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3712 :: Why macros can't find a local module?

• r3d9u11 (orginal) [2018-04-01T13:28:31+02:00] view original

  Hi. Why a local module can't be found at macro-time? myModyle.nim:

  echo "myModule loaded"
  Run

  main.nim:

  macro loadModule(): typed =
    result = parseStmt("import myModule")
  
  loadModule() # will rise exception "cannot open 'myModule'"
  Run

  Is it possible to load a local module inside a macros? What I'm doing wrong? Thanks.

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• mashingan (orginal) [2018-04-01T16:45:20+02:00] view original

  This can:

  import macros
  
  macro loadModule(): typed =
    result = quote do:
      import mymodule
  
  loadModule()
  Run

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• r3d9u11 (orginal) [2018-04-01T20:13:47+02:00] view original

  Thanks for hint, but idea that module name isn't hardcoded and contained inside of string.

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• c0ntribut0r (orginal) [2018-04-01T21:28:04+02:00] view original

  Heres a macro for importing by string, try it out

  Upd. Btw this works for me, could you import your module without macro at all?

  import macros
  
  macro loadModule(): typed =
    result = parseStmt("import strutils")
  
  loadModule()
  Run

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• r3d9u11 (orginal) [2018-04-01T22:21:44+02:00] view original

  yes, it works without macro. probably, your code works because strutils is a global module.

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• GULPF (orginal) [2018-04-01T23:12:26+02:00] view original

  This looks like a bug with parseStmt. I think the module resolution is done relative to macros.nim instead of relative to the module which called parseStmt. Here is a version that works and doesn't hard code the module name:

  import macros
  macro loadModule(module: static[string]): typed =
      result = quote do:
          import `module`
  loadModule "myModule"
  Run

  Edit: I've submitted it the issue tracker: https://github.com/nim-lang/Nim/issues/7466

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• r3d9u11 (orginal) [2018-04-02T07:47:08+02:00] view original

  many thanks!

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