gBASIC. `help` for prompt commands, `quit` to leave.
> node = { kind: "answer", text: "a dog", yes: nothing, no: nothing }
> node.text
a dog
> node["text"]
a dog
> node["wingspan"]
unknown
> node.wingspan
runtime error at <prompt>:1:5: unknown record field: wingspan
> keys(node)
["kind","text","yes","no"]
> node.text
a dog
> quit
Your program was not saved; `recover` will bring it back next time.
