What a pointless debate. I've worked with XML manuscript archives and I can be certain that if I'd had to do it in JSON I'd have killed myself.
This is about JSON being created or discovered and Doug struggling to convince people it was relevant when everyone was so bought in on XML.
Are you saying you think JSON shouldn't exist and everyone should use XML for everything?
Tooling around XML was certainly more established, but man there was a lot of complexity built up around it.
No. JSON is great as Javascript's serialization format, but it's not as readable and robust as XML, period.
I use both extensively, and for bigger objects and definitions, XML is a very clear winner.
I'm a big believer in horses for courses type of approach, and my personal gripe is the push to replace one thing with another. These data types can coexist, and can be used where they shine. XML can be read and written stupidly fast, so it's way better as a on disk file format if people gonna touch that file.
YAML and JSON are not the best fit for configuration files. JSON is good as an on-disk serialization format if humans not gonna touch that. XML is the best format for carrying complex and big data around. TOML is the best format for human readable, human editable config files.
What specifically about XML means it can be read/written "stupidly fast"?
It's still a text bound serialization format, you still have to parse a tree for it.
Is it just particularly mature libraries?
It is primarily mature libraries, but also XML is more straightforward to parse, because there are not many data types and tags makes it very deterministic.
By "stupidly fast", I mean I can read a 120K XML file, parse it, create the objects which generated from that file definition under 2ms. The library I use (RapidXML [0]) can parse the file almost with the same time cost of running strlen() on the same file. That's insane.
IME the XML spec is so complex that you either end up with a slow but compliant parser or a fast one that doesn't implement the spec completely.
JSON, unlike XML, is minimal enough that writing an entire compliant parser with SIMD intrinsics [1] is actually practically feasible. That library claims 3 GBps parsing speed, which could theoretically process your 120kb of data in 1/25000th of a second instead of 2/1000ths of a second.
I would wager that JSON is faster to parse, on balance.
[0] https://web.archive.org/web/20080209172554/https://rapidxml....