Hmm...

I need, in Perl, to split a string on whitespace

Unless it is quoted with double-quotes "
Single-quotes ' don't matter

Unless those double-quotes are themselves escaped with a backslash \...

Hmmmmmmmmmmmm

Maybe I could make do with two regexes?

First, use the negative lookbehind, to split on double-quotes unless they're preceded by backslash

Then iterate over the resulting array and split every second element on the whitespaces in it

Then flatten it, I guess

That sounds very inefficient