RE: CL package serious deficiencies

[Drew Adams]

I agree with what Juanma and others have said about some of the more commonly
used Common-Lisp functions, particularly the sequence functions.

I would add that being able to use generalized variables (`setf' generally, in
addition to `incf' etc.) would also be on my short list.

http://www.gnu.org/software/emacs/manual/html_node/cl/Generalized-Variables.html
#Generalized-Variables

http://www.cs.cmu.edu/Groups/AI/html/cltl/clm/node80.html

Note that this would also mean generalizing some existing Emacs things like
`push' in Emacs, letting you use generalized variables, not just variables
(symbols), as their args.  And it [wc]ould obsolete some existing things, like
`add-to-list' - see `pushnew'.

More generally, if generalized variable support were added, there would be other
existing Emacs functions/macros that currently require a variable as arg but
which could be generalized to accept a generalized variable.

IOW, adding a given CL feature doesn't necessarily mean just adding that feature
per se - it could also mean taking advantage of that feature to improve Emacs
Lisp more generally.

(But we've been through all of this more than once before, discussing various
lists of candidate CL features to add.  And little to nothing has come of it.
That does not mean that this time won't be the charm, but I'm skeptical...)