Crate miniextendr_engine 

miniextendr-engine: standalone R embedding for Rust binaries and tests.

This crate centralizes libR linking (via build.rs), R initialization, and a minimal runtime handle for processing events and interrupts. It is intended for Rust-only executables and integration tests that embed R.

Not for R packages: this crate uses non-API R internals (Rembedded.h, Rinterface.h). For R packages, depend on miniextendr-api and keep nonapi disabled.

When to use

• Rust binaries that embed R.
• Integration tests or benchmarks that need full control over R startup.

Quick start

// SAFETY: Must be called once, from the main thread.
let engine = unsafe {
    miniextendr_engine::REngine::build()
        .with_args(&["R", "--quiet", "--vanilla"])
        .init()
        .expect("Failed to initialize R")
};

// ... use R APIs from the main thread ...

std::mem::forget(engine); // optional: intentionally leak the handle

Initialization details

• Ensures R_HOME (via R RHOME) if missing.
• Calls Rf_initialize_R directly to avoid double setup_Rmainloop().
• Calls setup_Rmainloop() exactly once after initialization.

Runtime sentinel

if miniextendr_engine::r_initialized_sentinel() {
    // R has been initialized in this process.
}

Safety

• Must only be initialized once per process.
• Must be called from the main thread.
• No shutdown: Rf_endEmbeddedR is intentionally not called because the cleanup path is not reentrant-safe. The OS reclaims resources on exit.

Structs

REngine

Handle to an initialized R runtime.

REngineBuilder

Builder for configuring and initializing the R runtime.

Enums

REngineError

Errors that can occur during R engine initialization.

Statics

R_CStackDir 🔒 ^⚠

R_CStackStart 🔒 ^⚠

R_Interactive 🔒 ^⚠

R_SignalHandlers 🔒 ^⚠

Functions

R_CheckUserInterrupt 🔒 ^⚠

R_ProcessEvents 🔒 ^⚠

Rf_endEmbeddedR 🔒 ^⚠

Rf_initialize_R 🔒 ^⚠

ensure_r_home_env 🔒

r_initialized_sentinel

Check whether Rf_initialize_R has run by inspecting stack sentinels.

set_r_interactive 🔒 ^⚠

Write to R’s global R_Interactive flag.

set_r_signal_handlers 🔒 ^⚠

Write to R’s global R_SignalHandlers flag.

setup_Rmainloop 🔒 ^⚠