Okay I think I've worked out the basic structure. The heredoc gets split into an array of words, then every fourth word (the %4) is printed - puny and vast are Pirate for lc and uc, so the fourth words "just another Perl PIRATE" get re-cased and printed. I'm not sure what "squint at the dubloons" (Pirate for "study $_") does. I'm sure I've read about study somewhere, but perldoc doesn't know anything about it. Something to do with optimising a regex?
I'm not sure what "squint at the dubloons" (Pirate for "study $_") does.
Indeed, study looks at a string and indexes the chars for later regex use - pretty much made redundant by qr though. Here though, it's simply decoration. :)
study and qr are not the same thing at all. qr compiles a regex string into the data structure that represents that regex in memory. study processes a string that a regex is going to process later. So the difference is that qr speeds up the regex on the right side of =~ and study speeds up the string on the left side.