mine function $ naming?

[nhrones]

I'm having difficulty understanding the state machine code in the mine function.

I see functions with names that start with $, and in these functions, i see the same names without the $. I don't see any calls to any of these $-functions which take a char argument, and the same names used in these function without the $ don't seem to be declared anywhere, and don't seem to be making calls to the $-functions? Can someone explain this to me. I'm coming from a C# background and I'm having difficulty with just this 'mine' state-machine function.