> no edge-case of an implementation can make its way into programmers' habits, something that tends to happen a lot with JavaScript. Edge cases should not, and

> no edge-case of an implementation can make its way into programmers' habits, something that tends to happen a lot with JavaScript. Edge cases should not, and they almost never do... However performance optimizations is a very special area - you have to know how things are implemented and utilize this knowledge. > mostly it was stuff where the key is needed in a function/closure (just threw this together straight in the text area here): This code is also buggy - all closures will point to the same `key`.