of my own making calls into the LibSodium crypto library. https://github.com/Traadh/bittrex/search?q=ffi&unscoped_q=ffi If anybody doubts, try to use it the same way as > Lua engine: embed into existing C#/Java project, Embedding Pharo is getting better now that we have a headless VM http://forum.world.st/ANN-Pharo-Headless-Beta-Actually-what-is-between-Alph… able to use an external library like GTK3 for its graphics backend. > or bind it with any > randomly selected C++ library in a click, like Qt, LLVM, wxWidgets or > something fat like this. > Can you link to some info/tutorial on such one-click binding. What workflow should Pharo be trying to emulate? cheers -ben

Dec. 18, 2019

Re: [Pharo-users] Question on MetaLink: access to the calling MessageNode from a MethodNode

by Marcus Denker

> On 18 Dec 2019, at 14:06, Mehrdad Abdi <newmrd(a)gmail.com> wrote: > > Hello > > For a specific method, I need to log some information when the method is called, like the state of the receiver, values of arguments, where the method is called, ... . > > Using following MetaLink, Iâm able to capture the receiver and arguments and context. > > link := MetaLink new > metaObject: self; > selector: > #linkBeforeMethodArguments:receiver:selector:context:; > control: #before; > level: 0; > arguments: #( arguments receiver selector context ). > aMethod := MyClass methodNamed: #myMethodArg1:arg2. > aMethod ast link: link > > For capturing the information related to where this method is called, It's possible to extract it from Context, but itâs a dirty way. > Is there any way to access the MessageNode which called this MethodNode? > No, the information is only available via the contextâ¦ even the #sender reification is internally is compiled to "thisContext sender receiverâ. You could add your own reification (that is a class similar to RFSenderReification and implement your own âsendingMethodNodeâ reification, but this would just make it look nicer, not be different from an implementation point of viewâ¦ Marcus

Dec. 18, 2019

Question on MetaLink: access to the calling MessageNode from a MethodNode

by Mehrdad Abdi

Hello For a specific method, I need to log some information when the method is called, like the state of the receiver, values of arguments, where the method is called, ... . Using following MetaLink, Iâm able to capture the receiver and arguments and context. link := MetaLink new metaObject: self; selector: #linkBeforeMethodArguments:receiver:selector:context:; control: #before; level: 0; arguments: #( arguments receiver selector context ). aMethod := MyClass methodNamed: #myMethodArg1:arg2. aMethod ast link: link For capturing the information related to where this method is called, It's possible to extract it from Context, but itâs a dirty way. Is there any way to access the MessageNode which called this MethodNode? Best regards, Mehrdad

Dec. 18, 2019

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by ponyatov

Hello, colleague. I'm also working in the same domain, primarily on the target of adapting the Actor model (async distributed messaging) for IoT systems in a wide: from deeply embedded nodes to top-level north-side cloud cervices. I like Pharo as a workstation system and IDE, but I'm not looking Pharo as a self-hosted platform for my needs. The problem is all IoT infrastructure it tightly bound with low-level C for nodes and Java for top-side. There are dozens and hundreds of existing projects, firmware source codes, platforms, etc which I must integrate with as is. As you know, Smalltalk is well known as bad in interaction with other existing projects, due to its architecture mostly close to the guest OS but not a programming language. If anybody doubts, try to use it the same way as Lua engine: embed into existing C#/Java project, or bind it with any randomly selected C++ library in a click, like Qt, LLVM, wxWidgets or something fat like this. The way looks me affordable to survive Smalltalk as a development platform is metaprogramming = code generation. We can build a domain model of the system we want to build (and integrate) and next generate C(++) source code by transpiling this model to the required target language. The Pharo gives as a very comfortable environment for model transformations, playing with transpilation and generic knowledge representation, and at the same time, it will not be involved in a target system we build. -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

Dec. 18, 2019

Re: [pharo-project/pharo] Proposed improvement : performance of #atRandom: in class Bag (#5392)

by Benoit St-Jean

While I'm at it, another improvement would be to buffer #newFrom: by reading large chunks of the argument <aCollection> via a ReadStream, adding the objects read to a <Bag> buffer and inserting into the receiver via #add:withOccurrences:.Â That way, if you read say 1000 object (of which lots are similar), you don't have to "add" 1000 items, you could reduce the number of adds by reducing the duplicates with this buffer bag.Â Wouldn't make much of a difference in the worst case scenario but one can assume that since you're using a bag, you normally expect a lot of dups!Â So we could gain a lot that way.Â Anyway, that's what I'm seeing with my experiments (millions of objects) and I'm still contemplating that improvement with more & more tests (such as adjusting the buffer size).Â So far, this is really promising! On 2019-12-18 06:32, Sven Van Caekenberghe wrote: > > OK, now I see. I was thrown off by the weird formatting ;-) > > The final expression is not needed, since you started with an emptyCheck. > > Reformatted then: > > |Bag>>#atRandom: aGenerator "Answer a random element of the receiver. > Uses aGenerator which should be kept by the user in a variable and > used every time. Use this instead of #atRandom for better uniformity > of random numbers because only you use the generator. Causes an error > if self has no elements." | rand index | self emptyCheck. rand := > aGenerator nextInt: self size. index := 0. self doWithOccurrences: [ > :key :count | index := index + count. rand <= index ifTrue: [ ^ key ] ] | > > Still, we need a PR as well. And maybe a specific test unless this is > already covered by other tests. > > â > You are receiving this because you authored the thread. > Reply to this email directly, view it on GitHub > <https://github.com/pharo-project/pharo/issues/5392?email_source=notificatio…>, > or unsubscribe > <https://github.com/notifications/unsubscribe-auth/AEFVQ7ZNNUWBQZF7KKUDEBDQZ…>. > -- ----------------- BenoÃ®t St-Jean Yahoo! Messenger: bstjean Twitter: @BenLeChialeux Pinterest: benoitstjean Instagram: Chef_Benito IRC: lamneth GitHub: bstjean Blogue: endormitoire.wordpress.com "A standpoint is an intellectual horizon of radius zero". (A. Einstein)

Dec. 18, 2019

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by Tim Mackinnon

Steve - obviously there are a few books and tutorials to skim through, but worth mentioning the meta-enter key (eg Cmd-enter on Mac) - this is spotter which is a universal grep and browser to help find things, as well as users of things (and lots more tricks) Also, in the playground is where you can evaluate code like a repl- if you use meta-g on an expression you get a results inspector on the rhs which lets you explore and keep sliding over panes as you dive in (great for looking at results). You can also teach your own objects to add useful tabs to that browser to get a cheap ui (useful for starting out) Tim Sent from my iPhone > On 18 Dec 2019, at 08:47, Steve Davies <steve(a)connection-telecom.com> wrote: > > > > >> On Wed, 18 Dec 2019 at 10:42, CÃ©drick BÃ©ler <cdrick65(a)gmail.com> wrote: >> >> >> > Le 18 dÃ©c. 2019 Ã 09:37, Sven Van Caekenberghe <sven(a)stfx.eu> a Ã©crit : >> > >> > Here is the class comment of MQTTExperimentalClient, which would be the one to use: >> > > > Thank you Sven and CÃ©drick for the pointers. An existing implementation of MQTT Client is a huge help and of course very useful for my learning. > > I didn't know the Filter field could "or" so that is great to make things disappear. > > Thanks for taking the time to show me how to load the code with Metacello. > > Steve >

Dec. 18, 2019

Re: [Pharo-users] I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by Steve Davies

> > The stuff I need to look into for my project is mixed in with 1000s of classes that I (hopefully) can ignore for now - but there seems to be no way to hide away all the irrelevant stuff. > Is it classes or methods ? Well "Smalttalk allClasses size" gives 9018 Object allSubclasses size gives 17742 Object class allSubclasses size gives 8864 So there are thousands of classes, right? 9018 I think is the most sensible answer since it doesn't have the meta-classes. Steve

Dec. 18, 2019