[xq31] Why don't json-to-xml() and xml-to-json() process JSON as item() ?

[Reino17]

https://www.w3.org/TR/xpath-functions-31/#func-json-to-xml:

fn:json-to-xml($json-text as xs:string?) as document-node()?
[...]
json-to-xml('{"x": 1, "y": [3,4,5]}')

Why has it been decided to have this function accept the JSON as xs:string?
Intuitively, without reading the documentation, I would've entered json-to-xml(map{"x":1,"y":[3,4,5]}). It's in the name after all.

https://www.w3.org/TR/xpath-functions-31/#func-xml-to-json:

fn:xml-to-json($input as node()?) as xs:string?
[...]
The input <array xmlns="http://www.w3.org/2005/xpath-functions"><number>1</number><string>is</string><boolean>1</boolean></array> produces the result [1,"is",true].

Why has it been decided to have this function put out the JSON as xs:string?
Intuitively, without reading the documentation, I would've expected xml-to-json(<array xmlns="http://www.w3.org/2005/xpath-functions"><number>1</number><string>is</string><boolean>1</boolean></array>) to put out [1,"is",true] as item() (like parse-json()). It's in the name after all.

Why is XML processed as (document-)node(), but JSON not as item()? This...

fn:json-to-xml($json as item()?) as document-node()?

fn:xml-to-json($input as node()?) as item()?

...would've been much more obvious to me.

[michaelhkay]

It's always hard to give a definitive answer to "why" questions, but I suspect the answer can be found in the development timeline. The two functions were arlready defined in a 2014 draft of XSLT 3.0 https://www.w3.org/TR/2014/WD-xslt-30-20141002/ at which time there was no support in the XDM data model for arrays, and in fact the WG had become very bogged down trying to find an acceptable way to represent arrays in the data model. Direct conversion between the lexical representation of JSON and XML, bypassing any need for maps and arrays, was a solution to this problem. In fact right until the final release of XSLT 3.0 there was a reluctance among some members of the XSL Working Group to make the specification dependent on XPath 3.1, which is where arrays were first supported in the data model. Michael Kay Saxonica

…

On 10 Dec 2021, at 13:50, Reino Wijnsma ***@***.***> wrote: https://www.w3.org/TR/xpath-functions-31/#func-json-to-xml <https://www.w3.org/TR/xpath-functions-31/#func-json-to-xml>: fn:json-to-xml($json-text as xs:string?) as document-node()? [...] json-to-xml('{"x": 1, "y": [3,4,5]}') Why has it been decided to have this function accept the JSON as xs:string? Intuitively, without reading the documentation, I would've entered json-to-xml(map{"x":1,"y":[3,4,5]}). It's in the name after all. https://www.w3.org/TR/xpath-functions-31/#func-xml-to-json <https://www.w3.org/TR/xpath-functions-31/#func-xml-to-json>: fn:xml-to-json($input as node()?) as xs:string? [...] The input <array xmlns="http://www.w3.org/2005/xpath-functions"><number>1</number><string>is</string><boolean>1</boolean></array> produces the result [1,"is",true]. Why has it been decided to have this function put out the JSON as xs:string? Intuitively, without reading the documentation, I would've expected xml-to-json(<array xmlns="http://www.w3.org/2005/xpath-functions"><number>1</number><string>is</string><boolean>1</boolean></array>) to put out [1,"is",true] as item() (like parse-json()). It's in the name after all. Why is XML processed as (document-)node(), but JSON not as item()? This... fn:json-to-xml($json as item()?) as document-node()? fn:xml-to-json($input as node()?) as item()? ...would've been much more obvious to me. — You are receiving this because you are subscribed to this thread. Reply to this email directly, view it on GitHub <#34>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AASIQIUGVGYUTM4X5J3NR73UQIASXANCNFSM5JZF5CJA>. Triage notifications on the go with GitHub Mobile for iOS <https://apps.apple.com/app/apple-store/id1477376905?ct=notification-email&mt=8&pt=524675> or Android <https://play.google.com/store/apps/details?id=com.github.android&referrer=utm_campaign%3Dnotification-email%26utm_medium%3Demail%26utm_source%3Dgithub>.

[Reino17]

Thanks for the clarification. Can I then turn this into a request for XPath/XQuery 4.0?