Using Julia from the JVM (Clojure)

mkitti · December 10, 2020, 9:44am

I think what you were trying to do initially was exposing some C function as a built-in function in Julia as one might do in Python. However, in Julia, we just call the C function since LLVM does the work for us.

The conclusion of the following thread is just use ccall .

ccall is how many Base functions are implemented. For example,

github.com

JuliaLang/julia/blob/master/base/array.jl#L349


      
          original.
          
          See also [`copy!`](@ref Base.copy!), [`copyto!`](@ref), [`deepcopy`](@ref).
          """
          copy
          
          @eval function copy(a::Array{T}) where {T}
              ref = a.ref
              newmem = ccall(:jl_genericmemory_copy_slice, Ref{Memory{T}}, (Any, Ptr{Cvoid}, Int), ref.mem, ref.ptr_or_offset, length(a))
              return $(Expr(:new, :(typeof(a)), :(Core.memoryref(newmem)), :(a.size)))
          end
          
          ## Constructors ##
          
          similar(a::Array{T,1}) where {T}                    = Vector{T}(undef, size(a,1))
          similar(a::Array{T,2}) where {T}                    = Matrix{T}(undef, size(a,1), size(a,2))
          similar(a::Array{T,1}, S::Type) where {T}           = Vector{S}(undef, size(a,1))
          similar(a::Array{T,2}, S::Type) where {T}           = Matrix{S}(undef, size(a,1), size(a,2))
          similar(a::Array{T}, m::Int) where {T}              = Vector{T}(undef, m)
          similar(a::Array, T::Type, dims::Dims{N}) where {N} = Array{T,N}(undef, dims)
          similar(a::Array{T}, dims::Dims{N}) where {T,N}     = Array{T,N}(undef, dims)