Re: Re: Regex (lookahead) Confusion

[QM]

Bart's regex does the trick. I was thinking of a lazy approach using sort - slower, but easier for the regex neophytes to get a handle on:

#!/your/perl/here

use warnings;
use strict;

while (<DATA>)
{
    chomp;
    my $sort = join '', sort split '';
    ( ( $sort =~ /^[afhmstw]+$/ ) # only these chars
      and
      ( $sort !~ /([afhmstw])\1/ ) ) # no repeats
    ? print "<$_> OK\n"
    : print "<$_> Not OK\n";
}

__DATA__
smsa
smta
stmwhas

BADsmtaEXAMPLE

__END__
<smsa> Not OK
<smta> OK
<stmwhas> Not OK
<> Not OK
<BADsmtaEXAMPLE> Not OK