From: Robert C. Duvall <rcd@cs.duke.edu>
  To  : 
  Date: 02 Feb 1999 00:17:58 -0500

Error checking

While error checking is not the focus of this assignment, your program
should not crash (i.e., seg fault, abort, or bus error) on erroneous
input.  This means you should do something reasonable for the
following expressions:
  a += b
  a + 3 = 6
  print c

I do not care what you choose to do in these cases (you can print a
helpful error message, print an unhelpful error message, print no
error message and return 0, or create something bizarre (i.e., a
variable named "a +" or "a + 3").  But your program should not simply
die.

In any case, you should DOCUMENT the behavior you implement.
rcd


-- 
Robert C. Duvall
Lecturer, Duke University
rcd@cs.duke.edu