Calling C Code from Janet

A reproduction of the steps for calling C code from Janet in The Janet C API docs.

Prerequisites

• C Compiler
  • for Linux: gcc
  • for Windows: Visual Studio or Visual Studio Build Tools (see Janet repository)
• Janet source code
• Some Janet binaries on PATH
  • for Linux: janet and jpm
  • for Windows: janet.exe and jpm.bat

Linux Steps

• Clone this source:

  $ git clone https://github.com/sogaiu/c-from-janet
  

• Build the module:

  $ cd c-from-janet
  $ jpm build
  

  Look in build for results -- there should at least be a mymod.so file.

• Test from janet:

  $ janet
  Janet 1.9.0-dev-02f17bd  Copyright (C) 2017-2020 Calvin Rose
  janet:1:> (import build/mymod :as mymod)
  nil
  janet:2:> (mymod/myfun)
  hello from a module!
  nil
  janet:3:>
  

Windows Steps

• For the steps below it is assumed that the Janet source code is available in C:\Users\user\Desktop\janet and that janet.exe has been built.

• At the time of this writing, it was first necessary to copy the jpm file from the auxbin directory of Janet's source code to the tools sibling directory as jpm.janet (so copy-and-rename). This was so that the jpm.bat in the tools directory could function appropriately.

• Clone this source:

  C:\Users\user\Desktop>git clone https://github.com/sogaiu/c-from-janet
  

• Open a x64 Native Tools Command Prompt and build the module:

  ...
  C:\Program Files (x86)\Microsoft Visual Studio\2019\BuildTools>cd C:\Users\user\Desktop\c-from-janet
  C:\Users\user\Desktop\c-from-janet>set JANET_HEADERPATH=C:\Users\user\Desktop\janet
  C:\Users\user\Desktop\c-from-janet>jpm build
  

  Look in build for results -- there should at least be a mymod.dll file.

• Test from janet:

  C:\Users\user\Desktop\c-from-janet>janet
  Janet 1.9.0-dev-local  Copyright (C) 2017-2020 Calvin Rose
  janet:1:> (import build/mymod :as mymod)
  nil
  janet:2:> (mymod/myfun)
  hello from a module!
  nil
  janet:3:>