It's not really a standalone file format, it's executable Lua code.

It returns a new item with the given table contents.

That syntax with the keys in square brackets is the "long-form" method of creating a new table, that's allows the use of spaces and dashes in the key name.

https://stackoverflow.com/questions/34687498/what-is-the-function-of-square-brackets-around-table-keys-in-lua

Maybe this is the lua-equivelent of a python Pickle file?

WTFON

Almost looks like mongodb output. What's the file extension?

I think it's just normal Lua code.

Here's a quick json converter (based on https://stackoverflow.com/a/55575074), assuming you have lua installed:

local function to_json(obj)
    local result = {}
    for key, value in pairs(obj) do
        if type(value) == "string" then
            value = string.format("\"%s\"", value)
        elseif type(value) == "table" then
            value = to_json(value)
        end
        table.insert(result, string.format("\"%s\":%s", key, value))
    end
    return "{" .. table.concat(result, ",") .. "}"
end

function item(obj)
    print(to_json(obj))
end

dofile(arg[1])

It just defines the item function to print json, and executes the data file.

arg[1], the first command line argument, is the path to the data file:

$  lua to_json.lua path/to/datafile.list

and pipe the output to something.json or whatever else you want to do.

Looks like somebody rewrote json to require brackets around keys and to require semicolons? Very likely custom.

WTH is this shit? @postwatchbot@lemy.lol