roc/examples/hello-world

Hello, World!

To run, cd into this directory and run this in your terminal:

roc run

This will run main.roc because, unless you explicitly give it a filename, roc run defaults to running a file named main.roc. Other roc commands (like roc build, roc test, and so on) also default to main.roc unless you explicitly give them a filename.

About this example

This uses a very simple platform which does nothing more than printing the string you give it.

The line main = "Hello, World!\n" sets this string to be "Hello, World!" with a newline at the end, and the lines packages { pf: "c-platform" } and provides [main] to pf specify that the c-platform/ directory contains this app's platform.

This platform is called c-platform because its low-level code is written in C. There's also a rust-platform, zig-platform, and so on; if you like, you can try switching pf: "c-platform" to pf: "zig-platform" or pf: "rust-platform" to try one of those platforms instead. They all do the same thing, so the application won't look any different, but if you want to start building your own platforms, this Hello World example gives you some very simple platforms to use as starting points too.