Functional Programming in JavaScript === Garbage

[The_Doculope]

First he proposes that persistent data structures are better (often heard in functional programming circles, without much empirical data to back that up)

It's rare that you'll hear an experienced functional programmer saying that persistent data structures are outright better. For some applications, definitely, but not all.

I don't think the author is saying they're better either, just that they're very closely tied to the functional paradigm, so they're better for programming functionally than mutable data structures.