December 2019 - Pharo-users

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

I feel like an overwhelmed maintenance programmer - how to get some toeholds?

by Steve Davies

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: 1. How to implement a TCP client (subclass ProtocolClient? Or do I need to work at a lower level with SocketStream?) 2. Packing and unpacking binary data, working with bits. 3. 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] Localization of Months and Day names

by Sven Van Caekenberghe

I don't know, Locale is not a very useful class. You might want to have a look at ZTimestampFormat, part of https://github.com/svenvc/ztimestamp (ZTimestampFormat fromString: 'SATURDAY, FEBRUARY 03 2001 (16:05:06)') french; format: DateAndTime now. "'MECREDI, DÃCEMBRE 18 2019 (07:44:07)'" (ZTimestampFormat fromString: 'SATURDAY, FEBRUARY 03 2001 (16:05:06)') german; format: DateAndTime now. "'MITTWOCH, DEZEMBER 18 2019 (07:44:28)'" The first argument is an example, based on a reference date. There is lot of documentation. > On 18 Dec 2019, at 02:55, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > What is the "official way" (if any) to localize the printing of Date > Month and Day names? > > I saw there is a Locale class, but neither the primLongDateFormat and > primShortDateFormat have any senders, so if they're used, it's not > through message sends. > > Regards! > > Esteban A. Maringolo >

Dec. 18, 2019

Localization of Months and Day names

by Esteban Maringolo

What is the "official way" (if any) to localize the printing of Date Month and Day names? I saw there is a Locale class, but neither the primLongDateFormat and primShortDateFormat have any senders, so if they're used, it's not through message sends. Regards! Esteban A. Maringolo

Dec. 18, 2019

Re: [Pharo-users] TaskIt

by Ben Coman

On Mon, 16 Dec 2019 at 18:41, Santiago Bragagnolo < santiagobragagnolo(a)gmail.com> wrote: > Hi everybody! > We are starting to discuss with norbert about letting taskit to leave > my incubator (my github account to go elsewhere). I have being thinking > about it since long time, since i would like it to allow taskit to evolve > into more than just my needs and wishes. > > The sidequestion i am bringing today it may seem (or even be) almost > scholastic at this point, but i think it should have some space. > The question is if to move it to pharo-contributions, or if to create a > new pharo-processing. > I know a bit of what TaskIt is, but not what "processing" is in-general. Can you clue me in? cheers -ben

Dec. 17, 2019