Request for Object Serialization Support in cache() Function about react HOT 1 OPEN

Thanks for raising this @ryo-manba. I was just about to request similar as well! Being able to serialize non-primitives so they are cached will be very helpful, especially since fetch patch is being (temporarily) removed in #28896.

I gave this a little think to see what an API could look like, and I came up with the following:

Introduce a hash function that receives all function arguments and returns array of argument hashes.

function cache(fn, argsHashFn?){}

For example:

const x = cache((vec) => sum(vec), (vec) => [vec.join(',')])

// Example
x([1, 2]) // Cache miss
x([1, 2]) // Cache hit
x([1, 3]) // Cache miss

Interesting cases

• Explicitly hashing some arguments but not others by passing empty element or undefined. In this case, default behavior of hashing by the arg itself will apply.

const x = cache((s, vec) => scale(s, vec), (_s, vec) => [,JSON.stringify(vec)])

• Specifying constant hashes to cache all invocations to the same result

const x = cache((s, vec) => scale(s, vec),  () => [true, true])

Thoughts
This may introduce some overhead to the function invocation, but if building the hash array is cheaper than invoking the function, then caching in this way makes sense. Otherwise a different approach would be better suited.

Extra

Edit: could not figure this out. It looks like the best solution is from inside cache itself.
As I typed this, I thought of a more 'cursed' way of achieving memoized behavior without making changes to existing cache implementation. Potentially, you could introduce some Map managed in user-land that could be used to stabilize the references of non-primitive arguments to a function call. Not sure if I know enough to build this out, but I'll give it a go!

from react.