On Tue, 16 Jul 2002, Brent Dax wrote: > I was reading through the Monastery, and I noticed a node (about the > line between what's considered Perl discussion and what's off-topic) > that had this regex in it: > > m:iw/how [do[es]?|can] [I|one] @tasks in @non_perl_languages/ > > (Yes, people are already using Perl 6 regexes in text. :^) ) Reading > this, I noticed a potential problem in :w. > > To put it simply, what do these expand to? > > m:w/foo [~|bar]/ > m:w/[~|bar] foo/ > m:w/[~|bar] [^|baz]/ > m:w/@foo @bar/
A5 says: Another new modifier is :w, which causes an implicit match of whitespace wherever there's literal whitespace in a pattern. In other words, it replaces every sequence of actual whitespace in the pattern with a \s+ (between two identifiers) or a \s* (between anything else). So, since groups aren't identifiers, I imagine [the first] would expand to: m/ foo \s* [~ | bar] / But I could see reason for this: m/ foo [\s* ~ | \s+ bar] / But as your third and fourth case point out, this is not always easy to represent. Perhaps :w wouldn't transform the rexex, but keep "markers" on where there was whitespace in the regex. At each marker, If the last thing it matched was a \w, and it's currently trying to match a \w, match \s+ first, else match \s* first. This could have some problems that I'm not seeing... But I do think the idea would make sense. Luke
