Alright, well it sounded like something else. I'm still unclear exactly how to apply this:

> Less language-specific knowledge is needed to read any one piece of code.

to lispish and forthish languages? Obviously you "read" them quite differently than algol-style languages.

> I'm not sure if the cognitive load of knowing -- and maintaining that knowledge -- of most of the tricks that Perl offers will compensate with enough additional productivity. ... Perl has an exception to almost every rule, and they're easy to forget.

I disagree. Whenever you're typing tabs, or braces, or dots, or for(;;), or any other syntactic noise- even if you're typing over 100wpm, your brain shuts off and you're no longer thinking about the problem. It's not exactly rest, but it's not exactly productive either. Most of those exceptions are syntactic and not data-related which means they rarely cause problems with real data (as opposed to test data). The few corner cases (defined/undefined/0/1/0e0, for example) are common enough that almost anyone who spends any time in perl is familiar with them.

> Unless you're a Perl monk this will creep up and cause problems.

On the other hand, its not like striving toward perl monk-like status would do anything but make you a better programmer.