Your first program

Create a project

ignis init writes the project manifest and a source entry point. It works on a new directory or an existing one.

ignis init hello-app
cd hello-app

You get an ignis.toml and a src/main.ign. Passing --lib produces src/lib.ign instead, and --no-git skips the git init that otherwise runs.

Write something

An Ignis file is a sequence of declarations. Execution starts at main.

import Io from "std::io";

const VERSION: i32 = 1;

function main(): i32 {
    Io::println("Hello");
    return VERSION;
}

The return value of main is the process exit code. main may also return void, in which case the process exits with 0, or Result<i32, E>, in which case an error is reported and the process exits with 101.

Build and run

ignis build          # compile the project described by ignis.toml
./build/hello-app    # run the linked binary

ignis build accepts a path if you want to compile a single file without a project:

ignis build src/main.ign

To type-check without producing a binary — the fast loop while you are writing — use:

ignis check

What just happened

The compiler parsed the file, ran its analysis phases, lowered the result through two intermediate representations, emitted C, and handed that C to GCC. Nothing is interpreted and there is no runtime beyond a small C support library.