Why would you refuse a hash ?

There can't be so much regions as to not easily keep them in memory, in a simple hash like 

my %prefixes = ( '04025' = [ 'Region1, Region2, Region3' ],
                 ...
               );

[download]

And afterwards, a straightforward check like
my ($pref5, $pref4, $pref3, $pref2) = map { substr( $phone, 0, $_ ) }
                                          (5, 4, 3, 2);

my $prefix_length = exists $prefixes{$pref5} ? 5
                  : exists $prefixes{$pref4} ? 4
                  : exists $prefixes{$pref3} ? 3
                  : exists $prefixes{$pref2} ? 2
                  :                            0
                  ;

my $formatted_phone = join( ' ',
                            substr( $phone, 0, $prefix_length),
                            substr( $phone, $prefix_length),
                      );

[download]
should work rather very effectively. If you have thought about this already, why do you think it would be expensive/ineffective/inadequate ?

Krambambuli
---

In reply to Re^3: (german) region code detection - request for thoughts by Krambambuli
in thread (german) region code detection - request for thoughts by Skeeve

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