Is Koka a good language to call C with FFI

[sami-badawi]

Koka is a great language and it compiles to C, so it seem like it could be a good language to call C libs with.

I have not found much documentation for FFI to C.

Could you control Raylib from Koka?
Or are C and Koka just too different for this to make sense?

[TimWhiting]

You can definitely do this. There isn't a whole lot of official documentation about it, though I've written some unofficial docs here:
https://koka-community.github.io/koka-docs/koka-docs.kk.html#sec-less-known-features

The standard library is also a great reference for how to do this.

[sami-badawi]

Thanks @TimWhiting,

Your link, that was informative.

How do you access a C struct from Koka?

Is there any example C and Koka mix projects?

I saw references to vcpkg, any example of use of vcpkg?

[TimWhiting]

See this in the standard library for using vcpkg: https://github.com/koka-lang/koka/blob/dev/lib/std/text/regex.kk (you also need vcpkg installed)

To access a C struct you will need to create extern functions for each parameter you want to access, and using the appropriate C return types supported in Koka (https://github.com/koka-lang/koka/blob/dev/lib/std/core/types.kk), and treat the c struct as an intptr_t in koka (maybe creating an alias cstruct = intptr_t).

Sometimes it is easier to create the Koka struct representation of what you want, and then write some C code to translate the C struct to the Koka struct. You'll have to look at the generated C code for the Koka struct (in the header corresponding to your file), to see how to create / allocate it.

While it is possible to do all this, I'm hoping to get a PR merged sometime in the next few months to make it a lot easier to integrate with C libraries.

[sami-badawi]

Awesome.

I looked at some of your PRs already. Which one are you talking about?

[TimWhiting]

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