Dear Monks,

I would like to count the number of occurrences of some separator(s) in a string. For example:

$string='((1,2) (b,c)'
separators are '(' and ')'

[download]

The number of separators for the string is 5.

I use the tr operator to count the characters. Because the separators may vary and the transliteration table is built at compile time I use an eval. In the future more separators may be added. My code:

use strict;
use warnings;

sub count_separators {

    my $value = shift;
    my $delim = shift;
    my $set;

    SWITCH: {
        if ($delim eq '{') { 
        $set = '{|}'; 
    last SWITCH; 
    }
    if ($delim eq '(') { 
        $set = '(|)'; 
        last SWITCH; 
    }
    if ($delim eq '"') {  
        $set = '"';
        last SWITCH; 
    }
    # Should never occur...
    }
    print 'sub { return shift =~ tr/' . $set . '//; }' . "\n";
  
    return eval 'sub { return shift =~ tr/' . $set . '//; }';
}

my $str = '((1,2)( a,b)';
my $sep = '(';

my $result =  count_separators ($str, $sep);
$result=$result->($str);

print "$result \n";

[download]

I'm not to happy about the code. I have the feeling it can be done more simple/efficient/... but I'm kinda stuck. Any ideas? Constraint: it has to run under Perl 5.8.8

Thanks upfront!

In reply to count number of occurrences of specific character(s) in a string by dHarry

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