Re: HttpClient networking problem
Mark this one as Solved. I want to thank you all for pushing me to persist and for providing me with some information to help solve the problems. What helped was showing me to use the timeout. Once that happened the errors happened in a timely manner. And then I had to discover a few places where I forgot the timeouts. Now it fails and I catch it and keep going. The one thing I don't know is what is the best way to determine that the current connection has closed and I need to create a newHttpClient. I see in the docs that the HttpClient.connected var is private. If there is a good way to determined the connection closed status, I would appreciate it. Again thanks.
Re: Advent of Code 2018 megathread
Decided to use AoC as an opportunity to learn Nim. My solutions are in this repo: [https://github.com/anonanonymous/Advent_of_Code](https://github.com/anonanonymous/Advent_of_Code)
Re: How JSON object Syntax relates to table and array syntax?
Ok, After much RTFM and going through the JSON modules source code I'm going to answer my own question, please correct me on anything I have misunderstood: It looks to me like the argument to the JSON constructor '%*' is not actually a data type in the proper sense. It's an expression which is passed to a macro, and broken down into NimNodes for evaluation. It has the limitation that it can only contain compile-time constants because evaluation of the expression is done by the compiler (not by the runtime).
How JSON object Syntax relates to table and array syntax?
Hi, I'm very new to Nim, so sorry if this is a noob question.
Firstly, I'd like to thank the Nim developers, Nim really is a fantastic
system. I discovered it after trying Golang and finding it produced a 6MB
binary for a simple http client application. The application is designed for an
OpenWrt device with only 8Mb of flash! Nim on the other hand produces a very
useable 100kb https client binary in release mode. Wonderful!
Now my question is regarding the data type used to initialise JSON objects. I
understand that the syntax to create the object is:
var body = %*{
"id" : "NIMTEST12345",
"user" : "futurepoint",
"password" : "whatever",
"deviceClass" : 65535,
"pollingRate" : 5,
"event" : 0,
"fault" : false
}
Run
And this works fine. I understand that '%*' is a function name which
initialises the JSON object, but what type is the argument that follows? I've
tried:
var device_details = {
"id" : "NIMTEST12345",
"user" : "futurepoint",
"password" : "whatever",
"deviceClass" : 65535,
"pollingRate" : 5,
"event" : 0,
"fault" : false
}
body = %*(device_details)
Run
but I get the error **Error: type mismatch: got ((string, int)) but expected
'(string, string)'** at the line **" deviceClass" : 65535** which implies to me
that tables must have values of a consistent data type.
How can I create the device_details as a separate object (to be referenced by
other parts of the application) and convert it to json only when required?
Thanks.
Cross-compiling from Linux to Windows using the -d:mingw flag
Hello, I am trying to cross-compile to Windows using the MinGW toolchain. Here's what I'm doing: $ nim c -d:mingw --cpu:amd64 src/uitest.nim Run However, a regular Linux executable is produced. How can I compile an exe file for Windows?
Re: Deprecation of
Also note the conceptual difference: `for x in someIterable: foo(x)` deals with the _elements_ of someIterable, e.g. with the letters of a string. `for i in 0 ..> something.len: foo(i)` is conceptionally quite different albeit well known from most older languages and deals with the _indices_. More often than not the former is what is actually desired but the latter is used because it's what we grew up with in C. Also note that Nim has the very valuable option of low and high for the "indexed loop variant" which frees you from worrying about and using `..` vs. `..<`. For example `for i in someArray.low .. someArray.high: foo(i)` safely walks from the first element of someArray (whatever that may be) to the last element or more precisely yields all indices from the first to the last one.
Re: Advent of Code 2018 megathread
By the way, if you are trying to "right size" a set or table to streamline resizing costs, you can use rightSize(number of members to support). This is easier than trying to guess the power of two at which such a population is supported for both initSet and initTable. rightSize uses the same formula (its inverse, really) as the internal formula used to decide when doubling capacity is needed.
Re: How to lookup the IPV6 addr of a domain name?
@satoru Note that `getHostByName` is deprecated at least on linux. @Libman Nim (nativesockets) _does_ provide `getAddrInfo` but as you probably saw in your research it's all but worthless because it's a mess. Which btw. is hardly Nim's fault but rather a consequence of IPv6 being a makeshift insanity and mess. So I can perfectly well understand that the Nim developers basically just threw something very close to a blank importc at us. A proper clean Nim version would be quite some work due to both IPv6's insanity and plenty of OS implementation details. And as only a few proponents really use IPv6 while pretty much all servers still use IPv4 it's not exactly an attractive and urgent looking goal to do that work. My personal approach - and suggestion for those who absolutely want that functionality - would be to create a reasonably sane (well, as sane as anything IPv6 related can be) implementation in C, say, one simply returning a list of objects holding IPs, maybe with an extra field indicating IPv4 or IPv6, and to then create a Nim binding returning a sequence of those simple objects for that.
Re: Deprecation of
It is now for u in i ..< words.len: Run So no space between .. and <. The old notation with space could give wrong results in rare cases due to operator priority.
Deprecation of
Apologies if this has been asked before, I am new here. I started learning Nim yesterday, and read through the [tutorial|[https://nim-lang.org/docs/tut1.html]](https://nim-lang.org/docs/tut1.html\]), where it says: > > Zero-indexed counting have two shortcuts ..< and ..^ to simplify counting > > to one less than the higher index: But compiling the following program with <, I get a compiler deprecation warnings: import tables import strutils proc diff_by_one(w: string, w2: string): string = var d: int = 0 var pos: int = 0 for i, ch in w.pairs: if ch != w2[i]: d += 1 pos = i if d != 1: return "" let a = w[0 ..
Re: CountTable.inc() causes Error: unhandled exception: index out of bounds [IndexError]
Global example code can be done before the type definitions like here: [https://github.com/nim-lang/Nim/blob/72e15ff739cc73fbf6e3090756d3f9cb3d5af2fa/lib/pure/collections/tables.nim#L100](https://github.com/nim-lang/Nim/blob/72e15ff739cc73fbf6e3090756d3f9cb3d5af2fa/lib/pure/collections/tables.nim#L100) Procs and methods are already below there type definitions, see here: [https://github.com/nim-lang/Nim/blob/72e15ff739cc73fbf6e3090756d3f9cb3d5af2fa/lib/pure/collections/tables.nim#L872](https://github.com/nim-lang/Nim/blob/72e15ff739cc73fbf6e3090756d3f9cb3d5af2fa/lib/pure/collections/tables.nim#L872) Regarding your code you should init the countTable once and clear it in a loop. Otherwise you will put a lot of pressure on the GC and the memory allocator and memory allocation in a loop is very slow. var cnts = CountTable[char]() for line in f.lines: if line.len == 0: break cnts.clear() for c in line: cnts.inc(c) Run
Problem of running proc inside proc
I have the following code:
proc dynaChange(): proc =
var rules: seq[string]
for rule in rules:
echo(rule)
return proc(rule: string) =
rules.add(rule)
when isMainModule:
let addRule = dynaChange()
addRule("first")
addRule("second")
discard dynaChange()
Run
The last line: discard dynaChnage() doesn't display the output in the for
loops. I can't figure out the problem. Pls help.
Re: Advent of Code 2018 megathread
if i don't end up procrastinating like previous years, my solutions will be here [https://github.com/SolitudeSF/adventOfCode](https://github.com/SolitudeSF/adventOfCode)
Re: CountTable.inc() causes Error: unhandled exception: index out of bounds [IndexError]
I assume my comment on Inc() is fairly noncontroversial. Will moving the example code to the type definitions be accepted? Will moving the procs/methods below their corresponding type definitions be accepted?
Re: CountTable.inc() causes Error: unhandled exception: index out of bounds [IndexError]
> Constructors don't even have a consistent language convention. See `newSeq` > vs `initCountTable` See the first two lines of the big table here: [https://nim-lang.org/docs/nep1.html](https://nim-lang.org/docs/nep1.html) * `init` is used to create a **value** type `T` * `new` is used to create a **reference** type `P` As for other points you raise: Nim documentation really needs lots of improvements. Since you already burned yourself with the poor Tables documentation, how about creating a PR which will fix (some of) these issues you mention?
Re: CountTable.inc() causes Error: unhandled exception: index out of bounds [IndexError]
Thanks for the help, I'll fix my program if I get back to it. I feel this issue is easy to hit, and near-impossible for me to resolve myself by looking at the docs, without forum help. * CountTable doesn't have a default constructor, making it trivial to initialize an object to an invalid state. * The exception is a generic IndexError and has no indication to me about what mistake I made. It looks like a "CountTable.inc() doesn't support inc()" error, not a "CountTable is null" error or a "must use initCountTable" error. * Constructors don't even have a consistent language convention. See `newSeq` vs `initCountTable`. I looked at the docs: * Maybe [https://nim-lang.github.io/Nim/tables.html#inc%2CCountTable%5BA%5D%2CA%2Cint](https://nim-lang.github.io/Nim/tables.html#inc%2CCountTable%5BA%5D%2CA%2Cint) should say "key" does not need to be present, and is automatically created by inc()? * Maybe the "example code" belongs at [https://nim-lang.github.io/Nim/tables.html#CountTable](https://nim-lang.github.io/Nim/tables.html#CountTable) which is accessible via #fragment and the table of contents. * Maybe it would be better if each type had its own heading, examples of usage, followed by a list of functions operating on that type? (Like other languages' class+method documentation?) * The current location of "example code" is in the middle of several pages of free-form prose and code blocks, and has no heading indicating it's a "usage example" for CountTable.
