Hacker News Reader

Comment by bch | Hacker News Reader

I see that the julia page says that Julia can call out to C functions[0], but can C functions call into Julia? ie: make a program "myprog" like:

  cc -o myprog myprog.c -ljulia

and be able to call julia_domath()?

edit: reference to julia documentation

[0] http://docs.julialang.org/en/latest/manual/calling-c-and-for...

View on HN

It is a bit hidden, but calling julia from C is possible in the 0.3 prerelease: http://docs.julialang.org/en/latest/manual/embedding/

That is _exactly_ what I was imagining, and very exciting. Let the experimenting begin!

I don't see an 0.3.0rc or obvious github branch -- what's the best way to follow 0.3.0?

No RC yet, 0.3-pre is the github trunk.

You can get compiled nightlies at http://status.julialang.org/ Otherwise building the master branch will get you prerelease.

It is developed on the master branch, and there's a v0.3 milestone for the related issues. https://github.com/JuliaLang/julia/issues?milestone=7&page=1...

You can find recent binaries here: http://status.julialang.org/

You can also check the dev mailing list: https://groups.google.com/forum/?fromgroups#!forum/julia-dev

Julia can call out to C functions[0], but can C functions call into Julia?

There are several aspects to this:

- Julia cannot generate linkable shared libraries, yet.

- There is a fairly small "libjulia" C API (the embedding reference in another comment), but this is a means to interact with/control the program "julia" (for dynamic interop. or IDE use, for example). "libjulia" does not export symbols for arbitrary Julia code.

- It is possible to generate a C-callable function pointer from a Julia function at runtime and to pass this into a C routine controlled by Julia (for example, to pass a comparator to a sorting routine, or an objective function to an optimizer).

Reply on news.ycombinator.com