feature: encoding empty array

[bjne]

Would be nice to be able to set a flag to force a empty table to be
encoded as an array []

Also mentioned here: mpx/lua-cjson#11
and here: http://openmymind.net/Lua-JSON-turns-empty-arrays-into-empty-hashes/

[bungle]

Okay, I think I have fixed this now. Example code:

local json = require "cjson"
print(json.decode("[]").__jsontype) -- "array"

-- you could also check it like this:
print(getmetatable(json.decode("[]")) == json.object) -- false
print(getmetatable(json.decode("[]")) == json.array) -- true
-- or
print(json.decode("[]").__jsontype == "object") -- false
print(json.decode("[]").__jsontype == "array") -- true

print(json.decode("{}").__jsontype) -- "object"
print(json.encode(setmetatable(json.decode("[]"), json.object))) -- {}
print(json.encode(setmetatable(json.decode("{}"), json.array))) -- []
print(json.encode(json.decode("[]"))) -- []
print(json.encode(json.decode("{}"))) -- {}

Was this what you were looking for?

json.encode({}) returns [], but json.encode(setmetatable({}, json.object)) returns {}. And json.encode({ a = "b" }) returns { "a": "b" }. Also json.encode(setmetatable({ a = "b" }, json.array)) returns { "a": "b" } (I'm not sure though, is the last example "right", should it forcefully throw away all the keys instead, and return just []?).

And you are welcomed to reopen this issue, if you feel like it was not resolved.

Regards
Aapo

[goecho]

good works.

[apristen]

thanks!
in which version it is fixed?
I have lua-cjson-2.1.0.4 and cjson.encode(cjson.decode("[[],{}]")) returns me [{},{}]