I have a couple of questions that have been troubling me and I'm having a heck of a time finding useful (human)readable information on it. Let's say that Tom Christiansen isn't exactly light reading in his perlre and perlretut!
What's the difference, functionally, between a look-ahead and a look-behind?
IE: how is this: m/(?!foo)bar/ different from m/(?<foo)bar/
or this: m/(?!foo)bar/ different from m/(?<!foo)bar/
I'd prefer a written answer rather than a link to some tutorial online, unless it's a really solid and well-written tutorial.