From: Sam Smoot <ssmoot@...>
Date: 2008-06-19T10:23:50+09:00
Subject: Re: Rather validate values or use exceptions?

Yes, the second example. Because not finding the record for a known
key is "exceptional".

*But* I'd like to say that this is a minority rule. Generally
speaking:

* Exceptions should *NOT* be used for flow-control
* Exceptions should be reserved for exceptional situations

People always rail against these, but they're always wrong. ;-) throw/
catch will give you most of the benefits, without the draw-backs.
Namely:

Exceptions are _orders of magnitude slower_ than normal flow-control
structures.

There's probably languages these guidelines don't apply to, but Ruby/
MRI isn't one of them. ;-)

-Sam