This is more of a question with a potential follow-up suggestion: in the genre column, we do have drama/thriller and thriller/drama

Is there a valid reason behind this? If not, I would suggest making it more consistent (eg: pick one between the two and use it consistently across the list), so that sorting it properly groups them.

Also: since we do have categories already, why the column

In your list of examples, you have this piece of code:

let old = Array("abcd")
let new = Array("adbc")
let changes = diff(old: old, new: new)

// Move "d" from index 3 to index 1

Is this indeed correct or was this before introducing the Heckel algorithm?

Haven't verified this, but doesn't Heckel produce all three moves in this case? I.e.:

// Move "d" from i

It would be nice if a native English speaker reviewed the documentation and fixed my bad grammar. Also, I'd love to have a list of places where the existing text does a bad job of explaining the API.

From the readme, section on Package status:

Currently, METADATA has a tag system but not all package authors use it, making it harder for lay users to know if the package maintenance is active or not.

I don't know how to do this, please add a link, or small tutorial. I'd like to do it.

I'm looking for some clarification about the intended behavior for toArray(). As per the current project documentation, the toArray() method (emphasis mine):

Converts the collection to array recursively.

A recursive operation implies that a collection of collections would be converted into an array of arrays; however, the current behavior just calls iterator_to_array on the to