detach.diff

diff --git a/Changes b/Changes
index d508b80..bdfa978 100644
--- a/Changes
+++ b/Changes
@@ -1,5 +1,8 @@
 
 6.26  2015-10-23
+  - Added detach method to Mojo::DOM.
+  - Improved performance of DOM manipulation methods in Mojo::DOM significantly
+    when working with existing Mojo::DOM objects.
 
 6.25  2015-10-21
   - Deprecated Mojo::Message::Request::proxy with boolean and string arguments
diff --git a/lib/Mojo/DOM.pm b/lib/Mojo/DOM.pm
index 400e04d..4387e58 100644
--- a/lib/Mojo/DOM.pm
+++ b/lib/Mojo/DOM.pm
@@ -15,6 +15,7 @@ use Mojo::DOM::CSS;
 use Mojo::DOM::HTML;
 use Mojo::Util 'squish';
 use Scalar::Util qw(blessed weaken);
+use Storable 'dclone';
 
 sub all_text { shift->_all_text(1, @_) }
 
@@ -68,6 +69,13 @@ sub content {
 
 sub descendant_nodes { $_[0]->_collect(_all(_nodes($_[0]->tree))) }
 
+sub detach {
+  my $self = shift;
+  return $self if (my $tree = $self->tree)->[0] eq 'root';
+  _link(my $new = ['root', $tree], _nodes($tree));
+  return $self->_replace($self->_parent, $tree, ['root'])->tree($new);
+}
+
 sub find { $_[0]->_collect(@{$_[0]->_css->select($_[1])}) }
 
 sub following { _select($_[0]->_collect(@{$_[0]->_siblings(1)->[1]}), $_[1]) }
@@ -279,7 +287,17 @@ sub _offset {
 
 sub _parent { $_[0]->tree->[$_[0]->type eq 'tag' ? 3 : 2] }
 
-sub _parse { Mojo::DOM::HTML->new(xml => shift->xml)->parse(shift)->tree }
+sub _parse {
+  my ($self, $html) = @_;
+
+  return Mojo::DOM::HTML->new(xml => $self->xml)->parse($html)->tree
+    unless blessed $html && $html->isa('Mojo::DOM');
+
+  my $clone = dclone $html->tree;
+  return $clone if $clone->[0] eq 'root';
+  _link(my $parent = ['root', $clone], _nodes($clone));
+  return $parent;
+}
 
 sub _replace {
   my ($self, $parent, $tree, $new) = @_;
@@ -498,6 +516,7 @@ All selectors from L<Mojo::DOM::CSS/"SELECTORS"> are supported.
 
 =head2 append
 
+  $dom = $dom->append(Mojo::DOM->new);
   $dom = $dom->append('<p>I ♥ Mojolicious!</p>');
 
 Append HTML/XML fragment to this node.
@@ -512,6 +531,7 @@ Append HTML/XML fragment to this node.
 
 =head2 append_content
 
+  $dom = $dom->append_content(Mojo::DOM->new);
   $dom = $dom->append_content('<p>I ♥ Mojolicious!</p>');
 
 Append HTML/XML fragment (for C<root> and C<tag> nodes) or raw content to this
@@ -582,6 +602,7 @@ All selectors from L<Mojo::DOM::CSS/"SELECTORS"> are supported.
 =head2 content
 
   my $str = $dom->content;
+  $dom    = $dom->content(Mojo::DOM->new);
   $dom    = $dom->content('<p>I ♥ Mojolicious!</p>');
 
 Return this node's content or replace it with HTML/XML fragment (for C<root>
@@ -623,6 +644,13 @@ element as L<Mojo::DOM> objects.
     ->at('p')->descendant_nodes->grep(sub { $_->type eq 'text' })
     ->map(content => 'test')->first->root;
 
+=head2 detach
+
+  $dom = $dom->detach;
+
+Detach this node from L</"parent"> and turn it into a new subtree with its own
+C<root> node.
+
 =head2 find
 
   my $collection = $dom->find('div ~ p');
@@ -765,6 +793,7 @@ node as L<Mojo::DOM> objects.
 
 =head2 prepend
 
+  $dom = $dom->prepend(Mojo::DOM->new);
   $dom = $dom->prepend('<p>I ♥ Mojolicious!</p>');
 
 Prepend HTML/XML fragment to this node.
@@ -779,6 +808,7 @@ Prepend HTML/XML fragment to this node.
 
 =head2 prepend_content
 
+  $dom = $dom->prepend_content(Mojo::DOM->new);
   $dom = $dom->prepend_content('<p>I ♥ Mojolicious!</p>');
 
 Prepend HTML/XML fragment (for C<root> and C<tag> nodes) or raw content to this
@@ -835,6 +865,7 @@ Remove this node and return L</"root"> (for C<root> nodes) or L</"parent">.
 
 =head2 replace
 
+  my $parent = $dom->replace(Mojo::DOM->new);
   my $parent = $dom->replace('<div>I ♥ Mojolicious!</div>');
 
 Replace this node with HTML/XML fragment and return L</"root"> (for C<root>
@@ -969,6 +1000,7 @@ if none could be found.
 
 =head2 wrap
 
+  $dom = $dom->wrap(Mojo::DOM->new);
   $dom = $dom->wrap('<div></div>');
 
 Wrap HTML/XML fragment around this node, placing it as the last child of the
@@ -988,6 +1020,7 @@ first innermost element.
 
 =head2 wrap_content
 
+  $dom = $dom->wrap_content(Mojo::DOM->new);
   $dom = $dom->wrap_content('<div></div>');
 
 Wrap HTML/XML fragment around this node's content, placing it as the last
diff --git a/t/mojo/dom.t b/t/mojo/dom.t
index b6c01a9..c9a15ea 100644
--- a/t/mojo/dom.t
+++ b/t/mojo/dom.t
@@ -2120,6 +2120,22 @@ is $dom->at('a')->wrap_content('C<c><d>D</d><e>E</e></c>F')->parent->type,
 is "$dom", '<e:a>C<c><d>D1<b c="d">Test</b></d><e>E</e></c>F</e:a>',
   'right result';
 
+# Detach nodes
+$dom = Mojo::DOM->new('<p><b>Test</b>123</p>')->detach;
+is "$dom", '<p><b>Test</b>123</p>', 'right result';
+my $dom2 = $dom->at('b')->[0];
+is $dom2->type, 'text', 'right type';
+is $dom2->detach->type, 'root', 'right type';
+is "$dom2", 'Test', 'right result';
+is "$dom", '<p><b></b>123</p>', 'right result';
+$dom->at('p')->append($dom2);
+is "$dom", '<p><b></b>123</p>Test', 'right result';
+$dom->at('p')->prepend($dom2);
+is "$dom", 'Test<p><b></b>123</p>Test', 'right result';
+$dom->at('b')->content(Mojo::DOM->new('B'))
+  ->append_content(Mojo::DOM->new('C'))->prepend_content(Mojo::DOM->new('A'));
+is "$dom", 'Test<p><b>ABC</b>123</p>Test', 'right result';
+
 # Broken "div" in "td"
 $dom = Mojo::DOM->new(<<EOF);
 <table>