types got intertwined, has been fixed;
** the type system is now able to reason about the interaction
between INTEGER and RATIO types more completely;
+ ** APPEND checks its arguments for being proper lists;
* fixed CEILING optimization for a divisor of form 2^k.
* fixed bug 240 (emitting extra style warnings "using the lexical
binding of the symbol *XXX*" for &OPTIONAL arguments). (reported
((zerop count) result)
(declare (type index count))))
\f
-;;; The outer loop finds the first non-null list and the result is
-;;; started. The remaining lists in the arguments are tacked to the
-;;; end of the result using splice which cdr's down the end of the new
-;;; list.
(defun append (&rest lists)
#!+sb-doc
"Construct a new list by concatenating the list arguments"
- (flet ((fail (object)
- (error 'type-error
- :datum object
- :expected-type 'list)))
- (do ((top lists (cdr top))) ; CDR to first non-null list.
- ((atom top) '())
- (cond ((null (car top))) ; NIL -> Keep looping
- ((not (consp (car top))) ; Non CONS
- (if (cdr top)
- (fail (car top))
- (return (car top))))
- (t ; Start appending
- (return
- (if (atom (cdr top))
- (car top) ; Special case.
- (let* ((result (cons (caar top) '()))
- (splice result))
- (do ((x (cdar top) (cdr x))) ; Copy first list
- ((atom x))
- (setq splice
- (cdr (rplacd splice (cons (car x) ()) ))) )
- (do ((y (cdr top) (cdr y))) ; Copy rest of lists.
- ((atom (cdr y))
- (setq splice (rplacd splice (car y)))
- result)
- (if (listp (car y))
- (do ((x (car y) (cdr x))) ; Inner copy loop.
- ((atom x))
- (setq
- splice
- (cdr (rplacd splice (cons (car x) ())))))
- (fail (car y))))))))))))
+ (labels ((fail (object)
+ (error 'type-error
+ :datum object
+ :expected-type 'list))
+ (append-into (last-cons current rest)
+ "Set (CDR LAST-CONS) to (APPLY #'APPEND CURRENT REST)."
+ (declare (cons last-cons rest))
+ (cond ((consp current)
+ (append-into (setf (cdr last-cons) (list (car current)))
+ (cdr current)
+ rest))
+ ((not (null current)) (fail current))
+ ((null (cdr rest)) (setf (cdr last-cons) (car rest)))
+ (t (append-into last-cons (car rest) (cdr rest)))))
+ (append1 (lists)
+ (let ((current (car lists))
+ (rest (cdr lists)))
+ (cond ((null rest) current)
+ ((consp current)
+ (let ((result (truly-the cons (list (car current)))))
+ (append-into result
+ (cdr current)
+ rest)
+ result))
+ ((null current) (append1 rest))
+ (t (fail current))))))
+ (append1 lists)))
\f
;;;; list copying functions
args))))
(check-error (funcall (compile nil `(lambda () ,exp))) fail)))))
-(multiple-value-bind (result error)
- (ignore-errors (append 1 2))
- (assert (null result))
- (assert (typep error 'type-error)))
+(dolist (test '((1 2)
+ ((1 2) nil (3 . 4) nil)
+ (nil (1 2) nil (3 . 4) nil)))
+ (multiple-value-bind (result error)
+ (ignore-errors (apply 'append test))
+ (assert (null result))
+ (assert (typep error 'type-error))))