[z-machine] "State of play" for restart/restore

[Graham Nelson]

In particular, here's why you might not want the streams
to be reset by restarting. Suppose you're writing a long
test script of commands for a game. That may need to
include testing unsuccessful avenues of play as well
as the main line, and when you've gone far enough down
such an avenue, you need to get back. You could well
want to do this by saving and restoring, or by restarting:
this mustn't halt the process of input coming from a
script of commands (an input stream setting) or of
transcribing the output to a file (an output stream one).

Most of the other issues - cursor splits, etc. - are not
terribly important so no practical Z-machine story file
would ever save its state, or call for a restart, when
in the middle of mucking about with the status line.
If they do, it must be an emergency or a crash, in
which case it probably doesn't matter what the
interpreter does.

--
Graham Nelson