in reply to Trying to avoid line noise (brain cramp)

Avoiding line noise in Perl is mainly about how to handle regexes, IMHO.

A good tip here is to use variables in the regexes: 

# original: /([^(]+)(\([^)]+\))(.*)/

my $not_paren = "[^(]+";
my $paren     = "\\(";
my $rest      = ".*";

# now reads:
$string =~ /($not_paren)($paren$not_paren$paren)($rest)/;

[download]

This will do a good job to make the code readable to other programmers, in my experience.

Christian Lemburg
Brainbench MVP for Perl
http://www.brainbench.com

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Re: Re: Trying to avoid line noise (brain cramp)
by Ovid (Cardinal) on Mar 09, 2001 at 18:45 UTC
    I like your code, but there's a small error: 
    # original: /([^(]+)(\([^)]+\))(.*)/

my $not_paren  = "[^(]+";
my $leftparen  = "\\(";
my $rightparen = "\\)";
my $rest       = ".*";

# now reads:
$string =~ /($not_paren)($leftparen$not_paren$rightparen)($rest)/;

    [download]

    Cheers,
    Ovid

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[reply]
[d/l]

      Ah, yes, sorry. So much for not testing everything.

      Christian Lemburg
      Brainbench MVP for Perl
      http://www.brainbench.com

[reply]
      Here's one more way to de-line-noise-ify the code: 
      my $leftparen  = quotemeta "(";
my $rightparen = quotemeta ")";

      [download]
      This is more legible than "\\(" or "\Q(\E". -- Frag.
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Re: Re: Trying to avoid line noise (brain cramp)
by BrotherAde (Pilgrim) on Mar 09, 2001 at 18:53 UTC
    On the same subject, don't forget about the "x"-modifier for regexen. It basically allows you to split a regex into multiple lines and comment on every line.

    Allow me to quote from perlman:perlfaq6, Section 1

    /x lets you turn this:

        s{<(?:[^>'"]*|".*?"|'.*?')+>}{}gs;

    [download]
    into this: 

        s{ <                    # opening angle bracket
        (?:                 # Non-backreffing grouping paren
             [^>'"] *       # 0 or more things that are neither > nor 
+' nor "
                |           #    or else
             ".*?"          # a section between double quotes (stingy 
+match)
                |           #    or else
             '.*?'          # a section between single quotes (stingy 
+match)
        ) +                 #   all occurring one or more times
       >                    # closing angle bracket
    }{}gsx;                 # replace with nothing, i.e. delete

    [download]
    It's still not quite so clear as prose, but it is very useful for describing the meaning of each part of the pattern.

    Again, hope that helps,
    Brother Ade

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