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3877 :: '*' export marker and macros

• Swend (orginal) [2018-06-01T16:43:36+02:00] view original

  I am trying to write a class macro, and I have encountered a problem with '*'. I want a macro with a syntax like this:

  class TestClass*:
    ...
  Run

  but if I try to apply an export marker as in the example, I get "Error: expression expected, but found ':'". The only workaround I have been able to think up is with a pragma or by forcing inheritance like so:

  class TestClass {.public.}:
    ...
  class TestClass* of RootObj:
    ...
  Run

  Is there maybe a smarter solution anyone can think of?

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• mashingan (orginal) [2018-06-01T17:27:14+02:00] view original

  Postfix operator call is what you need https://nim-lang.org/docs/macros.html#calls-expressions-postfix-operator-call

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• Swend (orginal) [2018-06-01T19:30:36+02:00] view original

  Oh, no I am not talking about producing that code, but that being the syntax on the users side. The error is raised before the macro is even invoked.

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• planhths (orginal) [2018-06-01T22:17:13+02:00] view original

  I have also build a class macro :) with the syntax class Person*(Animal) and the super class must be class Animal*(RootObj) and it works fine.

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• Lando (orginal) [2018-06-02T10:54:04+02:00] view original

  @Swend This is a limitation of the parser that apparently can only be worked around in the manner your example code does. Ran into this myself, it's a pity IMHO.

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• dom96 (orginal) [2018-06-02T13:54:45+02:00] view original

  Looks like it indeed. It might be a good idea to create a proposal to make this syntax possible.

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• Lando (orginal) [2018-06-03T09:37:35+02:00] view original

  Will do that when I get the time.

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• Vantage (orginal) [2018-06-20T20:30:19+02:00] view original

  There are already a few class macros. I'm using a simple one based off the nim-for-beginners guide. https://github.com/CodeDoes/nim-extensions

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• jyapayne (orginal) [2018-06-21T08:26:40+02:00] view original

  It would have been nice to at least have some attribution of that code, since it was my work. But oh well, MIT license and all, so no harm done on the author's part. It's nice to see my code being used though :) I worked so hard to get it to work!

  Here's the original: https://github.com/jyapayne/nim-extensions/

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• jyapayne (orginal) [2018-06-21T08:31:22+02:00] view original

  If the forker of that code is willing (and reading this), I would graciously accept a PR!

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