The line at the top of the screen is a reminder of the commands you can give to control how Eden steps through a bug's life. You have several possible replies:
y
will run the life for one cycle. You will then be
invited to type another control command.
n
stops the life and returns to Prolog. You will
then get another ?-
prompt.
s
followed by a space and a number runs the life
for that number of cycles before asking for another control command.
We call this ``slow'' mode, because the screen is updated on every
cycle.
f
followed by a space and a number runs the world in
fast mode for that number of cycles. With fast mode enabled, Eden does
not update the screen between cycles. This allows you to run a large
number of cycles much faster than in slow mode. However, it also means
that you won't see what the bug is doing. This option is mainly useful
when testing machine-learning programs, and you won't need it much in
this course.
l
enables you to pass a sentence for Bug to
``listen'' to. You probably won't use this much either.
r
refreshes the screen. This is useful if, say, the
operators have just broadcast a general message, and you want to remove
it.
e
allows you to ``edit'' the world as the bug runs.
This is useful for experimenting with ``opportunism'' - testing how
well your bug can adapt to sudden changes. To do this, you need to know
how to use the editor, and I'll go into this in a separate handout.
v
allows you to edit the view window. Again, you
need to know the editor first. Editing the view window is useful if
there's a lot of output, and you want to go back and look at it. It's
also useful if you want to print the window.
In each case, you must hit RETURN after replying. Note that your keystrokes are not displayed as you respond to this question. One thing that catches many people out is if you accidentally type some extra characters before answering the question and hitting RETURN, Eden will not understand what you meant and will repeat the question. In such a case just be patient and retype.