Re: FOSDEM Call for Participation

[me7]

Hi All, Anyone have link of slide/video of fosdem conference please help post 
here. here's one of the talk that have slide 
[https://fosdem.org/2020/schedule/event/nimultralowoverheadruntime](https://fosdem.org/2020/schedule/event/nimultralowoverheadruntime)/

Re: Advent of Nim 2019 megathread

[me7]

First year of AoC and first year of Nim too. Each part I usually take 2 hours 
so I need dedicate 4 hours each day to finish it. 
[https://github.com/me7/AdventOfCode](https://github.com/me7/AdventOfCode)

Looking at other people code once I've done it is my favorite part. I've learn 
what's my mistake everyday

Re: use jester with SSE (server side event) example

[me7]

Hi dom, Thanks for point out. But I've try that and not success, here the 
reasons

1\. No documentation - while treeform/ws have jester example on first page 
(readme.md) but niv's one mention nowhere. Even sample code from issue 
[https://github.com/niv/websocket.nim/issues/61](https://github.com/niv/websocket.nim/issues/61)
 not working

2\. The word on readme.md scare me This is a pre-release and not final 
software. There might be bugs, unintended side-effects, the API might change 
without warning between releases, and features are missing

3\. I've look at example folder of the project and I think API is more 
complicate than threeform/ws (just my personal opinion)

Re: use jester with SSE (server side event) example

[me7]

Thank you for help looking on the problem!!

I think the problem is from this line 
[https://github.com/treeform/ws/blob/master/src/ws/jester_extra.nim#L5](https://github.com/treeform/ws/blob/master/src/ws/jester_extra.nim#L5)
 which you expect to detect defined(useHttpBeast) but it's fail to detect

Re: Nerve: RPC framework for Nim

[me7]

Thank for bump the thread. Just found it and it's look fit to my requirement

use jester with SSE (server side event) example

[me7]

Right now web socket library (treeform/ws) not working with httpBeast on jester 
yet 
[https://github.com/treeform/ws/issues/11#event-2831261507](https://github.com/treeform/ws/issues/11#event-2831261507).
 So I want to use SSE (server side event) instead.

After googling and do it myself several time I still cannot make it work yet. 
Anyone could here guide me what's the correct way to use it with jester? (I'll 
do pull request to jester to add this example after it work)

Here's code that working ok but using PHP 
[https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events](https://developer.mozilla.org/en-US/docs/Web/API/Server-sent_events/Using_server-sent_events)

Here's my code so far (that's not work)

server 


import jester
import os, random

routes:
  get "/":
resp "Home"
  get "/demo_sse":
request.headers.add "Content-Type", "text/event-stream"
request.headers.add "Cache-Control", "no-cache"
request.sendHeaders()
for i in 1..20:
  request.send($rand(100))
  sleep(100)


Run

client code in js


var source = new EventSource("/demo_sse");
source.onmessage = function (event) {
document.getElementById("result").innerHTML += event.data + 
"";
};


Run

Any example available?

Re: why md5.toMD5 violate {. noSideEffect .} pragma? and why modify var T not violate it?

[me7]

> I want to help to submit the nosideeffect version to you but I'm afraid that 
> my knowledge is not up to that level yet. If you can point me to nosideeffect 
> of python version I'll try to convert it to nim and do pull request

Re: I want to launch services with Apache and jester

[me7]

Maybe use  instead of 

file under /public/a.txt folder will be /a.txt not ./a.txt

[https://github.com/dom96/jester#static-files](https://github.com/dom96/jester#static-files)

Re: why md5.toMD5 violate {. noSideEffect .} pragma? and why modify var T not violate it?

[me7]

Thanks for clarify, so from my understand

nse5 --> Can compile because proc only changes locations that are reachable 
from its parameters (var s). OK

nse6 --> Cannot compile because use zeroMem, copyMem which modify memory. But 
this mean all MD5 function will never pure? (no side effect)

Re: Nim should be your language of choice for IoT

[me7]

Cool!!, good luck with your project.:) I'm in contract manufacturing factory 
and looking on implement IoT stuff to our machines in factory. Your post boost 
my confident that nim is suitable for this kind of work

why md5.toMD5 violate {. noSideEffect .} pragma? and why modify var T not violate it?

[me7]

I've just watched "Why is heskell so hard to learn and how to deal with it" 
youtube video. On minute 33 have a quote that "Functional purity is the most 
important thing that sets Heskell apart".

As soon as I see this slide, my first though is "wait... I remember that nim 
also have this feature. It's {. noSideEffect .} pragma, or just use "func" 
instead of "proc" and problem solved.

Here's what I've try 


# experiment no side effect
# could nim enforce pure function like Heskell?

import md5

# This is ok, no side effect
func nse1(s:int): string = $s

# This is not ok, echo have side effect
func nse2(s:string): string =
  echo s
  return s

# This is not ok, read from file have side effect
func nse3(s:string): string = readFile("secret") & s

# This is ok, use var but not modify var
func nse4(s: var string): string =  return s & " no side effect"

# This is not ok, use var and modify var
func nse5(s: var string): string =
  s = s & "hi"
  return s & " no side effect"

# This should ok, why not?
func nse6(s:string): string = $s.toMD5


when(isMainModule):
  echo 123.nse1
  var s = "hello"
  echo s.nse2
  echo s.nse3
  echo s.nse4
  echo s.nse5
  echo s #s was modified
  echo s.nse6


Run

my question is why nse5 not fail to compile? it's modify input --> s before 
call = "hello" while s after call = "hellohi" why nse6 fail to compile? it's 
just call md5.toMD5 and not modify anything

Re: Jester memory usage keep rising using sqlite

[me7]

Thank you for your answer. I think that's because Nim does not free memory to 
OS. It's still ok for me that it's not memory leak

Jester memory usage keep rising using sqlite

[me7]

My testing jester app memory keep rising. when start res mem around 2MB then go 
up to 12MB with about 50 load. I want to ask for how to use db_sqlite 
correctly? right now I'm just open in the beginning but no close (not know 
where to close) do I need to do db.close in every route?

import jester

let db = open("chinook.db","","","")

routes:


get "/":
var s = "header "

for x in db.fastRows sql"select * from albums;":
s.add "album " & $x & ""

s.add "footer" resp s