October 2017 - Pharo-users - lists.pharo.org

Netstyle/Workflow Package discovery - (was: Business process (declaration and orchestration), ontology/taxonomy)

by CÃ©drick BÃ©ler

A pleasure to discover ! To me, a wonderful(ly engineered) library. Big thanks to Netstyle ! Iâm just getting my hands around, but it looks to me like a great general purpose BP tool (modeling + engine + xpdl import export). It would be very useful for IS in industrial contexts (*). And before all a superb starting point to model my simple personal routines as executable processes. On the practical aspects, just a problem loading because of WADynamicVariable, but it kinds of load on Pharo 6. Running tests, there are (naturally) some failures. I think most come from the removed links to Omnibase/History support and seaside (WADynamicVariable). Some stuffs that are missing: #isOmniBaseTransaction #markDirty A reference to TimeStamp fixed: #beginInHistory â¦ Need to fix WADynamicVariable with shouldnât be hard. The History link (persistence) is a bit more difficult as I donât know its importance in the engine. All Workflow object are managed object which (if I understand well) are persistent object. So maybe It need a (local) persistent alternative, a stub ? Anyway, I need to understand more and I will probably come back with some questions about the dependencies and how to fix them. Cheers and thanks again, enligthening code :) CÃ©drick * Interoperability of is a field I try carefully not to enter because I found not really fun (as most of the tool Iâve soon were java based â¦ and slowâ¦ and java world !) but if only I had similar tools in pharo that could bring the fun back :) > Le 27 oct. 2017 Ã 09:37, CÃ©drick BÃ©ler <cdrick65(a)gmail.com> a Ã©crit : > > Thank you! > > I thons this just perfect as a starting point ! > > Cheers, > > Cedrick > > EnvoyÃ© de mon iPhone > >> Le 26 oct. 2017 Ã 19:38, Paul DeBruicker <pdebruic(a)gmail.com> a Ã©crit : >> >> Maybe the package described here has what you're looking for : >> >> http://forum.world.st/Ann-Workflow-td4963635.html >> >> >> >> >> >> >> >> CÃ©drick BÃ©ler wrote >>> Hi again, this is my last question and the more general one of the day :-) >>> >>> >>> Iâm looking for way of representing and executing simple "business >>> processes" in Pharo and a way of declaring domain ontologies/taxonomies. >>> >>> I didnât find any lib around this subjects except some projects in other >>> smalltalk dialects. >>> >>> I just wander if somebody has done some work in these field. Iâm also >>> interested in (KISS) design discussions around these topics, hence this >>> email. >>> >>> I donât want to do a full fledged business process middleware. >>> >>> I would need : >>> - a way to represent simple business processes (succession of activities >>> with logic gates (and/or/xor) => I might be able to do that by myself). >>> - a way to execute these processes (routines) in a semi-aotumatic manner >>> => This looks more difficult to do to me. >>> => my aim is to execute recurrent routines (my routines) with the help of >>> a Pharo application >>> >>> >>> For such a system, I also need a way to categorize information context. >>> Again, I donât think I need a full fledged ontology implementation like >>> Description Logic (or whatever). I think Iâll be happy with information >>> tagging according to a predefined taxonomy. Instead of flat tags, Iâd like >>> them to implement some sort of multiple inheritance. For instance, I may >>> need a tag #soccer that "inherit" #sport. >>> >>> Any information regarding taxonomy tagging in Pharo ? (Or eventually >>> ontology?). >>> >>> >>> >>> TIA, >>> >>> CÃ©drick >> >> >> >> >> >> -- >> Sent from: http://forum.world.st/Pharo-Smalltalk-Users-f1310670.html >>

Oct. 27, 2017

Re: [Pharo-users] QCMagritte on Github

by HernÃ¡n Morales Durand

Nice to know Laurent, Could you please comment or share how to install this version uploaded to GitHub? Any way to check the installed or current QCMagritte version? Cheers, HernÃ¡n 2017-10-27 7:39 GMT-03:00 laurent laffont <laurent.laffont(a)gmail.com>: > Hi, > > my team starts to use QCMagritte. For our needs we have imported > SmalltalkHub repository to Github here: > https://github.com/Afibre/QCMagritte > > I don't know if you (Diego, Stephan, Tobias) plan to use Github > instead of SmalltalkHub. At least Github allows branches & pull > request. > > Regards, > > Laurent Laffont >

Oct. 27, 2017

Re: [Pharo-users] Binary Decision Diagram Package in Smalltalk

by Steffen MÃ¤rcker

Dear Andrew, I didn't find time to answer earlier. Some time ago, I was looking for a (MT)BDD package in ST as well. I didn't found one. So the only two options left are 1) implementing a new BDD lib in ST and 2) doing FFI to some existing lib, e.g. CUDD, Sylvan, Jinc I'd prefer 2) since the existing libraries are feature-rich and highly optimized - which took quite some time. As a bonus, a solution could potentially switch between those backends. The biggest hurdle, in my option, is memory management, since most libs use some sort of reference counting. And you do not want to end up with nightmarish dozens of ref(bddNode) deref(bddNode) in your application code (like the probabilistic model checker PRISM does). This introduces hard to track bugs easily. However, I have an idea in mind how to tackle this but I didn't found the time to put it into code yet. May I ask, which sort of application do you have in mind? Best, Steffen Am .10.2017, 07:54 Uhr, schrieb Prof. Andrew P. Black <black(a)cs.pdx.edu>: > Thanks for the responses so far. I see that I need to clarify my > enquiry. > > B-Trees and BDDs are not the same. BDDs are an efficient and compact > representations for Boolean functions, sometimes used in SAT-solvers and > electronics design. The key idea is that since the output must be 0 or > 1, you can represent any Boolean function as a tree whose depth is the > same as the number of bits in the input. > > To make the tree small and efficient, though, you need to eliminate any > node whose two children are the same, and to share subtrees, so that you > really get a DAG, not a tree. The full name for these efficient > compressed trees is âReduced Order Binary Decision Diagramsâ, or > ROBDDs. I was hoping that someone else had implemented the algorithms > necessary to build this representation. > > Because sets can be considered to be Booleans functions (true => > argument is in the set), you can use ROBDDs to efficiently represent > large sets. > > To be clear, despite the word âdiagramâ in the name, one is not normally > interested in drawing the BDD â except in the documentation for the > package ;-). Normally, BDDs they are used to represent sets, or > functions, where the drawing would be hopelessly large. > > The BuDDy package (http://buddy.sourceforge.net/manual/main.html) is an > example of what Iâm looking for, but unfortunately itâs in C++. > > Andrew > > >> On 25 Oct 2017, at 21:39 , Stephane Ducasse <stepharo.self(a)gmail.com> >> wrote: >> >> Hi andrew >> >> I think that Avi did a package about BDD (but I thought it was special >> binary trees) so this is probably the same. >> Did you check on Squeaksource? >> http://www.squeaksource.com/BTree.html >> If this is what you are looking for I can help porting it to Pharo. >> >> Stef >> >> >> On Wed, Oct 25, 2017 at 9:02 PM, Prof. Andrew P. Black >> <black(a)cs.pdx.edu> wrote: >>> Does anyone know of a BDD â thatâs Binary Decision Diagram â package >>> written in Smalltalk? >>> >>> Andrew >>> >>> >> >

Oct. 27, 2017

UK Smalltalk User Group Meeting - Monday, October 30th - PharoLambda: Smalltalk running serverless on AWS

by Tim Mackinnon

The next meeting of the UK Smalltalk User Group Meeting will be on Monday, 30th October. We'll meet at The City Pride, London ( http://www.cityprideclerkenwell.co.uk/ <http://www.cityprideclerkenwell.co.uk/> ) at 7pm. Tim Mackinnon will show how recent Pharo advances with a small footprint 64bit image allow for Smalltalk to run happily on AWS Lambda and power things like an Alexa skill. While serverless architecture is interesting in its own right, the neat twist is using standard Smalltalk tooling to "~live" debug a failed execution and step through a post mortem stack. We will take a peak at the GitLab CI setup to deploy an Alexa application, look at how a simple lambda function can be hooked up and then discuss how we might leverage other Smalltalk strengths in a serverless world. If you'd like to join us, you can just show up at the pub. You can also sign up in advance at the meeting's Meetup page: https://www.meetup.com/UKSTUG/events/244451089/ <https://www.meetup.com/UKSTUG/events/244451089/>. See you there!

Oct. 27, 2017

Re: [Pharo-users] [Pharo-dev] [ANN] Pharo Consortium New Platinum Member: JPMorgan Chase

by Ben Coman

Wow! Thats three new platinum announcements in as many days. Great work guys. For me this is not just about the money it brings in for additional engineering resources to improve Pharo Its the implicit endorsement of the future value these companies expect to gain from Pharo, and of the open-source consortium model. Thank you to those that had the vision in the early years to create and support the consortium. The future looks bright for me to keep hacking on my favourite programming environment. cheers -ben On Thu, Oct 26, 2017 at 2:45 PM, Marcus Denker <marcus.denker(a)inria.fr> wrote: > The Pharo Consortium is very happy to announce that JPMorgan Chase > has joined the Consortium as a Platinum Member. > > About > - JPMorgan Chase: https://www.jpmorganchase.com > - 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 > >

Oct. 27, 2017

Re: [Pharo-users] Exchanging information between 2 pharo applications (2 images running on two different computers)

by CÃ©drick BÃ©ler

> > Existing implementations out there seems to uses whatever nodes on the network to replicate the information. > > Yes, because that makes them decentralized :) Yes :) But couldn't we limit the decentralized networks to some nodes (my node + nodes of persons/organization I trust) + eventually node they trusts. I have the feeling that limiting the networks would simplify the implementation cost as the underlying cryptographic system (I have a very naive understanding of such systems but I know I need them to sign/crypt information). I have no idea of a minimal node number that is acceptable to do content addressing. > > > Iâd like to control nodes where it is replicated. My nodes (all my app instances + nodes of person Iâm exchanging information with + eventually friend of friend). > > We've done recent work on capability-based content adressing, but, first it's very slow (so you use a two level cryptosystem: the crypted header contains the key to decrypt the content, and the crypted header can only be decrypted if your private key has the right level of capabilities on the data item. Interesting ! I need to get more knowledge on that. BTW, I found these introduction courses well done on cryptography in information theory (https://khanacademy.org/computing/computer-science <https://khanacademy.org/computing/computer-science>) Just thinking loud: I donât actually need a quick implementation as the default is to have not synced version that get synchronized on opportunistic connection. What if each node has by default private keys and all public key of the external node I have relation with ? Wouldnât it be simpler ? To prototype stuff, I think I can consider naive crypto and even do symmetric cryptography (and use Cryptography package or NaCL binding). I think Iâll do a very naive approach to sign and encrypt. If you know some existing applications that could help, please, let me know. > > > What hash function would you use ? > > Anything that is fast, bonus points if it uses CPU special instructions (that you can't use from Pharo, of course ;)), and has the right cryptographic properties. Unless you go into a specific cryptosystem, I'd say that it is not important. :) ok > > > To get something compatible with ipfs, Iâd need something like: https://github.com/multiformats/multihash <https://github.com/multiformats/multihash> > It looks to me quite universal as self describing. But any (existing) hash method compatible with content hashing would do the job. > > Interesting, but it looks like a minor issue in the overall scheme. Makes some of your system robust to evolution in the hash used, but, since first bytes are not well distributed, can you use it safely to build a multi-hash function system? Probably not. Yes I agree. One idea was to use only ipfs for public information shared with everybody (even outside of nodes I have relation with). Clearly, not a central point. > > > >> I wouldn't be against a slightly higher granularity when dealing with object transfers, however. > > You mean at the pharo level ? Higher granularity means having more control on the exchange/merge ? > > No, just that the content-based address scheme is costly... and that a practical implementation would probably look to provide addresses only to large enough entities (a page containing objects, for example, or a large objects containing smaller ones). So that you donc create an address for each character of the string object describing the name of a person, say). Oh ok. I think this is how I was seeing itâ¦ says I exchange my phone number with somebody, the content hashed would be the full information (full content + version number + (maybe) its model hash + its geolocalized timestamp). Thanks a lot for the exchange, CÃ©drick > > Regards, > > Thierry > > > Cheers, > > CÃ©drick >

Oct. 27, 2017

QCMagritte on Github

by laurent laffont

Hi, my team starts to use QCMagritte. For our needs we have imported SmalltalkHub repository to Github here: https://github.com/Afibre/QCMagritte I don't know if you (Diego, Stephan, Tobias) plan to use Github instead of SmalltalkHub. At least Github allows branches & pull request. Regards, Laurent Laffont

Oct. 27, 2017

Re: [Pharo-users] Exchanging information between 2 pharo applications (2 images running on two different computers)

by Thierry Goubier

2017-10-27 11:28 GMT+02:00 CÃ©drick BÃ©ler <cdrick65(a)gmail.com>: > > Hi Cedric, > > a short answer: some of what you're trying to do has been traditionnally > handled by object databases - multiple images retrieving and updating > objects on a central store ensuring lots of good properties : see Gemstone. > > > Yes , Iâd like to avoid this centralized approach. > I mean that they have already some of the mechanisms in place, even if centralized. > > > Another answer, since you're looking at content-addressable distributed > file systems. You can resolve the offline mode with object duplications > (duplicate all objects in the images using them), and, when coming back > online, have a merge approach to reconcile changes between versions of > shared objects. Content-based hashes as identifiers in a distributed store > have very nice properties for that purpose, because, if image C has > modified object 0xcdaff3, then that object has in fact become object > 0xee345d for that image (and the unmodified object is still 0xcdaff3 for > images A and B). > > > You nailed it. This is what Iâd like to reproduce. > > Existing implementations out there seems to uses whatever nodes on the > network to replicate the information. > Yes, because that makes them decentralized :) > > Iâd like to control nodes where it is replicated. My nodes (all my app > instances + nodes of person Iâm exchanging information with + eventually > friend of friend). > We've done recent work on capability-based content adressing, but, first it's very slow (so you use a two level cryptosystem: the crypted header contains the key to decrypt the content, and the crypted header can only be decrypted if your private key has the right level of capabilities on the data item. > > What hash function would you use ? > Anything that is fast, bonus points if it uses CPU special instructions (that you can't use from Pharo, of course ;)), and has the right cryptographic properties. Unless you go into a specific cryptosystem, I'd say that it is not important. > > To get something compatible with ipfs, Iâd need something like: > https://github.com/multiformats/multihash > It looks to me quite universal as self describing. But any (existing) hash > method compatible with content hashing would do the job. > Interesting, but it looks like a minor issue in the overall scheme. Makes some of your system robust to evolution in the hash used, but, since first bytes are not well distributed, can you use it safely to build a multi-hash function system? Probably not. > > > I wouldn't be against a slightly higher granularity when dealing with > object transfers, however. > > > You mean at the pharo level ? Higher granularity means having more control > on the exchange/merge ? > No, just that the content-based address scheme is costly... and that a practical implementation would probably look to provide addresses only to large enough entities (a page containing objects, for example, or a large objects containing smaller ones). So that you donc create an address for each character of the string object describing the name of a person, say). Regards, Thierry > > Cheers, > > CÃ©drick >

Oct. 27, 2017

Re: [Pharo-users] [Pharo-dev] [ANN] Iceberg 0.6.2 backported to Pharo 6.1

by Norbert Hartl

Super! Thanks for that! Norbert > Am 27.10.2017 um 11:36 schrieb Esteban Lorenzano <estebanlm(a)gmail.com>: > > Hi, > > I backported lastest Iceberg version to Pharo 6.1 to allow people to benefit for latest changes. > This version has an important amount of tweak and fixes, but most important is the inclusion of tonel file format (this is default for Pharo 7.0, optional for Pharo 6.1) and introduces a file-per-class format. > The advantages of this format has everything to do with the speed of access (is easier to reconstruct a package like) and the space on disk (methods are usually small but minimum space in disk is usually 4k so we waste a lot of space). Is also a better format for SSD disks. > > To backport Iceberg 0.6.2 I also needed to backport latest version of Metacello, so Pharo 6.1 and Pharo7+ users now also have the latest version of it available :) > > cheers! > Esteban

Oct. 27, 2017

[ANN] Iceberg 0.6.2 backported to Pharo 6.1

by Esteban Lorenzano

Hi, I backported lastest Iceberg version to Pharo 6.1 to allow people to benefit for latest changes. This version has an important amount of tweak and fixes, but most important is the inclusion of tonel file format (this is default for Pharo 7.0, optional for Pharo 6.1) and introduces a file-per-class format. The advantages of this format has everything to do with the speed of access (is easier to reconstruct a package like) and the space on disk (methods are usually small but minimum space in disk is usually 4k so we waste a lot of space). Is also a better format for SSD disks. To backport Iceberg 0.6.2 I also needed to backport latest version of Metacello, so Pharo 6.1 and Pharo7+ users now also have the latest version of it available :) cheers! Esteban

Oct. 27, 2017