I'm a proponent of strong type systems and I fancy myself somewhat skilled in dodging (run-time) program defects using constructive measurements. So I decided to test the power of Rust's type system, and my skills, by writing a game similar to Dr. Mario using a strict waterfall method and recording any issue I encounter. Development will be done in the following phases:

• Software requirements: we define the game mechanics and user interface, as detailed as feasible.
• Analysis/Design: we define the modules and their scope.
• Implementation: we implement each module. Compiling will be allowed, but running the program or any other form of dynamic test will not.
• Testing: we write unit tests for the individual modules, run them, and fix any defect we find. However, we do not run the program itself or perform any test which would involve any form of user-interaction.
• Operation: we do what game publisher do nowadays and let our customers find any remaining issues.

The program recognized the following command line options:

• -l <addr>, --listen <addr>: address to listen on (defaults to any)
• -p <num>, --port <num>: port to listen on for players (defaults to 2020)
• --max-players <num>: maximum number of players allowed
• --virs <num>: number of viruses placed on the field at the beginning of a round
• --tick <num>: duration of a tick (the time a capsule moved down one tile) in units of 100ms.
• --gm-sock <path>: make a game master console accessible via the UNIX domain socket at the given path

When started, connecting players will enter a lobby first. The game must be initiated by the game master or admin either via the game master console or by sending SIGUSR1 to the process.

Players connect to the game via TCP, from an ANSI-capable terminal. As the game relies on timely input, users will need to disable line buffering. In addition, users are encouraged to turn off local echoing.

For example, using nc, players may connect using the following commands (note that players may want to reset the TTY settings afterwards):

stty -icanon -iecho
nc <host> <port>

Using socat, players can let socat itself handle the TTY settings:

socat TCP:<host>:<port> STDIO,icanon=0,echo=0