RE: [External] : Use of an associated list with completing-read

[Drew Adams]

> Haw can I have an interactive function that
> displays a list of elements from an associated
> list using completing-read ?

The elements of an alist are conses.  Assuming
that you really meant that you want to see and
choose among the elements, then use this:

(completing-read
  "Choose an alist element: "
  (mapcar #'prin1-to-string my-alist)
  nil
  t)

That "displays" elements that match your
input.  Is that what you meant by "displays
a list of elements"?

It returns a string such as "(a . 42)" for
the alist element (a . 42).  Then you can
use (read "(a . 42)") to get a new cons
that's `equal' to the cons in your alist.
___

But if you don't really want to see the
elements of the alist as completions, but
instead you want to see their keys, then
just do this:

(completing-read
  "Choose an alist key: "
  my-alist
  nil
  t)

If the alist keys are symbols then apply
`intern' to the chosen string, to get
the symbol key.  Then use this to get
the element with that key (the exact
same cons, i.e., `eq', not just `equal):

(car (assq THE-SYMBOL my-alist)

I had to do a lot of guessing as to what
you're really requesting.  As usual, you
don't make clear what you're after.  And
you don't show any code that you've tried
so far.