Documentation for method AT-POS, assembled from the following types:
multi method AT-POS (::?CLASS: )
Expected to return the element at position
$index. This is what
postcircumfix [ ] normally calls.
If you want an element to be mutable (like they are for the built-in Array type), you'll have to make sure to return it in the form of an item container that evaluates to the element's value when read, and updates it when assigned to. (Remember to use
return-rw or the
is rw routine trait to make that work; see the example.)