William Reardon’s Blog

The OSCON conference is off to a good start, and the
first session I attended was Damian Conway’s Best
Practice Perl. I had heard that Conway was a terrific speaker,
and after having attended my first talk, I would have to agree.

Needless to say he had a lot of interesting things to say but here’s
some highlights of the bits I found most interesting:

• For data sets, attempt to format them so they look like a table.
  It makes a big step forward in readability.
  

  
  

• I generally haved tried to name my functions with verbs, and
  variables with nouns. He expounded on that quite a bit, suggesting
  things such as:
  
  • verb_noun_preposition (e.g., get_record_for)
    
  • verb_noun_participle (e.g., get_record_using)
  
  After thinking about it for a second, I liked it.
  

  
  

• He pointed out that when you localize a variable, you *don’t* get
  a copy of the variable’s value (as I and a lot of other people thougth
  you did). Instead you need to do local $Pkg::Foo = $Pkg::Foo.
  

  
  

• Several cool modules that I hadn’t heard about where pointed out,
  including:
  
  • List::Util - May cool operators for
    working on lists. What Damain said “was left out of Perl.”
    
  • Scalar::Util’s - in particular the weaken function
    
  • Readonly - like use CONSTANT but allows for variable
    interpolation & can be used to build-up very complex Regexes.
    
  • Regexp::Common
    

  
  

• Nested ternary blocks can be particularly useful for assign
  initial defaults. E.g.:

  my $foo = $n  0 && $n  10 && $n
  
  It took me a second but I liked this.  The big advantage here, as
  
  pointed out by Damain was that a value has to be assigned.
  
  With an if/elsif/etc. construct, having a final else cannot be enforced.
  
  
  
   Have a POD template for for modules & applications.
  
  
  
   POD’s =for doesn’t display when a user perldoc’s your manual and
  
  is a good place to include longer comments explaining the rational and
  
  work-arounds or suggesting possible optimization & improvements.
  
  
  
   Don’t use prototypes in Perl.  I never liked them because they’re
  
  not what most people thing they are, but Damian pointed out several other
  
  reasons as well, including that they’re ignored when subroutines are
  
  invoked as methods and, based on where the prototype is declared, can
  
  be ignored in other circumstancs as well.
  
  
  
   A bare return is better than return undef,
  
  as it’s content-sensitive and yields () in list context & undef in
  
  scalar.
  
  
  
   Somewhere around 5.5.3 lexical filehandles are supported.  (Very cool.)
  
  
  
   He’ll be releasing IO::Prompt.  This will make it easier to
  
  handle input from users (esp STDIN).  In the meantime, check if a
  
  program is being called in interactive mode & prompt instead of just
  
  sitting there waiting for input.
  
  
  
   The regex /m & /x flags are going to be defaults in Perl 6.
  
  
  
   Gave a good reminder to use ?> to turn of backtracking.  If you
  
  don’t need backtracking, this can be a big win.
  
  

This entry was posted on Monday, July 26th, 2004 at 2:02 pm and is filed under nerd-ness. You can follow any responses to this entry through the RSS 2.0 feed. You can skip to the end and leave a response. Pinging is currently not allowed.