You can read more on the nim website (opens in a new tab). You will need nim installed (opens in a new tab) and emscripten (opens in a new tab) to use it.

Here is some example code:

src/main.nim

proc load() {.null0.} =
  echo "Hello from justlog."
 
proc unload() {.null0.} =
  echo "Ok, bye."

easy build

If you use our template (opens in a new tab) or the CLI quick-starter, it's a bit easier to get started quickly:

nimble cart

manual build

For null0, you need to import the header (opens in a new tab), and you will get the {.null0.} pragma and some null0 functions and constants.

To compile to the correct wasm, you can use this config (opens in a new tab), which sets some flags and imports the header (opens in a new tab).

nimble install https://github.com/notnullgames/null0-nim
cd src
nim c main.nim

This will create main.wasm, so now you can create a zip file:

zip ../mycart.null0 -r main.wasm assets/

docker

If you have docker installed, you can use it to build, without needing to install anything else (no nim, etc.)

docker run -it -v $(pwd):/cart konsumer/null0 nimble cart