[lmkg]

> I'm not sure what you mean by this. What's the difference, syntactically, between a convention and a specialized structure?

The big difference is how people look at it, not what it really is. JavaScript has a built-in key-value map data structure. An assoc-list isn't a built-in data structure, it's a way of using a more primitive data structure (lists). In particular, assoc-lists don't really look different than normal lists, so it's a slightly larger mental leap to think in terms of them. Furthermore, Lisp doesn't use assoc-lists as often as JavaScript uses key-value maps, preferring flat lists instead, so even if there were a specialized reader-macro for assoc-lists it wouldn't have been as ubiquitous.

I agree that XML and Lisp grammars are basically interchangeable. My comment was answering a question about the emergence of JSON, and my comments about assoc-lists were only in relation to JSON, not XML.