Right, and amusingly, more than a few json parsers are very lenient in this. That or folks abandon ship fairly quickly and go for another spec that is far more friendly.
Me thinks you have never looked at the field. I'd as soon declare csv is an error free format. Only true if you ignore the proliferation of applications that get it wrong. In subtle ways, often. Still wrong.
csv is wildly ambiguous, to the frustration of ~every data science engineer in industry
json is not
show me an application that parses `{'a':'b'}` as valid JSON, i'm actually interested, probably there are some which exist, but there is no ambiguity about those applications being wrong
Sorry I don't understand your argument. HTML is fully and unambiguously defined, as you can see if you follow the link. Some tags are optional in certain contexts, but this is also precisely defined.
I think you're missing the point that it is defined, the current html5 spec says that <title> implies the existence of <head>, <body> implies the end of <head>, body tags imply the end of <head> and the start of <body> etc.
if `<title>A <h1>Heading` is equivalent to `<head><title>A</title></head> <body><h1>Heading</h1></body>` then this means the language is not precisely defined