(reoptimize-lvar prev)))
\f
;;; Return a new LEXENV just like DEFAULT except for the specified
-;;; slot values. Values for the alist slots are NCONCed to the
+;;; slot values. Values for the alist slots are APPENDed to the
;;; beginning of the current value, rather than replacing it entirely.
(defun make-lexenv (&key (default *lexenv*)
funs vars blocks tags
(macrolet ((frob (var slot)
`(let ((old (,slot default)))
(if ,var
- (nconc ,var old)
+ (append ,var old)
old))))
(internal-make-lexenv
(frob funs lexenv-funs)