I remembered this post today and saw it hadn't been submitted to HN in a while, so I thought it might be worth revisiting. I would be interested to know how the state of JSON parsing has evolved since the post's last update in 2018, but I haven't come across a more recent analysis like this.

Previous discussions:

https://news.ycombinator.com/item?id=16897061 (2018)

https://news.ycombinator.com/item?id=20724672 (2019)

https://news.ycombinator.com/item?id=28826600 (2021)

I think the title is pretty click-baity, and a much better one would be:

"Many JSON parsers fail to reject certain malformed JSON documents"

and while this can still be bad, it explains why this topic gets so little attention -- after all, generating well-formed JSON is pretty easy, and we don't often deal with slightly malformed JSON in our lives.

yesterday there was a rant about parsing yml and its different versions/datatypes support