error checking

[utzoo!decvax!harpo!ihps3!ihuxt!paulson]

Note that exception handling in C can be implemented using setjmp/longjmp
library calls, without adding anything to the language.

Exception handling of the form used in PL/1, "on any divide by zero do the
following", seems to me to be a particularly insidious attack on
structured programming.  I get a very unsettling feeling when I know
that control is being transferred in a program without any explicit
statement from the programmer.

			Bill Paulson
			ihuxt!paulson