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5153 :: Exporting a function to Objective C

• dwin (orginal) [2019-08-31T14:26:54+02:00] view original

  I'm writing a shared library to be used as a plugin in an Objective C based application. Is it possible to export my functions and type as an objective C class?

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• mratsim (orginal) [2019-08-31T17:30:36+02:00] view original

  You can either compile Nim to Objective-C with nim objc yourfile.nim

  Or compile Nim to C as a shared library.

  Tag the exported proc with {.exportc.} or {.exportc: "my_desired_name".} to ask Nim not to mangle them.

  Then you can compile to a shared library and associated header with: nim c --noMain --noLinking --header:my_header.h my_file.nim

  Or combine both (?): nim objc --noMain --noLinking --header:my_header.h my_file.nim

  When calling Nim code, you will need to initialize Nim runtime once by calling NimMain().

  Then you can follow any tutorial to call C from Objective-C.

  The full details of Nim interop are written here: https://nim-lang.org/docs/backends.html#interfacing-backend-code-calling-nim.

  Note that the Objective-C backend is less tested compared to C and C++ so I recommend you go the C way but if you get Objective-C to work that would be very nice.

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• dwin (orginal) [2019-09-06T06:42:26+02:00] view original

  Thanks, I tried it. Nim renamed the file extension to .m but the code was still C. I'll have to write a wrapper in Objective C to call the functions written in Nim. I was hoping that the objective C backend exported Objective C classes and methods directly. It's ok. That's not a big deal.

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