Re: Perl logical operators

In addition to what choroba said, if you really want to be able to use the keywords true and false in your script, there are a few CPAN modules which will provide them for you, such as boolean. Or you can just define them as constants.

use constant {qw( true 1 false 0 )};
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toby döt ink

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Re^2: Perl logical operators by tweetiepooh (Hermit) on Jul 10, 2019 at 13:38 UTC
When did this form become valid? I used on my dev box (5.28) but on production (5.16) I get a syntax error and need to use `use constant {true=>1,false=>0}`	[reply] [d/l]
Re^3: Perl logical operators by choroba (Cardinal) on Jul 10, 2019 at 13:49 UTC
Interestingly, it's a difference in Perl parser, not in constant. As usually, help the parser by telling it the `{` doesn't start a block, but a hash reference: `use constant +{ qw( true 1 false 0 ) };` [download] `map{substr$_->[0],$_->[1]\|\|0,1}[\\|\|{},3],[[]],[ref qr-1,-,-1],[{}],[sub{}^ARGV,3]`	[reply] [d/l] [select]
Re^3: Perl logical operators by hippo (Archbishop) on Jul 10, 2019 at 13:48 UTC
perldelta for 5.18.0 says: use no longer tries to parse its arguments as a statement, making `use constant { () };` a syntax error (perl #114222). which I believe refers to this.	[reply] [d/l]