Being lazy and full of hubris in the good way, I decided that if I wanted to be able to display data structures in a debugger, that I should be able to do it in the debugger. Why not? Why give up all those great functions it's got just because I want a new one of my own?
Why not, indeed. I began digging into the debugger, and it is a wonderful, fascinating, terminally underdocumented, and monolithic piece of code. It does a lot of very heavy magic to be able to do an awful lot of processing without disturbing the running program, it is optimized out the ying-yang, uses a lot of arcane but useful techniques, and is not well-suited for extension. But hey, why let that stop me?
I've taken on the task (following encouragement by Schwern) of reformatting, commenting, and understanding it, hopefully well enough to talk about it at TPC and or YAPC.
It's really quite fascinating, and I think it'll make a good paper -- or man page, anyway.