Re: 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

Comment on Re: Trying to avoid line noise (brain cramp) Download Code

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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 Join the Perlmonks Setiathome Group or just click on the the link and check out our stats.	[reply] [d/l]
Re: Re: Re: Trying to avoid line noise (brain cramp) by frag (Hermit) on Mar 09, 2001 at 20:51 UTC
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.	[reply] [d/l]
Re: Re: Re: Trying to avoid line noise (brain cramp) by clemburg (Curate) on Mar 09, 2001 at 18:47 UTC
Ah, yes, sorry. So much for not testing everything. Christian Lemburg Brainbench MVP for Perl http://www.brainbench.com	[reply]
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	[reply] [d/l] [select]


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