Defining "get" and "setf-get" on more objects? about generic-cl HOT 1 CLOSED

The function get retrieves an element from a map by key. Most commonly a map is either hash-map or a standard hash-table, however an ALIST or PLIST can also be used as a map. The get function already contains a method, specialized on lists, which treats the list as an ALIST or PLIST, depending on the whether the first element is a CONS, and retrieves the element with the given key.

The generic-cl:elt function performs the function you're looking for, retrieving an element from a sequence by index and it has methods which work on both lists and arrays. However, it doesn't have a method specialized for HASH-MAPS's that allows you to retrieve a map element by key.

If having a unified interface for retrieving a sequence element by index and by key is important, an elt method specialized on HASH-MAPS's can be added which simply treats its index argument as a key and retrieves the value of the map entry corresponding to the key.

from generic-cl.