- Fixed the Hash.flip() method

- Modified the Array.copy() and Hash.copy() methods to use Storable::dclone(), which is much faster and safer than recreating the objects.
- Added the alias Sys.clone() for Sys.copy()

lib/Sidef/Sys/Sys.pm

@@ -255,6 +255,8 @@ package Sidef::Sys::Sys {
         Storable::dclone($obj);
     }
 
+    *clone = \©
+
     sub select {
         my ($self, $fh) = @_;
         CORE::select(CORE::ref($fh) eq 'GLOB' ? $fh : $fh->get_value);

lib/Sidef/Types/Array/Array.pm

@@ -1190,11 +1190,9 @@ package Sidef::Types::Array::Array {
 
     sub copy {
         my ($self) = @_;
-        my $new = $self->new;
-        foreach my $item (map { $_->get_value } @{$self}) {
-            $new->append(eval { $item->can('copy') } ? $item->copy : $item);
-        }
-        $new;
+
+        state $x = require Storable;
+        Storable::dclone($self);
     }
 
     sub delete_first {

lib/Sidef/Types/Hash/Hash.pm

@@ -334,14 +334,18 @@ package Sidef::Types::Hash::Hash {
         my ($self) = @_;
 
         my $new_hash = $self->new();
-        @{$new_hash}{CORE::values %{$self->{data}}} =
-          (map { Sidef::Types::String::String->new($_) } CORE::keys %{$self->{data}});
+        @{$new_hash->{data}}{map { $_->get_value } CORE::values %{$self->{data}}} =
+          (map { Sidef::Variable::Variable->new(name => '', type => 'var', value => Sidef::Types::String::String->new($_)) }
+            CORE::keys %{$self->{data}});
+
         $new_hash;
     }
 
     sub copy {
         my ($self) = @_;
-        $self->new(map { ref($_) ? $_->get_value : $_ } %{$self->{data}});
+
+        state $x = require Storable;
+        Storable::dclone($self);
     }
 
     sub dump {