Bare essential commands that create Maya's scene

If you open .MA maya file in notepad, you will see many lines of code based on your scene size. If you go through the code, no matter how big the scene is or how many nodes are there, the whole scene is created by only 4 commands! That's it! It's very easy to find this information, but what amazes me is that the programmers were able to abstract the logic of scene creation to the following atomic tasks:

1. Creating nodes with parenting info
2. Adding attributes
3. Setting changed attributes
4. Connecting the nodes

It is very easy to generate .MA style code by following the example of MA exporter plugin. I am using some parts of it in Rigenerator to save the part of the rig as code. My next goal is to be able to analyze this code and extract metadata information for each line. This will allow me to extract scene graph information by just looking at the code. So I am currently in process of designing the logic for a code parser module which will parse the code to extract node/attribute/connection information.