Oh that's cool I thought there were special hooks with D3. The native inputs demo seems really compelling especially in a learning environment. I'll definitely play with this and bring it into my next mentoring group meeting. (They'll be so glad to get away from scratch!)

One cool thing that Swift playgrounds let you do is advance program state through loops and other flow-control line-by-line using a slider. I think they have to have cooperation with the compiler/runtime to make this happen. (I'm also not sure how truly useful it is after a few days of learning the basics.)

I suppose you could do something similar with the native inputs but not using native syntax. What I'm thinking would be a massive undertaking I realize - it's cool that this offering generates so many "ooh and what else" ideas.