On Friday, 30 April 2021 at 22:22:05 UTC, sfp wrote:
To be clear, I'm mostly interested in examples that show how to
structure a project. I'd like to know what the best way to
start using D in my current project is, how to call D from C,
and how to call C from D.
There is nothing special about the structure of a BetterC
_project_. It's just a D project without the full feature set, so
you can structure it in whatever way makes sense to you in terms
of packages and modules.
As for the code, your main function should be `extern(C)`.
Functions you want to make available to the C side should also be
`extern(C)`, and will need equivalent declarations in C. DMD has
an experimental feature to generate C headers for you via the
`-HC` (`dmd -HC=?` for options). Then all that's left is to link
the C objects into D or the D objects into C.
Beyond that, it's just a matter of making use of a limited subset
of D features:
https://dlang.org/spec/betterc.html
I'm unaware of any specific open source projects that do what
you're looking to (integrate new D code into an existing C
project) especially any using CMake. But I would approach by
isolating the new D code as a library. Then you can structure it
however you like and just add the library to your C project's
dependencies.
Alternatively, you could add individual D modules to your source
tree and configure CMake such that they are compiled with a D
compiler and a header generated for each.
I mean, there's no one way to go about this. But whatever you end
up doing, please consider writing it up in a blog post for the D
blog (email me at aldac...@gmail.com when you're ready)
describing how you approached it, then your project could be an
example for someone else.
