mrubyedge

A pure-Rust reimplementation of the mruby VM that keeps its core execution engine no_std-friendly while striving for behavioral compatibility with upstream mruby.

Overview

mruby/edge is an mruby-compatible virtual machine implementation written in Rust, specifically designed for WebAssembly environments and embedded systems. It aims to provide:

• WebAssembly-first design: Optimized for running Ruby code in browsers and edge computing environments
• Lightweight runtime: Minimal footprint and binary size suitable for constrained environments
• no_std core: Can run in environments without standard library support
• mruby compatibility: Executes mruby bytecode (.mrb files) and Ruby source code
• Rust safety: Built with Rust for memory safety and reliability

Installation

Add this to your Cargo.toml:

[dependencies]
mrubyedge = "1.0"

Usage

Running Precompiled Bytecode

Load and execute a precompiled *.mrb file produced by mrbc:

use mrubyedge::rite;
use mrubyedge::yamrb::vm;

// Bundle the compiled script at build time
const SCRIPT: &[u8] = include_bytes!("./examples/simple.mrb");

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let mut rite = rite::load(SCRIPT)?;
    let mut vm = vm::VM::open(&mut rite);
    let value = vm.run()?;
    println!("{:?}", value);
    Ok(())
}

Creating VMs Programmatically

You can also construct IREP (internal representation) structures directly:

use mrubyedge::yamrb::{op, vm, value::RSym};
use mrubyedge::rite::insn::{Fetched, OpCode};

fn main() -> Result<(), Box<dyn std::error::Error>> {
    let irep = vm::IREP {
        __id: 0,
        nlocals: 0,
        nregs: 7,
        rlen: 0,
        code: vec![
            op::Op { code: OpCode::LOADI_1, operand: Fetched::B(1), pos: 0, len: 2 },
            op::Op { code: OpCode::LOADI_2, operand: Fetched::B(2), pos: 2, len: 2 },
            op::Op { code: OpCode::ADD, operand: Fetched::B(1), pos: 4, len: 2 },
            op::Op { code: OpCode::STOP, operand: Fetched::Z, pos: 6, len: 1 },
        ],
        syms: vec![],
        pool: Vec::new(),
        reps: Vec::new(),
        catch_target_pos: Vec::new(),
    };

    let mut vm = vm::VM::new_by_raw_irep(irep);
    let value = vm.run()?;
    println!("{:?}", value);
    Ok(())
}

Use Cases

• Embedded Systems: Run Ruby in resource-constrained devices
• WebAssembly Applications: Deploy Ruby code in browsers and serverless environments
• Edge Computing: Lightweight Ruby runtime for edge nodes
• Rust Integration: Embed Ruby scripting in Rust applications

CLI Tool

For a command-line interface to compile and run Ruby scripts, see mrubyedge-cli.

Documentation

• API Documentation
• GitHub Repository

License

See the LICENSE file in the repository root.