Re: How do you add switched to the build task?
Thank you, that worked. I created a config.nims file in my main folder and
added one line: switch("define", "ssl")
Re: stdlib pegs: Accessing optional subexpressions
Afaik, stdlib peg is designed for nim compiler itself and somewhat limited. So,
you may consider using [npeg :](https://github.com/zevv/npeg)
import npeg
let parser = peg("example"):
example <- >?word * >?number
word <- +Alpha
number <- +Digit
echo parser.match("abc").captures # @["abc", ""]
echo parser.match("123").captures # @["", "123"]
Run
Re: Newbie question: Why am I getting the too many variables error on my loop index variable?
if that "split(',')" is from strutils, it returns seq[string], not tuple. I
guess you need to use something like this:
for line in readFile(day02PathAndName):
var data = line.split(',')
if data.len() == 2:
myKey = data[0]
myValue = data[1]
result...
else:
echo "Error in input: ", line
Run
Re: How do you add switched to the build task?
just put the switch into a "config.nims". it's nimscript. further reading [https://github.com/nim-lang/Nim/wiki/Using-nimscript-for-configuration](https://github.com/nim-lang/Nim/wiki/Using-nimscript-for-configuration)
Newbie question: Why am I getting the too many variables error on my loop index variable?
I'm currently having a bash at using nim by converting my efforts for Advent of
Code from VBA to nim. Unfortunately I've got stuck when trying to iterate over
the input from a file and push that input into an OrderedTable.
proc GetDay02Program(): OrderedTable[int64,int64] =
for myKey, myValue in readFile(day02PathAndName).split(','):
result[myKey.int64]=myValue.parseint.int64
Run
'''
In the code above the myKey variable is flagged and the error message is 'wrong
number of variables'. I'm a bit perplexed as the reading I've done indicates
that my for statement is as expected.
I'd appreciate being enlighteded as to why iI'm getting the error.
Re: How do you add switched to the build task?
Where do I put the line: switch("define", "ssl")?
I tried a few more things without luck:
* I tried adding a "before build" task:
before build:
switch("define", "ssl")
Run
* I tried adding it by itself in the my project nimble file.
* I tried adding it to different cnf files.
* I tried adding it to a project .nims file.
* I've reviewed the nimble readme and the nimscript docs.
In the nimble docs I found this:
> Make sure that Nimble is configured to run with SSL, adding a -d:ssl flag to
> the file src/nimble.nim.cfg. After that, you can run src/nimble install and
> overwrite the existing installation.
I'm not sure what "run src/nimble install" means but adding -d:ssl to the cfg
wasn't enough.
I'm running on a Mac.
Re: grim - graph structures in Nim
The short answer is probably that I've probably been exposed to too much Python over the last years... The longer answer is that I am thinking of a much more general data structure than a graph of ints, or floats, or any other single type. One where general data can be stored and searched efficiently, leveraging modern graph theory for performance. (Not there yet, though...) Regarding the Object vs ref Object it may be a misunderstanding of the concepts from my side... I was thinking of the ref as a shared data structure and the object as being copied around. For performance, I imagined that having one ref on the heap was better than copying data on the stack. But I could be wrong here, and I am glad to be enlightened by someone with more Nim experience. Thanks for the feedback.
Re: I wrote some nim code that works, but I don't understand how/why it works.
I think my problem is another case of [issue #11167](https://github.com/nim-lang/Nim/issues/11167). I've written a smaller code example that I added to the issue.
Re: I wrote some nim code that works, but I don't understand how/why it works.
Thanks **mashingan** for showing how to work around the error message. I just wanted confirmation that the problem is on the compiler side or the libraries and not in my minimal code before opening an issue. The strange thing is that the errors does not always appear, as I've shown when you use a single file instead of 2 modules. Like found by **MrZoraman** who opened that thread for the same compiler error, this bug is based on a small change in the code making it appear or not. It does not appear any more with the current compiler version for his code.
Setup Nim with Vim/NeoVim
Hello,
I'm new to Nim and I wanted to use Vim/NeoVim as my main editor.
Here's my setup with language server support, etc.
Maybe it helps someone else.
Prerequisites:
* NeoVim or Vim8 installed
* Nim installed
The original blog post (with better formatting) is here:
[https://www.rockyourcode.com/setup-nim-with-neovim](https://www.rockyourcode.com/setup-nim-with-neovim)/
# Language Server
Install a language server protocol implementation for Vim.
**[LanguageClient-neovim][languageclient]** is the only one I could get working
with several languages (Elixir, Reason, JavaScript, Nim).
For example, with [vim-plug](https://github.com/junegunn/vim-plug):
Plug 'autozimu/LanguageClient-neovim', {
\ 'branch': 'next',
\ 'do': 'bash install.sh',
\ }
Run
Install **[nimlsp][nimlsp]**. Run this command in your terminal:
nimble install nimlsp
Run
Configure the plugins within your vim configuration (`~/.vimrc` or similar):
set hidden
nnoremap :call LanguageClient_contextMenu()
let g:LanguageClient_serverCommands = {
\ 'nim': ['~/.nimble/bin/nimlsp'],
\ }
Run
The setup specifies the location of nimlsp. On your computer, it might be
different.
Now you can open a Nim file, and hit `F5`. The LanguageClient menu will pop up.
You can fine-tune the LanguageClient configuration to your liking.
Use `:h LanguageClient` within Vim to get more information.
[nimlsp][nimlsp] can be a bit peculiar about its setup. [The language server
needs some of Nim's files in order to work
properly.](https://github.com/PMunch/nimlsp/issues/22).
You might want to check out the [GitHub repository][nimlsp] for further
trouble-shooting.
# (Tab) Completion
You can use [Vim's inbuilt completion][vimtyping], but the easier way is to
install a completion plugin.
**[VimCompletesMe][vimcompletesme]** is a minimal plugin that does everything I
need.
Plug 'ajh17/VimCompletesMe'
Run
# Linting and Formatting Code
> [ALE (Asynchronous Lint Engine)][ale] is a plugin providing linting (syntax
> checking and semantic errors) in NeoVim 0.2.0+ and Vim 8 while you edit your
> text files.
Install it with your package manager (or find alternative instructions on
[GitHub](https://github.com/dense-analysis/ale#3-installation)):
Plug 'dense-analysis/ale'
Run
Example setup in your `init.vim` (or `~/.vimrc`, etc.):
let g:ale_sign_error = '✘'
let g:ale_sign_warning= '⚠'
highlight ALEErrorSign ctermbg=NONE ctermfg=red
highlight ALEWarningSign ctermbg =NONE ctermfg=yellow
let g:ale_linters_explicit= 1
let g:ale_lint_on_text_changed= 'never'
let g:ale_lint_on_enter = 0
let g:ale_lint_on_save= 1
let g:ale_fix_on_save = 1
let g:ale_linters = {
\ 'nim': ['nimlsp', 'nimcheck'],
\}
let g:ale_fixers = {
\ 'nim': ['nimpretty'],
\ '*':['remove_trailing_lines', 'trim_whitespace'],
\}
Run
Improve ALE's performance by setting the linters you need and don't lint every
time you type in something.
Fix a file when you save or call `:ALEFix` manually.
See `:h ale` for more information.
## Links
* [Nim language](https://nim-lang.org/)
* [NeoVim](https://neovim.io/)
Re: Compile-time string obfuscation
I wonder if it is possible to apply the encryption code to a module automatically, so that it won't be needed to mark all strings with "xs". I was trying something like that few years ago, I even created a topic about it on the forum I believe, but I don't remember how it all ended.
Re: Compile-time string obfuscation
I found it: [https://forum.nim-lang.org/t/338](https://forum.nim-lang.org/t/338)
Re: Compilation failure 1.0.4 on Pi3
What distribution are you using? Because if it's Raspbian it's 32-bit even if the hardware supports 64-bit. Also depending on your RAM you might need to increase your swap, see [https://github.com/status-im/nim-beacon-chain#raspberry-pi](https://github.com/status-im/nim-beacon-chain#raspberry-pi) sudo vi /etc/dphys-swapfile # Set CONF_SWAPSIZE=2048 # :wq sudo reboot Run
Re: How do you add switched to the build task?
switch("define", "ssl")
stdlib pegs: Accessing optional subexpressions
Assume I have the following PEG definition:
import pegs
let examplePeg = peg"""
A <- {L}? {D}?
L <- \a+
D <- \d+
"""
Run
If I test strings against this PEG, I get:
if "abc" =~ examplePeg:
# `["abc", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
"", "", "", ""]`
echo matches
if "123" =~ examplePeg:
# `["123", "", "", "", "", "", "", "", "", "", "", "", "", "", "", "",
"", "", "", ""]
echo matches
Run
Now, since the subexpressions `L` and `D` are optional, it seems I need to look
at the matched strings and check them _again_ despite the PEG already defines
whether I expect letters or digits for these subexpressions.
The only API I found that gives more control is `eventParser`, which on the
other hand seems far too complicated for a relatively simple case as this.
Is there a simpler API (or a combination of them) in the `pegs` module, which I
may have missed?
How do you add switched to the build task?
My nim package needs the -d:ssl compile switch. How do I add the switch to the
nimble build task used by nimble install? I tried a number of things but none
of them worked for me.
* I tried making a cfg file with the line "-d:ssl" in it.
* I tried adding a switch("d", "ssl") in a nimble build task.
* I tried overwriting the build task with an exec statement to run: "nim c
-d:ssl ...". It seems the you cannot overwrite the build task.
Re: How to create and manage a http users sessions?
Thank you @enthus1ast and everyone for showing me the way. Now all code
compiles without errors or warnings.
import asynchttpserver, asyncdispatch
import tables
import times
import oids
import cookies
import strformat
import strtabs
import strutils
type
Session = ref object
id: string
map: TableRef[string, string]
request_time: DateTime
callback: proc (id: string): Future[void]
type
AsyncHttpSessions = ref object of RootObj
pool: TableRef[string, Session]
session_timeout: int
sleep_time: int
proc sessions_manager(self: AsyncHttpSessions): Future[void] {.async.} =
while true:
await sleepAsync(self.sleep_time)
if self.pool == nil:
continue
echo "Number of active sessions: ", self.pool.len
echo "check for sessions timeout..."
var to_del = newSeq[string]()
for key, value in self.pool:
if (now() - self.pool[key].request_time).inSeconds >
self.session_timeout:
echo "session id timeout:", key
to_del.add(key)
for key in to_del:
if self.pool[key].callback != nil:
await self.pool[key].callback(key)
echo "the session will be deleted:", key
self.pool.del(key)
proc set_session(self: AsyncHttpSessions): Session =
let session_id = genOid()
return (self.pool[$session_id] = Session(
id: $session_id,
map: newTable[string, string](),
request_time: now(),
callback: nil
); self.pool[$session_id])
proc get_session(self: AsyncHttpSessions, id: string): Session =
(self.pool[id].request_time = now(); self.pool[id])
proc new_async_http_sessions(
sleep_time: int = 5000,
session_timeout: int = 3600): AsyncHttpSessions =
let self = AsyncHttpSessions()
self.sleep_time = sleep_time
self.session_timeout = session_timeout
self.pool = newTable[string, Session]()
asyncCheck self.sessions_manager()
return self
proc login(): string =
return """
Username:
Password:
"""
proc cb(req: Request, sessions: AsyncHttpSessions) {.async.} =
if req.url.path == "/login" and req.reqMethod == HttpPost:
var params = initTable[string, string]()
for part in req.body.split('&'):
let pair = part.split('=')
if pair.len == 2:
params[pair[0]] = pair[1]
if params.hasKey("username") and params["username"] == "test" and
params.hasKey("password") and params["password"] == "12345678":
proc timeout_session(id: string) {.async.} =
echo "expired session:", id
var session = sessions.set_session()
session.map["username"] = params["username"]
session.map["password"] = params["password"]
session.callback = timeout_session
let headers = newHttpHeaders([("Set-Cookie",
&"session={session.id}")])
await req.respond(Http200, &"""Hello User
{session.map["username"]}""", headers)
else:
await req.respond(Http200, login())
else:
var id = ""
if req.headers.hasKey("Cookie"):
let cookies = parseCookies(req.headers["Cookie"])
if cookies.hasKey("session"):
id = cookies["session"]
if id != "" and sessions.pool.hasKey(id):
var session = sessions.get_session(id)
await req.respond(Http200, &"""Hello User {session.map["username"]}
Again :-)""")
else:
await req.respond(Http200, login())
proc main() =
let server = newAsyncHttpServer()
let sessions = newAsyncHttpSessions(
sleep_time=1000,
session_timeout=30
)
waitFor server.serve(
Port(8080),
proc (req: Request): Future[void] = cb(req, sessions)
)
main()
Run
Re: Compilation failure 1.0.4 on Pi3
I downloaded the latest nightly build [https://github.com/nim-lang/nightlies/releases/download/2020-01-11-devel-767592a/nim-1.1.1-linux_armv6.tar.xz](https://github.com/nim-lang/nightlies/releases/download/2020-01-11-devel-767592a/nim-1.1.1-linux_armv6.tar.xz) which worked OK. So maybe things will work out better in the next release. Just something in the way of a feature request: I tried to cross-compile some code for ARM, like so: nim c --cpu=arm proc.nim Run and it was trying to use the gnueabifh compiler. Cross-compiling is a bit of a mystery to me, but I think gnueabifh assumes an architecture that is incompatible with armv6 (?). So it would be nice if I could do something like nim c --cpu=armv6 proc.nim Run Or maybe you already have some flags that I can set that actually does this?
Re: Compilation failure 1.0.4 on Pi3
Well, "internal compiler error: Segmentation fault" is not Nim's problem, it's your C compiler's problem (crash) I'd suggest updating GCC to a newer version
Re: How to create and manage a http users sessions?
well, as i've already written, i would not use globals to store sessions. I
would create a session object that holds all your data and pass it to every
procedure.
so feed the session table into your http callback:
import asynchttpserver, asyncdispatch, tables
type
Session = ref object
## your stuff
Sessions = Table[string, Session]
proc cb(req: Request, sessions: Sessions) {.async.} =
## do stuff
echo sessions.len
proc main() =
let server = newAsyncHttpServer()
var sessions: Table[string, Session]
# ...
waitFor server.serve(
Port(8080),
proc (req: Request): Future[void] = cb(req, sessions)
)
main()
Run
Compilation failure 1.0.4 on Pi3
I downloaded the sources for 1.0.4 and tried to compile them on my Raspberry Pi 3, which uses armv7l architecture). The first stage worked, but when I typed ./koch tools, it eventually aborted with the message: CC: ../compiler/ast.nim Error: execution of an external compiler program 'gcc -c -w -pthread -O3 -fno-strict-aliasing -I/home/pi/Downloads/nim-1.0.4/lib -I/home/pi/Downloads/nim-1.0.4/nimsuggest -o /home/pi/.cache/nim/nimsuggest_r/@m..@scompi...@sint128.nim.c.o /home/pi/.cache/nim/nimsuggest_r/@m..@scompi...@sint128.nim.c' failed with exit code: 1 during RTL pass: cse_local /home/pi/.cache/nim/nimsuggest_r/@m..@scompi...@sint128.nim.c: In function 'divMod__hJyv3l2B2Q9cPG2G6osz9cmA': /home/pi/.cache/nim/nimsuggest_r/@m..@scompi...@sint128.nim.c:1030:1: internal compiler error: Segmentation fault } ^ 0x76af411f ??? ../sysdeps/unix/sysv/linux/arm/sigrestorer.S:64 0x76ade717 __libc_start_main /build/glibc-FUvrFr/glibc-2.28/csu/libc-start.c:308 Please submit a full bug report, Run
Re: grim - graph structures in Nim
Thanks Erik for this lib. I'm curious why you store node attributes in heterogenous table. In compiled language i expect graph to be a generic with custom Node and Edge types known at compile time, smth like var g = newGraph[MyNodeType, MyEdgeType]() Run
Compile-time string obfuscation
If someone's still interested in this, updated code for latest Nim:
import macros
proc `xor` *(x, y: char): char {.magic: "BitxorI", noSideEffect.}
proc fnv32a*[T:
string|openArray[char]|openArray[uint8]|openArray[int8]](data: T): int32 =
result = -18652613'i32
for b in items(data):
result = result xor int32(ord(b))
result = result *% 16777619
proc decodeStr*(s: string, key: int32): string =
var k = key
result = newString(s.len)
for i in s.low .. s.high:
result[i] = s[i]
result[i] = result[i] xor chr(uint8(k and 0xFF))
result[i] = result[i] xor chr(uint8((k shr 8) and 0xFF))
result[i] = result[i] xor chr(uint8((k shr 16) and 0xFF))
result[i] = result[i] xor chr(uint8((k shr 24) and 0xFF))
k = k +% 1
proc encodeStr*(s: string, key: int32): string = decodeStr(s, key)
var encodedCounter {.compiletime.}: int32 = fnv32a(CompileTime &
CompileDate) and 0x7FFF
macro xs*(s: untyped): untyped =
var encodedStr = encodeStr($s, encodedCounter)
result = quote do:
decodeStr(`encodedStr`, `encodedCounter`)
encodedCounter = (encodedCounter *% 16777619) and 0x7FFF
when isMainModule:
echo xs("invisible")
echo xs("strings")
Run
Re: How to create and manage a http users sessions?
Well, you can just ignore these warnings, they tell you that your code wouldn't compile if you were to use threads
Re: How to create and manage a http users sessions?
I made some changes that corrected several warnings now it works as expected
with cookies. But it still shows warnings like these:
Warning: Cannot prove that 'n' is initialized. This will become a compile
time error in the future. [ProveInit]
Warning: 'set_session' is not GC-safe as it accesses 'sessions' which is a
global using GC'ed memory [GcUnsafe2]
Warning: 'get_session' is not GC-safe as it accesses 'sessions' which is a
global using GC'ed memory [GcUnsafe2]
Run
Can someone help me fix these warnings?
import asynchttpserver, asyncdispatch
import tables
import times
import oids
import cookies
import strformat
import strtabs
type
Session = object
id: string
map: TableRef[string, string]
request_time: DateTime
callback: proc (id: string): Future[void] {.gcsafe.}
var sessions: Table[string, Session]
const sessionTimeout = 30
proc sessions_manager(session_timeout: int = 3600): Future[void] {.async.} =
while true:
await sleepAsync(1000)
echo "Number of sessions: ", sessions.len
echo "check for sessions timeout..."
var to_del = newSeq[string]()
for key, value in sessions:
if (now() - sessions[key].request_time).inSeconds > session_timeout:
echo "session id timeout:", key
to_del.add(key)
for key in to_del:
if sessions[key].callback != nil:
await sessions[key].callback(key)
echo "the session will be deleted:", key
sessions.del(key)
proc set_session(): Session {.gcsafe.} =
let session_id = genOid()
return (sessions[$session_id] = Session(
id: $session_id,
map: newTable[string, string](),
request_time: now(),
callback: nil
); sessions[$session_id])
proc get_session(id: string): Session = (sessions[id].request_time = now();
sessions[id])
proc cb(req: Request) {.async,gcsafe.} =
proc timeout_session(id: string) {.async.} =
echo "expired session:", id
var id = ""
if req.headers.hasKey("Cookie"):
let cookies = parseCookies(req.headers["Cookie"])
if cookies.hasKey("session"):
id = cookies["session"]
var session: Session
if id != "" and sessions.hasKey(id):
session = get_session(id)
else:
session = set_session()
session.map["login"] = "test"
session.map["password"] = "123456789"
session.callback = timeout_session
let headers = newHttpHeaders([("Set-Cookie", &"session={session.id}")])
await req.respond(Http200, "Hello World", headers)
proc main() =
let server = newAsyncHttpServer()
asyncCheck sessions_manager(sessionTimeout)
waitFor server.serve(Port(8080), cb)
main()
Run
Code compilation messages
$ nim c test.nim
...
/home/hdias/Downloads/StatorHTTPServer/test.nim(49, 19) template/generic
instantiation of `[]=` from here
/usr/local/programs/x86_64/nim-1.0.4/lib/pure/collections/tableimpl.nim(49,
12) template/generic instantiation of `enlarge` from here
/usr/local/programs/x86_64/nim-1.0.4/lib/pure/collections/tables.nim(270,
10) Warning: Cannot prove that 'n' is initialized. This will become a compile
time error in the future. [ProveInit]
/home/hdias/Downloads/StatorHTTPServer/test.nim(46, 6) Warning:
'set_session' is not GC-safe as it accesses 'sessions' which is a global using
GC'ed memory [GcUnsafe2]
/home/hdias/Downloads/StatorHTTPServer/test.nim(58, 25) template/generic
instantiation of `async` from here
/home/hdias/Downloads/StatorHTTPServer/test.nim(56, 6) Warning:
'get_session' is not GC-safe as it accesses 'sessions' which is a global using
GC'ed memory [GcUnsafe2]
/home/hdias/Downloads/StatorHTTPServer/test.nim(58, 25) template/generic
instantiation of `async` from here
/usr/local/programs/x86_64/nim-1.0.4/lib/pure/asyncmacro.nim(272, 31)
Warning: 'cbIter' is not GC-safe as it calls 'get_session' [GcUnsafe2]
Hint: [Link]
Hint: operation successful (66967 lines compiled; 0.960 sec total;
89.562MiB peakmem; Debug Build) [SuccessX]
Run
Re: Check if a procedure exists for a given type at compile time
Wow, I didn't think about cyclic imports at first ! I ended up with the approach you mentioned: using a proc type field with a default value that can be overriden by the end user with a setter. Finally, messing around with type introspection would have been more complicated to understand compared to this simple solution. . # Define in the library type Callback = proc (self: Car) Car = ref object speed: int drive_callback*: Callback proc new*(car_type: type[Car]) Car = return Car (drive_callback: default_drive) proc default_drive(self: Car): echo "vroom" proc set_drive_callback*(self: Car, callback: Callback) = self.drive_callback = callback # Define by the user var car = Car() car.set_drive_callback( proc (self: Car) = echo "VROOM !!" ) Run PS: Thanks @dawkot for the hint, I might use it for another thing !
grim - graph structures in Nim
Hi all, My first post to this forum. I found out about Nim a month or so ago and have been playing around since. It's been a very pleasant experience, with Nim's clean syntax (especially coming recently from Python) and friendly learning curve. A big shout-out to the developers and the Nim community, you are doing a great job and if you keep going more great things will lie ahead. I'll also take the opportunity to share my first Nim project - [grim](https://github.com/ebran/grim). It brings graph data structures to Nim, similar to the Neo4j-style database. Probably there are similar libraries already available, this is my attempt to learn Nim. I'll happily discuss improvements and or PRs. In the future, if I have time, I hope to add graph searching tools and other cool graph algorithms + Neo4j integration. Best,
Re: Check if a procedure exists for a given type at compile time
Same case [https://forum.nim-lang.org/t/5792#35941](https://forum.nim-lang.org/t/5792#35941)
Re: Check if a procedure exists for a given type at compile time
var car: Car when compiles (drive car): .. else: .. Run When is a compile-time version of if
Re: Check if a procedure exists for a given type at compile time
A basic test is generally "when compiles()". But I think your case can not really work: The user of your lib would import your lib, and on the other hand your lib would import drive() proc from user module. So you have cyclic imports. Maybe your lib can define and export a proc var of type drive(), which is nil by default and user can assign his own proc to it?
Check if a procedure exists for a given type at compile time
Hello everyone, I would like to know if Nim allows me to check if a procedure exists for a given type at compile time ? . # As a library author I define a type `Car` type Car = object speed: int proc default_drive(self: Car): echo "vroom" # A user of this library define a procedure `drive` on this `Car` type proc drive(self: Car): echo "VROOM !!" var car = Car() # Somewhere in my library, I want to check if the procedure `drive` exists on type `Car` # NB: The code below is pseudo code if prodecure_exists(Car, "drive"): car.drive() else: car.default_drive() Run Have a nice day :)
