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I recently learned how to find out what Perl thinks I mean by my code. The magic of B::Deparse. This answered some mysteries, for example why this code will not stop on values that are seen as false:
while (<>) { }
When writing that loop explicitly I would be testing it like this:
while (defined( my $line = <>)) { }
It turns out that is exactly what perl is doing as well, as seen below:
perl -MO=Deparse -e 'while (<>) {}' while (defined($_ = <ARGV>)) { (); }
It's also interesting to see what the parser thinks about other code, such as:
perl -MO=Deparse -e ' if(1) {print "true"}' do { print 'true' };
And
perl -MO=Deparse -e ' print "true" if 1' print 'true';
And it is useful for seeing what some of the code from the Obfuscation section is actually doing.

In reply to Re: What I Most Recently Learned in Perl, But Should Have Already Known by imp
in thread What I Most Recently Learned in Perl, But Should Have Already Known by liverpole

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