Import an exported MLX function

Loads a function previously exported with the MLX Python utilities and returns an R callable.

Usage

mlx_import_function(path, device = mlx_default_device())

Arguments

path

Path to a .mlxfn file created via MLX export utilities.

device

Execution target: supply "gpu", "cpu", or an mlx_stream created via mlx_new_stream(). Defaults to the current mlx_default_device() unless noted otherwise (helpers that act on an existing array typically reuse that array's device or stream).

Value

An R function. Calling it returns an mlx array if the imported function has a single output, or a list of mlx arrays otherwise.

Details

Imported functions behave like regular R closures:

• Positional arguments are passed first and become the positional inputs the original MLX function expects.

• Named arguments (e.g. bias = ...) become MLX keyword arguments and must match the names that were used when exporting.

• Each argument is coerced to mlx via as_mlx() and automatically moved to the requested device/stream before execution.

• If the MLX function yields a single array the result is returned as an mlx object; multiple outputs are returned as a list in the order MLX produced them.

Because .mlxfn files can bundle multiple traces (different shapes or keyword combinations), the imported callable keeps a varargs (...) signature. MLX selects the appropriate trace at runtime based on the shapes and keyword names you provide.

Examples

add_fn <- mlx_import_function(
  system.file("extdata/add_matrix.mlxfn", package = "Rmlx"),
  device = "cpu"
)
x <- mlx_matrix(1:4, 2, 2)
y <- mlx_matrix(5:8, 2, 2)
add_fn(x, bias = y)  # positional + keyword argument
#> mlx array [2 x 2]
#>   dtype: float32
#>   device: cpu
#>   values:
#>      [,1] [,2]
#> [1,]    6   10
#> [2,]    8   12