Nim Days Progress
I added two more chapters on wit.ai client and creating a CacheTable. I hope you guys find it useful :) Now Nim days reached 20 chapters in total. thank you everyone for your kind responses and valuable input
Re: Documenting one liner
proc myProc = ##[my comment]## discard myProc() Run .
Re: How can I declare a constant ptr function argument?
Use a distinct ptr UncheckedArray[T] and overload `[]` like I do here: [https://github.com/numforge/laser/blob/d1e6ae6106564bfb350d4e566261df97dbb578b3/laser/tensor/datatypes.nim#L104-L105](https://github.com/numforge/laser/blob/d1e6ae6106564bfb350d4e566261df97dbb578b3/laser/tensor/datatypes.nim#L104-L105)
Why does `setCommand` exist?
As far as I can tell setCommand "js" Run is equivalent to switch "d", "js" Run Is it?
Re: Documenting one liner
@treeform, it seems that you are right. I had to split it to get it working.
Re: Documenting one liner
Well its not 1 line any more? I would just make it 3 lines :) proc createMap(this: VS):ptr VSMap = ## Creates a new property map. It must be deallocated later with freeMap(). this.vsapi.createMap() Run
Re: Table with generic type
That works and without any complaints from my editor (vs code). Thank you! This gets me through the roadblock that I am currently facing. I am a little dissatisfied with this solution however but it may be due to a lack of understanding of hashing or static typing. I am wanting to create a library with lots of procedures for the Node object which a user can easilyy associate with any data type. Ideally, I would like for a user to only have to define their data type and then be able to use any procedure that I have defined for the Node object, some of which store nodes in a table. Needing to create procs for hashing each data object is overhead that I had not anticipated and I expect that potential users (biologists like myself) will be unfamiliar with the concept as I was before now. Maybe the solution is to use Templates or Macros to create those procs? I still haven't delved into that part of the Nim language yet. Or perhaps there is a more flexible way to permit hashing with a generic type?
Re: Documenting one liner
proc createMap(this:VS):ptr VSMap = this.vsapi.createMap() ## \ ## Creates a new property map. It must be deallocated later with freeMap(). Run :)
Documenting one liner
What is the right way to document a one liner proc? I tried: proc createMap(this:VS):ptr VSMap = this.vsapi.createMap() ## Creates a new property map. It must be deallocated later with freeMap(). Run
Re: proc header: 'x' is of type which cannot be captured as it would violate memory safety
There is RFC that should allow to capture lent T/var T safely in future. But for now you need to use other types like ref T or ptr T
Re: FFI questions - VapourSynth
Good progress. It looks like the wrapper works fine now: $ ./ex01 ptr 0x557ede9361a8 --> [versionString = 0x7f0e3ea18860"VapourSynth Video Processing Library\10" "Copyright (c) 2012-2019 Fredrik Mellbin\10" "Core R48\10" "API R3.6\10" "Options: -\10" "", core = 48, api = 196614, numThreads = 8, maxFramebufferSize = 4294967296, usedFramebufferSize = 0] Still some work to do.
Re: Exporting the tostring procedure along with a type
Thanks, exporting seems to be a good way to do this, did not know about that.
Re: Arraymancer and --gc:arc
That's seriously awesome, thanks everyone ! @mratsim What I meant was the equivalent of Numpy's interpn / RegularGridInterpolator and interp3 in Matlab / Octave with typically Linear / Nearest Neighbour / Cubic methods.
Re: How can I declare a constant ptr function argument?
Overriding = might be enough but I get this: Error: signature for '=' must be
proc[T: object](x: var T; y: T) for proc `=`*(a: var Xp, b: Xp {.error:
"Copying is not allowed!".}
Re: How can I declare a constant ptr function argument?
But if I have something like Xp = distinct ptr X then how can I access the fields of X through an Xp?
Re: proc header: 'x' is of type which cannot be captured as it would violate memory safety
I can't, I just tried to mark the variable as var.
Re: proc header: 'x' is of type which cannot be captured as it would violate memory safety
Can you give code please?
Re: Arraymancer and --gc:arc
Interpolation? For FFT I was sure there was a package but maybe I misremembered. Edit: there was one [https://github.com/mratsim/Arraymancer/issues/394#issue-512574030](https://github.com/mratsim/Arraymancer/issues/394#issue-512574030), forgot to link the forum post though :P
Re: Exporting the tostring procedure along with a type
I think "tying procedures to objects" is a planned compiler behaviour for the future, but I think the accepted behaviour currently is doing `import story` in this case. If you come across this situation where you specifically need `utils` but not `story` more than once, you can do this: # utils.nim import story export story.`$` proc parseStory*(filename: string): Story = ... Run
Re: How can I declare a constant ptr function argument?
Use a distinct type
type MyReadOnlyPtr[T] = distinct ptr T
proc `==`(a: var MyReadOnlyPtr, b: MyReadOnlyPtr){.error: "Copying is
verboten".}
Run
For deep immutability, you can get some inspiration from what I describe here
in the deep immutability section:
[https://github.com/mratsim/Arraymancer/pull/420](https://github.com/mratsim/Arraymancer/pull/420)
Re: Arraymancer and --gc:arc
As far as I'm aware these two things aren't possible with Arraymancer at the moment. But using normal a seq[T] there's ways to do both: For interpolation: * numericalnim by @hugogranstrom: [https://github.com/HugoGranstrom/numericalnim#natural-cubic-splines](https://github.com/HugoGranstrom/numericalnim#natural-cubic-splines) * to an extent seqmath by @jlp765 (and me to an extent, but not on interpolation): [https://github.com/Vindaar/seqmath/blob/master/src/seqmath/smath.nim#L639](https://github.com/Vindaar/seqmath/blob/master/src/seqmath/smath.nim#L639) and below And for FFT the only way I'm aware of at the moment is via the C library kiss FFT: [https://github.com/m13253/nim-kissfft](https://github.com/m13253/nim-kissfft) I wrote down a couple of notes (mainly for myself and @kaushalmodi) about using kiss FFT from Nim a couple of days ago: [https://gist.github.com/Vindaar/fc158afbc75627260aed90264398e473](https://gist.github.com/Vindaar/fc158afbc75627260aed90264398e473)
Exporting the tostring procedure along with a type
I have a program with the following components: * a main.nim file, a utils.nim file and story.nim * story.nim defines a type Story and also its tostring procedure. A proc in utils returns the story object. main calls the proc to get the story and prints it. * I need to import story in utils but not in main, as due to type inference I do not need to actually specify story type anywhere in main. If I echo my story type in main, the tostring used is the default one for a type, and not the one I defined. If I import story in main, then my tostring is used. main.nim import utils let story = parseStory(...) echo(story) # this prints the default object string. if I import story in this file, then the custom tostring is used. Run utils.nim import story proc parseStory*(filename: string): Story = ... Run story.nim type Story* = object ... proc `$`*(s: Story): string = Run Is there a way to print story with the custom representation I defined without importing it in main, by binding it with the type somehow?
Re: Arraymancer and --gc:arc
I write some naive fft function use Arraymancer.But I don't have time to improve.(i'm writting web framework now) [https://github.com/xflywind/scim/blob/master/src/scim/fft.nim](https://github.com/xflywind/scim/blob/master/src/scim/fft.nim)
Re: HELP: async httpclient running out of response
Code looks good to me. you can drive your async loop with: runForever() Run which boils down to: while true: poll() Run or you can waitFor() # drives an async loop and also returns value. Run Then inside an async proc: await # blocks and returns a value Run or asyncCheck # does not block but does not return a value. Run So in your case, you could loop over futures and call await on your future. Or you could loop over futures and call asyncCheck Run then in another loop, check if all futures are finished.
Re: How can I declare a constant ptr function argument?
What I want is to "protect" the variable - I want a read-only resource without reference counting and without copying.
Re: Arraymancer and --gc:arc
Good to hear ! Also, do you support interpolation and FFT on Tensor in Arraymancer ?
Re: How can I declare a constant ptr function argument?
addresses are always relative dynamic context (the binary reserved memory, the
system allocator state), so no it is not. Unless you meant something like C
`void my_proc(const * const int){...}`?
Re: Arraymancer and --gc:arc
Reported there: [https://github.com/mratsim/Arraymancer/issues/423](https://github.com/mratsim/Arraymancer/issues/423) thanks. I'm currently significantly changing the Arraymancer internals (backed by raw memory buffers instead of sequences) so this might disappear by itself.
Re: parallel: bounds checker
for completeness sake, a working version of the first example (helping the
proof engine a bit)
still gonna give weave a try I guess
import strutils
import threadpool
{.experimental: "parallel".}
proc main =
let
w = 16
h = 8
var s = "a".repeat(w*h)
parallel:
## not yet
#for y in 0..
How can I declare a constant ptr function argument?
Is it possible?
Re: Arraymancer and --gc:arc
Report the Bug maybe.
Re: HELP: async httpclient running out of response
@enthus1ast I have changed my code to this, and it seems not be stucked
anymore.(Need more test after.)
proc checkUrlAsyncWithTimeOut*(url: string, saveName: string,
proxy: Proxy, timeOut:int=3000): Future[UrlCheckResult] {.async.} =
var client = newAsyncHttpClient(proxy = proxy, maxRedirects = 1)
let future = client.get(url)
let onTimeGet = await future.withTimeout(timeOut)
if not onTimeGet:
return UrlCheckResult(url: url, error: "Async timeOut [GET]")
else:
let bodyFuture = future.read().body()
let onTimeBody = await bodyFuture.withTimeout(timeOut)
if not onTimeBody:
return UrlCheckResult(url: url, error: "Async timeOut [BODY]")
else:
let body = await bodyFuture
return UrlCheckResult(url: url, saveName: saveName,
data: body)
client.close()
Run
But since I add the line "client.close()" in the end of the proc, it will get
some error like below:
> Exception message: Connection was closed before full request has been made
>
> Exception type: [ProtocolError]
\---
btw I am wonderring whether the "all" proc is the only way to begin a async
event. Is there any other way to write async code in Nim.
Arraymancer and --gc:arc
Hello, I am experimenting with arraymancer and when compiling with nimble install --gc:arc while using arraymancer I encounters weird behaviour such as : * code blocking on Matrix by scalar :code:* operation * SIGSEGV: Illegal storage access. (Attempt to read from nil?) when doing Matrix by Matrix :code:*. operation I am using the devel nim : Nim Compiler Version 1.1.1 [Linux: amd64] Compiled at 2020-03-05 Copyright (c) 2006-2019 by Andreas Rumpf I installed arraymancer with nimble install arraymancer@#head For reference here is the code that reproduce : import arraymancer proc doubleMe(data : Tensor[float]): Tensor[float]= result = data*2 proc squareMe(data : Tensor[float]): Tensor[float]= result = data*.data let A : seq[float] = @[0.11, 0.12, 0.13, 0.14] echo A.type echo A var B : Tensor[float] = A.toTensor echo B # Blocking var C = doubleMe(B) echo C #Segfault var D = squareMe(C) echo D Run If I remove the \--gc:arc flag it behaves normally. Is this "normal" behaviour (meaning arraymancer does not support arc) or am I miss something obvious ?
Re: parallel: bounds checker
damn you globals! I feel like I should have smelled that... thanks!
Re: Why not introduce the concept of Decimal in nim ???
I worked a lot IBM38 / AS400 / OS400 over 40 years RPG / ILE / C I think I'm too old (and my health requires it) I worked for a Nim port in github in the AS400 (DDS) way, I hesitated between starting from the source code "C" Mike Cowlishaw / IBM, finally for the moment I relied on the "mpdecimal" process and [https://github.com/status-im/nim-decimal](https://github.com/status-im/nim-decimal), reworked But the ideal would be to resume that of "Mike Cowlishaw / IBM" opensource of GNU to date it is not something that moves, on the other hand the repercussions in NIM for example for JSON and all that is related to the type of var ... The interest is in the drift calculations due to very large numbers, impalpable but how significant ... As well as compatibility with professional SQL Sorry for my english (shabby)
Re: parallel: bounds checker
Fwiw this works fine :P
import threadpool
{.experimental: "parallel".}
proc main =
var s = newSeq[char](3)
parallel:
for i in 0..s.high:
s[i] = spawn chr(i)
echo s
main()
Run
Re: proc header: 'x' is of type which cannot be captured as it would violate memory safety
But I'm using --gc:arc to avoid unnecessary overhead.
Re: parallel: bounds checker
thanks, I'll give weave a try :)
Re: proc header: 'x' is of type which cannot be captured as it would violate memory safety
i don't know much about arc but this is a common error on async. I would try to change the type to a "ref T"
proc header: 'x' is of type which cannot be captured as it would violate memory safety
I'm trying to avoid the copy of an object but the compiler doesn't let me. I'm using --gc:arc on #devel. ...nim-#devel/lib/core/macros.nim(557, 1) Error: 'x' is of type which cannot be captured as it would violate memory safety, declared here: ... lent only works with return types and var wouldn't be good anyway because I need it to be a constant.
Re: HELP: async httpclient running out of response
Thank you. I will have a try along with your suggestion once arriving my house. And I will give some feedbacks whatever it is succeeded or failed.
Re: HELP: async httpclient running out of response
You should close the HttClient after each request to avoid running out of file descriptors. Then try to make the requests with 'withTimeout' from the asyncdispatch module. This way you can react when a request timesout. If you still having troubles let me know. Later I can help you better (i'm on mobile atm)
