Can anyone tell me what format this uh.. nested dictionary is?

cross-posted from: https://lemmy.nz/post/4294116

I have a file with content like this:

item({
     ["attr"] = {
        ["size"] = "62091";
        ["filename"] = "qBuUP9-OTfuzibt6PQX4-g.jpg";
        ["stamp"] = "2023-12-05T19:31:37Z";
        ["xmlns"] = "urn:xmpp:http:upload:0";
        ["content-type"] = "image/jpeg";
     };
     ["key"] = "Wa4AJWFldqRZjBozponbSLRZ";
     ["with"] = "email@address";
     ["when"] = 1701804697;
     ["name"] = "request";
});

I need to know what format this is, and if there exists a tool in linux already to parse this or if I need to write one myself?

Thanks!