From: "Chas. Owens" <[EMAIL PROTECTED]>
> Yes, but I am the one making pronouncements about how people should
> code. Rob was just calling me on being a little pompous. I still
> think that use of $_ in places other than the start of a loop (with a
> function that uses the default variable like split, chomp, a regex,
> etc) is both dangerous and bad style. It is dangerous because $_ can
> be set by any number of things, so the farther from the place that you
> set it the more likely a bug will occur. It is bad style becuase $_
> carries no information about what it is being used for. It is easier
> to give people simple rules like "only use the default variable with
> functions that use it by default" than to explain all of the nuances
> of when it adds clarity.
I think the fourth sentence is the best rule. The further from the
place you set $_, the more likely you end up with problems. The
closer, the safer. And whether you use $_ invisibly, as the default
parameter for some builtins or visibly as an ordinary parameter is
irrelevant.
for (@some_array) {
$_ .= "\n";
}
would not be made any more clear by changing it to
for my $line (@some_array) {
$line .= "\n";
}
conversely
for (@some_array) {
fiveteen lines
of very involved code
calling god knows what
s/(blah)/(oops)/g;
some more code;
}
is IMHO fairly unclear no matter that you may be using the $_ only by
the builtins behind the scene.
IMHO, it's the size and complexity of the variable's scope that
affects whether it's OK to use $_ or whether you should use a named
variable. Not the operations you do with the variable.
Jenda
===== [EMAIL PROTECTED] === http://Jenda.Krynicky.cz =====
When it comes to wine, women and song, wizards are allowed
to get drunk and croon as much as they like.
-- Terry Pratchett in Sourcery
--
To unsubscribe, e-mail: [EMAIL PROTECTED]
For additional commands, e-mail: [EMAIL PROTECTED]
http://learn.perl.org/
