commenting regular expressions (take two)?

SeekerOKnowledge has asked for the wisdom of the Perl Monks concerning the following question:

I appreciate the previous responses received, but I'll take this question in a slightly different direction. The following code does not do what I want. If I substitute back in the commented out line, I restore the functionality I want. Is there a way to format qr blocks such that they can be more easily read by the uninitiated?

#!/usr/bin/perl

my $s = "blah,blah,blah <PgfTag `Normal \(T\)'> yadda,yadda,yadda";
print "s =\t\"$s\"\n";

#my $pattern = qr{\s*<PgfTag `Normal \(T\)'>\s*};
my $pattern = qr{
    \s*
        <PgfTag `Normal \(T\)'>
    \s*
};

my $k = 0;

$s =~ s/$pattern/++$k && ','/gex;

print "$k change(s)\n";
print "s =\t\"$s\"\n";
[download]

Thanks again for any comments passed on.

Comment on commenting regular expressions (take two)? Download Code

Replies are listed 'Best First'.
Re: commenting regular expressions (take two)? by Zeroth (Beadle) on Sep 04, 2003 at 18:32 UTC
The `/x` modifier does exactly what you want. See the section about modifiers in `perldoc perlre`.	[reply] [d/l] [select]
Re: commenting regular expressions (take two)? by tcf22 (Priest) on Sep 04, 2003 at 18:32 UTC
Use the `x` modifier in the qr//. my $pattern = qr/ \s* <PgfTag `Normal $T$'> \s* /x; [download]	[reply] [d/l] [select]
Re: Re: commenting regular expressions (take two)? by SeekerOKnowledge (Initiate) on Sep 04, 2003 at 19:50 UTC
Thanks for all replies. The /x did the trick, but I also had to escape the spaces within the desired strings as well.	[reply]