Door conveniences

My planned ECTOCOMP entry has a lot of doors, and I realized it would be helpful to players if they could OPEN SOUTH DOOR…but I didn’t really want to spend my coding time writing conditional Understand lines for each door.

Here’s my current solution:

Door-directionality relates a door (called the door-in-question) to a direction (called the direction-in-question) when the room-or-door direction-in-question from the location is the door-in-question.

Understand "[something related by door-directionality]" as a door.

This lets you use direction names to refer to doors in that direction: OPEN SOUTH, X SOUTH, HIT SOUTH, and so on will prefer doors over directions, while GO SOUTH will work as expected.

Is this something that’s covered by an existing extension? If not, I’ll toss it into the Github for others to use—it’s not much code, but understanding things through predicates is a weirdly arcane part of I7, so I think this wouldn’t be obvious to newer authors.