=pod

=for advent_year 2008

=for advent_day 18

=for advent_title The Toy-O-Matic (3000X!)

=for advent_author Steve Scaffidi & Jerrad Pierce

Elves are a creative bunch. Really, they're I<constantly> tweaking, updating, 
and adding features and options to the Toy-O-Matic (3000X!). What, you've
never I<heard> of the B<Toy-O-Matic>? (3000X!) Well let me tell you about
it! It slices, it dices, it can build just about any toy you can  dream up!
Sound complicated? You betcha! But elves are good engineers and the whole
thing is driven by simple, elf-readable configuration files. In the beginning
though, was the Doll-O-Matic. It accepted only a few parameters:

=begin pre

  gender=male
  jacket=red
  pants=green # just like an elf!

=end pre

But that was enough that the elves could offer dozens of custom dolls to suit
most sensible requests. Better yet, because they were using M<Config::General>,
only a few changes to the code were necessary to allow each elf to edit the
configs as they wanted&mdash;within reason&mdash;and actually expect it to work!

=begin code

  -my $config = Config::General->new( $cfg_file );
  +my $config = Config::General->new( 
  +   -ConfigFile     => $cfg_file,
  +   -SplitDelimiter => '\s*(?:\:|=|->)\s*|\s+',
  +   -SplitPolicy    => 'custom');

=end code

Now, even after several elves had commited edits of differing styles,
M<Config::General> could DWIM

=begin pre

  gender:  female
  #We're out of green dresses, blue is sort of like green, right? -Murphy
  #dress=green
  dress blue
  hairbow->pink #Arrows rule!

=end pre

Elves love Perl because, like them, it serves to please&hellip;
and Config::General is I<very> Perlish!

Before long, this level of customization simply wasn't enough. Seriously,
when have you ever heard (grand)parents complain about anything today being
I<simpler>? Therefore, the Doll-O-Matic was retooled and renamed Toy-O-Matic
(3000X!) to match. Now it could make more than dolls, but it's configuration
remained straight-forward and flexible, even though a single file could
contain parameters for a number of toys. An Army Dude with a Deluxe Rocket
Launcher for Jimmy, a Modern Career Woman with the Malibu Accessory Set for
Lisa and an Elf! for Tim.

=begin pre

  <toy elf_doll>
      Include elf.cfg
  </toy>

  <toy army_dude>
      nationality = antarctica
      accessories = rocket launcher
      accessories = jeep
      accessories = backpack
      speaks      = Viper commander is over the hill! Cover me! GO! GO! GO!
  </toy>

  <toy career_woman>
      phone = Raspberry 200
      <car>
          make = BMVV
          model = M3
          color = pink
      </car>
      hair = perfect
      speaks =<<END_PHRASE
Buy! Sell! Buy! Sell! 
Call my lawyer, check on the babysitter, 
book me a flight to london!
END_PHRASE
  </toy>

=end pre

That's right, M<Config::General> supports heredocs, (globbing) of includes,
and Apache-style structured files! Many elves work as webmasters in the
off-season, so these latter features were second nature to them. Plus, the
resulting data structures are easily inspected and understood:

=begin pre

% perl -MConfig::General -MData::Dumper -e "print Dumper{Config::General->new(-ConfigFile=>'@ARGV',-UseApacheInclude=>1)->getall()}" toys.conf
$VAR1 = {
           'toy' => {
                      'jimmy_doll' => {
                                        'pants' => 'green',
                                        'jacket' => 'red',
                                        'gender' => 'male'
                                      },
                      'career_woman' => {
                                          'car' => {
                                                     'color' => 'pink',
                                                     'make' => 'BMVV',
                                                     'model' => 'M3'
                                                   },
                                          'speaks' => 'Buy! Sell! Buy! Sell!
Call my lawyer, check on the babysitter, 
book me a flight to london!',
                                          'hair' => 'perfect',
                                          'phone' => 'Raspberry 200'
                                        },
                      'army_dude' => {
                                       'speaks' => 'Viper commander is over the hill! Cover me! GO! GO! GO!',
                                       'accessories' => [
                                                          'rocket launcher',
                                                          'jeep',
                                                          'backpack'
                                                        ],
                                       'nationality' => 'antarctica'
                                     }
                    }
         };

=end pre

The hacker elves were also quite happy to learn that M<Config::General>
also write configuration files from raw data structures. They even created
a GUI for designing new toys, and the results were written out to disk.
Productivity soared, creativity blossomed, and kids were happy everywhere!

=sourcedcode mod18.pl

=sourcedcode mod18b.pl

=cut