Here is something that I believe
almost satisfies your requirements (just needs a bit more work which I'm not ready to do at the moment, and its not thoroughly tested). It doesn't do very well without a min and max length for each pattern, so maybe if this was wrapped in a sub which adjusted the min and max to various sizes, and evaluated the results on each pass by some heuristic, it could do fairly well with all of the requirements (and that'll have to wait 'till later):
use warnings;
use strict;
# Min and max length for each pattern
my $min = 2;
my $max = 8;
# Number of patterns
my $num = shift;
# Generate pattern to capture words
my $words = join ('', map {
"(.{$min,$max})" .
"(?:" . join( '|', map("\\$_", 1..$_)) . ")*"
} 1..$num);
$_="bookhelloworldhellohellohihellohiworldhihelloworldhihellobookpenbo
+okpenworld";
if (my @pats = /^$words$/) {
for my $pat (@pats) {
print "[$pat]\n";
}
}
stan:~/tmp >./tst 5
[book]
[hello]
[world]
[hi]
[pen]
Update: Greatly simplified. Wondering if I'm doing
someone's homework. Noticed that its very similar to
nardo's
approach, but cleaner, I think, and slightly different behavior
due to the newest problem definition. Great minds think alike :)