I work like this every day in my game that I am building. I’m almost the only one using the engine, and 90% of my work is in lua. I use the source code and the lua 5.1 reference for everything.

I hardly google something in a week of work, since there is nothing online about anything. It is like heaven compared to other ”google driven” programming things I have done. I feel very productive pretty much all the time, even when debugging mysterious real time issues.