"y-or-n-p" but for other characters

[weber]

Hi folks!
I'm trying to come up with a interactive function for fixing my
code...

I present three options to the user (myself), that are mapped to three
characters (a,b,c say)
Even though read-from-minibuffer solves my problem, y-or-n-p behavior
is more interesting because doesn't require an extra [ret].

Is there a way to code a y-or-n for a-or-b-or-c ?

Thanks in advance,
weber