Rest assured: JSON::XS supports the same feature.

Interesting. Since you resurrected this thread, my curiosity has been piqued, and I couldn't remember whether I'd tried to do the same with JSON::XS three years ago or not.

Searching through the JSON::XS codebase finds 0 instances of sort_by , so I am not sure what line of code in the source of JSON::XS could be implementing that function (though maybe there's an inheritance in the XS source, because I'm not sure what the equivalent of use/require/parent/base/@ISA are in XS). Because of that uncertainty, I took the working code that LanX had posted three years ago, and changed every instance of JSON::PP to JSON::XS . When I ran that, I got the message sort_by is not supported by JSON::XS. at C:\....\11111902.pl line 32. and the is() test failed, because the $lanx version was not sorted. Based on that experiment, I cannot see how to use sort_by with JSON::XS in an equivalent manner to how it's used with JSON::PP.

Could you show an example of JSON::XS using sort_by (using the same data and structure as in the working example that LanX posted earlier)? And if it's just called something other than sort_by in the JSON::XS version, please let me know what the right name is (and whether or not it's documented in JSON::XS's POD). Because if it is possible, I'd like to see how. Thanks.