Beefy Boxes and Bandwidth Generously Provided by pair Networks
Think about Loose Coupling
 
PerlMonks  

comment on

( [id://3333] : superdoc . print w/replies, xml ) Need Help??

Okay I am trying to figure out why 'one' works but 'two' just hangs the script. I read perlre and perlretut again to see if the answer would just jump out at me and it didn't.

Edit: I forgot to paste part of the code below. See my follow-up comment for the correct full program.

#!/usr/bin/perl use v5.16; use warnings; use autodie qw( :all ); use utf8::all; use File::Slurp qw( read_file ); use Regexp::Assemble; use Benchmark qw( cmpthese :hireswallclock ); my %seen; my %seen2; my $fname = 'dracula.txt'; my $content = read_file($fname); $content =~ tr/!"#$%&'()*+,\-.\/:;<=>?@\[\\]^_`{|}~/ /; my @patterns = read_file('sample_patterns'); chomp @patterns; my $regex = join '|', map {quotemeta} @patterns; $regex = qr/\b($regex)\b/ixms; cmpthese( -5, { 'one' => sub { $seen{$1}++ while $content =~ /$regex/g; }, 'two' => sub { $seen2{$1}++ while $content =~ /$regex/; }, } );

The source text is Bram Stoker's Dracula a 836KB file with 16,248 lines. The sample_patterns file contains 4,000 patterns, one per line. The only difference between 'one' and 'two' is the g modifier on the regexp.


In reply to Regexp::Assemble hangs with a certain case by kimmel

Title:
Use:  <p> text here (a paragraph) </p>
and:  <code> code here </code>
to format your post; it's "PerlMonks-approved HTML":



  • Are you posting in the right place? Check out Where do I post X? to know for sure.
  • Posts may use any of the Perl Monks Approved HTML tags. Currently these include the following:
    <code> <a> <b> <big> <blockquote> <br /> <dd> <dl> <dt> <em> <font> <h1> <h2> <h3> <h4> <h5> <h6> <hr /> <i> <li> <nbsp> <ol> <p> <small> <strike> <strong> <sub> <sup> <table> <td> <th> <tr> <tt> <u> <ul>
  • Snippets of code should be wrapped in <code> tags not <pre> tags. In fact, <pre> tags should generally be avoided. If they must be used, extreme care should be taken to ensure that their contents do not have long lines (<70 chars), in order to prevent horizontal scrolling (and possible janitor intervention).
  • Want more info? How to link or How to display code and escape characters are good places to start.