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Comment by rjbwork | Hacker News Reader

I used to agree, but I've lately come over to the JSON side, I think. It's easier to read by a human, and it doesn't have this weird "should it be a node or an attribute" thing. Single things are properties, many things are arrays.

And now with Schemas and editor support for them, I think it is an acceptable replacement personally.

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Also whitespace handling. XML is still based on SGML and its idea that a document is basically a single string of text with certain substrings "marked up" with metadata. This assumption is of course completely false for the overwhelming majority of XML use cases. Yet, it still influences many design decisions and processing steps in the XML toolchain, the most prominent being that simply formatting an XML document may change its contents.

JSON is a lot more "honest" in this respect, in that it's core data model is already useful for many applications, even without additional standards bolted on top of it. (Though those exist, this article being one of them)

Explicit arrays are what I consider the most important advantage of JSON over XML. In XML, every element is repeatable by default and only out-of-band specification can restrict cardinality. Two bytes extra per array, that convey so much structural self-documentation that is just not there in an XML document.

So JSON succeeded because XML is not verbose enough? Really did not see that one coming.

Nodes for data, attributes for metadata.

I think you made a good argument, although I personally prefer the more mature XML tooling and metadata support for versioning.

That's fine in theory, but it's not a universal heuristic, and even then, different smart well-intentioned people independently applying it won't necessarily come to the same result.

It's hardly answers the question, as strictly speaking there's no such thing as "metadata". Everything you can pass to another person can be described as "data", whether it is a color of your coat or the statement that you are describing the color of your coat. Basically, you can think of any attribute of an object as "metadata" as long as it can be only one per object and doesn't have any attributes itself, and both things can change easily and depend on the point of view.

On the contrary, I don't remember one single case when the object was described easily using "node/attribute" separation, but couldn't be described as easily using JSON. In fact, I don't even think it's possible, as you can always make two children for each object: "attributes" and "nodes".

So I guess it actually is unnecessary complication and not the benefit of using XML over JSON.

> Nodes for data, attributes for metadata.

Its a nice soundbite, but it ends up being less than useful in practice, because all metadata is data, and almost any data can be viewed as metadata, a distinction which is both subjective and strongly influenced by the use to which a consumer is putting the data rather than being determined on the basis solely of the inherent nature of the data.

Its a rule of thumb (heuristic). Judgement is still required.

(A soundbite is something altogether different.)

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