Reply_json_dict: avoid losing distinction between atoms and strings

Help!
1

I have a dict in my server code that looks like this:

_337322{elements:[[name1,alice],[name2,“alice”]]}

After dispatching it off to the client using reply_json_dict, it arrives looking like this:

{
“elements”: [ [“name1”, “alice” ], [“name2”, “alice” ] ]
}

Atoms and strings both end up mapping onto strings, so crucial information has been lost. (name1 was paired with an atom, name2 was paired with a string.)

Is there some way I can preserve the info? I had a look at the options blurb for reply_json_dict/2 but didn’t see anything that would obviously help me.

2

If the distinction between atom and string is crucial to you you’ll have to map your data structure into something that preserves this. For example, you could map each atom into _{type:atom, text:alice}. As is, JSON has only a single string type and the Prolog mapping tries to be in sync what JSON documents typically mean as closely as possible. If you want to represent pure Prolog data I would serialize it using write_canonical/1

Note that then Pengines library also provides a JSON representation for arbitrary Prolog terms.