This sounds like a neat idea, but I'm not sure how useful it'll be. Relying on vendors to supply machine readable data explaining their file syntax seems... op

This sounds like a neat idea, but I'm not sure how useful it'll be. Relying on vendors to supply machine readable data explaining their file syntax seems... optimistic. Maybe "It's JSON" will be enough? Also, I'm curious how the patterns will be specified. I can imagine it quickly becoming complicated. I'm also not sure the problem is enough of a problem for people to learn the new pattern matching syntax. The occasions where I would have needed this have been inconvenient, but not enough that I bothered to look if tools existed. I usually just crank out a quick Python script to do it.