June 2021 - Pharo-users - lists.pharo.org

Re: Communication between different images

by Sven Van Caekenberghe

> On 30 Jun 2021, at 01:28, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > I like the Ansible approach using RabbitMQ, in particular because it > would also work to delegate tasks to workers (even if in the same > image), and the task queue would be preserved, whilst in MQTT if there > are no subscribers for a topic, then all messages sent to it are > discarded. That is correct but less of a problem in practice than it seems to be at first sight. As a client, you normally have to be able to start from scratch and load everything that came before the moment you start up. When a client with a specific ID has connected once with clean session false, QoS 1 and a subscription, the persistence of the queue will be enabled for a as long as the server lives (and maybe even beyond restarts). There is absolutely no question that Rabbit MQ has much more functionality, I found Mosquitto MQTT very nice to work with, but as always, YMMV. Sven

June 30, 2021

Re: Communication between different images

by Sven Van Caekenberghe

> On 29 Jun 2021, at 20:10, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > I already got MQTT running, It's not completely clear to me how the > QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't > remember using that setting in Java (it probably had a sensible > default). >From the comments in MQTTPacket class side atMostOnce "Quality of service level 0 - no acks, send and forget" ^ 0 atLeastOnce "Quality of service level 1 - single acks, possible duplicates" ^ 1 exactlyOnce "Quality of service level 2 - no loss, no duplicates" ^ 2 The lowest one is the fastest, but won't work with persistent queues. In most cases the middle level is OK and enough - duplicates can only occur when you do not receive the ack.

June 30, 2021

Re: Communication between different images

by Esteban Maringolo

Hi Gabriel, I like the Ansible approach using RabbitMQ, in particular because it would also work to delegate tasks to workers (even if in the same image), and the task queue would be preserved, whilst in MQTT if there are no subscribers for a topic, then all messages sent to it are discarded. Is there a way to "start fresh" when subscribing to a queue?, it is, to receive only messages _after_ you subscribed to it? How do you ensure that the publisher/subscriber (and particularly this last) keeps running for the lifetime of an image? It is, what are the failover/recovery options? Regards! Esteban A. Maringolo On Tue, Jun 29, 2021 at 3:44 PM Gabriel Cotelli <g.cotelli(a)gmail.com> wrote: > > If you want to use Rabbit you can also take a look at Ansible for connecting using the protocol instead of STOMP. > > On Tue, Jun 29, 2021 at 3:11 PM Esteban Maringolo <emaringolo(a)gmail.com> wrote: >> >> As far as I understand, ZeroMQ does not require a broker to perform >> the communication between publishers and subscribers, I don't know how >> that is implemented (what do they connect to? how each client >> discovers each other?). >> >> I already got MQTT running, It's not completely clear to me how the >> QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't >> remember using that setting in Java (it probably had a sensible >> default). >> >> Regards! >> >> >> Esteban A. Maringolo >> >> On Tue, Jun 29, 2021 at 2:45 PM Jesus Mari Aguirre >> <jmariaguirre(a)gmail.com> wrote: >> > >> > Maybe ZeroMQ fits you, but unlucky is not documented and there are only a few examples. I use ir in my jupyter kernel. You can install my port to pharo64 uFFI doing: >> > >> > Metacello new >> > baseline: 'JupyterTalk'; >> > repository: 'github://jmari/JupyterTalk:master/repository'; >> > load:'zmq' >> > >> > But it needs ZeroMQ previously installed on your system. >> > It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is at: https://github.com/dellani/zeroMQ but I'm not sure if the original repo works on newer Pharos....I had no time to contact the original author to join both repos... >> > >> > >> > >> > El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) escribiÃ³: >> >> >> >> Hi, >> >> >> >> I'm rearchitecting a web app to perform updates only when necessary >> >> (instead of computing them all the time) on each request, I can have a >> >> global announcer and subscribers to know when to update within an >> >> image, but is there a way to have something like that but for >> >> inter-image coordination? >> >> >> >> I'd only need to communicate the id and the class name (or a similar >> >> identifier), so on other images they'll update accordingly, and if >> >> there is an update in one image, it will notify the other images. The >> >> common data is on the database, so this is just to avoid re-reading a >> >> lot of things. >> >> >> >> Is a message queue a good fit for this? Pub/Sub? >> >> What is available in Pharo that works without having to set up a lot of things? >> >> >> >> Thanks! >> >> >> >> Esteban A. Maringolo

June 29, 2021

Re: Communication between different images

by Gabriel Cotelli

If you want to use Rabbit you can also take a look at Ansible <https://github.com/ba-st/Ansible>for connecting using the protocol instead of STOMP. On Tue, Jun 29, 2021 at 3:11 PM Esteban Maringolo <emaringolo(a)gmail.com> wrote: > As far as I understand, ZeroMQ does not require a broker to perform > the communication between publishers and subscribers, I don't know how > that is implemented (what do they connect to? how each client > discovers each other?). > > I already got MQTT running, It's not completely clear to me how the > QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't > remember using that setting in Java (it probably had a sensible > default). > > Regards! > > > Esteban A. Maringolo > > On Tue, Jun 29, 2021 at 2:45 PM Jesus Mari Aguirre > <jmariaguirre(a)gmail.com> wrote: > > > > Maybe ZeroMQ fits you, but unlucky is not documented and there are only > a few examples. I use ir in my jupyter kernel. You can install my port to > pharo64 uFFI doing: > > > > Metacello new > > baseline: 'JupyterTalk'; > > repository: 'github://jmari/JupyterTalk:master/repository'; > > load:'zmq' > > > > But it needs ZeroMQ previously installed on your system. > > It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is > at: https://github.com/dellani/zeroMQ but I'm not sure if the original > repo works on newer Pharos....I had no time to contact the original author > to join both repos... > > > > > > > > El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) > escribiÃ³: > >> > >> Hi, > >> > >> I'm rearchitecting a web app to perform updates only when necessary > >> (instead of computing them all the time) on each request, I can have a > >> global announcer and subscribers to know when to update within an > >> image, but is there a way to have something like that but for > >> inter-image coordination? > >> > >> I'd only need to communicate the id and the class name (or a similar > >> identifier), so on other images they'll update accordingly, and if > >> there is an update in one image, it will notify the other images. The > >> common data is on the database, so this is just to avoid re-reading a > >> lot of things. > >> > >> Is a message queue a good fit for this? Pub/Sub? > >> What is available in Pharo that works without having to set up a lot of > things? > >> > >> Thanks! > >> > >> Esteban A. Maringolo >

June 29, 2021

Re: Communication between different images

by Esteban Maringolo

As far as I understand, ZeroMQ does not require a broker to perform the communication between publishers and subscribers, I don't know how that is implemented (what do they connect to? how each client discovers each other?). I already got MQTT running, It's not completely clear to me how the QoS setting works (atLeastOnce, exactlyOnce, atMostOnce), I don't remember using that setting in Java (it probably had a sensible default). Regards! Esteban A. Maringolo On Tue, Jun 29, 2021 at 2:45 PM Jesus Mari Aguirre <jmariaguirre(a)gmail.com> wrote: > > Maybe ZeroMQ fits you, but unlucky is not documented and there are only a few examples. I use ir in my jupyter kernel. You can install my port to pharo64 uFFI doing: > > Metacello new > baseline: 'JupyterTalk'; > repository: 'github://jmari/JupyterTalk:master/repository'; > load:'zmq' > > But it needs ZeroMQ previously installed on your system. > It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is at: https://github.com/dellani/zeroMQ but I'm not sure if the original repo works on newer Pharos....I had no time to contact the original author to join both repos... > > > > El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) escribiÃ³: >> >> Hi, >> >> I'm rearchitecting a web app to perform updates only when necessary >> (instead of computing them all the time) on each request, I can have a >> global announcer and subscribers to know when to update within an >> image, but is there a way to have something like that but for >> inter-image coordination? >> >> I'd only need to communicate the id and the class name (or a similar >> identifier), so on other images they'll update accordingly, and if >> there is an update in one image, it will notify the other images. The >> common data is on the database, so this is just to avoid re-reading a >> lot of things. >> >> Is a message queue a good fit for this? Pub/Sub? >> What is available in Pharo that works without having to set up a lot of things? >> >> Thanks! >> >> Esteban A. Maringolo

June 29, 2021

Re: Communication between different images

by Jesus Mari Aguirre

Maybe ZeroMQ fits you, but unlucky is not documented and there are only a few examples. I use ir in my jupyter kernel. You can install my port to pharo64 uFFI doing: Metacello new baseline: 'JupyterTalk'; repository: 'github://jmari/JupyterTalk:master/repository'; load:'zmq' But it needs ZeroMQ previously installed on your system. It was ported from http://smalltalkhub.com/#!/~panuw/zeromq now it is at: https://github.com/dellani/zeroMQ but I'm not sure if the original repo works on newer Pharos....I had no time to contact the original author to join both repos... El mar, 29 jun 2021 a las 4:56, Esteban Maringolo (<emaringolo(a)gmail.com>) escribiÃ³: > Hi, > > I'm rearchitecting a web app to perform updates only when necessary > (instead of computing them all the time) on each request, I can have a > global announcer and subscribers to know when to update within an > image, but is there a way to have something like that but for > inter-image coordination? > > I'd only need to communicate the id and the class name (or a similar > identifier), so on other images they'll update accordingly, and if > there is an update in one image, it will notify the other images. The > common data is on the database, so this is just to avoid re-reading a > lot of things. > > Is a message queue a good fit for this? Pub/Sub? > What is available in Pharo that works without having to set up a lot of > things? > > Thanks! > > Esteban A. Maringolo >

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Sebastian Jordan

No problem Steffen. Have a nice day too! Sebastian ________________________________ De : Steffen MÃ¤rcker <merkste(a)web.de> EnvoyÃ© : mardi 29 juin 2021 Ã 18:27 Ã : Any question about pharo is welcome Objet : [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Thanks Sebastian, that's exactly what I was looking for. I vaguely remembered that such a site exits. =) Have a nice day! Steffen Sebastian Jordan schrieb am Dienstag, 29. Juni 2021 18:23:23 (+02:00): Here https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo<https://na01.safelinks.protection.outlook.com/?url=https%3A%2F%2Fgithub.com…> Sebastian ________________________________ From: Steffen MÃ¤rcker <merkste(a)web.de> Sent: Tuesday, June 29, 2021 6:13:00 PM To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter. -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Steffen MÃ¤rcker

Thanks Sebastian, that's exactly what I was looking for. I vaguely remembered that such a site exits. =) Have a nice day! Steffen Sebastian Jordan schrieb am Dienstag, 29. Juni 2021 18:23:23 (+02:00): Here https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo Sebastian From: Steffen MÃ¤rcker <merkste(a)web.de> Sent: Tuesday, June 29, 2021 6:13:00 PM To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter. -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Sebastian Jordan

Here https://github.com/pharo-project/pharo/wiki/Contribute-a-fix-to-Pharo Sebastian ________________________________ From: Steffen MÃ¤rcker <merkste(a)web.de> Sent: Tuesday, June 29, 2021 6:13:00 PM To: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Subject: [Pharo-users] Re: Fwd: [vwnc] Exception in Regex11 1.4.6 Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Fwd: [vwnc] Exception in Regex11 1.4.6

by Steffen MÃ¤rcker

Dear all! I just checked and found that Regex in Pharo is indeed based on Regex11. It suffers from the same bug as the original. I'd like to bring the fix to Pharo. As a first-timer, where can I read about the procedure of contributing code? Kind regards, Steffen Steffen MÃ¤rcker schrieb am Donnerstag, 24. Juni 2021 18:52:16 (+02:00): Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 29, 2021

Re: Communication between different images

by Sven Van Caekenberghe

> On 29 Jun 2021, at 15:50, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > Hi Sven, > > I thought about both RabittMQ and MQTT too. > > For RabittMQ I noticed you provide a docker config to get a container > running quickly. That was done for GitHub action testing, by Santiago, you could indeed (re)use part of that. > What is the easy-go solution for MQTT? Installing mosquitto is very simple, just apt install. See also the GitHub action. There is much to say about both, you can find lots of information on the internet on how to configure these services, getting started is quite easy. > Regards! > > Esteban A. Maringolo > > On Tue, Jun 29, 2021 at 3:15 AM Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >> >> Hi Esteban, >> >>> On 29 Jun 2021, at 04:55, Esteban Maringolo <emaringolo(a)gmail.com> wrote: >>> >>> Hi, >>> >>> I'm rearchitecting a web app to perform updates only when necessary >>> (instead of computing them all the time) on each request, I can have a >>> global announcer and subscribers to know when to update within an >>> image, but is there a way to have something like that but for >>> inter-image coordination? >>> >>> I'd only need to communicate the id and the class name (or a similar >>> identifier), so on other images they'll update accordingly, and if >>> there is an update in one image, it will notify the other images. The >>> common data is on the database, so this is just to avoid re-reading a >>> lot of things. >>> >>> Is a message queue a good fit for this? Pub/Sub? >>> What is available in Pharo that works without having to set up a lot of things? >>> >>> Thanks! >>> >>> Esteban A. Maringolo >> >> RabbitMQ (for which there is the STOMP client 'STAMP' https://github.com/svenvc/stamp) is one option, but it is a bit more complex. >> >> I guess Redis would work too (https://medium.com/concerning-pharo/quick-write-me-a-redis-client-5fbe4ddfb…) >> >> More recently I have been using MQTT (with the client https://github.com/svenvc/mqtt) which is much simpler. >> >> You post a message on a topic and have one or more listeners see it. You can even arrange for the broker to keep the messages you miss (within a reasonable window) - which is very nice for all kinds of reasons (especially operational). I have a system in production that uses this mechanism to coordinate different images (and handle ingress of data) for more than a year now. >> >> Sven

June 29, 2021

Re: Communication between different images

by Esteban Maringolo

Hi Sven, I thought about both RabittMQ and MQTT too. For RabittMQ I noticed you provide a docker config to get a container running quickly. What is the easy-go solution for MQTT? Regards! Esteban A. Maringolo On Tue, Jun 29, 2021 at 3:15 AM Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > Hi Esteban, > > > On 29 Jun 2021, at 04:55, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > > > Hi, > > > > I'm rearchitecting a web app to perform updates only when necessary > > (instead of computing them all the time) on each request, I can have a > > global announcer and subscribers to know when to update within an > > image, but is there a way to have something like that but for > > inter-image coordination? > > > > I'd only need to communicate the id and the class name (or a similar > > identifier), so on other images they'll update accordingly, and if > > there is an update in one image, it will notify the other images. The > > common data is on the database, so this is just to avoid re-reading a > > lot of things. > > > > Is a message queue a good fit for this? Pub/Sub? > > What is available in Pharo that works without having to set up a lot of things? > > > > Thanks! > > > > Esteban A. Maringolo > > RabbitMQ (for which there is the STOMP client 'STAMP' https://github.com/svenvc/stamp) is one option, but it is a bit more complex. > > I guess Redis would work too (https://medium.com/concerning-pharo/quick-write-me-a-redis-client-5fbe4ddfb…) > > More recently I have been using MQTT (with the client https://github.com/svenvc/mqtt) which is much simpler. > > You post a message on a topic and have one or more listeners see it. You can even arrange for the broker to keep the messages you miss (within a reasonable window) - which is very nice for all kinds of reasons (especially operational). I have a system in production that uses this mechanism to coordinate different images (and handle ingress of data) for more than a year now. > > Sven

June 29, 2021

SerialPort hangs image in combination with Raspberry Pico (Windows)

by Rob van Lopik

I have the following strange situation, where SerialPort>>nextPutAll: hangs when sending to a COM port that is (USB) connected to a Raspberry Pico (RP2040). The Pico contains a simple program (sketch) that echoes all input on it USB-serial port. This is written with the Arduino IDE. The echo function works OK with the Arduino Serial monitor, PuTTY and a simple Python progran. When I put the same echo program on another Arduino board (e.g. Uno or Adafruit Feather) Pharo's SerialPort does work fine. I have tested with 32 and 64 bits versions of Pharo 5, 7 and 8. All on Windows; on Raspbian there is no problem. So, there is something peculiar with the combination of the SerialPlugin and the USBserial implementation on the Pico (which uses TinyUSB), but I am at a loss as to where to search. Maybe somebody has a hint. I have seen problems with the Serial Plugin in the past. I ran into this when developing a driver for the Raspberry Pico, where the Pico runs the picod daemon (http://abyz.me.uk/picod/index.html) This code is in https://github.com/robvanlopik/picod-pharo and does not work on Windows. Rob van Lopik

June 29, 2021

Re: Is there an easy way to cherry pick methods from another branch in iceberg?

by Tim Mackinnon

Hi Guille - thanks for Chipping in on this - I have bookmarked the revert commands you have mentioned and see if that works better for me (rather than flailing around and making a mess of it). Possibly this scenario is one that could get its own menu option in the future - its a quite a common thing to want to just get bak to a safe point. For the cherry picking - I have raised an Issue (in Iceberg?) - https://github.com/pharo-vcs/iceberg/issues/1519 Tim > On 28 Jun 2021, at 13:12, Guillermo Polito <guillermopolito(a)gmail.com> wrote: > > Hi Tim, > >> El 22 jun 2021, a las 1:39, Tim Mackinnon <tim(a)testit.works <mailto:tim@testit.works>> escribiÃ³: >> >> Hi guys - while I mostly get along with Iceberg and can do common stuff - there are still a few things that I'm not sure on the best way to work. >> >> A recent one, was that I created a branch for an experiment - decided not to use and then went back to master to try again. However if I want to cherry pick code (particularly a few methods) - is there nothing I can use to do this easily? I can browse the branch in the repo explorer and see diffs of methods to master - but why can't I load any of those methods (or am I missing something obvious here?) > > This seems to be a feature that was not migrated in the iceberg-to-spec2 migration. > Would you mind opening an issue? > >> >> The other item that still confuses me today - how can I easily revert back to previous point in time, essentially undo work I've commited and possible pushed to my git repo. I also struggle with this one - end up with a detached head and flail around. I don't understand why this is so hard to do - and can only think its because everything is based on graphs of graphs and so there is the potential that going back in time can break this? Anyway - what is the foolproof way to go back to the older point, and then start coding so that this becomes the new Head? > > There are two different questions in here. > > - How can you go back to some older commit? > > In iceberg this is done by creating a new branch from the commit youâre interested in. The âBranchâ¦â menu will open a pop-up to allow you creating a new branch from that point in time. > Then you can checkout that branch and work as with any other branch. > > <PastedGraphic-5.png> > > > - How can you undo some history (that was even pushed)? > > Iceberg does not support this scenario yet, as it could be very problematic when working in teams. > Undoing some history / removing some commit will produce undesired effects on people that had pulled that commit. > This is one of the scenarios that in git requires a `âforce` flag. > > If you want to do such a thing, you need for now to do it from the command line > > ```sh > $ git reset âhard THE_COMMIT_ID_YOU_WANT_TO_GO_BACK_TO > $ git push -f > ``` > > And then checkout the branch back from iceberg (which will show a detached working copy â see https://books.pharo.org/booklet-ManageCode/pdf/2020-05-12-ManageCode.pdf <https://books.pharo.org/booklet-ManageCode/pdf/2020-05-12-ManageCode.pdf>). > > G > >> >> Pointers on these two items greatly appreciate for my road to vcs greatness (and gosh I mess Envy - as I haven't asked about showing me deleted "available methods" and "classes") >> >> Tim >

June 29, 2021

Re: Communication between different images

by Sven Van Caekenberghe

Hi Esteban, > On 29 Jun 2021, at 04:55, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > Hi, > > I'm rearchitecting a web app to perform updates only when necessary > (instead of computing them all the time) on each request, I can have a > global announcer and subscribers to know when to update within an > image, but is there a way to have something like that but for > inter-image coordination? > > I'd only need to communicate the id and the class name (or a similar > identifier), so on other images they'll update accordingly, and if > there is an update in one image, it will notify the other images. The > common data is on the database, so this is just to avoid re-reading a > lot of things. > > Is a message queue a good fit for this? Pub/Sub? > What is available in Pharo that works without having to set up a lot of things? > > Thanks! > > Esteban A. Maringolo RabbitMQ (for which there is the STOMP client 'STAMP' https://github.com/svenvc/stamp) is one option, but it is a bit more complex. I guess Redis would work too (https://medium.com/concerning-pharo/quick-write-me-a-redis-client-5fbe4ddfb…) More recently I have been using MQTT (with the client https://github.com/svenvc/mqtt) which is much simpler. You post a message on a topic and have one or more listeners see it. You can even arrange for the broker to keep the messages you miss (within a reasonable window) - which is very nice for all kinds of reasons (especially operational). I have a system in production that uses this mechanism to coordinate different images (and handle ingress of data) for more than a year now. Sven

June 29, 2021

Communication between different images

by Esteban Maringolo

Hi, I'm rearchitecting a web app to perform updates only when necessary (instead of computing them all the time) on each request, I can have a global announcer and subscribers to know when to update within an image, but is there a way to have something like that but for inter-image coordination? I'd only need to communicate the id and the class name (or a similar identifier), so on other images they'll update accordingly, and if there is an update in one image, it will notify the other images. The common data is on the database, so this is just to avoid re-reading a lot of things. Is a message queue a good fit for this? Pub/Sub? What is available in Pharo that works without having to set up a lot of things? Thanks! Esteban A. Maringolo

June 29, 2021

Re: Is there an easy way to cherry pick methods from another branch in iceberg?

by Guillermo Polito

Hi Tim, > El 22 jun 2021, a las 1:39, Tim Mackinnon <tim(a)testit.works> escribiÃ³: > > Hi guys - while I mostly get along with Iceberg and can do common stuff - there are still a few things that I'm not sure on the best way to work. > > A recent one, was that I created a branch for an experiment - decided not to use and then went back to master to try again. However if I want to cherry pick code (particularly a few methods) - is there nothing I can use to do this easily? I can browse the branch in the repo explorer and see diffs of methods to master - but why can't I load any of those methods (or am I missing something obvious here?) This seems to be a feature that was not migrated in the iceberg-to-spec2 migration. Would you mind opening an issue? > > The other item that still confuses me today - how can I easily revert back to previous point in time, essentially undo work I've commited and possible pushed to my git repo. I also struggle with this one - end up with a detached head and flail around. I don't understand why this is so hard to do - and can only think its because everything is based on graphs of graphs and so there is the potential that going back in time can break this? Anyway - what is the foolproof way to go back to the older point, and then start coding so that this becomes the new Head? There are two different questions in here. - How can you go back to some older commit? In iceberg this is done by creating a new branch from the commit youâre interested in. The âBranchâ¦â menu will open a pop-up to allow you creating a new branch from that point in time. Then you can checkout that branch and work as with any other branch. - How can you undo some history (that was even pushed)? Iceberg does not support this scenario yet, as it could be very problematic when working in teams. Undoing some history / removing some commit will produce undesired effects on people that had pulled that commit. This is one of the scenarios that in git requires a `âforce` flag. If you want to do such a thing, you need for now to do it from the command line ```sh $ git reset âhard THE_COMMIT_ID_YOU_WANT_TO_GO_BACK_TO $ git push -f ``` And then checkout the branch back from iceberg (which will show a detached working copy â see https://books.pharo.org/booklet-ManageCode/pdf/2020-05-12-ManageCode.pdf) G > > Pointers on these two items greatly appreciate for my road to vcs greatness (and gosh I mess Envy - as I haven't asked about showing me deleted "available methods" and "classes") > > Tim

June 28, 2021

Re: Is there an easy way to cherry pick methods from another branch in iceberg?

by Clint Moore

+1 person who would like to know this so I don't have to do it from a terminal. On Sat, Jun 26, 2021 at 11:18 AM Tim Mackinnon <tim(a)testit.works> wrote: > > Just nudging this one - as Iâd like to improve my Iceberg foo - and cherry picking methods and reverting are things Iâd like to learn how to do better? > > > On 22 Jun 2021, at 00:39, Tim Mackinnon <tim(a)testit.works> wrote: > > > > Hi guys - while I mostly get along with Iceberg and can do common stuff - there are still a few things that I'm not sure on the best way to work. > > > > A recent one, was that I created a branch for an experiment - decided not to use and then went back to master to try again. However if I want to cherry pick code (particularly a few methods) - is there nothing I can use to do this easily? I can browse the branch in the repo explorer and see diffs of methods to master - but why can't I load any of those methods (or am I missing something obvious here?) > > > > The other item that still confuses me today - how can I easily revert back to previous point in time, essentially undo work I've commited and possible pushed to my git repo. I also struggle with this one - end up with a detached head and flail around. I don't understand why this is so hard to do - and can only think its because everything is based on graphs of graphs and so there is the potential that going back in time can break this? Anyway - what is the foolproof way to go back to the older point, and then start coding so that this becomes the new Head? > > > > Pointers on these two items greatly appreciate for my road to vcs greatness (and gosh I mess Envy - as I haven't asked about showing me deleted "available methods" and "classes") > > > > Tim

June 27, 2021

Re: Is there an easy way to cherry pick methods from another branch in iceberg?

by Tim Mackinnon

Just nudging this one - as Iâd like to improve my Iceberg foo - and cherry picking methods and reverting are things Iâd like to learn how to do better? > On 22 Jun 2021, at 00:39, Tim Mackinnon <tim(a)testit.works> wrote: > > Hi guys - while I mostly get along with Iceberg and can do common stuff - there are still a few things that I'm not sure on the best way to work. > > A recent one, was that I created a branch for an experiment - decided not to use and then went back to master to try again. However if I want to cherry pick code (particularly a few methods) - is there nothing I can use to do this easily? I can browse the branch in the repo explorer and see diffs of methods to master - but why can't I load any of those methods (or am I missing something obvious here?) > > The other item that still confuses me today - how can I easily revert back to previous point in time, essentially undo work I've commited and possible pushed to my git repo. I also struggle with this one - end up with a detached head and flail around. I don't understand why this is so hard to do - and can only think its because everything is based on graphs of graphs and so there is the potential that going back in time can break this? Anyway - what is the foolproof way to go back to the older point, and then start coding so that this becomes the new Head? > > Pointers on these two items greatly appreciate for my road to vcs greatness (and gosh I mess Envy - as I haven't asked about showing me deleted "available methods" and "classes") > > Tim

June 26, 2021

Fwd: [vwnc] Exception in Regex11 1.4.6

by Steffen MÃ¤rcker

Hi! Does Pharo use the Regex11 package? If yes, has it already diverged from the version shipped with VisualWorks? The reason I am asking is that I just pushed an update to the public store. It addresses a bug that prevented $[ to be used in a character class. For details, see the excerpt below. Furthermore, you might have an opinion on allowing more escape sequences in character classes, don't you? Kind regards, Steffen ----- Weitergeleitete Nachricht ----- Von: Steffen MÃ¤rcker <merkste(a)web.de> An: 'VWNC' <vwnc(a)cs.uiuc.edu> Betreff: Re: [vwnc] Exception in Regex11 1.4.6 Datum: Thu Jun 24 2021 18:47:01 GMT+0200 (MitteleuropÃ¤ische Sommerzeit) Hi! I just published Regex11 version 1.4.7 with the following changes: 1. Fix: Character sets could not contain an opening bracket $[. 2. Fix: Character sets could not contain the characters '[:', e.g. as in '[[:something]' asRegex. I also provided additional tests for the improved functionality. I might tidy the code a bit later in a minor version bump. Just to note that Regex11 uses [[:xxx:]] as a special syntax, which might interfere with attempts to allow [[] and []]. Indeed. If I did no mistake, the new version does not break this. I agree with the idea to allow backslash escaping in character classes too, with the default being that backslash followed by any character is parsed as that character. I also like the idea of allowing more backslash escaping in character classes. However, I still have the bad feeling that this might change the semantics of existing code. Hence, I refrained from implementing this right away until I am more confident that this does not break other peoples stuff. Currently only a few explicitly defined backslash escapes are recognized, forcing the user to remember whether a given character can be used as-is in a given context, or must be escaped. A couple of gotchas (probably not applicable in a character set?): \< an empty string at the beginning of a word \> an empty string at the end of a word Thanks, I'll keep them in mind and consider them when I decide to implement the changes. OT: I also noticed that repetition, e.g. '.{5}' behaves strange. For instance, '.{{5}}' should match 'a{{{{{}' but it doesn't. Has anyone an opinion on that one? Best regards, Steffen -- Gesendet mit Vivaldi Mail. Laden Sie Vivaldi kostenlos von vivaldi.com herunter.

June 24, 2021

[ANN] Pharo Consortium New Academic Member: DGtal Aqua Lab

by Marcus Denker

The Pharo Consortium is very happy to announce that the DGtal Aqua Lab has joined the Consortium as an Academic Member. About ===== - DGtal Aqua Lab: https://wwp.shizuoka.ac.jp/dgtalaqualab/ - MOBYDIC: https://wwp.shizuoka.ac.jp/dgtalaqualab/mobydic/ - Pharo Consortium: http://consortium.pharo.org The goal of the Pharo Consortium is to allow companies and institutions to support the ongoing development and future of Pharo. Individuals can support Pharo via the Pharo Association: http://association.pharo.org/

June 24, 2021

UK Smalltalk User Group meeting - Wednesday June 30th

by Giovanni Corriga

The next meeting of the UK Smalltalk User Group will be on Wednesday, June 30th. Hernan Wilkinson ( https://twitter.com/HernanWilkinson ) will talk about his LiveTyping project. Currently, almost all mainstream dynamically typed languages support type annotation a la Strongtalk. Python calls it "type hints", TypeScript is JavaScript+type annotations, PHP calls it "type declarations" and Ruby does it through a tool called Sorbet. All of them annotate the types in the source code and it is the programmer who must write and maintain the annotation. In all cases, it is not mandatory for the system to correctly type check for it to run. LiveTyping ( https://github.com/hernanwilkinson/LiveTyping ) is a type system proposal for Smalltalk, that seeks similar objectives but implemented in a different way. First, it is the environment itself that collects and maintains the types based on the execution of the system, not the programmer. Second, the types are not interleaved in the source code, thus maintaining the syntax and simplicity of the language. And finally, the main objective is not to carry out a static type checking (although it supports it), but to augment the programmers experience increasing the usability of current tools such as searching for senders and implementers, and performing more accurate and safe refactorings. In this talk Hernan will briefly show how LiveTyping is implemented to later concentrate on the improvements made to the tools and the benefits it brings when developing software with Smalltalk. LiveTyping is currently implemented in Cuis Smalltalk ( https://cuis-smalltalk.org/ ) and has been successfully used for the last two years in three different universities in Argentina when teaching Object Oriented Programming and Design. Given the current COVID-19 restrictions, this will be an online meeting from home. If you'd like to join us, please sign up in advance on the meeting's Meetup page ( https://www.meetup.com/UKSTUG/events/cbklbryccjbfc/ ) to receive the meeting details. Donât forget to bring your laptop and drinks!

June 23, 2021

Is there an easy way to cherry pick methods from another branch in iceberg?

by Tim Mackinnon

Hi guys - while I mostly get along with Iceberg and can do common stuff - there are still a few things that I'm not sure on the best way to work. A recent one, was that I created a branch for an experiment - decided not to use and then went back to master to try again. However if I want to cherry pick code (particularly a few methods) - is there nothing I can use to do this easily? I can browse the branch in the repo explorer and see diffs of methods to master - but why can't I load any of those methods (or am I missing something obvious here?) The other item that still confuses me today - how can I easily revert back to previous point in time, essentially undo work I've commited and possible pushed to my git repo. I also struggle with this one - end up with a detached head and flail around. I don't understand why this is so hard to do - and can only think its because everything is based on graphs of graphs and so there is the potential that going back in time can break this? Anyway - what is the foolproof way to go back to the older point, and then start coding so that this becomes the new Head? Pointers on these two items greatly appreciate for my road to vcs greatness (and gosh I mess Envy - as I haven't asked about showing me deleted "available methods" and "classes") Tim

June 21, 2021

Re: Implementing DataFrame>>dtypes feature in Pharo PolyMath Project

by Balaji G

Thank you sir for the clarification. On Sat, Jun 19, 2021 at 7:24 PM Konrad Hinsen <konrad.hinsen(a)cnrs.fr> wrote: > Dear Balaji, > > > I am working on implementing the DataFrame>>dtypes feature which > > checks the datatypes of columns in a DataFrame, as part of my GSOC > > project. I have tried to explain my theoretical work done so far on > > this blog post. Please kindly go through it , as I need advice on what > > could be the optimal way to implement this feature. Any kind of input > > and discussions is most welcome. > > Your post looks like an overall accurate description of the current > state of everything - with one exception, and that is Pandas. You say > you didn't look at the Pandas code yet, so that's not surprising. > > You seem to assume that Pandas stores Python objects as elements of > DataFrames, but that isn't true. Pandas uses NumPy arrays instead. And > NumPy arrays are very different from standard Python objects, because > their internal data layout is by design the same as used in C or > Fortran. For a full description, see > > https://numpy.org/doc/stable/user/basics.rec.html > > However, I am not sure you need to understand this in all detail, as I > am pretty sure that you do not want to copy this approach in Pharo. > > The one point that does matter for you is where NumPy and Pandas take a > column's dtype from. The answer is that it's defined when a DataFrame is > created, and it cannot be changed afterwards. If a column is "integer", > it will remain "integer" forever. If you try to assign a string to an > element of such a column, you get an error message. When you create a > DataFrame from existing data, e.g. by reading a CSV file, Pandas scans > the data and determines a suitable dtype, much in the same way as V1.0 > in Pharo/PolyMath did. But since Pandas doesn't allow any later change, > there is no serious performance issue. > > So that's an option you can add to your list: define the dtypes once and > for all when the DataFrame is created. The main drawback is that you > would have to change the API for DataFrame creation to make this work. > > Cheers, > Konrad > -- > --------------------------------------------------------------------- > Konrad Hinsen > Centre de Biophysique MolÃ©culaire, CNRS OrlÃ©ans > Synchrotron Soleil - Division ExpÃ©riences > Saint Aubin - BP 48 > 91192 Gif sur Yvette Cedex, France > Tel. +33-1 69 35 97 15 > E-Mail: konrad DOT hinsen AT cnrs DOT fr > http://dirac.cnrs-orleans.fr/~hinsen/ > ORCID: https://orcid.org/0000-0003-0330-9428 > Twitter: @khinsen > --------------------------------------------------------------------- >

June 19, 2021

Implementing DataFrame>>dtypes feature in Pharo PolyMath Project

by Balaji G

Hi I am working on implementing the DataFrame>>dtypes feature which checks the datatypes of columns in a DataFrame, as part of my GSOC project. I have tried to explain my theoretical work done so far on this blog post. Please kindly go through it , as I need advice on what could be the optimal way to implement this feature. Any kind of input and discussions is most welcome. Link to the post : Background work on DataFrame dtypes <https://balaji612141526.wordpress.com/2021/06/19/background-work-on-datafra…> Thank you Balaji G

June 19, 2021

Re: [ANN] Camp Smalltalk Supreme Finalized!

by Russ Whaley

I will be required to take personal time from my employer, so primarily weekend is appreciated from my perspective :) On Fri, Jun 18, 2021 at 11:04 AM James Foster <Smalltalk(a)jgfoster.net> wrote: > Is there anyone else out there for whom weekdays (M-F) would be better > than a primarily weekend event? > > James > > On Jun 17, 2021, at 11:31 AM, Richard Kenneth Eng < > horrido.hobbies(a)gmail.com> wrote: > > As of today, Wednesday, June 17, 2021, I have successfully nailed down the > most exciting roster of keynote speakers for *Camp Smalltalk Supreme* next > year. Here they are: > > 1. *Adele Goldberg* â co-creator of Smalltalk > 2. *Dan Ingalls* â co-creator of Smalltalk > 3. *Kent Beck* â Smalltalk pioneer > 4. *David Buck* â Smalltalk veteran and podcaster > > This will be the greatest programming language birthday bash ever. As I > wrote to Dan Ingalls... > > "I checked birthday celebrations for other languages like FORTRAN, LISP, > COBOL, BASIC, and Pascal, and they were quite anemic." > > For more information, visit: https://gofund.me/225341e3 > > I invite presenters to register. > > Cheers, > Richard > > > -- Russ Whaley whaley.russ(a)gmail.com

June 18, 2021

Re: [ANN] Camp Smalltalk Supreme Finalized!

by James Foster

Is there anyone else out there for whom weekdays (M-F) would be better than a primarily weekend event? James > On Jun 17, 2021, at 11:31 AM, Richard Kenneth Eng <horrido.hobbies(a)gmail.com> wrote: > > As of today, Wednesday, June 17, 2021, I have successfully nailed down the most exciting roster of keynote speakers for Camp Smalltalk Supreme next year. Here they are: > Adele Goldberg â co-creator of Smalltalk > Dan Ingalls â co-creator of Smalltalk > Kent Beck â Smalltalk pioneer > David Buck â Smalltalk veteran and podcaster > This will be the greatest programming language birthday bash ever. As I wrote to Dan Ingalls... > > "I checked birthday celebrations for other languages like FORTRAN, LISP, COBOL, BASIC, and Pascal, and they were quite anemic." > > For more information, visit: https://gofund.me/225341e3 <https://gofund.me/225341e3> > > I invite presenters to register. > > Cheers, > Richard

June 18, 2021

Re: Zn and AWS - retrieving object versions?

by Sven Van Caekenberghe

Tim, > On 17 Jun 2021, at 19:05, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > PS: I think there is other AWS S3 for Pharo out there, but I can't remember. I found two of them: - https://github.com/newapplesho/aws-sdk-smalltalk - https://github.com/jvdsandt/pharo-aws-toolbox I am sure both of these are more up to date and get more AWS details right that my old minimal, proof of concept package. Sven

June 18, 2021

[ANN] Camp Smalltalk Supreme Finalized!

by Richard Kenneth Eng

As of today, Wednesday, June 17, 2021, I have successfully nailed down the most exciting roster of keynote speakers for *Camp Smalltalk Supreme* next year. Here they are: 1. *Adele Goldberg* â co-creator of Smalltalk 2. *Dan Ingalls* â co-creator of Smalltalk 3. *Kent Beck* â Smalltalk pioneer 4. *David Buck* â Smalltalk veteran and podcaster This will be the greatest programming language birthday bash ever. As I wrote to Dan Ingalls... "I checked birthday celebrations for other languages like FORTRAN, LISP, COBOL, BASIC, and Pascal, and they were quite anemic." For more information, visit: https://gofund.me/225341e3 I invite presenters to register. Cheers, Richard

June 17, 2021

Re: Zn and AWS - retrieving object versions?

by Sven Van Caekenberghe

Tim, I think that from the moment there is a query part added to the REST URL something goes wrong. Step 1 is to make sure the signing works. Now, ZnAWSS3RequestSignatureTool was written for an earlier version (I don't remember which one, probably V1). This is tricky to figure out. I know for example that if there are multiple query arguments, they have to be sorted, which is currently not happening. But that won't be the only problem (encoding could be another). The challenge is to construct the correct 'canonical' string to sign. First you got a clear 'signature wrong' error, that seems to be gone. But you still get an authentication error, I am not sure what is going on. I am afraid you will have to try to debug this a bit yourself. It has been years since I looked at this code. If you get this to work with another tool, maybe you can enable debug logging to see what is happening with the URL and headers. Sven PS: I think there is other AWS S3 for Pharo out there, but I can't remember. > On 17 Jun 2021, at 18:32, Tim Mackinnon <tim(a)testit.works> wrote: > > Hi Sven - actually I think its not just the versions thing - I canât get filtering to work on the standard query either: > > client keysIn: âmtt-data' query: (Dictionary with: 'prefix'->'sampleâ). > > Given a normal query works, there must be something extra that is being missed/added that impacts things. > > Tim > >> On 17 Jun 2021, at 17:19, Tim Mackinnon <tim(a)testit.works> wrote: >> >> Hi Sven - thanks for taking a quick look, this change did stop me getting an immediate error - but I seem to get no results back. >> >> Digging into it a bit more - I seem to be issuing the GET request as indicated by https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectVersions.html >> >> e.g. >> >> GET /?versions HTTP/1.1 >> >> Headers: >> a ZnMultiValueDictionary('User-Agent'->'Zinc HTTP Components 1.0 (Pharo/8.0)â >> 'Accept'->'*/*' 'Host'->'mtt-data.s3.amazonaws.comâ >> 'Date'->'Thu, 17 Jun 2021 16:08:44 GMTâ >> 'Authorization'->'AWS AKIAIP2xxxxxxx:DqPPbDyyyyyâ) >> >> From the spec (which Iâm no expert on) - the get command looks right (the other params are optional) and the Bucket name is prefixed onto s3.amazonaws.com in the header. >> >> But is seems that I am getting a 200 - 403 response : >> "a ZnResponse(200 OK application/xml 1899B)" >> HTTP/1.1 403 Forbidden >> >> (Aside - the code should possibly handle this better - the spec seems to say that response content needs to be interpreted - but thatâs something I can look to help with when we know the actual issue). >> >> But Iâm a bit mystified why the previous: client keysIn: 'mtt-dataâ >> Invocation would work, but this seemingly extra step would be forbidden. My IAM role says it has full S3 access, so Iâm not sure if this is still that we havenât got the right fix or if its something environmental. Iâm not sure what to do - if you have another idea, Iâm happy to be a guniea pig to try it. >> >> Tim >> >> >> >>> On 17 Jun 2021, at 09:06, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >>> >>> Hi Tim, >>> >>> It has been a very long time since I last looked at this code. It is a good thing that at least part of it still works. >>> >>> Just by reading the code and reasoning about your problem, I would suggest you try the following change: >>> >>> In ZnAWSS3RequestSignatureTool>>#canonicalStringFor: replace the last >>> >>> request uri pathPrintString >>> >>> by >>> >>> request uri pathQueryFragmentPrintString >>> >>> I did not try this myself, so it might not solve your issue. >>> >>> Please let me know if this works. >>> >>> Sven >>> >>>> On 17 Jun 2021, at 03:05, Tim Mackinnon <tim(a)testit.works> wrote: >>>> >>>> Hi everyone - Iâm wondering if someone knows the trick to listing object versions in AWS S3? >>>> >>>> I was previously using a non-Zn library (there are a few around - but they are quite old and Iâm not sure how much they are maintained) - however I hadnât realised that Zn actually supports S3 until I read it a bit carefully and realised that I needed to load an extra AWS group. >>>> >>>> So - I have a bucket that is versioned, and I wanted to read the versions of an object - and hopefully be able to read the contents of an older version. >>>> >>>> I can list the contents of a bucket, but when I try to read the versions of an object - I get a forbidden error - which when I dig deeper gives a stranger explanation? >>>> >>>> I have confirmed that the AWS CLI is able to list versions in that bucket - so Iâm a bit confused what the issue might be? >>>> >>>> (client := ZnAWSS3Client new) >>>> accessKeyId: 'xxx'; >>>> secretAccessKey: âyyyyy'; >>>> checkIntegrity: true. >>>> >>>> client buckets. âWorks" >>>> client keysIn: 'mtt-dataâ. âWorks" >>>> >>>> client at: 'mtt-data' -> 'sample.txtâ. âWorks" >>>> >>>> client keysIn: 'mtt-data' query: (Dictionary with: 'versions'->nil). âGives an error?â >>>> >>>> >>>> HTTP/1.1 403 Forbidden >>>> >>>> <?xml version="1.0" encoding="UTF-8"?> >>>> <Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>xxx</AWSAccessKeyId><StringToSign>GET >>>> >>>> >>>> Has anyone tried doing this - Iâm sure there is something really simple that I am missing? >>>> >>>> Tim

June 17, 2021

Re: Zn and AWS - retrieving object versions?

by Tim Mackinnon

Hi Sven - actually I think its not just the versions thing - I canât get filtering to work on the standard query either: client keysIn: âmtt-data' query: (Dictionary with: 'prefix'->'sampleâ). Given a normal query works, there must be something extra that is being missed/added that impacts things. Tim > On 17 Jun 2021, at 17:19, Tim Mackinnon <tim(a)testit.works> wrote: > > Hi Sven - thanks for taking a quick look, this change did stop me getting an immediate error - but I seem to get no results back. > > Digging into it a bit more - I seem to be issuing the GET request as indicated by https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectVersions.html > > e.g. > > GET /?versions HTTP/1.1 > > Headers: > a ZnMultiValueDictionary('User-Agent'->'Zinc HTTP Components 1.0 (Pharo/8.0)â > 'Accept'->'*/*' 'Host'->'mtt-data.s3.amazonaws.comâ > 'Date'->'Thu, 17 Jun 2021 16:08:44 GMTâ > 'Authorization'->'AWS AKIAIP2xxxxxxx:DqPPbDyyyyyâ) > > From the spec (which Iâm no expert on) - the get command looks right (the other params are optional) and the Bucket name is prefixed onto s3.amazonaws.com in the header. > > But is seems that I am getting a 200 - 403 response : > "a ZnResponse(200 OK application/xml 1899B)" > HTTP/1.1 403 Forbidden > > (Aside - the code should possibly handle this better - the spec seems to say that response content needs to be interpreted - but thatâs something I can look to help with when we know the actual issue). > > But Iâm a bit mystified why the previous: client keysIn: 'mtt-dataâ > Invocation would work, but this seemingly extra step would be forbidden. My IAM role says it has full S3 access, so Iâm not sure if this is still that we havenât got the right fix or if its something environmental. Iâm not sure what to do - if you have another idea, Iâm happy to be a guniea pig to try it. > > Tim > > > >> On 17 Jun 2021, at 09:06, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: >> >> Hi Tim, >> >> It has been a very long time since I last looked at this code. It is a good thing that at least part of it still works. >> >> Just by reading the code and reasoning about your problem, I would suggest you try the following change: >> >> In ZnAWSS3RequestSignatureTool>>#canonicalStringFor: replace the last >> >> request uri pathPrintString >> >> by >> >> request uri pathQueryFragmentPrintString >> >> I did not try this myself, so it might not solve your issue. >> >> Please let me know if this works. >> >> Sven >> >>> On 17 Jun 2021, at 03:05, Tim Mackinnon <tim(a)testit.works> wrote: >>> >>> Hi everyone - Iâm wondering if someone knows the trick to listing object versions in AWS S3? >>> >>> I was previously using a non-Zn library (there are a few around - but they are quite old and Iâm not sure how much they are maintained) - however I hadnât realised that Zn actually supports S3 until I read it a bit carefully and realised that I needed to load an extra AWS group. >>> >>> So - I have a bucket that is versioned, and I wanted to read the versions of an object - and hopefully be able to read the contents of an older version. >>> >>> I can list the contents of a bucket, but when I try to read the versions of an object - I get a forbidden error - which when I dig deeper gives a stranger explanation? >>> >>> I have confirmed that the AWS CLI is able to list versions in that bucket - so Iâm a bit confused what the issue might be? >>> >>> (client := ZnAWSS3Client new) >>> accessKeyId: 'xxx'; >>> secretAccessKey: âyyyyy'; >>> checkIntegrity: true. >>> >>> client buckets. âWorks" >>> client keysIn: 'mtt-dataâ. âWorks" >>> >>> client at: 'mtt-data' -> 'sample.txtâ. âWorks" >>> >>> client keysIn: 'mtt-data' query: (Dictionary with: 'versions'->nil). âGives an error?â >>> >>> >>> HTTP/1.1 403 Forbidden >>> >>> <?xml version="1.0" encoding="UTF-8"?> >>> <Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>xxx</AWSAccessKeyId><StringToSign>GET >>> >>> >>> Has anyone tried doing this - Iâm sure there is something really simple that I am missing? >>> >>> Tim

June 17, 2021

Re: Zn and AWS - retrieving object versions?

by Tim Mackinnon

Hi Sven - thanks for taking a quick look, this change did stop me getting an immediate error - but I seem to get no results back. Digging into it a bit more - I seem to be issuing the GET request as indicated by https://docs.aws.amazon.com/AmazonS3/latest/API/API_ListObjectVersions.html e.g. GET /?versions HTTP/1.1 Headers: a ZnMultiValueDictionary('User-Agent'->'Zinc HTTP Components 1.0 (Pharo/8.0)â 'Accept'->'*/*' 'Host'->'mtt-data.s3.amazonaws.comâ 'Date'->'Thu, 17 Jun 2021 16:08:44 GMTâ 'Authorization'->'AWS AKIAIP2xxxxxxx:DqPPbDyyyyyâ) >From the spec (which Iâm no expert on) - the get command looks right (the other params are optional) and the Bucket name is prefixed onto s3.amazonaws.com in the header. But is seems that I am getting a 200 - 403 response : "a ZnResponse(200 OK application/xml 1899B)" HTTP/1.1 403 Forbidden (Aside - the code should possibly handle this better - the spec seems to say that response content needs to be interpreted - but thatâs something I can look to help with when we know the actual issue). But Iâm a bit mystified why the previous: client keysIn: 'mtt-dataâ Invocation would work, but this seemingly extra step would be forbidden. My IAM role says it has full S3 access, so Iâm not sure if this is still that we havenât got the right fix or if its something environmental. Iâm not sure what to do - if you have another idea, Iâm happy to be a guniea pig to try it. Tim > On 17 Jun 2021, at 09:06, Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > Hi Tim, > > It has been a very long time since I last looked at this code. It is a good thing that at least part of it still works. > > Just by reading the code and reasoning about your problem, I would suggest you try the following change: > > In ZnAWSS3RequestSignatureTool>>#canonicalStringFor: replace the last > > request uri pathPrintString > > by > > request uri pathQueryFragmentPrintString > > I did not try this myself, so it might not solve your issue. > > Please let me know if this works. > > Sven > >> On 17 Jun 2021, at 03:05, Tim Mackinnon <tim(a)testit.works> wrote: >> >> Hi everyone - Iâm wondering if someone knows the trick to listing object versions in AWS S3? >> >> I was previously using a non-Zn library (there are a few around - but they are quite old and Iâm not sure how much they are maintained) - however I hadnât realised that Zn actually supports S3 until I read it a bit carefully and realised that I needed to load an extra AWS group. >> >> So - I have a bucket that is versioned, and I wanted to read the versions of an object - and hopefully be able to read the contents of an older version. >> >> I can list the contents of a bucket, but when I try to read the versions of an object - I get a forbidden error - which when I dig deeper gives a stranger explanation? >> >> I have confirmed that the AWS CLI is able to list versions in that bucket - so Iâm a bit confused what the issue might be? >> >> (client := ZnAWSS3Client new) >> accessKeyId: 'xxx'; >> secretAccessKey: âyyyyy'; >> checkIntegrity: true. >> >> client buckets. âWorks" >> client keysIn: 'mtt-dataâ. âWorks" >> >> client at: 'mtt-data' -> 'sample.txtâ. âWorks" >> >> client keysIn: 'mtt-data' query: (Dictionary with: 'versions'->nil). âGives an error?â >> >> >> HTTP/1.1 403 Forbidden >> >> <?xml version="1.0" encoding="UTF-8"?> >> <Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>xxx</AWSAccessKeyId><StringToSign>GET >> >> >> Has anyone tried doing this - Iâm sure there is something really simple that I am missing? >> >> Tim

June 17, 2021

Re: Spec Gtk Applications - Implementing File open/save/(print?) dialogs

by kmo

Wow! Thanks so much Esteban for taking all the time and trouble to provide this. I'll have a play with it. Ken -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

June 17, 2021

Re: Spec Gtk Applications - Implementing File open/save/(print?) dialogs

by Esteban Lorenzano

lol, I just realised I forgot to push my changes to it (I am working on fixing a leak on dialogs, so probably you will need to pull again soon, btw :P) anyway, you can pull gtk-bindings now and you will have the right accessors. Also, I have been working on a wrapper to help with the Gtk details (the idea is to integrate something to the newtools, so I need something that eventually can be mapped to a morphic component too ;) ) You can file in the exports I sending you (check the right order ;) ) And you should be able to execute what is in NmFileChooserDialog class>>example to get something like this: I think this can point you in the right direction. BUT! This is very early work... do not expect something ready for production :) Esteban On Jun 17 2021, at 2:47 pm, kmo <voxkmp(a)gmail.com> wrote: > Thanks Esteban. That's what I needed. I've got the dialog to open, like this > - > > generateRoseButton action: [ > (GtkFileChooserDialog newOpenFileTitle: 'Hello') > showAll; > run ] > > > But how do you get the chosen filename back? > Ken > > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >

June 17, 2021

Re: Spec Gtk Applications - Implementing File open/save/(print?) dialogs

by kmo

Thanks Esteban. That's what I needed. I've got the dialog to open, like this - generateRoseButton action: [ (GtkFileChooserDialog newOpenFileTitle: 'Hello') showAll; run ] But how do you get the chosen filename back? Ken -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

June 17, 2021

Re: Spec Gtk Applications - Implementing File open/save/(print?) dialogs

by Esteban Lorenzano

Hello, if you want to play with the direct Gtk dialog, you have GtkFileChooserDialog... take a look at it :) Esteban On Jun 17 2021, at 1:45 pm, kmo <voxkmp(a)gmail.com> wrote: > Hi - > > When writing a Gtk app using Pharo Spec2 are there any facilities for > standard system dialogs - open file / save file / etc - or do you have to > create them from scratch yourself (perhaps using SpDialogPresenter) ? > > Thanks in advance for any clarification. > Ken > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >

June 17, 2021

Spec Gtk Applications - Implementing File open/save/(print?) dialogs

by kmo

Hi - When writing a Gtk app using Pharo Spec2 are there any facilities for standard system dialogs - open file / save file / etc - or do you have to create them from scratch yourself (perhaps using SpDialogPresenter) ? Thanks in advance for any clarification. Ken -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

June 17, 2021

Re: Reading http post data using Zinc

by Davide Varvello

Hi Sven, I'm sending a FormData, so the right code is in ZnDefaultServerDelegate>>#formTest3: that you pointed out. Thank you very much. To help other people of the list, I summarize that in case of multipart form-data you have to read the entity and its parts, for example: (aRequest entity partNamed: #myPartName) fieldValueString. or also: aRequest entity parts first fieldName. aRequest entity parts first fieldValue Cheers Davide Sven Van Caekenberghe-2 wrote > Hi Davide, > >> On 16 Jun 2021, at 23:17, Davide Varvello via Pharo-users < > pharo-users@.pharo > > wrote: >> >> Hi Guys, >> I'm posting from an http form and I'm wondering how to read data from the >> post. It seems the request should give a ZnMultiPartFormDataEntity, but I >> can't find how to use it. >> >> Can you help me please? >> Davide >> >> >> >> >> -- >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html > > It depends on how the form is posted (there are two approaches). > > A working example of both can be found in > ZnDefaultServerDelegate>>#formTest2: and #formTest3: > > ZnServerTest>>#testFormTest2: and #testFormTest3: exercise this > functionality > > Basically, you just take the entity from the request and use it. > > HTH, > > Sven -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

June 17, 2021

Re: Zn and AWS - retrieving object versions?

by Sven Van Caekenberghe

Hi Tim, It has been a very long time since I last looked at this code. It is a good thing that at least part of it still works. Just by reading the code and reasoning about your problem, I would suggest you try the following change: In ZnAWSS3RequestSignatureTool>>#canonicalStringFor: replace the last request uri pathPrintString by request uri pathQueryFragmentPrintString I did not try this myself, so it might not solve your issue. Please let me know if this works. Sven > On 17 Jun 2021, at 03:05, Tim Mackinnon <tim(a)testit.works> wrote: > > Hi everyone - Iâm wondering if someone knows the trick to listing object versions in AWS S3? > > I was previously using a non-Zn library (there are a few around - but they are quite old and Iâm not sure how much they are maintained) - however I hadnât realised that Zn actually supports S3 until I read it a bit carefully and realised that I needed to load an extra AWS group. > > So - I have a bucket that is versioned, and I wanted to read the versions of an object - and hopefully be able to read the contents of an older version. > > I can list the contents of a bucket, but when I try to read the versions of an object - I get a forbidden error - which when I dig deeper gives a stranger explanation? > > I have confirmed that the AWS CLI is able to list versions in that bucket - so Iâm a bit confused what the issue might be? > > (client := ZnAWSS3Client new) > accessKeyId: 'xxx'; > secretAccessKey: âyyyyy'; > checkIntegrity: true. > > client buckets. âWorks" > client keysIn: 'mtt-dataâ. âWorks" > > client at: 'mtt-data' -> 'sample.txtâ. âWorks" > > client keysIn: 'mtt-data' query: (Dictionary with: 'versions'->nil). âGives an error?â > > > HTTP/1.1 403 Forbidden > > <?xml version="1.0" encoding="UTF-8"?> > <Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>xxx</AWSAccessKeyId><StringToSign>GET > > > Has anyone tried doing this - Iâm sure there is something really simple that I am missing? > > Tim

June 17, 2021

R: Re: Rounding in Floats

by Lorenzo

You are right! Lorenzo -----Messaggio originale----- Da: ducasse [mailto:stepharo@netcourrier.com] Inviato: mercoledÃ¬ 16 giugno 2021 22:44 A: Any question about pharo is welcome <pharo-users(a)lists.pharo.org> Oggetto: [Pharo-users] Re: Rounding in Floats Richard As I said it thousands of times, - first we are not good in math - second Pharo is what we have and we never said that it is the best system ever we just enhanced daily - third, I never saw a piece of code from you. - if you want to see Pharo improve (which I doubt about) just send us code and tests Iâm sad that you systematically ignore any of my emails on the topic. You could have an impact but you prefer to hide yourselves in your tower. Good luck with it. S.

June 17, 2021

Zn and AWS - retrieving object versions?

by Tim Mackinnon

Hi everyone - Iâm wondering if someone knows the trick to listing object versions in AWS S3? I was previously using a non-Zn library (there are a few around - but they are quite old and Iâm not sure how much they are maintained) - however I hadnât realised that Zn actually supports S3 until I read it a bit carefully and realised that I needed to load an extra AWS group. So - I have a bucket that is versioned, and I wanted to read the versions of an object - and hopefully be able to read the contents of an older version. I can list the contents of a bucket, but when I try to read the versions of an object - I get a forbidden error - which when I dig deeper gives a stranger explanation? I have confirmed that the AWS CLI is able to list versions in that bucket - so Iâm a bit confused what the issue might be? (client := ZnAWSS3Client new) accessKeyId: 'xxx'; secretAccessKey: âyyyyy'; checkIntegrity: true. client buckets. âWorks" client keysIn: 'mtt-dataâ. âWorks" client at: 'mtt-data' -> 'sample.txtâ. âWorks" client keysIn: 'mtt-data' query: (Dictionary with: 'versions'->nil). âGives an error?â HTTP/1.1 403 Forbidden <?xml version="1.0" encoding="UTF-8"?> <Error><Code>SignatureDoesNotMatch</Code><Message>The request signature we calculated does not match the signature you provided. Check your key and signing method.</Message><AWSAccessKeyId>xxx</AWSAccessKeyId><StringToSign>GET Has anyone tried doing this - Iâm sure there is something really simple that I am missing? Tim

June 17, 2021

Re: Rounding in Floats

by Richard O'Keefe

"first we are not good in math" First, I am not criticising YOU. Pharo's weird ScaledDecimal is Squeak's weird ScaledDecimal and you have not changed it. Fine. "second Pharo is what we have and we never said that it is the best system ever" True, but irrelevant. "third I never saw a piece of code from you" That is not true. Why, in this thread alone I contributed #roundOut. I have provided several pieces of code in this mailing list over the years. You can say that my code is no good, or that you don't want it, or that you think there is a better way to do the (admittedly small) things that I have provided, but if you never saw them you must have shut your eyes. In addition, a snapshot of my system is available on the web for anyone to play with. I shall post here when my GitHub repository is populated; I just have to clear a few more things out of the local directory that I don't have the right to distribute. (For example, benchmarking my CSV library against NeoCSV meant having to have NeoCSV, but it's not mine to distribute.) On Thu, 17 Jun 2021 at 08:45, ducasse <stepharo(a)netcourrier.com> wrote: > > Richard > > As I said it thousands of times, > - first we are not good in math > - second Pharo is what we have and we never said that it is the best system ever > we just enhanced daily > - third, I never saw a piece of code from you. > - if you want to see Pharo improve (which I doubt about) just send us code and tests > > Iâm sad that you systematically ignore any of my emails on the topic. > You could have an impact but you prefer to hide yourselves in your tower. Good luck with it. > > S.

June 17, 2021

Re: Rounding in Floats

by Richard O'Keefe

2Decimal floats are (a) part of the IEEE 758-2008 standard for floating-point arithmetic, (b) implemented as part of the instruction set in IBM z/Series and POWER computers, (c) allowed for in the current C standard, (d) partially supported by GCC https://gcc.gnu.org/onlinedocs/gcc-8.1.0/gcc/Decimal-Float.html and (e) available for most machines via the "reference implementation" in C. The current COBOL standard basically defines its arithmetic in terms of this. Java of course has BigDecimal. While decimal floats became part of IEEE 754 in 2008, they were previously covered by IEEE 854. Reverting to ScaledDecimal, let us consider the 10.0s1 / 3 example. There is a huge problem here with no really satisfactory answer. In my library, it currently answers 3.3s1, exactly equal to 33/10. In Squeak/Pharo, it answers "I am really 10/3 but print me with one decimal", so you see 3.3a1 but it *behaves* like 10.3. In VisualAge Smalltalk you get 3.333333333333333333333333333333 If it were not for the fact that the ANSI Smalltalk standard appears to require that <scaled decimal> / <integer> yield a <scaled decimal>, I would prefer to answer 10/3. Decimals just plain are not closed under division (although they are closed under addition, subtraction, and multiplication). When it comes to scaled decimals, the ANSI Smalltalk standard is frankly a mess. Amongst other things, it defers the semantics of operations on them to the Language-Independent Arithmetic standard, which explicitly denies having anything to say about them! I understand why my library does what it does. I even tried to publish a paper about it. I understand why VisualAge Smalltalk does what it does. (I've read IBM/360 PrincOps.) I do NOT understand why Squeak and Pharo do what they do, and if anyone knows the rationale for their ScaledDecmal please tell me. On Thu, 17 Jun 2021 at 06:29, Esteban Maringolo <emaringolo(a)gmail.com> wrote: > > I didn't know there were decimal floats. > > Are they used elsewhere? > > Esteban A. Maringolo > > On Wed, Jun 16, 2021 at 11:20 AM Konrad Hinsen > <konrad.hinsen(a)fastmail.net> wrote: > > > > On 16/06/2021 15:52, Sven Van Caekenberghe wrote: > > > I am also a bit intrigued by this. Like you said: several other programming languages (I tried a couple of Common Lisp and Scheme implementations) do the same as Pharo, but handheld calculators, normal and scientific, do not. > > > > Handheld calculators use decimal floats, not binary floats. That doesn't > > remove rounding issues, but it makes conversion to and from print > > representations loss-free. > > > > > > Konrad

June 17, 2021

Re: Reading http post data using Zinc

by Sven Van Caekenberghe

Hi Davide, > On 16 Jun 2021, at 23:17, Davide Varvello via Pharo-users <pharo-users(a)lists.pharo.org> wrote: > > Hi Guys, > I'm posting from an http form and I'm wondering how to read data from the > post. It seems the request should give a ZnMultiPartFormDataEntity, but I > can't find how to use it. > > Can you help me please? > Davide > > > > > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html It depends on how the form is posted (there are two approaches). A working example of both can be found in ZnDefaultServerDelegate>>#formTest2: and #formTest3: ZnServerTest>>#testFormTest2: and #testFormTest3: exercise this functionality Basically, you just take the entity from the request and use it. HTH, Sven

June 16, 2021

Reading http post data using Zinc

by Davide Varvello

Hi Guys, I'm posting from an http form and I'm wondering how to read data from the post. It seems the request should give a ZnMultiPartFormDataEntity, but I can't find how to use it. Can you help me please? Davide -- Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html

June 16, 2021

Re: Rounding in Floats

by ducasse

Richard As I said it thousands of times, - first we are not good in math - second Pharo is what we have and we never said that it is the best system ever we just enhanced daily - third, I never saw a piece of code from you. - if you want to see Pharo improve (which I doubt about) just send us code and tests Iâm sad that you systematically ignore any of my emails on the topic. You could have an impact but you prefer to hide yourselves in your tower. Good luck with it. S.

June 16, 2021

Re: Rounding in Floats

by Konrad Hinsen

Sven Van Caekenberghe <sven(a)stfx.eu> writes: > It would be possible (and maybe it has already been done) to > implement/add such a decimal floating point number to Pharo. It would > require reimplementing all operations from scratch (esp. sin/cos/tan > log/exp and so on), it would be slow, but interesting. That would be an interesting experiment indeed. Either use one of the IEEE754 decimal float formats (https://en.wikipedia.org/wiki/Decimal_floating_point) or Douglas Crockford's DEC64 proposal (https://www.crockford.com/dec64.html, which strangely enough does not refer to the older IEEE standard). There are implementations of both for various other languages that can serve as inspiration. Konrad.

June 16, 2021

Re: Rounding in Floats

by Sven Van Caekenberghe

> On 16 Jun 2021, at 16:20, Konrad Hinsen <konrad.hinsen(a)fastmail.net> wrote: > > On 16/06/2021 15:52, Sven Van Caekenberghe wrote: >> I am also a bit intrigued by this. Like you said: several other programming languages (I tried a couple of Common Lisp and Scheme implementations) do the same as Pharo, but handheld calculators, normal and scientific, do not. > > Handheld calculators use decimal floats, not binary floats. That doesn't remove rounding issues, but it makes conversion to and from print representations loss-free. > > > Konrad > mmm, this is interesting. It would be possible (and maybe it has already been done) to implement/add such a decimal floating point number to Pharo. It would require reimplementing all operations from scratch (esp. sin/cos/tan log/exp and so on), it would be slow, but interesting.

June 16, 2021

Re: Rounding in Floats

by Esteban Maringolo

I didn't know there were decimal floats. Are they used elsewhere? Esteban A. Maringolo On Wed, Jun 16, 2021 at 11:20 AM Konrad Hinsen <konrad.hinsen(a)fastmail.net> wrote: > > On 16/06/2021 15:52, Sven Van Caekenberghe wrote: > > I am also a bit intrigued by this. Like you said: several other programming languages (I tried a couple of Common Lisp and Scheme implementations) do the same as Pharo, but handheld calculators, normal and scientific, do not. > > Handheld calculators use decimal floats, not binary floats. That doesn't > remove rounding issues, but it makes conversion to and from print > representations loss-free. > > > Konrad

June 16, 2021

Re: Rounding in Floats

by Esteban Maringolo

On Wed, Jun 16, 2021 at 10:52 AM Sven Van Caekenberghe <sven(a)stfx.eu> wrote: > > I am also a bit intrigued by this. Like you said: several other programming languages (I tried a couple of Common Lisp and Scheme implementations) do the same as Pharo, but handheld calculators, normal and scientific, do not. > > I think that going for 1/10 fractions/precision is not going to help: you got a division by 113 in your formula [https://en.wikipedia.org/wiki/Handicap_(golf)] this will give smaller fractions. And the reasons behind why they chose 113 are still unknown, because that number is used to get a "difficulty coefficient", so if the course is rated a 125, then 125/113 will give you roughly a ~1.1 coefficient. They could have used 100. > The problem is not the calculation (modern 64-bit floats as in Pharo are plenty accurate), it is how you handle results. You should just round it correctly and be done with it. > Note that > a roundTo: 0.00000000000001. (1e-14) still gives 4.5 > it is only one step further that you hit the limit and get the ugly but correct result. I'm not doing that, and I only store the original number (which has a fixed decimal) and the "rounded" (to no decimals) number, all intermediate numbers are re-calculated (maybe cached) but not stored elsewhere. What I might be doing wrong is to store the original index as float instead of a Decimal number. > When computing with money, you would be inclined to put everything in cents (because you cannot divide them further). But once you start computing percentage discounts or taxes, you again get problems. At each of those steps you must make sure that no cents are lost. And that includes adding a "rounding" item for any difference in all invoices, orders, etc. Regards! Esteban A. Maringolo

June 16, 2021