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#!perl -w
use strict;
# Creating a class called ValueRing
package ValueRing;
# Class method to construct a ValueRing object, a blessed ARRAY reference
# this is the constructor for scalar ties
# my $ring = tie $color, "ValueRing", qw(red blue);
# foreach my $value (@$ring) { print "$value "; }
sub TIESCALAR {
my ($class, @values) = @_;
bless \@values, $class;
return \@values;
}
# Object method to read the ValueRing
# this intercepts read accesses
# my $ring = tie $color, "ValueRing", qw(red blue);
# prints "red blue red"
# print "$color $color $color\n";
sub FETCH {
my $self = shift;
push(@$self, shift(@$self));
return $self->[-1];
}
# Object method to add to the ValueRing
# this intercepts write accesses
# my $ring = tie $color, "ValueRing", qw(red blue);
# $color = "green"
# Now the ring is ("green", "red", "blue")
sub STORE {
my ($self, $value) = @_;
unshift @$self, $value;
return $value;
}
1;
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