Component with lifetime

[old dove]

I use cosmic-text editor (external crate) that I keep in component per entity here: https://github.com/StaffEngineer/velo/blob/85f75bd0859638d5f33c8ada1eab093618b51ae1/crates/bevy_cosmic_edit/src/lib.rs#L65

Now I want to extend it to keep SyntaxEditor (that is a wrapper of Editor): https://github.com/pop-os/cosmic-text/blob/bfb5eefbfa869915e47824877af68a5307cf301c/src/edit/syntect.rs#L32 and ViEditor (that is a wrapper of SyntaxEditor): https://github.com/pop-os/cosmic-text/blob/bfb5eefbfa869915e47824877af68a5307cf301c/src/edit/vi.rs#L19

The issue is SyntaxEditor and ViEditor has lifetimes, so is there a way to keep them on component... or is there any other better way to solve this issue? Any advice is welcome.

* I access editor in different systems through component
** Editor, SyntaxEditor, ViEditor are all implement Edit trait

ping @gritty turtle

[brisk plover]

I'm not 100% sure about the details, but you may want to take a look at https://crates.io/crates/ouroboros. Maybe it'll allow you to put the syntax/vi editor and the things they refer to in the same component?

[old dove]

Looks a bit complicated... considering my nooby rust experience... but thanks for suggestion.

[sullen adder]

@old dove I think there might be some ways, but one important consideration might be to figure out how long these components with lifetimes live, relative to the bevy app

do they outlive the bevy app?

or does the thing they are referencing live at least as long as the bevy app?

what we kind of have to think about is what the references mean if the thing that they are referencing end up dying while the app is running

@old dove another thing to think about is whether editor should be a Component, or a Resource

for this line: https://github.com/pop-os/cosmic-text/blob/bfb5eefbfa869915e47824877af68a5307cf301c/src/edit/syntect.rs#L34

why can't you just have the SyntaxEditor carry around the SyntaxSystem? why is the SyntaxSystem an external struct, which the SyntaxEditor only carries a reference to? in some sense, the two are tightly coupled, right? why not put them (and other things) together like this:

/// A wrapper of [`Editor`] with syntax highlighting provided by [`SyntaxSystem`]
pub struct SyntaxEditor {
    editor: Editor,
    syntax_system: SyntaxSystem,
    syntax: SyntaxReference,
    theme: Theme,
    highlighter: Highlighter,
    syntax_cache: Vec<(ParseState, HighlightState)>,
}

[old dove]

@sullen adder I don't have power over cosmic-text, this is external crate I am using.

I use it inside my bevy app, so the max lifetime they can have the same as bevy app

if they die some part of bevy app will be broken in theory

[old dove]

Okay, I tested ViEditor it's too feature incomplete.. and syntax highlighting I can integrate externally using syntect by myself, so I don't need SyntaxEditor & ViEditor from cosmic-text for now, only Editor without lifetime.

[sullen adder]

oh I think I see, sorry, I thought the link you provided was a link to your code

@old dove okay, but what about the choice between Resource and Componet for editor? what is the thinking there?

[old dove]

Do you see any advantages to put it in resource? Currently every widget (entity) has component with editor, so it's pretty convenient.

[sullen adder]

Resource is for things that need to be globally accessible in that way, and I was wondering if it might be easier to somehow to define a resource wrapping a struct with a lifetime, than a component

but I don't think so: https://github.com/bevyengine/bevy/discussions/1691

[old dove]

Makes sense, I love that it's attached to an entity via component though