Using the Compiler
The Raven compiler is distributed as a Julia package, so you'll need to run it from inside a Julia REPL. (The workflow is currently geared towards language developers, rather than users.)
The following is a valid Raven script, in its entirety:
println("Hello, World!")
Like Ruby, Python and other scripting languages, there's no need for a main function. Code at the top level (outside of a function) will just run.
Here's how we ran our "hello, world" program.
julia> using Raven
julia> Raven.exec("hello.rv")
Hello, World!
This runs our code immediately, as if using an interpreter. But Raven.exec actually involves two separate steps: (1) compiling the code to WebAssembly, and (2) running the compiled code using Node.js. Here's how we can break those steps down.
julia> Raven.compile("hello.rv");
shell> node hello.js
Hello, World!
After running Raven.compile, you'll notice that two extra files have been created, hello.wasm and hello.js. The Raven code itself has been compiled into WebAssembly, contained in hello.wasm. hello.js is just a support script that tells Node.js how to run hello.wasm.
Although we used it to compile our code, the Julia compiler/runtime isn't involved at all when executing Raven. We can equally run our compiled code from the shell.
$ node test.js
Hello, World!