Another way:
>perl -wMstrict -le
"my $s =
'aaaa bb ccccc ddd eeeeeee ffff gg hhhhh iii jjjjjjj';
;;
for my $ar ([2, 5, 3], [3, 7, 4], [4, 2],) {
my $rx = rxg(@$ar);
print $rx;
my @groups = $s =~ m{ ($rx) }xmsg;
print qq{'$_' } for @groups;
}
;;
sub rxg {
my ($rx) =
map qr{ \b $_ \b }xms,
join ' \s+ ',
map qq{\\w{$_}},
@_
;
;;
return $rx;
}
"
(?^msx: \b \w{2} \s+ \w{5} \s+ \w{3} \b )
'bb ccccc ddd'
'gg hhhhh iii'
(?^msx: \b \w{3} \s+ \w{7} \s+ \w{4} \b )
'ddd eeeeeee ffff'
(?^msx: \b \w{4} \s+ \w{2} \b )
'aaaa bb'
'ffff gg'