Use WeakMap

[kof]

We are using in many cases some property directly on an object/function when we need to associate a value with that object. I think WeakMap support is good enough now that we can start using it and assume people will include a WeakMap polyfill for older browsers.

I think React is also using WeakMap.

Todo

• [ ] use it in plugin-syntax-rule-value-function
• [x] use it in plugin-cache
• [x] update docs which refer required polyfils
• [x] search where else it could be used

[HenriBeck]

👍

[HenriBeck]

WeakMap can't be used inside plugin-syntax-rule-value-function because a WeakMap needs objects as keys.

[kof]

Function is an object, can be used as a key

[HenriBeck]

Ohh yeah, so the function would be the keys and the actual css prop name would be the value in the WeakMap

[kof]

@HenriBeck I think we can close this one, no?

[HenriBeck]

No, not yet, we haven't converted the function plugin to use it.