Re: Canonical Way to Mask SETF?

Robert Uhl <eadmund42@xxxxxxxxxxxxxxx> writes:

> (defsetf menu-title (menu) (title)
> `(setf (getf ,menu :title) ,title))

I've never been able to grok defsetf. But I find that for my uses,
(defun (setf ...) ...) has always done the trick.

As an example, I have an application that makes extensive use of a
cache of data, contained in a data structure built up of nested hashes
(yes, I've been a perl programmer).

The handling of the nested hashes are in a package of its own, but to
save some typing in my application, I defined the following two
functions.

(defun cache-get (&rest keys)
(nh:nhget keys *portfolio-cache*))

(defun (setf cache-get) (newval &rest keys)
(setf (nh:nhget keys *portfolio-cache*) newval))

This allows me to write things like

(cache-get :traversal :path through :tree) => value1
(setf (cache-get :traversal :path through :tree) value2) => value2

This works flawlessly, at least in lispworks 4.3.

(As you may infer, the nested hash package contains its own
(defun (setf nhget) ...), but its definition is rather more complex.)

....Peder...
--
This must be Thursday. I never could get the hang of Thursdays.
.