[no subject]

[Alan Bawden <ALAN at MIT-MC>]

    Date: 12 FEB 1980 1243-EST
    From: JONL at MIT-MC (Jon L White)

    (SUBST () () (HUNK 1 2 3 4))  MAKES A ** LIST **

also (append (hunk 1 2 3 nil) '(b c)) makes (1 b c).
Now perhaps you could argue that append is a list-hacking
function and that this is therefore reasonable.  But other behaviors
could also be justified:

1) subst hacks non-atomic structure and should make hunks, while append
   hacks lists and thus should barf since it is about to treat a hunk as
   a list.

2) subst and append are both cons-hacking functions and they should both do
   the same thing (both barf or both do what they do now).

3) subst and append are both non-atom hacking functions and should
   make conses or hunks as appropriate.

I have always thought it was a pain that hunks are not atoms.  It
seems that whenever one writes code that deals with lists that include
structures made of hunks (like those produced by a defstruct), one really
wants ATOM to return nil for hunks.  Oh well, too late to change it now!