perlmeditation
gav^
<p>We were reviewing the following code for part of a membership site
I've been working on when another developer pointed out that I used
a <i>goto</i> and this was evil. The code is:</p>
<code>RE_TIE: eval {
tie %session, 'Apache::Session::MySQL', $session, {
Handle => HH::DB->db_Main, LockHandle => HH::DB->db_Main
}
};
if ($@) {
if ($@ =~ /^Object does not exist/) {
$session = undef;
goto RE_TIE;
} else {
print $cgi->header;
die_nice('Database Error', 'Unable to connect at this time');
}
}
</code>
<readmore>
<p>The <i>goto</i> is to handle a "shouldn't really happen" case (somebody
sending us a session id which is invalid). I like the use of <i>goto</i> because
it doesn't distract from the "normal" case which a loop would. He suggested:</p>
<code>my $tied = 0;
while (!$tied) {
eval {
tie %session, 'Apache::Session::MySQL', $session, {
Handle => HH::DB->db_Main, LockHandle => HH::DB->db_Main
};
if ($@) {
if ($@ =~ /^Object does not exist/) {
$session = undef;
} else {
print $cgi->header;
die_nice('Database Error', 'Unable to connect at this time');
}
} else {
$tied = 1;
}
}
</code>
<p>Personally I think this is harder to read and it makes you read through
to work out how the loop is exited.</p>
<p>I was wondering what the general consensus here was, is <i>goto</i> (in this case) really
evil?</p>
<p>gav^