I-JSON (short for "Internet JSON") is a restricted profile of JSON designed to maximize interoperability and increase confidence that software can process it successfully with predictable results.
An old proposal (2015, not sure why OP posted it now), that basically proposes to put some more standards and limitations around JSON formatting to make it more predictable. Most of it seems pretty reasonable:
Must be UTF-8 encoded and properly escape Unicode characters
Numbers must respect the JavaScript number Type and it’s limitations (i.e. max magnitude of an int etc.)
Objects can’t have duplicate keys
The order of keys in objects does not matter
A JSON file does not need to have a top level object or array, it can be any JSON value (i.e. just a string or a number is still valid JSON).
It proposes that when processing JSON, any unrecognized keys should be ignored rather than errored
It recommends:
Specific formats for date-time data
That binary data be stored as a bas64url string
Honestly, the only part of this I dislike is the order of keys not mattering. I get that in a bunch of languages they use dictionary objects that don’t preserve order, but backend languages have a lot more headroom to adapt and create objects that can, vs making a JavaScript thread loop over an object an extra time to reorder it every time it receives data.
I’m honestly unsure if they intend the ‘must-ignore’ policy to mean to eat duplicate keys without erroring, or just to eat keys that are unexpected based on some contract or schema…
A summary:
An old proposal (2015, not sure why OP posted it now), that basically proposes to put some more standards and limitations around JSON formatting to make it more predictable. Most of it seems pretty reasonable:
It recommends:
Honestly, the only part of this I dislike is the order of keys not mattering. I get that in a bunch of languages they use dictionary objects that don’t preserve order, but backend languages have a lot more headroom to adapt and create objects that can, vs making a JavaScript thread loop over an object an extra time to reorder it every time it receives data.
Personally, I prefer duplicate keys to be eaten by the parser but I can see how it’d be beneficial to prevent them.
I’m honestly unsure if they intend the ‘must-ignore’ policy to mean to eat duplicate keys without erroring, or just to eat keys that are unexpected based on some contract or schema…