Rcpp-like interface

Hi Non-contradiction,

Thanks for the great package! I was just wondering if there were any thoughts about implementing a more Rcpp like interface. By that I mean having julia functions in a file with some sort of export tag and then a function to generate R wrappers around them. I don't think that would be super difficult to implement and would be an amazing interface to have.

Something like:

# JuliaCall::Export
function j_add(x, y)
   x + y
end

would generate:

j_add <- function(x,y) {
    julia_call(j_add, x, y)
}

which could then be used in R as normal

Thanks!

No implementation files, tests, or entry points are named. Start by reviewing JuliaCall’s existing R/Julia interface, then clarify how export tags and wrapper generation should work; done means a Julia function such as j_add can produce a callable R wrapper.