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 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 getting 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 ...