Can I set a custom key (instead of element index) in

LazyColumnFor

composable?

I thought

LazyColumnFor

used the element itself as the key, unless that changed recently.

It probably has then. Here is the source.

What do you need a custom key for? Can you not just put the keys you want in the list?

I have a list of items that have unique ids. I want to avoid recomposing the entire tree under

LazyColumnFor

when I insert a new item at the beginning of the list. So I was hoping that I could solve this by specifying the key as the id of the item (similarly to how it is usually done in React).

You could do a couple things: 1. Just pass a list of IDs, and look up the actual element in a map. 2. Either change the definition of

equals

for your element type to only consider ID, or wrap your values in a type that does this. Either way, I would file a feature request issue to the compose project to ask for this feature (tracked link is in channel topic/description)

Thanks for the suggestions! I have filed an issue.