If a SO answer is in REPL transcript form, people want to be able to copy/paste it to their REPL and save the session.

That's not currently possible, although the transcript can be edited from history (but they could have pasted directly to their editor at that point).

A session is not exactly valid code, so it would be nice if save command had an option to fix things up a bit.

scala> scala> import PartialFunction._

// Detected repl transcript paste: ctrl-D to finish.

import PartialFunction._

scala> // more transcript and ctrl-D
// Replaying 3 commands from transcript.

scala> import PartialFunction._
import PartialFunction._

scala> // more


scala> :save useful.script
No replay commands in session

scala> "abc"
res2: String = abc

scala> .length
res3: Int = 3

scala> :save useful.script

The script from the last commands looks like:

"abc"
res2.length