A Python extension module using C, C++, FORTRAN and Rust

One of the advantages of using a a general build system is that combining code written in different languages is easy. To demonstrate this I wrote a simple Python module called Polysnake. It compiles and links four different compiled languages into one shared extension module. The languages are C, C++, FORTRAN and Rust.

The build system setup consists of five declarations in Meson. It should be doable in four, but Rust is a bit special. Ignoring the boilerplate the core business logic looks like this:

rustlib = static_library('func', 'func.rs')

py3_mod.extension_module('polysnake',
  'polysnake.c',
  'func.cpp',
  'ffunc.f90',
  link_with : rustlib,
  dependencies : py3_dep)

The code is available on Github.

Compiling and running.

Compiling is done using the default Meson commands:

meson build
ninja -C build

Once built the main script can be run with this command:

PYTHONPATH=build ./main.py

The script just calls into the module and prints the string it returns. The output looks like this:

Combining many languages is simple.

This line is created in C.
This line is created in FORTRAN.
This line is created in C++.
This line is created in Rust.

Why not COBOL?

It has already been done.