Re: Regexp help

This uses the range operator:

use strict;
use warnings;

my $head_re = qr/^(?:Heading Here|Another Heading):/;
my $end_re  = qr/^End of section:/;

while (<DATA>) {
    state $saw = 0;
    if (my $seq = /$head_re/ ... /$head_re|$end_re/) {
        if ($seq == 1) {
            s/^/\n/ unless $saw++;
        } elsif ($seq =~ /E0$/) {
            $saw = 0 if /$end_re/;
            redo;
        } else {
            s/^/  /;
        }
    }
    print;
}
[download]

Comment on Re: Regexp help Download Code

Replies are listed 'Best First'.
Re^2: Regexp help by thewebsi (Scribe) on Sep 17, 2011 at 07:57 UTC
This didn't run as fast as the previously posted solution. It took me a while to wrap my head around the range operator, but I modified the code as follows, and now it runs faster than Kc12349's solution, though not quite as fast as ikegami's: `foreach ( split ( /^/m, $string ) ) { state $saw = 0; if ( my $seq = ( /^Heading Here:$/ .. /^Another Heading:$/ or /^Another Heading:$/ .. /^End of section:/ ) ) { redo if $seq =~ /E0$/; print $seq != 1 ? " " : ! $saw++ ? "\n" : ""; } print; }` [download] I do find this solution quite elegant though - thanks! Arnon Weinberg Back2Front - The Web Site People	[reply] [d/l]

Replies are listed 'Best First'.

Re^2: Regexp help
by thewebsi (Scribe) on Sep 17, 2011 at 07:57 UTC

This didn't run as fast as the previously posted solution. It took me a while to wrap my head around the range operator, but I modified the code as follows, and now it runs faster than Kc12349's solution, though not quite as fast as ikegami's:

foreach ( split ( /^/m, $string ) )
{
  state $saw = 0;
  if ( my $seq = ( /^Heading Here:$/ .. /^Another Heading:$/ or
                   /^Another Heading:$/ .. /^End of section:/ ) )
  {
    redo if $seq =~ /E0$/;
    print $seq != 1 ? "  " : ! $saw++ ? "\n" : "";
  }
  print;
}
[download]

I do find this solution quite elegant though - thanks!

Arnon Weinberg Back2Front - The Web Site People

[reply]
[d/l]