NAME

Data::DeepFilter - Deep modification of structures using callbacks. Optional Copy-On-Write.

SYNOPSIS

  use Data::DeepFilter qw(:all);
  deepfilter(
      data   => \%deep_hash,
      filter => filter_regex(qr/(abc)/, '\U\1')
      test   => name_in(qw(foo bar)),
  );

DESCRIPTION

Data::DeepFilter provides a mechanism for performing modifications to nodes within a deep structure. Optional support for Copy-On-Write, which protects the original structure.

deepfilter

  my $filtered_copy = deepfilter(
      data => \%deep_hash,
      filter => \&filter,
      test => \&test,
      safe => 1,
  );

Applies &filter to every node of $data that &test returns true for.

$data can be an arrayref or hashref.

The default behaviour is destructive in that it changes the structure that was passed. This behaviour can be overridden by specifying 'safe'.

Builtin filters

filter_regex()

  filter => filter_regex(qr/foo/,'bar')

Builtin tests

name_in()

  test => name_in(qw(foo bar))

name_not_in()

  test => name_not_in(qw(foo bar))

name_like()

  test => name_like(qr/foo/)

name_not_like()

  test => name_not_like(qr/foo/)

Filter callback specification

 sub filter_example {
     my ($value_ref) = @_;
     $$value_ref++;
 }

Test callback specification

 sub test_example {
     my ($name,$value_ref) = @_;
     return 1 if $name eq 'foo';
     return 1 if $$value_ref > 5;
     return;
 }