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.
assuming you run it in the right lua environment. The item function must be defined, and we're only speculating about its return value without seeing proper docs, or the source
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.