Re: Learning & Using Nim as a C# user + Fan logo Redesign
Hi, I am a Windows + Nim user. I found VS Code is the best editor for Nim. These are the reasons 1. It's very good IDE 2. Installing a Nim extension in VS Code is very very easy. 3. There is an extension named code-runner, which helps us to run our nim files in VS Code. I tried vim, but extension installation process is horrible or i am not smart enough to do it.
Re: Calling =destroy on parent class
Thanks @Yardanico, A simple example will explain the idea very clearly, Not everyone didn't know everything.
Re: Learning & Using Nim as a C# user + Fan logo Redesign
That is a clean looking logo indeed, I like it and could be an nice alternative for people that are looking for other looks. 1\. Not for C# specifically no, BUT if you know C# well learning the necessary for Nim is easy, only thing you have to stumble over is the OOP-ness which Nim doesn't enforce. The beginner resources in the "Learn" tab should work fine for you: [https://nim-lang.org/learn.html](https://nim-lang.org/learn.html) 2\. Sorry not that I know of, but if you have any questions feel free to post here or in the gitter/discord/irc. 3\. Godot-nim works fine, it uses GDNative. It is usable albeit some bugs need to be ironed out because of Nim 1.0 support. It doesn't support web export. Compared to C# (a lot less edge cases) imho it's on par, however they're making a lot of progress in improving C# support. If you like a code-only workflow try out nimgame2: [https://github.com/Vladar4/nimgame2](https://github.com/Vladar4/nimgame2) 4\. Check the 'GUI' section here: [https://github.com/nim-lang/Nim/wiki/Curated-Packages](https://github.com/nim-lang/Nim/wiki/Curated-Packages) 5\. I've never used debugging and nim before but this might help: [https://nim-lang.org/blog/2017/10/02/documenting-profiling-and-debugging-nim-code.html](https://nim-lang.org/blog/2017/10/02/documenting-profiling-and-debugging-nim-code.html) Hoping someone else can chime in on this 6\. For Windows, in my experience, yes. NeoVim is big too but I haven't gotten it to work on Windows (yet). 7\. Yes! Multiple even. Personally I use: [https://github.com/nimgl/nimgl](https://github.com/nimgl/nimgl) but there are alternatives like: [https://github.com/jackmott/easygl](https://github.com/jackmott/easygl) and a BGFX wrapper [https://github.com/zacharycarter/bgfx.nim](https://github.com/zacharycarter/bgfx.nim)
Re: conditional compilation from macro-generated code?
although thinking about it - what's the difference between if and when in a macro? Shouldn't it be the same since macros are evaluated at compile-time?
Re: conditional compilation from macro-generated code?
scope (?).
Re: conditional compilation from macro-generated code?
doh! Looking at old code of mine, I should have recalled that.
Re: conditional compilation from macro-generated code?
You need to use 'when' instead of 'if'.
conditional compilation from macro-generated code?
if I do: var x:int if declared(joe): x = joe() else: x = 4 Run Essentially, that is conditional compilation: the existence or non-existence of "joe" is checked at compile time. All is good. If I use a macro to generate some code, that works also. All good. But if I use a macro to generate code that contains a conditional compilation check; not so good. If "joe" is not declared, I get a `Error: undeclared identifier: 'joe'`; despite the conditional nature of the check. Is this correct behavior? If so, that is fine; I can see how the order of compilation makes some things not possible. If it is correct behavior, what are some good workarounds?
Re: conditional compilation from macro-generated code?
I guess the question would be: is there a good way for the macro itself to detect, using a string, if an identifier has been declared?
Re: How can I find the minimum value of given type T?
thanks
How can I find the minimum value of given type T?
In this code: proc findMaxCrossingSubArray[T](arr: seq[T]; lo, mid, hi: int64): SliceResult[T] = var leftSum = T.min # ... Run I want leftSum to be the minimum value of the type T. The compiler complains: Error: type mismatch: got but expected one of: proc min(x, y: int): int first type mismatch at position: 1 required type for x: int but expression 'T' is of type: type int proc min(x, y: int64): int64 first type mismatch at position: 1 required type for x: int64 but expression 'T' is of type: type int proc min(x, y: float32): float32 first type mismatch at position: 1 required type for x: float32 but expression 'T' is of type: type int proc min[T: not SomeFloat](x, y: T): T first type mismatch at position: 1 required type for x: T: not SomeFloat but expression 'T' is of type: type int proc min(x, y: int8): int8 first type mismatch at position: 1 required type for x: int8 but expression 'T' is of type: type int proc min(x, y: int16): int16 first type mismatch at position: 1 required type for x: int16 but expression 'T' is of type: type int proc min(x, y: int32): int32 first type mismatch at position: 1 required type for x: int32 but expression 'T' is of type: type int proc min[T](x: openArray[T]): T first type mismatch at position: 1 required type for x: openArray[T] but expression 'T' is of type: type int proc min(x, y: float64): float64 first type mismatch at position: 1 required type for x: float64 but expression 'T' is of type: type int Run
Re: How can I find the minimum value of given type T?
T.low or low(T) should work in your case
Re: Will --gc:arc address finalizers for closure iterator variables?
> Well that's not how it works, when the closure iterator's refcount is zero
> and thus provably dead the attached resources will be freed.
Like I said, the problem is not only freeing memory but also releasing shared
resources. How can I intercept such event I write code to release the resources?
It is a bit tricky to exhibit a small example of the problem, showing that
iterator destruction/finalization not only related to memory.
## Demonstrate that resources leak when allocated in
## closure iterator and the iterator loop is aborted.
## In that example, the resource is a thread.
import os
import strutils
type
TArgs = object
max: int
var ch: Channel[int]
proc foo(args: TArgs) {. thread .} =
## Iterate up to max.
var
max = args.max
i = 0
while i < max:
ch.send(i)
echo "Sent ", i
# Pause between message so threads play nice
sleep(100)
inc(i)
# Iterator complete
ch.send(-1)
echo "Thread completed!"
proc bar(m: int): iterator: int =
## Create a closure iterator
iterator iter: int {.closure.} =
var t: Thread[TArgs]
# Calculate one result at a time
ch.open(1)
# Delegate to counting thread
var args: TArgs = TArgs(max: m)
createThread[TArgs](t, foo, args)
while true:
let val = recv(ch)
echo "Received ", val
sleep(100)
if val == -1:
# Iterator max reached: break loop
break
yield val
joinThread(t)
ch.close()
result = iter
proc main =
let max = parseInt(paramStr(1))
echo "Counting up to ", max
let iter = bar(max)
for i in iter():
echo "i=", i
if i >= 10:
echo "Aborting iteration in main after 10 items..."
sleep(1_000)
break
echo "Out of iterator in main"
# Not using global variables or iterator
main()
# Force GC collection to be sure that out of scope
# `iter` variable has been claimed by GC.
GC_fullCollect()
echo "GC Stats: ", GC_getStatistics()
Run
The iterator uses a thread to do calculations. You call it with the maximum
number of calculations, but if `> 10` it will abort the loop and terminate.
I'm using nim '#head' from choosenim:
$ nim --version
Nim Compiler Version 1.1.1 [Linux: amd64]
Compiled at 2020-01-11
Copyright (c) 2006-2019 by Andreas Rumpf
active boot switches: -d:release
Run
This is compiled with `nim c --gc:arc --threads -d:useMalloc poc.nim`
Running a loop of 5 calculations (the iterator completes) shows that there is
no memory leak.
$ valgrind ./poc 5
==5479== Memcheck, a memory error detector
==5479== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==5479== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==5479== Command: ./poc 5
==5479==
Counting up to 5
Sent 0
Received 0
Sent 1
i=0
Received 1
Sent 2
i=1
Received 2
Sent 3
i=2
Received 3
Sent 4
i=3
Received 4
Thread completed!
i=4
Received -1
Out of iterator in main
GC Stats: [GC] total memory: 0
[GC] occupied memory: 0
==5479==
==5479== HEAP SUMMARY:
==5479== in use at exit: 0 bytes in 0 blocks
==5479== total heap usage: 51 allocs, 51 frees, 9,841 bytes allocated
==5479==
==5479== All heap blocks were freed -- no leaks are possible
==5479==
==5479== For counts of detected and suppressed errors, rerun with: -v
==5479== ERROR SUMMARY: 0 errors from 0 contexts (suppressed: 0 from 0)
Run
If we try with a loop of 15 calculations (it will be aborted at 10!), valgrind
complains that there is a possible leak: in fact, the thread is still alive
when the program completes.
$ valgrind ./poc 15
==5490== Memcheck, a memory error detector
==5490== Copyright (C) 2002-2017, and GNU GPL'd, by Julian Seward et al.
==5490== Using Valgrind-3.13.0 and LibVEX; rerun with -h for copyright info
==5490== Command: ./poc 15
==5490==
Counting up to 15
Sent 0
Received 0
...
Received 10
Sent 11
i=10
Aborting iteration in main after 10 items...
Out of iterator in main
GC Stats: [GC] total memory: 0
[GC] occupied memory: 0
==5490==
==5490== HEAP SUMMARY:
==5490== in use at exit: 337 bytes in 2 blocks
==5490== total heap usage: 87 allocs, 85 frees, 11,052 bytes allocated
==5490==
==5490== LEAK SUMMARY:
==5490==definitely lost: 0 bytes in 0 blocks
==5490==indirectly lost: 0 bytes in 0 blocks
==5490== possibly lost: 288 bytes in 1
Re: Calling =destroy on parent class
-r should always be the last argument before the source filename and arguments for it gc:arc is a compiler argument, so it should be put before -r
Re: Calling =destroy on parent class
Thank you for show me an example of how to use "gc:arc". When i first see the introductory post by Araq, I didn't understand anything about it. But from this post, it's usage is very clear
Re: Code golfing in Nim
Some examples: Leap years from 1801 to 2400: import times for x in 1801..2400: if x.isleapyear:echo x Run Without stdlib - for x in 1801..2400: if x%%(if x%%25>0:4 else:16)<1:echo x Run Fibonacci of numbers from 0 to 30: for i in ..30:echo (var(a,b)=(0, 1);(for x in 0..
Code golfing in Nim
So in [https://forum.nim-lang.org/t/5855](https://forum.nim-lang.org/t/5855) @juancarlospaco shared a website [https://code-golf.io](https://code-golf.io) It's a website for competitive code golfing and it supports Nim! So if someone considers it fun and has free time, we can try making new solutions, and, only if you want to, share the solutions (CodeGolf doesn't allow you to see other people's solutions) or the tricks for making Nim code smaller here. Some tricks: * I've learned it from [https://forum.nim-lang.org/t/5855#36306](https://forum.nim-lang.org/t/5855#36306), but you can use a%%b instead of a mod b, %% is actually different from mod (it should be used for unsigned ints only, but it works if both arguments are positive) * <1 is shorter than ==0 if you don't care about negative * You don't need spaces around .. or ..< in for a in 0..<5 * You don't need to specify first argument in case of using .. - for x in ..4 \- [https://nim-lang.org/docs/system.html#..%2CT](https://nim-lang.org/docs/system.html#..%2CT) * **You can replace indentation with `;` and parentheses** (although be aware that in some cases it doesn't reduce save char count) , for example: Before: proc a(x:int):int= result=5 if x>5: if x<3: if x==0: echo x echo x-1 elif x==0: echo 0 echo 5 else:return 5 Run After: proc b(x:int):int=(result=5;(if x>5:(if x<3:(if x==0:(echo x;echo x-1)))elif x==0:(echo 0;echo 5) else:return 5)) Run 15 characters less And of course, **don 't follow these tips in your real projects**
Re: Introducing --gc:arc
> Is there a reason why you still used that pragma? It'll see a comeback.
Re: Karax seems to only update button when text changes. Even other onclick should be bound.
Works for me without changing anything on stable and devel. Maybe try reinstalling karax?
Re: Introducing --gc:arc
Probably because ARC can't really deal with cycles I think
Learning & Using Nim as a C# user + Fan logo Redesign
I'm not a programmer, but I'm currently using C# and Unity to make games as a hobby. And I recently discovered this fantastic language! I really want to make games with this lovely language but as an intermediate C# user I can't make a Game Engine by myself * * * So my Questions are: 1. Any Learning resource targeted at C# user? (comparison, difference, equivalent, etc...) 2. Any Korean Learning resource? (I'm not very good at English ) 3. Is there any Good Game Engine for Nim? (maybe Godot? [https://github.com/pragmagic/godot-nim](https://github.com/pragmagic/godot-nim) <\- is it actually usable and better than C# or GD Script?) 4. Is there any UI app Framework beside using web app? 5. How do I Debug in VS Code? 6. Is VS Code the best editor for Nim? (I'm using Windows) 7. I'm not going to make a Game Engine, but is it possible to use 3d Graphics Library? (maybe directX or Vulkan? _just curious :)_ ) # Fan logo Redesign * * * I actually don't think Nim needs to change a logo. I did a logo redesign just for fun! (Inspired by Gitlab Logo)
Re: Introducing --gc:arc
Hi, off-topic question, in your [https://gist.github.com/Araq/74fc6cfe26e807f7279f65b65500251a#file-binary_trees-nim-L4](https://gist.github.com/Araq/74fc6cfe26e807f7279f65b65500251a#file-binary_trees-nim-L4) you use the acyclic pragma. [https://nim-lang.org/docs/manual.html#pragmas-acyclic-pragma](https://nim-lang.org/docs/manual.html#pragmas-acyclic-pragma) states that this pragma is deprecated and ignored. Is there a reason why you still used that pragma?
Re: Karax seems to only update button when text changes. Even other onclick should be bound.
I can force redraw with: # ... of 0: text "Hello World!" button(onclick = () => (comp.menu = 1; avoidDomDiffing())): text "FOO" of 1: text "Other World!" button(onclick = () => (comp.menu = 0; avoidDomDiffing())): text "FOO" #... Run
Karax seems to only update button when text changes. Even other onclick should be bound.
I have a strange issue with karax. When the text in the buttons are the same (so both are "FOO") then i can not toggle back and forth. When the text in one of them is changed, lets say = "BAA" Run than toggle works. Is this a bug? include karax / prelude import jsffi, future type Comp = object menu: int proc createDom(comp: var Comp): VNode = result = buildHtml(tdiv): text repr comp case comp.menu of 0: text "Hello World!" button(onclick = () => (comp.menu = 1)): text "FOO" of 1: text "Other World!" button(onclick= () => (comp.menu = 0)): text "FOO" else: discard var comp = Comp() comp.menu = 0 setRenderer(proc (): VNode = createDom(comp), root="ROOOT") Run
Re: Fizzbuzz game
This is great! really creative.
Re: Fizzbuzz game
Yes but that's not the point of this thread, we want to look at each others solutions after making them
Re: Fizzbuzz game
[https://github.com/code-golf/code-golf/issues/6#issue-259618460](https://github.com/code-golf/code-golf/issues/6#issue-259618460) & [https://github.com/code-golf/code-golf/issues/34#issue-322536856](https://github.com/code-golf/code-golf/issues/34#issue-322536856)
Re: Fizzbuzz game
[https://code-golf.io/scores/all-holes/nim](https://code-golf.io/scores/all-holes/nim) & [https://code-golf.io/fizz-buzz#nim](https://code-golf.io/fizz-buzz#nim)
Re: Fizzbuzz game
Sadly you can't actually see other people's solutions there
Re: Fizzbuzz game
Ok, something a _bit_ more sophisticated - I've used v as a base and created a version of it which can represent any Nim code in "fizz", "buzz" and "fizzbuzz". This code works like this - we import v and v library "decodes" the code written with v's which is a modified (and minified) version of v which can translate "fizz", "buzz" and "fizzbuzz" back to original nim code, which then runs actual FizzBuzz by @zevv [https://gist.github.com/Yardanico/c6495e6b8d0776ff07b6feabab0b1d17#file-lol-nim](https://gist.github.com/Yardanico/c6495e6b8d0776ff07b6feabab0b1d17#file-lol-nim) (all other files are here too)
Re: Fizzbuzz game
Well, not really creative but still, just use [v](https://github.com/belamenso/v) (used @zevv's solution as a basis): import v v v v v v v vv vvv vv v v v v vv v v v v v vv v v vv vvv vv vvv v vv vvv v vv vvv vv vv vv vv vvv v vv v vvv v vvv v v v vv v v vv v vv v v v v vv vvv vvv vv v vvv vvv vvv v v v v v vv v vvv vv vvv vvv vv v vvv vvv vv v v vvv v v v v v vv v vvv vv vvv vvv vv v vvv vvv vvv v v v v v vvv vv v v vvv v v v v v vv v vvv vvv vv vv v v v v v vv v vv vv v v vv vv v vv vv v vv v vvv v vv vvv vv vv v vv vvv vv vv vv vvv v v v v v vv v vv vv v v vv vv v vv vv v vv v vv vvv v vv vvv vv vv v vvv vv v v v v Run
Re: Why inherit RootObj?
> It probably should say "Object Oriented Programming style Classes should > inherit from RootObj or one of its descendants." This wouldn't help really, since it is creating the same confusion. (At least for me.) I still don't understand **_why_** one should do it. What do I gain/loose putting it there or not?
Re: Fizzbuzz game
@miran: I was just hinting at using the `case` as an expression. I wonder though why you missed the obvious since you are trying so hard: :) for n in 1..100:echo [$n,"Fizz","Buzz","FizzBuzz"][int(n%%3<1)+2*int(n%%5<1)] Run 78
Re: Fizzbuzz game
@zevv, you're not even trying! 43 whitespace characters saved: for i in 1..100: echo case i mod 15 of 0:"FizzBuzz" of 3,6,9,12:"Fizz" of 5,10:"Buzz" else: $i Run
Re: Fizzbuzz game
> one where you try to get the shortest amount of characters for n in 1..100:echo [$n,"Fizz","Buzz","Fizz Buzz"][(n mod 3==0).int+2*(n mod 5==0).int] Run 89 characters
Re: Fizzbuzz game
for i in 1..100: echo case i mod 15: of 0: "FizzBuzz" of 3,6,9,12: "Fizz" of 5,10: "Buzz" else: $i
