On: XML is almost always misused

[thom]

XML (and JSON) have the advantage of names, which makes it slightly easier when it comes to querying (and indeed building indexes) over lots of data. I'd be amazed if there wasn't tons of work on this for S-expressions, but I can imagine it's slightly clunky.

[rauhl → thom]

What do you mean by names here? S-expressions have symbols, which serve the exact same purpose as what I think you might mean: an interned string value which can be cheaply used more than once.

[thom → rauhl]

Positions within lists aren't named. Sure you can do:

((foo . (bar . baz)) (foo . (bar . baz)) (foo . (bar . baz)) (foo . (bar . baz)))

And say "index all the foos", but you're mixing the structure and the content, in a way that JSON and XML explicitly separate.

[thom → thom]

Not saying you can't specify some schema here, but there's nothing native to S-expressions that makes it quite as transparent and simple to specify a path into a data structure.