package Catmandu::Fix::retain;
use Catmandu::Sane;
use Moo;
use Catmandu::Fix::Has;
with 'Catmandu::Fix::Base';
has paths => (fix_arg => 'collect', default => sub { [] });
sub emit {
my ($self, $fixer) = @_;
my $paths = $self->paths;
my $var = $fixer->var;
my $tmp_var = $fixer->generate_var;
my $perl = $fixer->emit_declare_vars($tmp_var, '{}');
for (@$paths) {
my $path = $fixer->split_path($_);
my $key = pop @$path;
$perl .= $fixer->emit_walk_path($var, $path, sub {
my ($var) = @_;
$fixer->emit_get_key($var, $key, sub {
my ($var) = @_;
$fixer->emit_create_path($tmp_var, [@$path, $key], sub {
my ($tmp_var) = @_;
"${tmp_var} = ${var};";
});
});
});
}
# clear data
$perl .= $fixer->emit_clear_hash_ref($var);
# copy tmp data
$perl .= $fixer->emit_foreach_key($tmp_var, sub {
my ($key) = @_;
"${var}\->{${key}} = ${tmp_var}\->{${key}};";
});
# free tmp data
$perl .= "undef ${tmp_var};";
$perl;
}
=head1 NAME
Catmandu::Fix::retain - delete everything except the paths given
=head1 SYNOPSIS
# Delete everything except foo.bar and baz.bar
retain(foo.bar, baz.bar)
{bar => 3, foo => {bar => 1, baz => 2}}
# becomes
{foo => {bar => 1}}
=head1 SEE ALSO
L<Catmandu::Fix>
=cut
1;