[catnaroek]

> Just define your own equality operator?

Have fun doing that in JavaScript. Have fun making objects/hashtables use your custom equality operator when comparing field names. Have fun making sure that every single part of your program respects the notion of equality defined by your custom equality operator.

> Eg in Haskell, whether things can be compared for equality depends on their representation.

In any higher-order langauge, that's a feature, not a bug.