A modern programming language that makes developers happier.

kotlinlang

Are there some property delegates for computing something expensive, preferably using suspending fun?

Is 'lazy' what you're looking for? Computes value once on first usage. See built in delegates in docs. I'm afk or I'd provide direct link.

Something thread-safe like `lazy` but actually eager

Considering it's expensive to compute, I'd like to preload it before anyone needs it and avoid blocking clients

a suspended delegate doesn’t really make sense. Property access is synchronous, suspense is not. You’d have to block the property access to run a suspending calculation in the getter. Access to that property should be put behind a suspending getter-type function, and clients just need to manage the coroutine themselves