Re^2: Announcing Perl-Critic-0.14

Please forgive my ignorance, but what's wrong with it? $foo ends up as 1 when $bar is true and is undefined when $bar is false. Just as I expect it to be. (Active Perl 5.8.7)

use warnings;
use strict;

my $t_bar = 1;
my $t_foo = 1 if $t_bar;

my $f_bar = 0;
my $f_foo = 1 if $f_bar;

print "true $t_foo false $f_foo";


#->true 1 false 
#->Use of uninitialized value in concatenation (.) or string ...
[download]

holli, /regexed monk/

Comment on Re^2: Announcing Perl-Critic-0.14 Download Code

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Re^3: Announcing Perl-Critic-0.14 by bart (Canon) on Jan 30, 2006 at 16:47 UTC
Please forgive my ignorance, but what's wrong with it? $foo ends up as 1 when $bar is true and is undefined when $bar is false. Just as I expect it to be. (Active Perl 5.8.7) Wrong. This piece of code is one of the weird things in perl, in this case, something that is sometimes used as a dirty trick, to create a static variable. `#!/usr/bin/perl -lw print $]; for (1 .. 5) { my $i = 123 if $bar; print ++$i; }` [download] Result: `Name "main::bar" used only once: possible typo at test.pl line 4. 5.008003 1 2 3 4 5` [download]	[reply] [d/l] [select]
Re^4: Announcing Perl-Critic-0.14 by holli (Abbot) on Jan 30, 2006 at 17:26 UTC
Conclusion: Always assign something in a `my` declaration? The following works as expected. `my $i = $bar ? 123 : undef;` [download] And yeah, that's really weird. holli, /regexed monk/	[reply] [d/l] [select]
Re^5: Announcing Perl-Critic-0.14 by Aristotle (Chancellor) on Jan 30, 2006 at 17:59 UTC
Conclusion: Always assign something in a `my` declaration? More precisely: make sure an assignment with a `my` on the left-hand side is never conditional. Makeshifts last the longest.	[reply] [d/l] [select]
Re^6: Announcing Perl-Critic-0.14 by diotalevi (Canon) on Jan 30, 2006 at 21:08 UTC
Re^5: Announcing Perl-Critic-0.14 by ysth (Canon) on Jan 30, 2006 at 18:43 UTC
Always assign something in a my declaration? I think it boils down to: Never modify a lexical unless the my() was executed during the current execution of the enclosing block.	[reply]