You could initialize your %elements has quite a bit more easily: 
my @set = ('A000','A123'..'A456','A999'..'B000','B789'..'B888');
my %elements;
@elements{@set} = (undef)x@set;

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The PerlMonk tr/// Advocate

In reply to Re^2: Need Set-like Regex for Perl and Java (golf OK) by Roy Johnson
in thread Need Set-like Regex for Perl and Java (golf OK) by QM

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