Ha ha :)

Pod::Simple, Pod::POM, Pod::Parser, Pod::Escapes

How can I hope to use regular expressions without creating illegible and unmaintainable code?

perlfaq6#Can I use Perl regular expressions to match balanced text?

Re: Regex prioritiesSee

• ** Eternal question of parsing parentheses
• Re^2: parsing XML fragments (xml log files) with... a regex
• recursive algorithm for nested data structures
• balanced parens regexp hangs - solved
• A regexp to parse nested brackets containing strings
• Elegant examples to parse parenthesised strings
• Regexp::Common balanced curlies substitution
• RFC: A walkthrough from JSON ABNF to Regexp::Grammars

Here is another sample, with a mix.

SPAN<text I<italic text>|class="span_class"> some more text B<bold tex
+t>.
[download]

Here is the desired output:

<span class="span_class">text <i>italic text</i></span> some more text
+ <b>bold text</b>.
[download]

*shakes head * marpa+family are so much less work :)

#!/usr/bin/perl --
use strict; use warnings; 
use Test::More qw' no_plan ';
use Regexp::Common qw/ balanced /;
use Data::Dump qw/ dd pp /;
sub TRACE; sub DEBUG;
*TRACE = *DEBUG = sub { print STDERR @_,"\n" };
#~ *TRACE = *DEBUG = sub {  };


our $allowed = join '|', qw[
ABBR ACRONYM B BIG
CITE CODE DFN EM I KBD SAMP SMALL
SPAN STRONG SUB SUP TT VAR
];

{
    my $in = 'SPAN<text I<italic text>|class="span_class"> some more t
+ext B<bold text>.';
    my $out = shabba($in);
    my $wanted = '<span class="span_class">text <i>italic text</i></sp
+an> some more text <b>bold text</b>.';

    is( $out, $wanted , 'shabba');
}

{
    my $in = 'SPAN<text I<italic B<and bold> text>|class="span_class">
+ some more text B<bold text>.';
    my $out = shabba($in);
    my $wanted = '<span class="span_class">text <i>italic <b>and bold<
+/b> text</i></span> some more text <b>bold text</b>.';

    is( $out, $wanted , 'shabba');
}

exit( 0 );

sub shabba {
    local $_ = $_[0];
    my $dent = $_[1] || 0;
    pos = 0;
    my $ret = "";
SHABBALOOP:
    while( length > pos ){
        m{\G(\s+)}gcsx and do {
            $ret .= $1;
            next SHABBALOOP;
        };
        
        m{
\G( $allowed )( $RE{balanced}{-parens=>'<>'} )
        }gcsx and do {
            TRACE "# $dent allowed<> { $1 ( $2 ) }";
            $ret .= shabba_allowed( "$1" , "$2" , $dent );
            next SHABBALOOP;
        };


#~ confusion :)
#~ \G(\w+\b)
#~ fail #~ \G([^<]+)(?!:$allowed)\b
#~ \w+\b #~ \G([^<]+?)(?!:$allowed\<)\b
#~ fail #~ \G([^<]+?)(?!:$allowed\<)
#~ fail #~ \G([^<]+)(?!:$allowed\<)
#~ fail \G([^<]+)(?!:\<)
#~ inch #~ \G([^<]+?)(?!:\<)
#~ \G([^<]+?\b[^<])
#~ \G([^<]+?[^<])
#~ FAIL #~ \G([^<]+[^<])
#~ \G([^<]+[^<]\b)
#~ 2same#~ \G( (?!:$allowed\<) .+ )
#~ 2same#~ \G( .+(?!:$allowed\<) )

        m{
\G([^<]+\s)
        }gcmx and do {
            TRACE "# $dent text { $1 }";
            $ret .= shabba_text( "$1" );
            next SHABBALOOP;
        };;;
        
        m{
\G([\<\>])
        }gcmx and do {
            TRACE "## $dent error-stray<> { $1 } at pos(@{[pos]})";
            last SHABBALOOP;
        };;;
        m{
\G(\S)
        }gcmx and do {
            TRACE "# $dent inch-forward { $1 }";
            $ret .= shabba_text( "$1" );
            next SHABBALOOP;
        };;;
    }
    $ret;
}


#~ sub shabba_allowed { join'',@_ }
#~ confusion :)
#~ use Text::Balanced qw' :ALL ';
#~ dd([ extract_multiple( $stuff,[\&extract_bracketed, ],)]);
#~     my $extract_allowed = gen_extract_tagged(qw/$allowed</,'>');dd(
+[ extract_multiple( $stuff,[ $extract_allowed , $extract_allowed , ],
+)]);
#~ 
#~     0 and $stuff =~ s{
#~ ( $allowed )( $RE{balanced}{-parens=>'<>'} )
#~ |
#~ (.)
#~ }{
#~    if( defined $2 ){
#~      $ret .= $2;
#~    } else {
#~      $ret .= shabba_allowed( "$1" );
#~    }
#~   "";
#~ }gsex;


sub shabba_allowed {
    my( $tag , $stuff, $dent ) = @_;
    $stuff = $1 if $stuff =~ m{^<(.*)>$}gs;
    
    my $ret = "";
    $ret .= "<\L$tag\E" if $tag;
    
    $stuff =~ s{\|([^<>]+)$}{
$ret .= " $1"; ## shabba_allowed_atts($tag,$1);
"";
    }gsex if defined $stuff ;
    
    $ret .= ">" if $tag;
    
    if( defined $stuff and length $stuff and $stuff =~ m{[<>]}g ){
        $ret .= shabba( $stuff , $dent+1) ; ## recurse
    } else {
        $ret .= $stuff;
    }
    
    $ret .= "</\L$tag\E>" if $tag;
    $ret;
}
sub shabba_text { join'',@_ }
__END__
$ prove -vb lady.alena.balanced.podlike.pl
lady.alena.balanced.podlike.pl .. # 0 allowed<> { SPAN ( <text I<itali
+c text>|class="span_class"> ) }
# 1 text { text  }
# 1 allowed<> { I ( <italic text> ) }
# 0 text { some more text  }
# 0 allowed<> { B ( <bold text> ) }
# 0 inch-forward { . }
# 0 allowed<> { SPAN ( <text I<italic B<and bold> text>|class="span_cl
+ass"> ) }
ok 1 - shabba

# 1 text { text  }
# 1 allowed<> { I ( <italic B<and bold> text> ) }
# 2 text { italic  }
# 2 allowed<> { B ( <and bold> ) }
# 2 inch-forward { t }
# 2 inch-forward { e }
# 2 inch-forward { x }
# 2 inch-forward { t }
# 0 text { some more text  }
# 0 allowed<> { B ( <bold text> ) }
# 0 inch-forward { . }
ok 2 - shabba
1..2
ok
All tests successful.
Files=1, Tests=2,  0 wallclock secs ( 0.11 usr +  0.02 sys =  0.12 CPU
+)
Result: PASS
[download]

This would be beautiful as a module. I am having problems wading through it. There are a lot of things in this I do not understand, and I am cargo culting it as best I can. Thank you for your work, Anonymous Monk (whoever you are).

PS. If you see this, would you please tell me what shabba stands for? :)

Have a cookie and a very nice day!
Lady Aleena

I tried Text::Balanced the other night, however, the output wasn't useful to me. Here is the code I used...

#!/usr/bin/perl
use strict;
use warnings FATAL => qw( all );

use Text::Balanced qw(extract_bracketed);
use Data::Dumper;

my $text = 'A line with B<bold>, I<italic>, and B<I<bold and italic>> 
+text.';

my @line = extract_bracketed( $text, '<>');

print Dumper(\@line);
[download]

Here is the returned results...

$VAR1 = [
          undef,
          'A line with B<bold>, I<italic>, and B<I<bold and italic>> t
+ext.',
          undef
        ];
[download]

Either I did something horribly wrong, or it doesn't extract anything just returns the original string with undefs in an array.

No matter how hysterical I get, my problems are not time sensitive. So, relax, have a cookie, and a very nice day!
Lady Aleena

Hi Aleena,

The extract_* functions are meant to operate on the start of a string, not from an arbitrary point. As mentioned in the Text::Balanced description, you may skip a prefix before the start of the balanced text, but by default this will only skip whitespace.

So if you were to change text to:

my $text = '  <bold>, I<italic>, and B<I<bold and italic>> text.';
[download]

Your output would be:

$VAR1 = [
          '<bold>',
          ', I<italic>, and B<I<bold and italic>> text.',
          '  '
        ];
[download]

Where the return is a triple of the bracketed text, the remaining string, and the prefix that was bypassed before the bracketed text was found.

If you leave your $text input as it was in your example but change the function call to consider everything preceding a < as a prefix:

my @line = extract_bracketed($text, '<>', qr(.*?(?=<)));
[download]

You'll get:

$VAR1 = [
          '<bold>',
          ', I<italic>, and B<I<bold and italic>> text.',
          'A line with B'
        ];
[download]

Where the prefix is again everything before the <. but includes the bold code at the end, which you'd have to deal with appropriately.

HTH