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7975 :: Seq of procs

• asrp (orginal) [2021-05-14T01:38:06+02:00] view original

  I'm very new to nim and am getting

  
  Error: type mismatch: got <proc (){.locks: 0.}> but expected 'proc (){.gcsafe, locks: 0.}'
  Run

  on the line var my_seq = @[foo, bar] where both foo and bar are nullary with no return values.

  I wasn't able to find anyone else who got this error in the forums.

  Using nim version 1.4.6

  Some other questions

  I can post these separately if that's better.

  1. Is --hotcodereloading:on still well supported? I'm having a lot of issue when not using small test examples. nil errors at compilation time, segfaults at runtime, doesn't play well with other flags like --debugger:on and some other libraries.
  2. Is there a way to print the source instead of just filename and line number? Is there some way to also get column numbers?
  3. What's the idiomatic way to name a variable (or proc) that clashes with a reserved work like end or type? end_ isn't allowed.
  4. Can I display an inferred type somehow?

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• ElegantBeef (orginal) [2021-05-14T07:09:55+02:00] view original

  To your currently hit issue it seems the difference is one is not gcSafe which you can force by adding {.gcSafe.} for example proc someName(somVal: T): SomeRetType{.gcSafe.}.

  2: you can do --hintSource:on in your global config to enable source printing.

  3: You can do `end` to strop

  4: You can echo var.type, most editor support you can hover values.

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• Araq (orginal) [2021-05-14T08:09:17+02:00] view original

  Is --hotcodereloading:on still well supported?

  It never was well supported, I'm afraid. Maybe we need to make this clearer in the documentation.

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• pietroppeter (orginal) [2021-05-14T09:17:03+02:00] view original

  On 3, yes you can strop and in some case you have to use stropping, but it is awkward to use when you need the name often and I see more people using stuff like typ or kind for type. See also usage of tdiv in karax. If I would have to infer this (adding or removing a letter, use a similar word) as the idiomatic way, I would use something like endd or ends or fin for end.

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• asrp (orginal) [2021-05-14T15:02:36+02:00] view original

  Thanks everyone!

  2: you can do --hintSource:on in your global config to enable source printing.

  invalid command line option: '--hintSource'.

  I didn't any similar https://nim-lang.org/docs/nimc.html (anything with src seems to be doc related). And config files seems to only store extra command line parameters?

  It never was well supported, I'm afraid.

  Ah, that's unfortunate. I think this was one of the only dynamic features. Does using dynlib/dlopen work well? Are modules able to find each other's proc and vars if they are all Nim?

  On 3, yes you can strop and in some case you have to use stropping, but it is awkward to use when you need the name often

  That's my throught when reading about strop. I'll likely end up adding or removing a letter, though this makes the different choices for different keywords somewhat arbitrary.

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• asrp (orginal) [2021-05-14T15:23:31+02:00] view original

  Also, adding {.gcSafe.} works for getting around the compilation error but what did I just declare? Will I have to do this for all procs in the seq (I intend to have many)?

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• ElegantBeef (orginal) [2021-05-14T21:28:46+02:00] view original

  Ah sorry it is --hint[source]:on. What gcsafe annotation does is override the analysis that says whether it touches gc'd memory. To prevent this issue from appearing again you can follow this, it also does show the types of the procs so you can see their effects.

  var a = @[100, 200]
  
  type YourProc = proc()
  
  proc doThing() =
    echo a[0]
    a[0] = 300
  
  proc doOtherThing =
    echo 100 + 30
  
  echo doThing.type, doOtherThing.type
  var b = @[doThing.YourProc, doOtherThing]
  
  Run

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• asrp (orginal) [2021-05-15T02:52:49+02:00] view original

  Thanks, again.

  So --hint[source]:on gives me the source line for compiler warnings and errors, but not for runtime errors and explicit calls to getStackTrace.

  To prevent this issue from appearing again you can follow this

  Ah, I see so .<type> is some kind of type conversion since doThing.YourProc.type is YourProc and (3.14).int is 3.

  When I was still adding {.gcsafe}, there were some compiler warnings that these functions were gcunsafe. Should I be worried when converting these functions and calling them?

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• ElegantBeef (orginal) [2021-05-15T03:08:47+02:00] view original

  The gcsafe and unsafeness is mostly for threading, as long as you are not threading or if you are and you know what you're doing they're harmless(assuming using orc/arc + threading).

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• nimnam (orginal) [2023-12-01T21:20:12+01:00] view original

  I just spend like 6+ hours to try it on Nixos Linux also Windows with 2.0.0 compiling myself using nimchooser and 1.6.6 and wihth --mm:rfc using samples from doc and internet (opengl gist).. But I always ran into segfault, or some function missing .. I wanted to reload some code, that's why I looked into it. But trying and failing and failing is bad experience. So yes please :-) However some people have had success. unsure whether its my GCC version or whatever. Maybe it would be nice to put a known set of versions like known to work with GCC-X on operating system and with nim-XXX :-) However the internet old all OS should be working. So maybe 10 lines of docker :-) would serve both: Show it works and help finding a starting point. But maybe the problem is me.

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• Araq (orginal) [2023-12-01T21:23:09+01:00] view original

  But maybe the problem is me.

  Well, you do use Nixos, so... :P

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• Isofruit (orginal) [2023-12-01T21:50:27+01:00] view original

  I'd like to note that none of this is an actionable statement.

  If you want help, minimal examples to produce the problem would be the way to go, so that either you can get correction suggestions or it turns out that this is an actual bug and it turns into a github issue.

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