Cache size understanding

[Noitidart]

I'm not understanding the cache size of proxy-memoize. How long does it hold on to the argument values is it forever?

Example:

memo(number => {
  return number + 10;
})

The number will always change. So does that mean it is never caching?

[Daishi Kato]

First things first, memoize only accepts one object.

It has a "result" cache, which is a weak map. So, it will remember the result for the same object forever.

const plusTen = memoize(obj => obj.num + 10);

const obj1 = { num: 1 };

plusTen(obj1); // running function
plusTen(obj1); // returning cached result
plusTen(obj1); // returning cached result

However, if you pass a fresh object, if will check it against "memo" cache.
The default size of the "memo" cache is 1 and can be configurable at creation.

const plusTenDefault = memoize(obj => obj.num + 10);

plusTenDefault({ num: 1 }); // running function
plusTenDefault({ num: 1 }); // returning memo'd result
plusTenDefault({ num: 2 }); // running function
plusTenDefault({ num: 2 }); // returning memo'd result
plusTenDefault({ num: 1 }); // running function again

const plusTenSize2 = memoize(obj => obj.num + 10, { size: 2 });

plusTenSize2({ num: 1 }); // running function
plusTenSize2({ num: 1 }); // returning memo'd result
plusTenSize2({ num: 2 }); // running function
plusTenSize2({ num: 2 }); // returning memo'd result
plusTenSize2({ num: 1 }); // returning memo'd result
plusTenSize2({ num: 3 }); // running function
plusTenSize2({ num: 1 }); // running function as the first one is gone

[Noitidart]

Oh this is so great thank you for this learning! This helps put together some great docs from the info in the issues!

[Daishi Kato]

Look forward to a PR then. Please try it first if it really works as expected. 😎

[Noitidart]

Haha for sure. I'm real keen on writing docs for this and jotai. Will definitely be in touch with the team! :)

[Daishi Kato]

Have you joined our discord servers?
Daishi's OSS: https://discord.gg/MrQdmzd
Poimandres: https://discord.gg/poimandres

[Noitidart]

Oh no I haven't! Thank you! Joining now