It won't be covered in the book. The source code has to be useful for something, after all.

Don't wear rollerskates to a tug-of-war.

As someone pointed out, you could have an attribute that says 'optimize the heck out of this routine', and your definition of heck would be a parameter to the optimizer.

Even if you aren't in doubt, consider the mental welfare of the person who has to maintain the code after you, and who will probably put parens in the wrong place.

I'm definitely a night owl. I get going about the time my wife crashes and goes to bed. And in some sense, I've had to learn to be more of a cat napper in recent years because Perl development, Perl design and development, has become a worldwide phenomenon - not just mailing lists, but RSC channels, Twitter even. This all happens 24 hours a day. And people come up with questions at any time of the day or night.

Human languages tend to be much more ambiguous than computer languages because humans are much smarter about interpreting the context.

The way I see it, if you declare something portable, you'll always be wrong, and if you declare it non-portable, you'll always be right.