Chapter 13
Looking Good When Things Take Unexpected Turns
IN THIS CHAPTER
Recovering from bad input and other nasty situations
Making your code (more or less) crash-proof
Defining your own exception class
September 9, 1945: A moth flies into one of the relays of the Harvard Mark II computer and gums up the works. This becomes the first recorded case of a real-life computer bug.
April 19, 1957: Herbert Bright, manager of the data processing center at Westinghouse in Pittsburgh, receives an unmarked deck of computer punch cards in the mail (which is like receiving an unlabeled CD-ROM in the mail today). Mr. Bright guesses that this deck comes from the development team for FORTRAN — the first computer programming language. He’s been waiting a few years for this software. (No web downloads were available at the time.)
Armed with nothing but this good guess, Bright writes a small FORTRAN program and tries to compile it on his IBM 704. (The IBM 704 lives in its own, specially built, 2,000-square-foot room. With vacuum tubes instead of transistors, the machine has a whopping 32K of RAM. The operating system has to be loaded from tape before the running of each program, and a typical program ...