I've been working a few hours a day to get a foreign function interface implemented for rholisp, and at last I have something which can load a library, find a symbol in said library, and parse (at least in theory) the arguments and return type for the function. All that remains is to call it!
> (!ffi-load "libm.so.6")
(clib 94310737492496)
> (def libm _)
()
> (!ffi-sym libm "sin")
(csym 139683202493344)
> (def sin _)
()
> (!ffi-call sin ' i64 ' i64 1024) ; yes, this is incorrect, but floats will trigger an assertion for now, so I'm just going to pretend it takes and returns integers
Calling function 0x7f0a87aa6ba0 with 1 arguments...
()
> (!ffi-unload libm)
()
>Above is some output demonstrating a seemingly working implementation