Callables do not support keyword arguments

[devmotion]

Callables do not support keyword arguments currently:

> library(JuliaCall)
> julia_setup()
> julia_command("struct Callable end")
> julia_command("(::Callable)(x...; a=3.0, b=2) = print(\"a=\", a, \", b=\", b)")
> r <- julia_eval("Callable()")
> r$.(1, 2, 3, a=3.2)
Error: Error happens in Julia.
MethodError: no method matching apply(::Callable, ::Float64, ::Float64, ::Float64; a=3.2)
Closest candidates are:
  apply(::Any, ::Any...) at /home/david/R/x86_64-pc-linux-gnu-library/4.0/JuliaCall/julia/setup.jl:233 got unsupported keyword argument "a"
Stacktrace:
 [1] docall(call1::Ptr{Nothing})
   @ Main.JuliaCall ~/R/x86_64-pc-linux-gnu-library/4.0/JuliaCall/julia/setup.jl:168
> sessionInfo()
R version 4.0.5 (2021-03-31)
Platform: x86_64-pc-linux-gnu (64-bit)
Running under: Arch Linux

Matrix products: default
BLAS:   /usr/lib/libopenblasp-r0.3.14.so
LAPACK: /usr/lib/liblapack.so.3.9.1

locale:
 [1] LC_CTYPE=en_US.UTF-8          LC_NUMERIC=C                 
 [3] LC_TIME=en_US.UTF-8           LC_COLLATE=en_US.UTF-8       
 [5] LC_MONETARY=en_US.UTF-8       LC_MESSAGES=en_US.UTF-8      
 [7] LC_PAPER=en_US.UTF-8          LC_NAME=en_US.UTF-8          
 [9] LC_ADDRESS=en_US.UTF-8        LC_TELEPHONE=en_US.UTF-8     
[11] LC_MEASUREMENT=en_US.UTF-8    LC_IDENTIFICATION=en_US.UTF-8

attached base packages:
[1] stats     graphics  grDevices utils     datasets  methods   base     

other attached packages:
[1] JuliaCall_0.17.2

loaded via a namespace (and not attached):
[1] compiler_4.0.5 tools_4.0.5    Rcpp_1.0.6     knitr_1.31     xfun_0.22

[devmotion]

I'd like to help to fix this issue if it is feasible since I'd like to change the API of my package without dropping support for R, but unfortunately I don't know where to look and where to start in JuliaCall.

[Non-Contradiction]

Thank you very much for the feedback and the use of JuliaCall for your package!

I just made a commit that should fix the problem.
The fix is quite straightforward. The message in the traceback

apply(::Any, ::Any...) at /home/david/R/x86_64-pc-linux-gnu-library/4.0/JuliaCall/julia/setup.jl:233 got unsupported keyword argument "a"

points out to the lines in setup.jl that the original apply function does not support keyword arguments.
https://github.com/Non-Contradiction/JuliaCall/blob/6431e0eca7e0c3f8b073d8dce2fcaa1beceddd88/inst/julia/setup.jl#L241-L243
So I just made a little modification to the function to accept keyword arguments.

[devmotion]

Great, thanks a lot!