Re: Perlish while loop

Perl allows postfix flow control, which would tighten this up a bit. Personally, I also find this version much more readable, but there are those who would disagree:

...
            $people = 1 if ($filename eq 'people.pdf');
            $animal = 1 if ($filename eq 'animal.pdf');
            $msi    = 1 if ($filename eq 'setup.msi');
        }
    }
    print "People not found\n"   unless defined $people;
    print "animal not found\n"   unless defined $animal;
    print "MSI file not found\n" unless defined $msi;
...
[download]

rovf's suggestion with using a hash to store the mapping of filenames to file descriptions is definitely the way to go for longer-term maintenance, since it allows you to expand the range of things you're looking for by simply adding a new hash entry, turning this into:

my %filenames = (
                 people.pdf => 'Person',
                 animal.pdf => 'animal',
                 setup.msi  => 'MSI file',
                );
...
            for (keys %filenames) {
                delete $filenames{$_} if $filename eq $_;
            }
        }
    }
    for (values %filenames) {
        print "$_ not found\n";
    }
...
[download]

Comment on Re: Perlish while loop Select or Download Code

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Re^2: Perlish while loop by doug (Pilgrim) on Jul 16, 2009 at 19:45 UTC
ESPer, why did you go with `for (keys %filenames) { delete $filenames{$_} if $filename eq $_; }` [download] instead of simply `delete $filenames{$filename};` [download] and just not worry about the cases where the $filename wasn't one of the ones that you're interested in? `keys` has to build a list, then that has to be traversed, and each value compared. I could understand `if ( exists $filenames{$filename} ) { delete $filenames{$filename}; }` [download] especially if there is a chance that %filenames is tied to something big and slow. Is there something that I overlooked? - doug	[reply] [d/l] [select]
Re^3: Perlish while loop by dsheroh (Monsignor) on Jul 17, 2009 at 08:55 UTC
Honestly? Because I was translating from the non-hash version above it and just copied the structure without thinking about it. Thanks for catching that!	[reply]