http://qs321.pair.com?node_id=32316


in reply to cursebox v0.9 - "The Cursed Jukebox"

Update: Please use strict; !

Though I have not used this code, I have one comment to make in the spirit of TIMTOWTDI (hopefully a good comment) - I find the simulated switch statement to map a keypress to an action rather clumsy, as it does not really allow to easily add other actions later or add other actions dynamically.

In such situations, I prefer to use a hash of code references, like this : 

my %actions = (
 "n" => \&skip,
 "m" => \&movesong,
# ... rest ommited ...
 "\n" => \&goto,
);

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and the routine interpretplay() would then look like this (sadly, untested) : 
sub interpretplay {
  if (exists $actions{$char}) {
    &$actions{$char};
  } else {
    &invalid;
  };
};

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or, if the whole state machine would be changed to use hashes, one could even use a single interpret() method that would simply look at the $current_state hash reference to find the action to be executed.

Dynamically loaded actions would then simply modify the %actions hash with their entry.

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(jcwren) RE: cursebox v0.9 - switch{} coding style
by jcwren (Prior) on Sep 15, 2000 at 05:57 UTC
    This is sample code for odie to look at, and will probably be changing. Please don't vote on this node. 
    #!/usr/local/bin/perl -w

use strict;

{
   my %hash = ('a' => {-func => \&sub_one,    -parm => 'subone'},
               'b' => {-func => \&sub_two,    -parm => 'two,two_a,two_
+b'},
               'c' => {-func => \&sub_three,  -parm => ''},
              );

   &{$hash {'a'}->{-func}} (split ',', $hash {'a'}->{-parm});
   &{$hash {'b'}->{-func}} (split ',', $hash {'b'}->{-parm});
   &{$hash {'c'}->{-func}} (split ',', $hash {'c'}->{-parm});
}

sub sub_one
{
   print "sub_one got ", scalar @_, " parameters\n";

   print "sub_one parameters: $_\n" foreach (@_);
}

sub sub_two
{
   print "sub_two got ", scalar @_, " parameters\n";

   print "sub_two parameters: $_\n" foreach (@_);
}

sub sub_three
{
   print "sub_three got ", scalar @_, " parameters\n";

   print "sub_three parameters: $_\n" foreach (@_);
}

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    --Chris

    e-mail jcwren
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[d/l]
RE: RE: cursebox v0.9 - switch{} coding style
by odie (Sexton) on Sep 13, 2000 at 23:06 UTC
    Well... As I said, it is version 0.9 and the code is a complete mess. The whole thing started as a sinple recursive hack that played every mp3 file found, using mpg123. I honestly didn't expect to continue building it... =)
    I will naturally make the code a lot more efficient, and less spammy, and use strict. This code is still very much in a state of "hack". Version 1.0 will be posted when complete.
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