csnover/core — pull request #2 by kitsonk (2014-07-10 19:58:32+00:00)
Title: Add core/SideTable

**SideTable** is a polyfill for WeakMap.

It is impossible to fully polyfill WeakMap (in particular you cannot provide `.clear()` and `.length`) so a functional alternative is useful. It will use WeakMap when not present.

I would think some of the "private" queues for the Observation API could be moved over to SideTable as the WeakMap-like API is a lot cleaner and discourages end developers from trying to exploit "private" data and creating dependancies that may introduce breaking changes down the road.