use Types::Standard qw( is_ArrayRef is_HashRef );
   use Carp qw( croak );
   
   sub process_data {
      my ($self, $data) = @_;
      if (is_ArrayRef($data)) {
         $self->_process_value($_) for @$data;
      }
      elsif (is_HashRef($data)) {
         $self->_process_value($_) for values %$data;
      }
      else {
         croak "Could not grok data";
      }
   }

##</code><code>##

   use Types::Standard qw( ArrayRef HashRef Any );
   use Type::Utils qw( match_on_type );
   use Carp qw( croak );
   
   sub process_data {
      my ($self, $data) = @_;
      match_on_type $data,
         ArrayRef, sub { $self->_process_value($_) for @$data },
         HashRef,  sub { $self->_process_value($_) for values %$data },
         Any,      sub { croak "Could not grok data" };
   }

##</code><code>##

   use Types::Standard qw( ArrayRef HashRef Any );
   use Type::Utils qw( compile_match_on_type );
   use Carp qw( croak );
   
   sub process_data {
      my ($self, $data) = @_;
      state $matcher = compile_match_on_type
         ArrayRef, sub { $self->_process_value($_) for @$data },
         HashRef,  sub { $self->_process_value($_) for values %$data },
         Any,      sub { croak "Could not grok data" };
      $matcher->($data);
   }

##</code><code>##

   use Types::Standard qw( ArrayRef HashRef Any );
   use Type::Utils qw( compile_match_on_type );
   use Carp qw( croak );
   
   sub process_data {
      my ($self, $data) = @_;
      state $matcher = compile_match_on_type
         ArrayRef, sub { my ($d, $s) = @_; $s->_process_value($_) for @$d },
         HashRef,  sub { my ($d, $s) = @_; $s->_process_value($_) for values %$d },
         Any,      sub { croak "Could not grok data" };
      $matcher->($data, $self);
   }

##</code><code>##

   use Types::Standard qw( ArrayRef HashRef Any );
   use Type::Utils qw( compile_match_on_type );
   use Carp qw();
   
   sub process_data {
      my ($self, $data) = @_;
      state $matcher = compile_match_on_type
         ArrayRef, q{ my ($d, $s) = @_; $s->_process_value($_) for @$d },
         HashRef,  q{ my ($d, $s) = @_; $s->_process_value($_) for values %$d },
         Any,      q{ Carp::croak("Could not grok data") };
      $matcher->($data, $self);
   }