Wrap C interface

[baggepinnen]

Strategy 1: C calls into Julia

1. Write problem and solver settings into a JSON file
2. Call the template engine Tera (Rust program) to have the templates expanded with the provided settings
3. Create @ccallable julia functions for all functions that are expected by the expanded templates. These use jl_call or @cfunction to call into the julia runtime.
4. Generate the required C main file with julia embedded.
5. (optionally) use PackageCompiler or juliac to generate a shared-object file which the C program can call, instead of embedding a julia runtime into C.

---

Strategy 2: Julia calls C solver

1. Generate julia bindings for the C interface using Clang.jl
2. Generate higher-level julia wrapper functions that feel more like julia than C
3. Write a function that initializes the required C structures