Adding new commands

[psychemedia]

I've been experimenting with using the anywidget package as a way of bundling wasm packages so that they can be called from a python kernel (e.g. pandoc, tesseract). anywidget runs in Jupyter browser UIs and VSCode, so this provides a way of using the browser to call wasm libraries that might normally be expected to run as o/s/commandline packages.

What steps are required to add a new command to terminal? Eg to tweak the anywidget so that it could also install a command? Or maybe even install a commandline command based on a magic line command in the anywidget app package?

[ianthomas23]

There aren't any official guidelines on how to add new commands to the terminal, and there won't be until it supports a decent cross-section of functionality and is working robustly. Before that any of the API and internals, and certainly the wasm build system, will definitely change, probably a number of times. So I don't recommend that anyone invests any time in this yet, the situation will be more stable in a few months time.

After that warning, if you still want to try something out then you could look at the flags used to build grep on emscripten-forge at https://github.com/emscripten-forge/recipes/blob/main/recipes/recipes_emscripten/grep/build.sh (and other files in the same directory). This is currently building with emscripten 3.1.58. When you have built a something.js and associated something.wasm then you can look at PR jupyterlite/cockle#73 in cockle which shows how to add pre-build wasm files not from emscripten-forge to a deployment which is really a question of getting the right cockle-config-in.json in the base directory that you run jupyter lite build in.