jlview: Create a zero-copy R view of a Julia array

In jlview: Zero-Copy Julia to R Array Bridge via ALTREP

Create a zero-copy R view of a Julia array

Description

Creates an ALTREP vector (or matrix, if 2D+) backed by Julia memory. The resulting R object shares the same memory as the Julia array, avoiding data copying. Modifications to the R object trigger copy-on-write (unless writeable = TRUE).

Usage

jlview(julia_array, writeable = FALSE, names = NULL, dimnames = NULL)

Arguments

julia_array	A JuliaObject referencing a Julia array
writeable	If TRUE, allow R to write directly to Julia's memory. Use with caution — this enables shared mutation. Default FALSE.
names	Optional character vector of names to attach to the result. Attached atomically during construction to avoid ALTREP materialization.
dimnames	Optional list of dimnames to attach to the result. Attached atomically during construction to avoid ALTREP materialization.

Value

An ALTREP vector backed by Julia memory, or a standard R vector if the Julia type is not supported for zero-copy.

Examples

## Not run: 
JuliaCall::julia_setup()
# Create a Julia array and view it in R without copying
JuliaCall::julia_command("x = randn(1000)")
x <- jlview(JuliaCall::julia_eval("x"))
sum(x) # operates directly on Julia memory

## End(Not run)

jlview documentation built on March 24, 2026, 1:07 a.m.