Serialize/dump/pretty print game state into file system (save game state to disk)

[hyiltiz]

I've been looking into saving game state to file system. Specifically, serialize all the lua tables relevant to the game state into json. This will pose two obvious challenges: a) some game objects may be recursive; b) functions cannot be sensibly serialized in general.

There are quite a few libraries and methods to go about this [1]. And the game already uses a few methods (namely `./scripts/json.lua` and `./scripts/inspect.lua`). The idea is that we can iterate over the common game tables such as `TheWorld`, `ThePlayer`, `TheNet` etc. recursively, and convert each key-value pair into string, indenting appropriately. This is already implemented in `debugtoosl.lua:dumptable()` as well as `table.inspect()` both of which can serialize/convert a `lua_object` into `String`, which can then be printed or saved into a file.

The issue is, when I tried `table.inspect(ThePlayer)`, or `table.inspect(ThePlayer.components)` or even `table.inspect(ThePlayer.components.Builder)`, the game simply ate all my 8G of RAM and got killed by the OS. I wonder if it would be possible to write to a file incrementally instead of creating the whole representation in RAM, holding the string in RAM then writing it to a file.

 Using common tools to inspect (deeply nested) `json` data, it would make it easier for Modders to learn about how this game works in general and would prove to be a very good mental model and guideline for reading and modding the game source code.

In the end, I'm looking to get something like this (after loading the `json` into some `json` inspector; heck even Chrome can inspect `json` files with tree-like inspection support):

_G
├── TheNet
├── ThePlayer
│   └── Components
│       └── Builder
└── TheWorld
   └── SeasonManager
 

p.s. This would also make tools like DSTed [2] very powerful, enabling users to traverse game state that was stored during game play.

[1] http://lua-users.org/wiki/TableSerialization

[2]