01:32 <polypus74> i've got a pointer to a struct being returned bt an ffi call. i have defined a struct in pony. i'd like to access a field of that pointer to struct. how to dereference the pointer?

01:32 <polypus74> s/bt/by

01:34 <Praetonus> polypus74: A struct in Pony is implicitly a pointer, accessing the field will dereference it

01:35 <Praetonus> Oh, sorry, I misread

01:36 <Praetonus> Or not. I'm confusing myself, that's not good

01:36 <polypus74> :)

01:37 <Praetonus> So, does that solve your problem?

01:39 <polypus74> no. basically i have 'struct X var x: Y' and then i have a 'let z: Pointer[X]'. and i want to read z.x. but i'm getting an error that x is not defined on None

01:39 <polypus74> should i not wrap X in a Pointer is that what you are saying

01:40 <polypus74> because the C side has 'X* getX()'

01:44 <Praetonus> What is the declaration of your FFI function?

01:44 <polypus74> getX[Pointer[X]](...)

01:46 <Praetonus> You can do getX[X](...), you'll get a pointer in Pony

01:46 <Praetonus> A Pointer[T] is a T** under the hood

01:47 <polypus74> T**, applies only to structs then i take it

01:47 <polypus74> in that case how do you handle the case of struct returned by value?

01:48 <polypus74> how do you write the signature for 'X getXVal()'

01:51 <Praetonus> You can destructure it with a tuple. That's not really convenient and there are unresolved issues (see #1240 on Github), but I hope my upcoming RFC on some FFI stuff will improve that

01:54 <polypus74> ahh ok, so when dealing with values, use tuples, else a struct has an implicit *. merci

01:55 <polypus74> indeed it compiles :)

01:56 <Praetonus> Great!

02:07 <polypus74> so if a struct is an mplicit pointer, how do you check it for NULL? is_null() from Pointer is not defined on it

02:19 <Praetonus> You'll have to use MaybePointer for this. The name is a bit misleading, it doesn't behave like Pointer and doesn't add a level of indirection. Doing MaybePointer[X](myX) will construct a MaybePointer with the same value as the original object. You can then use is_none() to check for NULL and apply() to "re-encode" the MaybePointer into the original object type

02:20 <polypus74> ok ty. i was trying to use tuples but was running into problems with recursive type aliases. i hope pony gets those soon.

02:21 <polypus74> i'll have a look at MaybePointer

02:50 <SeanTAllen> I still don't have anything for the October Pony VUG yet. If you are interested in presenting, drop a line.

02:50 <polypus74> what about the game engine talk?

02:52 <polypus74> i hope that's still on

03:39 <SeanTAllen> O wow

03:39 <SeanTAllen> I forgot about that

03:39 <SeanTAllen> Dur

03:46 <SeanTAllen> November! Need folks for novrmber!

03:47 <polypus74> :)

04:01 <polypus74> how to deal with a wchar_t string from C-land?

04:02 <polypus74> i want to convert it to String

13:48 <dimiii> Hi there.

13:48 <dimiii> Please, add to appendices of tutorial some words about USE_TELEMETRY. Also It's interesting, is there any description of details of implementation? I see source code is excellent and has many comments, sure it would be fine to see some conceptual/general remarks over code.

14:00 <avsej> is it possible to destructure tuple so that I will capture first two memebers separately, and eveyrhing else into third variable as tuple: (var x, var y, var rest) = ("foo", "bar", "baz", "extra")

14:51 <SeanTAllen> avsej: i'm not sure, did you try? i suspect it wouldn't work.

14:52 <SeanTAllen> dimiii: we'd welcome a PR for that. there's nothing out there for that right now.

14:52 <avsej> yes, I tried, and it didn't work

14:52 <avsej> :)

15:04 <Praetonus> Being able to slice tuples would be interesting, and I think it could cover that use case

17:32 <avsej> SeanTAllen, I'm trying to use FilePath, but I'm getting error. How I can determine what gone wrong in the error handler?

17:33 <avsej> https://github.com/ponylang/ponyc/blob/master/packages/files/file_path.pony#L18-L50 from source code I can see three places which generate error

17:34 <avsej> and it is not clear how to open files with absolute path

17:34 <avsej> like /etc/fstab

17:59 <avsej> okay. nevermind. I traced it

18:54 <avsej> if I have an actor, may I call it somehow to instruct it mutate itself? actor is a tag, but my function-mutator is a ref, so it does not allow to invoke the function

18:56 <avsej> oh, my fault. I didn't use 'be' for that function

19:00 <SeanTAllen> yes, using a behavior is the normal way to do it. you might also find this interesting avsej: https://patterns.ponylang.org/async/access.html

19:05 <avsej> is there some idiom how to wait until all actors done?

19:08 <SeanTAllen> what exactly do you mean>

19:08 <SeanTAllen> ?

19:10 <avsej> maybe I misunderstood the actors, but do they behave like a threads when application exits when Main actor returns?

19:10 <avsej> if so I have wait until all actors will finish in some loop, right?

19:12 <Praetonus> avsej: A program terminates when all actors have terminated

19:13 <Praetonus> There is nothing special about the Main actor other than it being the program entry point

19:13 <avsej> thanks. I think I found good example: examples/yield

19:16 <SeanTAllen> actors are garbage collected when their queue is empty and they have reached quiescience

19:16 <SeanTAllen> basically when they arent going to be able to do more work

19:27 <avsej> what is "their queue"?

19:28 <SeanTAllen> each actor has a queue, its mailbox

19:28 <SeanTAllen> an actor will not be garbage collected if it has messages waiting

19:32 <avsej> each message is a call of be?

19:33 <jemc> avsej: right