User:Catrope/Unwrap
The conceptually correct way
[edit]Initial state:
<list> <item> <par> Foo </par> </item> <item> <par> Bar </par> </item> <item> <par> Baz </par> </item> </list>
First split:
<list> <item> <par> Foo </par> </item> </list> <list> <item> <par> Bar </par> </item> <item> <par> Baz </par> </item> </list>
Second split:
<list> <item> <par> Foo </par> </item> </list> <list> <item> <par> Bar </par> </item> </list> <list> <item> <par> Baz </par> </item> </list>
Unwrapping (note that the removed item tags precede the previously inserted list tags, so the transaction processor's cursor would have to move backwards)
<list> <item> <par> Foo </par> </item> </list><list> <item><par> Bar </par></item> </list><list> <item> <par> Baz </par> </item> </list>
Final state:
<list> <item> <par> Foo </par> </item> </list> <par> Bar </par> <list> <item> <par> Baz </par> </item> </list>
The condensed way, and why it probably won't work
[edit]Combined diff of all the changes above:
<list> <item> <par> Foo </par> </item> </list><list><item><par> Bar </par></item> </list><list> <item> <par> Baz </par> </item> </list>
Reduced/condensed diff (dropping the list tags that are added and immediately removed again):
<list> <item> <par> Foo </par> </item> </list><item><par> Bar </par></item><list> <item> <par> Baz </par> </item> </list>
However, the intermediate state would look like this:
<list> <item> <par> Foo </par> </item> </list> <item> <par> Bar </par> </item> <list> <item> <par> Baz </par> </item> </list>
which is invalid, because the second list item is not the child of a list. Most likely, the prepare functions will refuse to construct such a transaction, and the transaction processor will refuse to execute it (and those are good things). Hacking around that for this special case is probably hard and probably a bad idea.