Parsing a string character by character in Perl

Question

I want to parse a string character by character. I am using perl to do that. Is there any way where we can start from the first character of the string and then loop character by character. Right now I have split the string into an array and I am loo[ping through the array.

$var="junk shit here. fkuc lkasjdfie.";
@chars=split("",$var);

But instead of spliting the wholes string before itself, is there any descriptor which would point to the first character of the string and then traverse each character? Is there any way to do this?

Answer 1

my $var = "junk sit here. fkuc lkasjdfie.";

while ($var =~ /(.)/sg) {
   my $char = $1;
   # do something with $char 
}

or

for my $i (1 .. length $var) {
  my $char = substr($var, $i-1, 1);
}

and when bench-marked, substr method is better performing than while,

use Benchmark qw( cmpthese ) ;
my $var = "junk sit here. fkuc lkasjdfie." x1000;

cmpthese( -5, {
    "while" => sub{
      while ($var =~ /(.)/sg) {
         my $char = $1;
         # do something with $char 
      }
    },
    "substr" => sub{
      for my $i (1 .. length $var) {
        my $char = substr($var, $i-1, 1);
      }
    },
});

result

         Rate  while substr
while  56.3/s     --   -53%
substr  121/s   114%     --

Answer 2

This can be the skeleton of the script/regex:

use strict;
use warnings;
use Data::Dumper qw(Dumper);

my $str = "The story of Dr. W. Fletcher who is a dentist. The hero of the community.";

my @sentences = split /(?<!(Dr| \w))\./, $str;
print Dumper \@sentences;

And the output is:

$VAR1 = [
      'The story of Dr. W. Fletcher who is a dentist',
      undef,
      ' The hero of the community'
    ];