@Mothra@mander.xyz @Slein4273@feddit.org @mvirts@lemmy.world
Sorry for the tags, but otherwise I would have had to respond to all your comments individually.

I also wanted to read on, so I searched for the book and found a page where it was possible to 'read a preview'

You could wrap the entirety of your file in a monster macro but you'd still have to assign the macro result to a variable you need to register, which doesn't sound viable to me at least.

Maybe you can use a script that would extract all the trait implementations and create the boilerplate glue code for you, something like this:

grep --recursive --only-matching "impl PluginFunction for \w*" functions/ | sed --quiet "s/functions\/\(.*\)\.rs:impl PluginFunction for \(\w*\)/crate::functions::\1::\2{}.register(\&mut functions_map)/p"

I tried to recreate your situation locally but it may not match perfectly, maybe you'll have to adjust it a little. When I run it on my file tree which looks like this

functions
├── attr.rs
├── export.rs
└── render.rs

1 directory, 3 files

where every file has a content like this

// comment

pub struct MyAttrStructName {}

impl PluginFunction for MyAttrStructName {

}

Then I receive the following output:

crate::functions::attr::MyAttrStructName{}.register(&mut functions_map)
crate::functions::export::MyExportStructName{}.register(&mut functions_map)
crate::functions::render::MyRenderStructName{}.register(&mut functions_map)

You can use backreferences \1 \2 etc. but you can also give them names explicitly.
it looks like this: (?<name>inner-regex)
Some flavors support it, kotlins doesn't apparently.

I don't actually know whether POSIX grep would support named groups :o

Ich bin leider jetzt furchtbar neugierig, wo die Vorlage herkommt, wonach kann ich bei knowyourmeme o.ä. suchen?

You can, another comment mentioned that. Only, I didn't mean to spread misinformation because I haven't used anything else in years.

I feel this, I like to see my wallpaper

I was amazed to find out you can open a new tab by using middle-click in firefox.

Fair point. My browser (FF) supports 'search in tabs' as well and suggest it over a new search engine result when typed in the address bar. I don't know what about the style makes me think this, but it looks like FF on Windows in the Screenshot.