On Wed, Jun 27, 2007 at 02:26:35PM -0500, [EMAIL PROTECTED] wrote:
> Mine (borrowing RJK's testing code): $1 will be the last letter
> (non-underscore) before or at the target location; $2 will be the first
> letter at or after the target location, or the last letter if no such
> letter exists.
>
> for (qw/ A_Z_K_ A_____ _____K /) {
> print "$_\n";
> for my $n (1 .. 6) {
> my $r = $n - 1;
> print "$n: ";
> print /^(?=.{0,$r}([^_]))?.{0,$r}.*?([^_])/
> ? "[$1] ($2)" : "no match";
> print "\n";
> }
> }
I wish I'd thought of doing it that way!
If you want $2 to only ever be the first letter at or after the target
location, you can just tweak the second half of the regex:
/^(?=.{0,$r}([^_]))?(?:.{$r}.*?([^_]))?/
Ronald
