Installation

Rue is currently in early development. To try it out, you'll need to build from source. If you do try it out, you'll certainly find bugs, and if you do please file them!

Prerequisites

• Dotslash - Used to bootstrap Buck2 and the Rust toolchain
• clang - Used as the system linker on platforms where the internal linker is not used

The repository includes everything else. Buck2 and the Rust toolchain are bootstrapped hermetically, and the first build downloads what it needs.

Building from Source

git clone https://github.com/rue-language/rue
cd rue
scripts/rue build

The first build may take a minute. Subsequent builds are fast.

Running an Example

Try the checked-in setup smoke test:

scripts/rue exec examples/welcome.rue

You should see 1, 2, 3, and 42 printed, and the command exits 0 — so you know your toolchain works even inside a script or CI step. scripts/rue exec builds the compiler if needed, compiles the Rue source to a temporary executable, and runs it, propagating the program's exit code. (In the next chapter you'll see how a program's main return value becomes that exit code.)

Compiling Manually

When you want to keep the executable, ask the wrapper for the compiler path and run the compiler directly:

RUE="$(scripts/rue-bin)"
"$RUE" examples/welcome.rue -o welcome
./welcome

Rue currently supports native code generation for x86-64-linux, aarch64-linux, and aarch64-macos. Cross-target assembly and machine-code emission are available, but producing an executable may require target-specific system tools.

Lower-Level Buck2 Commands

Most users should start with scripts/rue. If you're working on the compiler itself, you may also see lower-level Buck2 commands such as:

./buck2 build root//crates/rue:rue
./buck2 test root//:spec-tests

The ./buck2 binary is also bootstrapped by Dotslash.

That's it! You now have a working Rue compiler. In the next chapter, we'll write our first program.