(setq trees '((pine . cones) (oak . acorns) (maple . seeds)))
;;=> ((pine . cones) (oak . acorns) (maple . seeds))
(assoc 'oak '((pine . cones) (oak . acorns) (maple . seeds)))
;;=> (oak . acorns)
(alist-get 'oak '((pine . cones) (oak . acorns) (maple . seeds)))
;;=> acorns
(cdr (assoc 'oak '((pine . cones) (oak . acorns) (maple . seeds))))
;;=> acorns
(setq alist '((pine . cones) (oak . acorns) (maple . seeds)))
;;=> ((pine . cones) (oak . acorns) (maple . seeds))
(setf (alist-get 'pine alist) 'pine-tree)
;;=> pine-tree
alist
;;=>((pine . pine-tree) (oak . acorns) (maple . seeds))