File Coverage

blib/lib/Data/Focus/Lens/Composite.pm

Criterion	Covered	Total	%
statement	24	24	100.0
branch	2	2	100.0
condition			n/a
subroutine	7	7	100.0
pod	2	3	66.6
total	35	36	97.2

package Data::Focus::Lens::Composite;
use strict;
use warnings;
use parent qw(Data::Focus::Lens);

sub new {
    my ($class, @lenses) = @_;
    require Data::Focus;
    $_ = Data::Focus->coerce_to_lens($_) for @lenses;
    return bless \@lenses, $class;
}

## class method: internal use only.
sub apply_composite_lens {
    my (undef, $lenses, $applicative_class, $part_mapper, $whole) = @_;
    my $top_lens = $lenses->[0];
    if(!defined($top_lens)) {
        return $part_mapper->($whole);
    }
    foreach my $lens (reverse @{$lenses}[1 .. $#$lenses]) {
        my $cur_part_mapper = $part_mapper;
        $part_mapper = sub { $lens->apply_lens($applicative_class, $cur_part_mapper, shift) };
    }
    return $top_lens->apply_lens($applicative_class, $part_mapper, $whole);
}

sub apply_lens {
    ref($_[0])->apply_composite_lens(@_);
}


1;
__END__