@cgrand: > I've come up with `"\uE5CA\n[)\"[)" as an escape sequence with low probability of buffering and not being valid input. Why that sequence in particular, any reason or just a combination of unlikely characters?

@cfleming I'm backpedaling a lot on all input aspects. I'm on vacation this week, hopefully I'll get some hammock time. However there was a logic behind this escape sequence: first a rare private character to limit buffering. Then a new line in case we are in a comment. Then mismatched parens to be sure it's invalid clojure then a double quote in case we were in a strong. And mismatched parens again.