Phoenix.pm: Parameter parser

[Doug Miles]

Doug Miles wrote:
> Hey all,
> 
> I just implemented a parser that takes something like this:
> 
> command param1 param2="value2" param3="value3 \"foo\""
> 
> and puts the parameters and values into a hash.  The value for param1 
> would be "1".  I'm not sure I implemented it the best way, though.  I 
> thought I'd get some ideas from you folks to get a different 
> perspective.  I'll post what I did after I get some responses.  I don't 
> want to contaminate your thinking. :)
> 
> 

I left out a few details that I forgot to mention.  There can be 
optional whitespace around the '=' and command may be a command, a 
scalar, an array, or a method call.  What the program does from there 
depends on which it is.  Right now the program is putting the data in an 
array, but this will change to a hash in the future.  Oh, and ignore the 
$tag_parser parameter. :)

I have to pay around with Scott and Eden's examples some more, but here 
is what I did (I'm sure the formatting will be screwed up):

#!/usr/bin/perl

use Regexp::Common;

my $tag_content = '$scalar param1 param2="\"test2\""';
my @parameters = process_tags('', $tag_content);
print join('|', @parameters) . "\n";

$tag_content = q{@array format="'test3'" default_format="test4"};
@parameters = process_tags('', $tag_content);
print join('|', @parameters) . "\n";

$tag_content = 'command doug="test5" julie="test6"';
@parameters = process_tags('', $tag_content);
print join('|', @parameters) . "\n";

# process_tags #########################################################

sub process_tags
{

   my $tag_parser  = shift;
   my $tag_content = shift;

   # Suppress "Use of uninitialized value in" warnings.
   pos($tag_content) = 0;

   my @parameters;

   while(pos($tag_content) < length($tag_content))
   {

     if(my ($match, $scalar) = $tag_content =~ /\G^(\$([a-zA-Z0-9_:.]+))/)
     {

       pos($tag_content) += length($match);

     }
     elsif(my ($match, $array) = $tag_content =~ /\G^(\@([a-zA-Z0-9_:.]+))/)
     {

       pos($tag_content) += length($match);

     }
     elsif(my ($command) = $tag_content =~ /\G^([a-zA-Z0-9_:.]+)/)
     {

       pos($tag_content) += length($command);

     }
     elsif($tag_content =~
            /
              \G                                            # Start at 
last match pos.
              (([a-zA-Z0-9_:.]+)                            # A parameter.
               (?:\s*?=\s*?                                 # '=' & 
optional WS.
               $RE{delimited}{-delim=>'"'}{-esc=>'\\'}{-keep})?) # '"' 
delimited value.
            /x # / Fix VIM syntax highlighting problem.
          )
     {

       my $match     = $1;
       my $parameter = $2;
       my $value     = defined($5) ? $5 : 1;

       $value =~ s/\\"/"/g;

#print "$1|$2|$3|$4|$5|$6|$7|$8|$9\n";
       push(@parameters, ($parameter, $value));

       pos($tag_content) += length($match);

     }
     else
     {

       pos($tag_content) += 1;

     }

   } # END: while(pos($tag_content) < length($tag_content))