in reply to Bloated code of loops and conditionals

Instead of array refs $data11a, $data11b, etc., make a hash whose keys are 11a, 11b, etc., and store the array refs in it. Then, instead of accessing $data11a->[ $n ] you'd access $data{ 11a }[ $n ]. Or use push to avoid explicit indices. 

# my %goals; @goals{ qw( 11a 11b 22 33 ) } = ();
my @flds = qw( id title summary );
if ($sqldata) { 
   my %data;
   for my $d ( @$sqldata ) {
      my $g = $d->{ 'goal' };
#     next unless exists $goals{ $g };
      my %h;
      @h{ @flds } = @{ $d }{ @flds };  # hash slice assignment
      push @{ $data{ $g } }, \%h;
   }

   for my $g ( keys %data ) {
     $template ->param( "list$g" => $data{ $g } );
   }
}

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If you really want to control the valid values for the "goal" parameters, then uncomment the two commented lines. This will cause any record with a "goal" not in this list to be ignored.

Update: Filled in the details. Fixed typo pointed out by bradcathey.

the lowliest monk

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Re^2: Bloated code of loops and conditionals
by bradcathey (Prior) on Apr 23, 2005 at 00:07 UTC

    Thanks tlm (the artist formerly known as PP). It looks brilliant, but a bit beyond my experience. I have a couple of questions.

    - in the line: 

    next unless exists $goal { $g }

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    should $goal be goals with an 's'?

    - not sure what is going on with the 'hash slice assignment' line

    I'll plug this into my code, but I just wanted to understand it at the same time.


    —Brad
    "The important work of moving the world forward does not wait to be done by perfect men." George Eliot
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      Regarding your first question, yes, that was a typo (now fixed).

      A hash slice is a way to access several values of a hash using a list of keys. For regular hashes, for example, 

      @hash{ qw( foo bar baz ) } = ( 1, 2, 3 );

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      has the same effect as 
      $hash{ foo } = 1;
$hash{ bar } = 2;
$hash{ baz } = 3;

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      You can use slices to copy several values from one hash to another. E.g. 
      @keys = qw( foo bar baz );
@copy{ @keys } = @orig{ @keys };

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      The last line copies three key-value pairs from %orig to %copy. In the code I posted earlier, the only difference is that the accessing of the RHS slice is done via a reference ($d) to a hash instead of a regular hash: 
      @h{ @flds } = @{ $d }{ @flds };  # hash slice assignment

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      Once you dereference a hash ref you can use it like any other hash.

      Slices are discussed in perldata, and using references in perlreftut and perlref.

      the lowliest monk

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