Lists are hashes on acid. The default return value of indexing in is NULL. That's a weird semantic for a list, but maybe not so much a hash. The weird part i

Lists are hashes on acid. The default return value of indexing in is NULL. That's a weird semantic for a list, but maybe not so much a hash. The weird part is that if you explicitly assign null to an element of the list, it deletes the element. That's particularly weird because the list has knows all the elements in it, so it's not like it can't tell the difference between a value that has been set to NULL and a value that has never been set. See http://gist.github.com/578110 http://gist.github.com/578110 for a little transcript.