zigimports

Call Zig code from R. Works on Linux (.so) and Windows (.dll).

Function What it does
zig_load(path) Load a Zig-compiled .so / .dll
zig_bind(lib, name, args, returns) Bind an exported Zig function (from zig_load()) to an R function
zig_call(code, ..., fn) Compile and run arbitrary Zig code from inside R

Install

install.packages("path/to/zigimports_0.1.0.tar.gz", repos = NULL, type = "source")

Installing needs a C compiler (Rtools on Windows). zig_call() also needs the zig compiler (0.11 or later) on your PATH, or options(zigimports.zig = "C:/zig/zig.exe"), or the env var ZIGIMPORTS_ZIG.

Types

Arguments are passed by value with the native C calling convention, so mixed signatures like add(i32, f64) -> f64 work.

args / returns Zig type R value
"i32" i32, c_int single integer
"f64" f64 single double
"bool" bool single logical
"str" [*:0]const u8 single string (arguments and return values)
"ptr_f64" [*]f64 double vector (argument only)
"ptr_i32" [*]i32 integer / logical vector (argument only)
"void" void return type only

Up to 6 arguments. Vectors are copied before the call, and the modified copies are returned (in attr(, "args"), or as the result for void functions). Functions must be export fn.

Usage

// mathlib.zig
export fn add(a: i32, b: f64) f64 {
    return @as(f64, @floatFromInt(a)) + b;
}

zig build-lib mathlib.zig -dynamic -O ReleaseFast   # libmathlib.so / mathlib.dll

library(zigimports)
lib <- zig_load("libmathlib.so")                    # "mathlib.dll" on Windows
add <- zig_bind(lib, "add", args = c("i32", "f64"), returns = "f64")
add(2L, 0.5)                                        # 2.5

# Run Zig inline (function mode)
zig_call("export fn inc(x: f64) f64 { return x + 1; }",
         fn = "inc", returns = "f64", 41)           # 42

# Snippet mode: named args become pointers; lengths are in zig_lens
zig_call("x[0] *= 2;", x = c(1, 2))$x               # 2 2

Notes