Manually adding delimiters instead of join()

Anonymous Monk has asked for the wisdom of the Perl Monks concerning the following question:

Why must you join() these values instead of just storing them with common separators?

$users{$username}"$password::$name::$email::$website::$start";
[download]

This stores only the first form field/variable and forgets everything else. But if you join the variables, it works.

  my $data = join("::", $password, $name, $email, $website, $start);
  $users{$username} = $data;
[download]

Can someone explain why you can't manually add your own delimiters in this particular line?

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Re: Manually adding delimiters instead of join() by borisz (Canon) on Oct 12, 2004 at 17:23 UTC
Thats becourse perl tries to expand a var in another namespace as requested with ::. Try this instead or use another seperator: `$data = "${password}::${name}::${email}::${website}::${start}";` [download] Boris	[reply] [d/l]
Re: Manually adding delimiters instead of join() by kvale (Monsignor) on Oct 12, 2004 at 17:26 UTC
The answer is that your particular delimiter '::' has syntactic significance in Perl -- it is the package delimiter. Thus the first form is parsed as a (rather gnarly) package variable. But the second does what you want: substitute each variable individually and then join with the syntax sensitive ::. If your delimiter had been something more benign, like whitespace, both forms would work. -Mark	[reply]
Re: Manually adding delimiters instead of join() by dragonchild (Archbishop) on Oct 12, 2004 at 17:37 UTC
Because :: is a special delimiter in Perl. If you tried ;; or \|\| or anything else, for that matter, I suspect it would it would work. Also, turn strict on. :-) Being right, does not endow the right to be rude; politeness costs nothing. Being unknowing, is not the same as being stupid. Expressing a contrary opinion, whether to the individual or the group, is more often a sign of deeper thought than of cantankerous belligerence. Do not mistake your goals as the only goals; your opinion as the only opinion; your confidence as correctness. Saying you know better is not the same as explaining you know better.	[reply]
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Re: Manually adding delimiters instead of join() by dave_the_m (Monsignor) on Oct 12, 2004 at 17:30 UTC
The double colon can be part of a variable name, as in `$foo::bar`. Try putting parentheses around the variable name, eg `"${password}::${name}::${email}::${website}::$start"` [download] Dave.	[reply] [d/l] [select]
Re: Manually adding delimiters instead of join() by gawatkins (Monsignor) on Oct 12, 2004 at 20:32 UTC
If you are set on using :: as your separator, you would have to escape them like any other special characters. You could do something like this: `$users{$username}"$password\:\:$name\:\:$email\:\:$website\:\:$start";` Thanks Greg W	[reply] [d/l]
Re^2: Manually adding delimiters instead of join() by periapt (Hermit) on Oct 13, 2004 at 12:23 UTC
Alternately, since you only need to break up the :: variable interpolation `$users{$username} = "$password\::$name\::$email\::$website\::$start";` [download] or even (although this isn't any better than join-not that there is anything wrong with join) `$password.'::'.$name.'::'.$email.'::'.$website.'::'.$start` [download] PJ use strict; use warnings; use diagnostics;	[reply] [d/l] [select]

use strict; use warnings; use diagnostics;