May 2020 - Pharo-dev - lists.pharo.org

Re: [Pharo-dev] uFFI: What is the difference between FFIExternalObject and FFIOpaqueObject?
by Esteban Lorenzano May 24, 2020

May 24, 2020

Hi, Thatâs not really possible :) In your case, Method is already a pointer (with arity 1). Which means Method * Is in fact a pointer to a pointer (arity 2), something like "void**" This is a typical case, but you are not âhaving the two casesâ, you still have one :) UFFI will try to box/unbox that for you, btwâ¦ but sometimes this is not what you want (because pointers to pointers is a typical way to answer lists, for example). And UFFI does not know what you want thereâ¦ in this cases (when you want the list), the recommended way is to get the pointer and create the list yourself. Instead: Method *methodList() You call void *methodList() To avoid the unbox attempt, and then you process your answer âin rawâ (for example using the #readArrayOf:until: method). If it happens that you use both SomeStructure, and SomeStructure*, then is not an opaque type, and you need to map it by subclasses FFIExternalStructure and implementing fieldsDesc, etc. Esteban > On 23 May 2020, at 20:00, Sean P. DeNigris <sean(a)clipperadams.com> wrote: > > Esteban Lorenzano wrote >> The easiest way I have to explain is: >> >> You use an OpaqueObject when you will refer to the opaque type in calls >> as: someFunction(opaqueobject *someArg). >> You use an ExternalObject when you will refer to the opaque type in calls >> as: someFunction(externalobject someArg). > > Very clear! We're getting somewhere :) But... > > What if a type is used both ways? > > For example: > ^ self ffiCall: #(Method * class_copyMethodList(Class self, uint > *outCount)) > and > ^ self ffiCall: #(struct objc_method_description * > method_getDescription(Method self)) > > > > ----- > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html >

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Re: [Pharo-dev] uFFI: What is the difference between FFIExternalObject and FFIOpaqueObject?
by Esteban Lorenzano May 24, 2020

May 24, 2020

> On 22 May 2020, at 04:24, Sean P. DeNigris <sean(a)clipperadams.com> wrote: > > Esteban Lorenzano wrote >> The class comments are not clear? > > Maybe it's me ;-) > > > Esteban Lorenzano wrote >> Opaque object = https://en.wikipedia.org/wiki/Opaque_data_type >> <https://en.wikipedia.org/wiki/Opaque_data_type> >> External object = a pointer to something. > > For example, why is ObjCClass a subclass of FFIExternalObject instead of > FFIOpaqueObject when the docs say that a "Class [is] An opaque type that > represents an Objective-C class"? Also, is the distinction just conceptual? > I don't see what either class "buys" you in behavior since they are siblings > that both pretty much have no methods. This is because ObjCClass = SomeOpaqueStructurePointer (is already a pointer), same as ObjCSelector and ObjCMethod. Difference is subtle, because is just a different way of representing the same. The easiest way I have to explain is: You use an OpaqueObject when you will refer to the opaque type in calls as: someFunction(opaqueobject *someArg). You use an ExternalObject when you will refer to the opaque type in calls as: someFunction(externalobject someArg). Esteban > > > > ----- > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html <http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html>

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Project of Interest => Jekyll + Dynamic processing integration + Git(hubs)Pages => pharo in the middle
by CÃ©drick BÃ©ler May 23, 2020

May 23, 2020

Hi there, This post is just to talk about one side project Iâm exploring and interested in from a long time. I think it may interest other people here. Iâd like to have powerful (static based) web site so hosting is really cheap (even free) and hassle free. Iâve my own server for years, it is cheap and simple but, of course, it needs some maintenance (linux update, nginx scripts, â¦) even if tools are the simplest Iâve found. Recently thanks to student projects ;-), I found some time to learn what I find is a wonderful solution. This solution is to use GitHub DSCM, GitHub Pages and Jekyll (a ruby static site generator that is natively integrated) all together. https://jekyllrb.com <https://jekyllrb.com/> The beauty is that you can edit the site straight on GitHub. We get the power of version system and hosting for freeâ¦ It literally is a CMS and the cheapest and reliable that I know of (grav might be another option). Of course, there are some Â« dynamic Â» content possibilities too (otherwise GitHub Pages is enough) - blog posts are natively generated through new files according to a name convention. - there are plugins too (but you have to watch for compatibility in GitHub). Dealing with forms and comments is possible - solutions that are hosted on a third-party. Solution like Discus or formspree, â¦ (thatâs a NO GO to me) - web service integration that you can host (note that form spree is on GitHub too https://github.com/formspree/formspree <https://github.com/formspree/formspree>) This last point is where Iâd like Pharo (Zinc, Iceberg) to be integrated. Again we could imagine a web service system based on Zinc. I could manage form submissions that way and everything Iâd like but it may end up complex. Do I need a database ? Do I need to store information and therefore manage the underlying architecture. If it crash, I want only the endpoint to be not available but the whole site still working. An in between elegant solution os to use git for what itâs good at (versioning collaboratively through PR, and also reliable hosting in classic platforms). The idea is to use the PR mechanisms to submit stuff like blog comments (note that you have a free moderation system). This is actually not limited to comments but all kinds of possible interactionâ¦ This way is (to me) better in terms of infrastructure management. Such a service also needs to be available (and maintained) but this is a very minimalist machinery (hanling POST request service only - no real content management as deferred to github). And again, a fail safe version (for the last version of the generated pages). Staticman (https://staticman.net <https://staticman.net/>) is a nice node application that allows to do this. Itâs possible to host the service too. I can use this node app of course, but I believe we could have quite easily such an application in Pharo with Zinc. I also wonder if we could use Iceberg to deal with this information straight in a pharo image (thatâd be cherry on the cake). The super cherry of the cake would be pharo core and lib documentation, demos (you can have one gihub page by organization and/or users - in paid plans, you can have more for private stuff)â¦ One place, one process to contribute, either for code or documentation. Anyway, I have no real question except than asking for feedback and also to know if some people are interested in such project. Cheers, CÃ©drick nb: my hidden goal is to provide web site for people, unipersonal and small organizations. So you know, they pay for the service of creation, but then they own it and can do whatever they like. Of course we can also offer paid services like managing dynamic information content. More than comments, Iâd like to be able to deal with stuff like orders, facturation, even meeting planning through ics versioned files, etc. This really is something Iâd like to be able to provide soon (less than 1 yr time - simplest web site with contact form and comments at least). It might become something more serious the future...

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[Pharo 9.0] Build #308: Add tests for Athens Cairo SVG and PDF creation + some renames in examples
by ci-pharo-ci-jenkins2＠inria.fr May 22, 2020

May 22, 2020

There is a new Pharo build available! The status of the build #308 was: FAILURE. The Pull Request #6384 was integrated: "Add tests for Athens Cairo SVG and PDF creation + some renames in examples" Pull request url: https://github.com/pharo-project/pharo/pull/6384 Issue Url: https://github.com/pharo-project/pharo/issues/6382 Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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Re: [Pharo-dev] uFFI: What is the difference between FFIExternalObject and FFIOpaqueObject?
by Esteban Lorenzano May 22, 2020

May 22, 2020

> On 22 May 2020, at 15:07, Ben Coman <btc(a)openinworld.com <mailto:btc@openinworld.com>> wrote: > > > > On Fri, 22 May 2020 at 15:25, Esteban Lorenzano <estebanlm(a)netc.eu <mailto:estebanlm@netc.eu>> wrote: >> On 22 May 2020, at 04:24, Sean P. DeNigris <sean(a)clipperadams.com <mailto:sean@clipperadams.com>> wrote: >> >> Esteban Lorenzano wrote >>> The class comments are not clear? >> >> Maybe it's me ;-) > > > No. I struggled with this also, and still don't have it fully grasped. I could follow Eteban's advice in a particular case I asked about, but still feel hard to reason about next time. > http://forum.world.st/typedef-pointerArity-for-FFIOpaqueObjects-td4914975.h… <http://forum.world.st/typedef-pointerArity-for-FFIOpaqueObjects-td4914975.h…> > http://forum.world.st/UFFI-isPointer-absolute-or-versus-naturalPointerArity… <http://forum.world.st/UFFI-isPointer-absolute-or-versus-naturalPointerArity…> > >> >> >> Esteban Lorenzano wrote >>> Opaque object = https://en.wikipedia.org/wiki/Opaque_data_type <https://en.wikipedia.org/wiki/Opaque_data_type> >>> <https://en.wikipedia.org/wiki/Opaque_data_type&gt <https://en.wikipedia.org/wiki/Opaque_data_type&gt>; >>> External object = a pointer to something. >> >> For example, why is ObjCClass a subclass of FFIExternalObject instead of >> FFIOpaqueObject when the docs say that a "Class [is] An opaque type that >> represents an Objective-C class"? Also, is the distinction just conceptual? >> I don't see what either class "buys" you in behavior since they are siblings >> that both pretty much have no methods. > > > This is because ObjCClass = SomeOpaqueStructurePointer (is already a pointer), same as ObjCSelector and ObjCMethod. > Difference is subtle, because is just a different way of representing the same. > > The easiest way I have to explain is: > > As a prelude to my next comment, how does "External" distinguish between the two case? > Aren't both cases dealing with external C data? > > You use an OpaqueObject when you will refer to "the opaque type" in calls as: someFunction(opaqueobject *someArg). > You use an ExternalObject when you will refer to "the opaque type" in calls as: someFunction(externalobject someArg). > > That makes the distinction really clear. So if now IIUC, both cases deal with "opaque types" > with the *only* difference between the two being the arity? > Then I propose the following naming would be more intention revealing... > > OpaqueObject when you will refer to "the opaque type" in calls as: someFunction(opaqueobject *someArg). > OpaquePointer when you will refer to "the opaque type" in calls as: someFunction(opaquepointer someArg). > > > And to test my new understanding, the matching typdefs and FFI calls would be... > > OPAQUE OBJECT > - typedef MyOpaqueType opaqueobject. > - int someFunction(opaqueobject *someArg) > > - FFIOpaqueObject subclass: #MyOpaqueType. > - self ffiCall: #(int someFunction( MyOpaqueType *ot ) ). > - opaque type has arity 0, so FFI needs to take a pointer to it > > OPAQUE POINTER > - typedef MyOpaqueObject *opaquepointer. > - int someFunction(opaquepointer someArg) > > - FFIOpaquePointer subclass: # MyOpaqueType. > - self ffiCall: #(int someFunction( MyOpaqueType ot ) ). > - opaque type has arity of 1, so FFI uses it directly > > The latter FFI call is without the *â¦ because FFIOpaquePointer is already a pointer. > In practice, both FFI calls are identical, and you use the one that matches the C header definitions. > > > ...or maybe I still don't get it. No, you got it :) Part of the confusion is the horribly bad name that FFIExternalObject has :/ Other part is my inability to explain it ;) But yes, this is all as you say. If someone wants to do a PR changing the names and maybe enhancing my commentsâ¦ it would be nice :D Esteban > > cheers -ben

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Re: [Pharo-dev] uFFI: What is the difference between FFIExternalObject and FFIOpaqueObject?
by Esteban Lorenzano May 22, 2020

May 22, 2020

Hi, The class comments are not clear? Opaque object = https://en.wikipedia.org/wiki/Opaque_data_type <https://en.wikipedia.org/wiki/Opaque_data_type> External object = a pointer to something. > On 21 May 2020, at 21:53, Sean P. DeNigris <sean(a)clipperadams.com <mailto:sean@clipperadams.com>> wrote: > > I'm working on improving the documentation. I'd like examples of situations > when you'd use one or the other and why... > > Also, the FFIOpaqueObject class comment could be fleshed out a bit. Check > out this excerpt: > "this means we always access them through a reference. > Now, we could declare the pointer to the structures, but > then our declarations wouldn't be as close to C as we want." > > What would be an example of "declar[ing] the pointer to the structures" and > the resulting declarations that "wouldn't be as close to C as we want"? There are plenty of cases in C where you do: struct MyStruct *s; Buy tou cannot do (or you cannot use): struct MyStruct s; This is like that because most modern frameworks use the opaque type as a place to keep state, but to interact with them you use functions. e.g: MyOpaqueType *ot = newOpaqueType(); opaque_type_someFunction(ot, âa parameterâ); Then an opaque object would be: FFIOpaqueObject subclass: #MyOpaqueType. And you can do an ffi call like this: self ffiCall: #(void opaque_type_someFunction(MyOpaqueType *ot, char *aString)). Note the declaration of "MyOpaqueType *otâ This is how C declaration looks. We can say that an opaque type is a pointer type with arity 0. Now, an FFIExternalObject (which should be called FFIExternalPointer), has already an arity of 1. Which means, if you declare: FFIExternalObject subclass: #MyOpaqueTypePtr. The same ffiCall you did before would be: self ffiCall: #(void opaque_type_someFunction(MyOpaqueTypePtr ot, char *aString)). Note the declaration without the *â¦ this is because FFIExternalObject is already a pointer. Of course, you can write the function call both ways and it works identicallyâ¦ but the first one is closer to what you do in C regularly. Esteban > > > > ----- > Cheers, > Sean > -- > Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html <http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html>

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uFFI: What is the difference between FFIExternalObject and FFIOpaqueObject?
by Sean P. DeNigris May 21, 2020

May 21, 2020

I'm working on improving the documentation. I'd like examples of situations when you'd use one or the other and why... Also, the FFIOpaqueObject class comment could be fleshed out a bit. Check out this excerpt: "this means we always access them through a reference. Now, we could declare the pointer to the structures, but then our declarations wouldn't be as close to C as we want." What would be an example of "declar[ing] the pointer to the structures" and the resulting declarations that "wouldn't be as close to C as we want"? ----- Cheers, Sean -- Sent from: http://forum.world.st/Pharo-Smalltalk-Developers-f1294837.html

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[ANN] Scheduler moved to GitHub pharo-contributions/Scheduler
by Torsten Bergmann May 21, 2020

May 21, 2020

Hi; "Scheduler" ws migrated from SmalltalkHub to GitHub - it is an easy-to-use task scheduler that can run arbitrary blocks. See attached image for a quick example. A few things have been cleaned as well: - separate tests into own package - class comments - categorize classes and methods - fix lint problems - follow SUnit best practices (super tearDown, super setUp) - removed unnecessary "super new initialize" call on class side - add a Travis CI job - ... https://github.com/pharo-contributions/Scheduler It is usable and working in recent Pharo versions Enjoy! Bye T.

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[Pharo 9.0] Build #307: Load Iceberg 1.8.0
by ci-pharo-ci-jenkins2＠inria.fr May 20, 2020

May 20, 2020

There is a new Pharo build available! The status of the build #307 was: FAILURE. The Pull Request #6381 was integrated: "Load Iceberg 1.8.0" Pull request url: https://github.com/pharo-project/pharo/pull/6381 Issue Url: https://github.com/pharo-project/pharo/issues/iceberg180 Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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[Pharo 9.0] Build #306: SimplifyOCASTTranslater-by-tempVarNamesWithoutArguments
by ci-pharo-ci-jenkins2＠inria.fr May 20, 2020

May 20, 2020

There is a new Pharo build available! The status of the build #306 was: FAILURE. The Pull Request #6336 was integrated: "SimplifyOCASTTranslater-by-tempVarNamesWithoutArguments" Pull request url: https://github.com/pharo-project/pharo/pull/6336 Issue Url: https://github.com/pharo-project/pharo/issues/SimplifyOCASTTranslater Build Url: https://ci.inria.fr/pharo-ci-jenkins2/job/Test%20pending%20pull%20request%2…

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