RL

A statically-typed interpreted language written in Rust with a clean syntax, a TUI REPL, and a growing standard library.

get println, len from std::io
get pow, mod, factorial, fibonacci, is_prime from std::math
get PI from std::math::consts

fn collatz(int n) {
    dec int steps = 0
    while (n != 1) {
        if (mod(n, 2) == 0) {
            n = n / 2
        } else {
            n = n * 3 + 1
        }
        steps += 1
    }
    return steps
}

println(factorial(10))    // 3628800
println(fibonacci(15))    // 610
println(is_prime(97))     // true
println(collatz(27))      // 111

dec float r = 5.0
println(PI() * pow(r, 2.0))  // 78.53981633974483

Prebuilt binaries are published for every release. The install script downloads the build you pick (or the latest stable) and puts it on your PATH.

Linux / WSL (installs to $HOME/.local/bin; set RL_INSTALL_DIR to override):

curl -fsSL https://raw.githubusercontent.com/rl-lang/rl-lang/main/install.sh -o install.sh
bash install.sh

Android (Termux) - works the same way on aarch64 devices (install script detects Termux and downloads the Android build):

curl -fsSL https://raw.githubusercontent.com/rl-lang/rl-lang/main/install.sh -o install.sh
bash install.sh

Non-interactively (install the standard rl build of v1.0.0):

RL_VARIANT=rl bash install.sh v1.0.0

Windows (PowerShell) (installs to %LOCALAPPDATA%\rl-lang\bin and adds it to your user PATH - restart your terminal afterwards):

Invoke-WebRequest https://raw.githubusercontent.com/rl-lang/rl-lang/main/install.ps1 -OutFile install.ps1
.\install.ps1

Available builds include rl (treewalker + VM), rlc (VM-only), rlp (treewalker-only), and rlsp (language server). Debug variants are suffixed with d (e.g. rld).

git clone https://github.com/rl-lang/rl-lang
cd rl-lang/crates/rl-cli
cargo build --release
# binary at target/release/rl

cargo install rl-cli

from releases you can choose nightly builds or the latest build

Firstly i highly suggest using the docs command

rl docs

# for TUI mode
rl docs --tui

for using the compiled rl binary

# to check available commands
rl -h
# or
rl --help

# to start a new project
rl new example-project

# in project root you can run it via
rl dev
# or run the file directly
rl run src/main.rl

Full language reference and stdlib documentation is available on the wiki.

• Install the rl-lang extension for syntax highlighting in .rl files.
• Install the rl-lang runner extension to run and check files from the editor.
• Install the rl-lang LSP extension for diagnostics and hover.

A Tree-sitter grammar is available at rl-lang/tree-sitter-rl for editors that support it (Neovim, Helix, Zed, etc.).

Criterion benchmarks live in crates/rl-benches. Run with:

cargo bench

cargo test --all-features   # full test suite
cargo clippy -- -D warnings # lints
cargo bench                 # criterion benchmarks

Feature flags:

Licensed under either of MIT or Apache 2.0 at your option.