our $VERSION = '0.18';
sub new ( $class, $array, $pars = {} ) {
$class->_throw( parameter => "argument must be an ARRAY reference" )
unless Ref::Util::is_arrayref( $array );
$class->SUPER::new( { array => $array }, $pars );
}
sub construct ( $class, $state ) {
$class->_throw( parameter => "'state' parameter must be a HASH reference" )
unless Ref::Util::is_hashref( $state );
my ( $arr, $prev, $current, $next )
= @{$state}{qw[ array prev current next ]};
$class->_throw( parameter => "state 'array' parameter must be a HASH reference" )
unless Ref::Util::is_arrayref( $arr );
my $len = @$arr;
$next = 0 unless defined $next;
$class->_throw( parameter => "illegal value for state 'prev' argument" )
if defined $prev && ( $prev < 0 || $prev >= $len );
$class->_throw( parameter => "illegal value for state 'current' argument" )
if defined $current && ( $current < 0 || $current >= $len );
$class->_throw( parameter => "illegal value for state 'next' argument" )
if $next < 0 || $next > $len;
my $self;
return {
( +_SELF ) => \$self,
( +RESET ) => sub {
$prev = $current = undef;
$next = 0;
},
( +REWIND ) => sub {
$next = 0;
},
( +PREV ) => sub {
return defined $prev ? $arr->[$prev] : undef;
},
( +CURRENT ) => sub {
return defined $current ? $arr->[$current] : undef;
},
( +NEXT ) => sub {
if ( $next == $len ) {
$prev = $current
if !$self->is_exhausted;
return $current = $self->signal_exhaustion;
}
$prev = $current;
$current = $next++;
return $arr->[$current];
},
( +FREEZE ) => sub {
return [
$class,
{
array => $arr,
prev => $prev,
current => $current,
next => $next,
},
];
},
};
}
__PACKAGE__->_add_roles( qw[
State::Registry
Next::ClosedSelf
Rewind::Closure
Reset::Closure
Prev::Closure
Current::Closure
Freeze
] );
1;