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1435 :: Get Exception Types as String

• jyapayne (orginal) [2015-07-10T06:53:05+02:00] view original

  Is it possible to get the type of exception as a string when doing a generic exception catch?

  try:
    someCode()
  except Exception:
    var exc = getCurrentException()
    # Somehow echo exc's actual type? ie: OSError, etc.
  Run

  For einheit, I'd like to print out what exception was actually thrown by a piece of code for a checkRaises() template.

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• Varriount (orginal) [2015-07-10T08:05:53+02:00] view original

  You might be able to use the typeinfo module. As far as I know, Nim's exceptions are just ordinary types, so that should work. Another solution might be to use a typeinfo parameter, or a generic.

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• jyapayne (orginal) [2015-07-10T08:26:17+02:00] view original

  The typeinfo module didn't seem to do the trick, but maybe I'm using it wrong. I used e.toAny().kind. Is that the correct way of using it? The result of those calls is the kind akRef.

  What did you mean by a Toronto parameter? I'm not familiar with the term :)

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• Varriount (orginal) [2015-07-10T11:23:09+02:00] view original

  Woops, I meant 'typeinfo'. Silly autocorrect.

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• Araq (orginal) [2015-07-10T11:46:00+02:00] view original

  I don't think this possible without hacks. PRs welcome, it's a private name: cstring field in the Exception object.

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• Varriount (orginal) [2015-07-10T12:12:11+02:00] view original

  @Araq How would we go about modifying the compiler to allow this? Just make the field public, or make an accessor method?

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• Araq (orginal) [2015-07-10T12:26:19+02:00] view original

  The rest of it is already public anyway.

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• skyfex (orginal) [2015-07-10T12:35:27+02:00] view original

  Isn't it possible to get an objects runtime type as a typedesc?

  The code the OP was trying to get to would be something similar to:

  import typetrait
  ...
  name(type(exc))
  Run

  But that only returns "ref Exception".

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• jyapayne (orginal) [2015-07-10T17:05:32+02:00] view original

  @Araq, Ok, I'll try modifying the name field to be public and submit a PR. Is there any reason why the field was private?

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• jyapayne (orginal) [2015-07-10T18:27:02+02:00] view original

  @Araq, Is there some trick to modifying system.nim? My changes don't appear to be reflected when I compile Nim after exposing the name field.

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• Araq (orginal) [2015-07-10T19:23:00+02:00] view original

  No, just ensure that you don't use the stdlib from /usr/etc/bananajoe.

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• OderWat (orginal) [2015-07-10T20:10:25+02:00] view original

  @jyapayne Since some time we use https://github.com/ekarlso/nim-vm for Nim installations on our Mac and Linux systems and removed all other Nim installations. That works pretty well to switch between the use of devel, "local repository" and all the release versions of Nim.

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• jyapayne (orginal) [2015-07-10T22:58:08+02:00] view original

  @Araq, you were right :) I had another stdlib installation messing with me. It works now and I've created a pull request.

  @OderWat, that looks awesome! I will definitely give it a try :)

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