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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

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

by Steve Davies

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

Proposed improvement : performance of #atRandom: in class Bag

by Benoit St-Jean

For those interested, I proposed a fix to *drastically* improve the performance of Bag>>#atRandom: ! See https://github.com/pharo-project/pharo/issues/5392 -- ----------------- 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 CÃ©drick BÃ©ler

> Le 18 dÃ©c. 2019 Ã 09:37, Sven Van Caekenberghe <sven(a)stfx.eu> a Ã©crit : > > > >> On 18 Dec 2019, at 09:30, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >> >> There is not much handholding documentation though, check out the unit tests. > > Here is the class comment of MQTTExperimentalClient, which would be the one to use: > I just wish all Â« not much handholding documentation Â» was like that ;-) And this are expression nice to debug (especially stepping into methods like #open, #sendMessage, #subscribeToTopic, â¦). Cheers, CÃ©drick

Dec. 18, 2019

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

by Sven Van Caekenberghe

> On 18 Dec 2019, at 09:30, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > There is not much handholding documentation though, check out the unit tests. Here is the class comment of MQTTExperimentalClient, which would be the one to use: I am MQTTExperimentalClient. I am an MQTTPrimitiveClient and a MQTTAbstractClient. I am an experimental / proof of concept implementation of a simple MQTT client. Examples: Send a single message to a topic to the local broker, say a temperature reading of a sensor, using QoS level 1. MQTTExperimentalClient new atLeastOnce; open; sendMessage: 20 asByteArray toTopic: '/device/42/outside-temperature'; close. Same message to a remote host, using the default QoS level 0. MQTTExperimentalClient new host: 'iot.example.com'; open; sendMessage: 21 asByteArray toTopic: '/device/42/outside-temperature'; close. Read a single message, using QoS level 2 (client should be closed afterwards) MQTTExperimentalClient new exactlyOnce; open; subscribeToTopic: '/new-user-notifications'; readMessage. Read and collect 10 temperature readings Array streamContents: [ :stream | | count | count := 1. MQTTExperimentalClient new open; subscribeToTopic: '/device/42/outside-temperature'; runWith: [ :message | stream nextPut: message contents asInteger. (count := count + 1) > 10 ifTrue: [ ConnectionClosed signal ] ] ]. Collect 100 system notifications Array streamContents: [ :stream | | count | count := 1. MQTTExperimentalClient new host: 'iot.eclipse.org'; open; subscribeToTopic: '$SYS/#'; runWith: [ :message | stream nextPut: message. (count := count + 1) > 100 ifTrue: [ ConnectionClosed signal ] ] ]. Implementation note: I use an inbox when reading messages so that I can store unexpected out of band messages. Reading a message requires a condition filter. I handle keepalive and ping. I implement #runWith: to program in event driven style.

Dec. 18, 2019

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

by Sven Van Caekenberghe

Hi Steve, Welcome! Yes, Pharo and similar dynamic object system can seem overwhelming, but they are also powerful. The trick is to find the shortest path from the system to your application, (re)using as much as possible. You should indeed also learn to skip over details and look at the interfaces of objects. There are a couple of books, see http://books.pharo.org (and much more other documentation). As for an MQTT client, that already exists: https://github.com/svenvc/mqtt There is not much handholding documentation though, check out the unit tests. Don't hesitate to ask questions. HTH, Sven > On 18 Dec 2019, at 09:11, 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. > > 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 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. > > 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. > > My first task is to write an MQTTClient. MQTT is a messaging protocol. MQTT has "clients" - who subscribe for "topics" and receive matching messages, and which can publish to topics. And there are brokers which distribute published messages to subscribing clients. > > I only need to implement a client. The protocol is binary, not text. It runs over TCP. Here's a description of the messaging > > SInce I envision objects inside Pharo that model the real external objects then I will need some sort of background process running the connection to the mqtt broker, and each object would receive and send MQTT messages via that process. > > So to tackle this I need to understand: > â¢ How to implement a TCP client (subclass ProtocolClient? Or do I need to work at a lower level with SocketStream?) > â¢ Packing and unpacking binary data, working with bits. > â¢ How to talk to and from a background process. > Any and all suggestions and help to get going would be welcome. I do understand the principles of Smalltalk and can read code OK. > > Thanks, > Steve > > >

Dec. 18, 2019

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

by CÃ©drick BÃ©ler

Hi Steve, > > Hi, > > I'm having yet another go to get to grips with Pharo. > > My project is for home automation. Interesting, this si the kind of side project I always have in mind. You should look at PharoThings that may help in some respects. > 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. I guess this is the usual feeling and also the learning curve is steep. Iâll suggest do the Mooc (or at least partially) http://mooc.pharo.org > > 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? Classic browsing of main class moments is possible but o-k there are a lot. This is really a system where you can learn everyday (but itâs also a pandora box ^^ eating all you attention sometimes). Also, to me revelation that could be your Â« progressing Â» revelation of code is exactly thatâ¦ instead of browsing endless classes, methods, class hierarchy, using the debugger was incredible to reveal the inner working of some packageâ¦ this is code flowing browsing. Find something you want to understand, write an expression that exposes it, and debug it (CTRL + D). > > 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 ? There are ways to filter packages at least in the browser but putting text and logical OR, lets says Zinc | iCal | whatever > > 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. Same. You look at packages and classes. Again the debugger to have a real feeling of the dynamic. I remember back in 2005, I was struggling to draw some class hierarchy to understand... > > 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. Sure ;) > > My first task is to write an MQTTClient. MQTT is a messaging protocol. MQTT has "clients" - who subscribe for "topics" and receive matching messages, and which can publish to topics. And there are brokers which distribute published messages to subscribing clients. Uhm magic of pharo, and especially for this field, Sven at least did an implementation of MQTT (the guy behind Zinc which is a great central framework). And this is great code: https://github.com/svenvc/mqtt To load it: Metacello new repository: 'github://svenvc/mqtt/repository'; baseline: 'MQTT'; load. > > I only need to implement a client. The protocol is binary, not text. It runs over TCP. Here's a description of the messaging > > SInce I envision objects inside Pharo that model the real external objects then I will need some sort of background process running the connection to the mqtt broker, and each object would receive and send MQTT messages via that process. > > So to tackle this I need to understand: > How to implement a TCP client (subclass ProtocolClient? Or do I need to work at a lower level with SocketStream?) > Packing and unpacking binary data, working with bits. > How to talk to and from a background process. > Any and all suggestions and help to get going would be welcome. I do understand the principles of Smalltalk and can read code OK. So this is kind of done ;-) I suggest you just learn it. Sven is according to me one of the best pharo code out there ;-) Do the Mooc(slides and video too). Cheers, CÃ©drick > > Thanks, > Steve > > >

Dec. 18, 2019