src/code/list.lisp

   1 ;;;; functions to implement lists
   2
   3 ;;;; This software is part of the SBCL system. See the README file for
   4 ;;;; more information.
   5 ;;;;
   6 ;;;; This software is derived from the CMU CL system, which was
   7 ;;;; written at Carnegie Mellon University and released into the
   8 ;;;; public domain. The software is in the public domain and is
   9 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  10 ;;;; files for more information.
  11
  12 (in-package "SB!IMPL")
  13
  14 ;;; Limitation: no list might have more than INDEX conses.
  15
  16 ;;;; KLUDGE: comment from CMU CL, what does it mean?
  17 ;;;;   NSUBLIS, things at the beginning broken.
  18 ;;;; -- WHN 20000127
  19
  20 (declaim (maybe-inline
  21           adjoin tree-equal nth %setnth nthcdr make-list
  22           member-if member-if-not tailp union
  23           nunion intersection nintersection set-difference nset-difference
  24           set-exclusive-or nset-exclusive-or subsetp acons
  25           assoc-if assoc-if-not rassoc rassoc-if rassoc-if-not subst subst-if
  26           subst-if-not nsubst nsubst-if nsubst-if-not sublis nsublis))
  27
  28 ;;; These functions perform basic list operations.
  29 (defun car (list) #!+sb-doc "Return the 1st object in a list." (car list))
  30 (defun cdr (list)
  31   #!+sb-doc "Return all but the first object in a list."
  32   (cdr list))
  33 (defun cadr (list) #!+sb-doc "Return the 2nd object in a list." (cadr list))
  34 (defun cdar (list) #!+sb-doc "Return the cdr of the 1st sublist." (cdar list))
  35 (defun caar (list) #!+sb-doc "Return the car of the 1st sublist." (caar list))
  36 (defun cddr (list)
  37   #!+sb-doc "Return all but the 1st two objects of a list."
  38   (cddr list))
  39 (defun caddr (list)
  40   #!+sb-doc "Return the 1st object in the cddr of a list."
  41   (caddr list))
  42 (defun caadr (list)
  43   #!+sb-doc "Return the 1st object in the cadr of a list."
  44   (caadr list))
  45 (defun caaar (list)
  46   #!+sb-doc "Return the 1st object in the caar of a list."
  47   (caaar list))
  48 (defun cdaar (list)
  49   #!+sb-doc "Return the cdr of the caar of a list."
  50   (cdaar list))
  51 (defun cddar (list)
  52   #!+sb-doc "Return the cdr of the cdar of a list."
  53   (cddar list))
  54 (defun cdddr (list)
  55   #!+sb-doc "Return the cdr of the cddr of a list."
  56   (cdddr list))
  57 (defun cadar (list)
  58   #!+sb-doc "Return the car of the cdar of a list."
  59   (cadar list))
  60 (defun cdadr (list)
  61   #!+sb-doc "Return the cdr of the cadr of a list."
  62   (cdadr list))
  63 (defun caaaar (list)
  64   #!+sb-doc "Return the car of the caaar of a list."
  65   (caaaar list))
  66 (defun caaadr (list)
  67   #!+sb-doc "Return the car of the caadr of a list."
  68   (caaadr list))
  69 (defun caaddr (list)
  70   #!+sb-doc "Return the car of the caddr of a list."
  71   (caaddr list))
  72 (defun cadddr (list)
  73   #!+sb-doc "Return the car of the cdddr of a list."
  74   (cadddr list))
  75 (defun cddddr (list)
  76   #!+sb-doc "Return the cdr of the cdddr of a list."
  77   (cddddr list))
  78 (defun cdaaar (list)
  79   #!+sb-doc "Return the cdr of the caaar of a list."
  80   (cdaaar list))
  81 (defun cddaar (list)
  82   #!+sb-doc "Return the cdr of the cdaar of a list."
  83   (cddaar list))
  84 (defun cdddar (list)
  85   #!+sb-doc "Return the cdr of the cddar of a list."
  86   (cdddar list))
  87 (defun caadar (list)
  88   #!+sb-doc "Return the car of the cadar of a list."
  89   (caadar list))
  90 (defun cadaar (list)
  91   #!+sb-doc "Return the car of the cdaar of a list."
  92   (cadaar list))
  93 (defun cadadr (list)
  94   #!+sb-doc "Return the car of the cdadr of a list."
  95   (cadadr list))
  96 (defun caddar (list)
  97   #!+sb-doc "Return the car of the cddar of a list."
  98   (caddar list))
  99 (defun cdaadr (list)
 100   #!+sb-doc "Return the cdr of the caadr of a list."
 101   (cdaadr list))
 102 (defun cdadar (list)
 103   #!+sb-doc "Return the cdr of the cadar of a list."
 104   (cdadar list))
 105 (defun cdaddr (list)
 106   #!+sb-doc "Return the cdr of the caddr of a list."
 107   (cdaddr list))
 108 (defun cddadr (list)
 109   #!+sb-doc "Return the cdr of the cdadr of a list."
 110   (cddadr list))
 111 (defun cons (se1 se2)
 112   #!+sb-doc "Return a list with SE1 as the CAR and SE2 as the CDR."
 113   (cons se1 se2))
 114 \f
 115 (declaim (maybe-inline tree-equal-test tree-equal-test-not))
 116
 117 (defun tree-equal-test-not (x y test-not)
 118   (declare (type function test-not))
 119   (cond ((consp x)
 120          (and (consp y)
 121               (tree-equal-test-not (car x) (car y) test-not)
 122               (tree-equal-test-not (cdr x) (cdr y) test-not)))
 123         ((consp y) nil)
 124         ((not (funcall test-not x y)) t)
 125         (t ())))
 126
 127 (defun tree-equal-test (x y test)
 128   (declare (type function test))
 129   (cond ((consp x)
 130          (and (consp y)
 131               (tree-equal-test (car x) (car y) test)
 132               (tree-equal-test (cdr x) (cdr y) test)))
 133         ((consp y) nil)
 134         ((funcall test x y) t)
 135         (t ())))
 136
 137 (defun tree-equal (x y &key (test #'eql testp) (test-not nil notp))
 138   #!+sb-doc
 139   "Return T if X and Y are isomorphic trees with identical leaves."
 140   (when (and testp notp)
 141     (error ":TEST and :TEST-NOT were both supplied."))
 142   (if test-not
 143       (tree-equal-test-not x y (%coerce-callable-to-fun test-not))
 144       (tree-equal-test x y (%coerce-callable-to-fun test))))
 145
 146 (defun endp (object)
 147   #!+sb-doc
 148   "This is the recommended way to test for the end of a proper list. It
 149    returns true if OBJECT is NIL, false if OBJECT is a CONS, and an error
 150    for any other type of OBJECT."
 151   (endp object))
 152
 153 (defun list-length (list)
 154   #!+sb-doc
 155   "Return the length of the given List, or Nil if the List is circular."
 156   (do ((n 0 (+ n 2))
 157        (y list (cddr y))
 158        (z list (cdr z)))
 159       (())
 160     (declare (type fixnum n)
 161              (type list y z))
 162     (when (endp y) (return n))
 163     (when (endp (cdr y)) (return (+ n 1)))
 164     (when (and (eq y z) (> n 0)) (return nil))))
 165
 166 (defun nth (n list)
 167   #!+sb-doc
 168   "Return the nth object in a list where the car is the zero-th element."
 169   (car (nthcdr n list)))
 170
 171 (defun first (list)
 172   #!+sb-doc
 173   "Return the 1st object in a list or NIL if the list is empty."
 174   (car list))
 175 (defun second (list)
 176   "Return the 2nd object in a list or NIL if there is no 2nd object."
 177   (cadr list))
 178 (defun third (list)
 179   #!+sb-doc
 180   "Return the 3rd object in a list or NIL if there is no 3rd object."
 181   (caddr list))
 182 (defun fourth (list)
 183   #!+sb-doc
 184   "Return the 4th object in a list or NIL if there is no 4th object."
 185   (cadddr list))
 186 (defun fifth (list)
 187   #!+sb-doc
 188   "Return the 5th object in a list or NIL if there is no 5th object."
 189   (car (cddddr list)))
 190 (defun sixth (list)
 191   #!+sb-doc
 192   "Return the 6th object in a list or NIL if there is no 6th object."
 193   (cadr (cddddr list)))
 194 (defun seventh (list)
 195   #!+sb-doc
 196   "Return the 7th object in a list or NIL if there is no 7th object."
 197   (caddr (cddddr list)))
 198 (defun eighth (list)
 199   #!+sb-doc
 200   "Return the 8th object in a list or NIL if there is no 8th object."
 201   (cadddr (cddddr list)))
 202 (defun ninth (list)
 203   #!+sb-doc
 204   "Return the 9th object in a list or NIL if there is no 9th object."
 205   (car (cddddr (cddddr list))))
 206 (defun tenth (list)
 207   #!+sb-doc
 208   "Return the 10th object in a list or NIL if there is no 10th object."
 209   (cadr (cddddr (cddddr list))))
 210 (defun rest (list)
 211   #!+sb-doc
 212   "Means the same as the cdr of a list."
 213   (cdr list))
 214
 215 (defun nthcdr (n list)
 216   #!+sb-doc
 217   "Performs the cdr function n times on a list."
 218   (flet ((fast-nthcdr (n list)
 219            (declare (type index n))
 220            (do ((i n (1- i))
 221                 (result list (cdr result)))
 222                ((not (plusp i)) result)
 223              (declare (type index i)))))
 224     (typecase n
 225       (index (fast-nthcdr n list))
 226       (t (do ((i 0 (1+ i))
 227               (r-i list (cdr r-i))
 228               (r-2i list (cddr r-2i)))
 229              ((and (eq r-i r-2i) (not (zerop i)))
 230               (fast-nthcdr (mod n i) r-i))
 231            (declare (type index i)))))))
 232
 233 ;;; LAST
 234 ;;;
 235 ;;; Transforms in src/compiler/srctran.lisp pick the most specific
 236 ;;; version possible. %LAST/BIGNUM is admittedly somewhat academic...
 237 (macrolet ((last0-macro ()
 238              `(let ((rest list)
 239                     (list list))
 240                 (loop (unless (consp rest)
 241                         (return rest))
 242                   (shiftf list rest (cdr rest)))))
 243            (last1-macro ()
 244              `(let ((rest list)
 245                     (list list))
 246                 (loop (unless (consp rest)
 247                         (return list))
 248                   (shiftf list rest (cdr rest)))))
 249            (lastn-macro (type)
 250              `(let ((returned-list list)
 251                     (checked-list list)
 252                     (n (truly-the ,type n)))
 253                 (declare (,type n))
 254                 (tagbody
 255                  :scan
 256                    (pop checked-list)
 257                    (when (atom checked-list)
 258                      (go :done))
 259                    (if (zerop (truly-the ,type (decf n)))
 260                        (go :pop)
 261                        (go :scan))
 262                  :pop
 263                    (pop returned-list)
 264                    (pop checked-list)
 265                    (if (atom checked-list)
 266                        (go :done)
 267                        (go :pop))
 268                  :done)
 269                 returned-list)))
 270
 271   (defun %last0 (list)
 272     (declare (optimize speed (sb!c::verify-arg-count 0)))
 273     (last0-macro))
 274
 275   (defun %last1 (list)
 276     (declare (optimize speed (sb!c::verify-arg-count 0)))
 277     (last1-macro))
 278
 279   (defun %lastn/fixnum (list n)
 280     (declare (optimize speed (sb!c::verify-arg-count 0))
 281              (type (and unsigned-byte fixnum) n))
 282     (case n
 283       (1 (last1-macro))
 284       (0 (last0-macro))
 285       (t (lastn-macro fixnum))))
 286
 287   (defun %lastn/bignum (list n)
 288     (declare (optimize speed (sb!c::verify-arg-count 0))
 289              (type (and unsigned-byte bignum) n))
 290     (lastn-macro unsigned-byte))
 291
 292   (defun last (list &optional (n 1))
 293     #!+sb-doc
 294     "Return the last N conses (not the last element!) of a list."
 295     (case n
 296       (1 (last1-macro))
 297       (0 (last0-macro))
 298       (t
 299        (typecase n
 300          (fixnum
 301           (lastn-macro fixnum))
 302          (bignum
 303           (lastn-macro unsigned-byte)))))))
 304
 305 (define-compiler-macro last (&whole form list &optional (n 1) &environment env)
 306   (if (sb!xc:constantp n env)
 307       (case (constant-form-value n env)
 308         (0 `(%last0 ,list))
 309         (1 `(%last1 ,list))
 310         (t form))
 311       form))
 312
 313 (defun list (&rest args)
 314   #!+sb-doc
 315   "Return constructs and returns a list of its arguments."
 316   args)
 317
 318 ;;; LIST* is done the same as LIST, except that the last cons is made
 319 ;;; a dotted pair.
 320
 321 (defun list* (arg &rest others)
 322   #!+sb-doc
 323   "Return a list of the arguments with last cons a dotted pair"
 324   (cond ((atom others) arg)
 325         ((atom (cdr others)) (cons arg (car others)))
 326         (t (do ((x others (cdr x)))
 327                ((null (cddr x)) (rplacd x (cadr x))))
 328            (cons arg others))))
 329
 330 (defun make-list (size &key initial-element)
 331   #!+sb-doc
 332   "Constructs a list with size elements each set to value"
 333   (declare (type index size))
 334   (do ((count size (1- count))
 335        (result '() (cons initial-element result)))
 336       ((<= count 0) result)
 337     (declare (type index count))))
 338 \f
 339 (defun append (&rest lists)
 340   #!+sb-doc
 341   "Construct a new list by concatenating the list arguments"
 342   (declare (dynamic-extent lists) (optimize speed))
 343   (labels ((fail (object)
 344              (error 'type-error
 345                     :datum object
 346                     :expected-type 'list))
 347            (append-into (last-cons current rest)
 348              ;; Set (CDR LAST-CONS) to (APPLY #'APPEND CURRENT REST).
 349              (declare (cons last-cons rest))
 350              (if (listp current)
 351                  (if (consp current)
 352                      ;; normal case, cdr down the list
 353                      (append-into (setf (cdr last-cons) (list (car current)))
 354                                   (cdr current)
 355                                   rest)
 356                      ;; empty list
 357                      (let ((more (cdr rest)))
 358                        (if (null more)
 359                            (setf (cdr last-cons) (car rest))
 360                            (append-into last-cons (car rest) more))))
 361                  (fail current)))
 362            (append1 (lists)
 363              (let ((current (car lists))
 364                    (rest (cdr lists)))
 365                (cond ((null rest)
 366                       current)
 367                      ((consp current)
 368                       (let ((result (truly-the cons (list (car current)))))
 369                         (append-into result
 370                                      (cdr current)
 371                                      rest)
 372                         result))
 373                      ((null current)
 374                       (append1 rest))
 375                      (t
 376                       (fail current))))))
 377     (append1 lists)))
 378
 379 (defun append2 (x y)
 380   (declare (optimize speed (sb!c::verify-arg-count 0)))
 381   (if (null x)
 382       y
 383       (let ((result (list (car x))))
 384         (do ((more (cdr x) (cdr more))
 385              (tail result (cdr tail)))
 386             ((null more)
 387              (rplacd tail y)
 388              result)
 389           (rplacd tail (list (car more)))))))
 390
 391 (define-compiler-macro append (&whole form &rest lists)
 392   (case (length lists)
 393     (0 nil)
 394     (1 (car lists))
 395     (2 `(append2 ,@lists))
 396     (t form)))
 397 \f
 398 ;;;; list copying functions
 399
 400 (eval-when (:compile-toplevel :load-toplevel :execute)
 401   (sb!xc:defmacro !copy-list-macro (list &key check-proper-list)
 402     ;; Unless CHECK-PROPER-LIST is true, the list is copied correctly
 403     ;; even if the list is not terminated by NIL. The new list is built
 404     ;; by CDR'ing SPLICE which is always at the tail of the new list.
 405     `(when ,list
 406        (let ((copy (list (car ,list))))
 407          (do ((orig (cdr ,list) (cdr orig))
 408               (splice copy (cdr (rplacd splice (cons (car orig) nil)))))
 409              (,@(if check-proper-list
 410                     '((endp orig))
 411                     '((atom orig)
 412                       (unless (null orig)
 413                         (rplacd splice orig))))
 414               copy))))))
 415
 416 (defun copy-list (list)
 417   #!+sb-doc
 418   "Return a new list which is EQUAL to LIST. LIST may be improper."
 419   (!copy-list-macro list))
 420
 421 (defun copy-alist (alist)
 422   #!+sb-doc
 423   "Return a new association list which is EQUAL to ALIST."
 424   (if (endp alist)
 425       alist
 426       (let ((result
 427              (cons (if (atom (car alist))
 428                        (car alist)
 429                        (cons (caar alist) (cdar alist)))
 430                    nil)))
 431         (do ((x (cdr alist) (cdr x))
 432              (splice result
 433                      (cdr (rplacd splice
 434                                   (cons
 435                                    (if (atom (car x))
 436                                        (car x)
 437                                        (cons (caar x) (cdar x)))
 438                                    nil)))))
 439             ((endp x)))
 440         result)))
 441
 442 (defun copy-tree (object)
 443   #!+sb-doc
 444   "Recursively copy trees of conses."
 445   (if (consp object)
 446       (cons (copy-tree (car object)) (copy-tree (cdr object)))
 447       object))
 448 \f
 449 ;;;; more commonly-used list functions
 450
 451 (defun revappend (x y)
 452   #!+sb-doc
 453   "Return (append (reverse x) y)."
 454   (do ((top x (cdr top))
 455        (result y (cons (car top) result)))
 456       ((endp top) result)))
 457
 458 ;;; NCONC finds the first non-null list, so it can make splice point
 459 ;;; to a cons. After finding the first cons element, it holds it in a
 460 ;;; result variable while running down successive elements tacking
 461 ;;; them together. While tacking lists together, if we encounter a
 462 ;;; null list, we set the previous list's last cdr to nil just in case
 463 ;;; it wasn't already nil, and it could have been dotted while the
 464 ;;; null list was the last argument to NCONC. The manipulation of
 465 ;;; splice (that is starting it out on a first cons, setting LAST of
 466 ;;; splice, and setting splice to ele) inherently handles (nconc x x),
 467 ;;; and it avoids running down the last argument to NCONC which allows
 468 ;;; the last argument to be circular.
 469 (defun nconc (&rest lists)
 470    #!+sb-doc
 471    "Concatenates the lists given as arguments (by changing them)"
 472    (declare (dynamic-extent lists) (optimize speed))
 473    (flet ((fail (object)
 474             (error 'type-error
 475                    :datum object
 476                    :expected-type 'list)))
 477      (do ((top lists (cdr top)))
 478          ((null top) nil)
 479        (let ((top-of-top (car top)))
 480          (typecase top-of-top
 481            (cons
 482             (let* ((result top-of-top)
 483                    (splice result))
 484               (do ((elements (cdr top) (cdr elements)))
 485                   ((endp elements))
 486                 (let ((ele (car elements)))
 487                   (typecase ele
 488                     (cons (rplacd (last splice) ele)
 489                           (setf splice ele))
 490                     (null (rplacd (last splice) nil))
 491                     (atom (if (cdr elements)
 492                               (fail ele)
 493                               (rplacd (last splice) ele))))))
 494               (return result)))
 495            (null)
 496            (atom
 497             (if (cdr top)
 498                 (fail top-of-top)
 499                 (return top-of-top))))))))
 500
 501 (defun nreconc (x y)
 502   #!+sb-doc
 503   "Return (NCONC (NREVERSE X) Y)."
 504   (do ((1st (cdr x) (if (endp 1st) 1st (cdr 1st)))
 505        (2nd x 1st)              ;2nd follows first down the list.
 506        (3rd y 2nd))             ;3rd follows 2nd down the list.
 507       ((atom 2nd) 3rd)
 508     (rplacd 2nd 3rd)))
 509 \f
 510 (flet (;; Return the number of conses at the head of the
 511        ;; possibly-improper list LIST. (Or if LIST is circular, you
 512        ;; lose.)
 513        (count-conses (list)
 514          (do ((in-list list (cdr in-list))
 515               (result 0 (1+ result)))
 516              ((atom in-list)
 517               result)
 518            (declare (type index result)))))
 519   (declare (ftype (function (t) index) count-conses))
 520   (defun butlast (list &optional (n 1))
 521     (if (typep n 'index)
 522         (let ((n-conses-in-list (count-conses list)))
 523           (cond ((zerop n)
 524                  ;; (We can't use SUBSEQ in this case because LIST isn't
 525                  ;; necessarily a proper list, but SUBSEQ expects a
 526                  ;; proper sequence. COPY-LIST isn't so fussy.)
 527                  (copy-list list))
 528                 ((>= n n-conses-in-list)
 529                  nil)
 530                 (t
 531                  ;; (LIST isn't necessarily a proper list in this case
 532                  ;; either, and technically SUBSEQ wants a proper
 533                  ;; sequence, but no reasonable implementation of SUBSEQ
 534                  ;; will actually walk down to the end of the list to
 535                  ;; check, and since we're calling our own implementation
 536                  ;; we know it's reasonable, so it's OK.)
 537                  (subseq list 0 (- n-conses-in-list n)))))
 538         nil))
 539   (defun nbutlast (list &optional (n 1))
 540     (cond ((zerop n)
 541            list)
 542           ((not (typep n 'index))
 543            nil)
 544           (t (let ((n-conses-in-list (count-conses list)))
 545                (unless (<= n-conses-in-list n)
 546                  (setf (cdr (nthcdr (- n-conses-in-list n 1) list))
 547                        nil)
 548                  list))))))
 549
 550 (defun ldiff (list object)
 551   "Return a new list, whose elements are those of LIST that appear before
 552    OBJECT. If OBJECT is not a tail of LIST, a copy of LIST is returned.
 553    LIST must be a proper list or a dotted list."
 554   (do* ((list list (cdr list))
 555         (result (list ()))
 556         (splice result))
 557        ((atom list)
 558         (if (eql list object)
 559             (cdr result)
 560             (progn (rplacd splice list) (cdr result))))
 561     (if (eql list object)
 562         (return (cdr result))
 563         (setq splice (cdr (rplacd splice (list (car list))))))))
 564 \f
 565 ;;;; functions to alter list structure
 566
 567 (defun rplaca (cons x)
 568   #!+sb-doc
 569   "Change the CAR of CONS to X and return the CONS."
 570   (rplaca cons x))
 571
 572 (defun rplacd (cons x)
 573   #!+sb-doc
 574   "Change the CDR of CONS to X and return the CONS."
 575   (rplacd cons x))
 576
 577 ;;; The following are for use by SETF.
 578
 579 (defun %rplaca (x val) (rplaca x val) val)
 580
 581 (defun %rplacd (x val) (rplacd x val) val)
 582
 583 ;;; Set the Nth element of LIST to NEWVAL.
 584 (defun %setnth (n list newval)
 585   (typecase n
 586     (index
 587      (do ((count n (1- count))
 588           (list list (cdr list)))
 589          ((endp list)
 590           (error "~S is too large an index for SETF of NTH." n))
 591        (declare (type fixnum count))
 592        (when (<= count 0)
 593          (rplaca list newval)
 594          (return newval))))
 595     (t (let ((cons (nthcdr n list)))
 596          (when (endp cons)
 597            (error "~S is too large an index for SETF of NTH." n))
 598          (rplaca cons newval)
 599          newval))))
 600 \f
 601 ;;;; :KEY arg optimization to save funcall of IDENTITY
 602
 603 ;;; APPLY-KEY saves us a function call sometimes.
 604 ;;;    This isn't wrapped in an (EVAL-WHEN (COMPILE EVAL) ..)
 605 ;;;    because it's used in seq.lisp and sort.lisp.
 606 (defmacro apply-key (key element)
 607   `(if ,key
 608        (funcall ,key ,element)
 609        ,element))
 610 \f
 611 ;;;; macros for (&KEY (KEY #'IDENTITY) (TEST #'EQL TESTP) (TEST-NOT NIL NOTP))
 612
 613 ;;; Use these with the following &KEY args:
 614 (defmacro with-set-keys (funcall)
 615   `(if notp
 616        ,(append funcall '(:key key :test-not test-not))
 617        ,(append funcall '(:key key :test test))))
 618
 619 (defmacro satisfies-the-test (item elt)
 620   (let ((key-tmp (gensym)))
 621     `(let ((,key-tmp (apply-key key ,elt)))
 622       (cond (testp (funcall test ,item ,key-tmp))
 623             (notp (not (funcall test-not ,item ,key-tmp)))
 624             (t (funcall test ,item ,key-tmp))))))
 625 \f
 626 ;;;; substitution of expressions
 627
 628 (defun subst (new old tree &key key (test #'eql testp) (test-not #'eql notp))
 629   #!+sb-doc
 630   "Substitutes new for subtrees matching old."
 631   (when (and testp notp)
 632     (error ":TEST and :TEST-NOT were both supplied."))
 633   (let ((key (and key (%coerce-callable-to-fun key)))
 634         (test (if testp (%coerce-callable-to-fun test) test))
 635         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 636     (declare (type function test test-not))
 637     (labels ((s (subtree)
 638                (cond ((satisfies-the-test old subtree) new)
 639                      ((atom subtree) subtree)
 640                      (t (let ((car (s (car subtree)))
 641                               (cdr (s (cdr subtree))))
 642                           (if (and (eq car (car subtree))
 643                                    (eq cdr (cdr subtree)))
 644                               subtree
 645                               (cons car cdr)))))))
 646       (s tree))))
 647
 648 (defun subst-if (new test tree &key key)
 649   #!+sb-doc
 650   "Substitutes new for subtrees for which test is true."
 651   (let ((test (%coerce-callable-to-fun test))
 652         (key (and key (%coerce-callable-to-fun key))))
 653     (labels ((s (subtree)
 654                (cond ((funcall test (apply-key key subtree)) new)
 655                      ((atom subtree) subtree)
 656                      (t (let ((car (s (car subtree)))
 657                               (cdr (s (cdr subtree))))
 658                           (if (and (eq car (car subtree))
 659                                    (eq cdr (cdr subtree)))
 660                               subtree
 661                               (cons car cdr)))))))
 662       (s tree))))
 663
 664 (defun subst-if-not (new test tree &key key)
 665   #!+sb-doc
 666   "Substitutes new for subtrees for which test is false."
 667   (let ((test (%coerce-callable-to-fun test))
 668         (key (and key (%coerce-callable-to-fun key))))
 669     (labels ((s (subtree)
 670                (cond ((not (funcall test (apply-key key subtree))) new)
 671                      ((atom subtree) subtree)
 672                      (t (let ((car (s (car subtree)))
 673                               (cdr (s (cdr subtree))))
 674                           (if (and (eq car (car subtree))
 675                                    (eq cdr (cdr subtree)))
 676                               subtree
 677                               (cons car cdr)))))))
 678       (s tree))))
 679
 680 (defun nsubst (new old tree &key key (test #'eql testp) (test-not #'eql notp))
 681   #!+sb-doc
 682   "Substitute NEW for subtrees matching OLD."
 683   (when (and testp notp)
 684     (error ":TEST and :TEST-NOT were both supplied."))
 685   (let ((key (and key (%coerce-callable-to-fun key)))
 686         (test (if testp (%coerce-callable-to-fun test) test))
 687         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 688     (declare (type function test test-not))
 689     (labels ((s (subtree)
 690                (cond ((satisfies-the-test old subtree) new)
 691                      ((atom subtree) subtree)
 692                      (t (do* ((last nil subtree)
 693                               (subtree subtree (cdr subtree)))
 694                              ((atom subtree)
 695                               (if (satisfies-the-test old subtree)
 696                                   (setf (cdr last) new)))
 697                           (if (satisfies-the-test old subtree)
 698                               (return (setf (cdr last) new))
 699                               (setf (car subtree) (s (car subtree)))))
 700                         subtree))))
 701       (s tree))))
 702
 703 (defun nsubst-if (new test tree &key key)
 704   #!+sb-doc
 705   "Substitute NEW for subtrees of TREE for which TEST is true."
 706   (let ((test (%coerce-callable-to-fun test))
 707         (key (and key (%coerce-callable-to-fun key))))
 708     (labels ((s (subtree)
 709                (cond ((funcall test (apply-key key subtree)) new)
 710                      ((atom subtree) subtree)
 711                      (t (do* ((last nil subtree)
 712                               (subtree subtree (cdr subtree)))
 713                              ((atom subtree)
 714                               (if (funcall test (apply-key key subtree))
 715                                   (setf (cdr last) new)))
 716                           (if (funcall test (apply-key key subtree))
 717                               (return (setf (cdr last) new))
 718                               (setf (car subtree) (s (car subtree)))))
 719                         subtree))))
 720       (s tree))))
 721
 722 (defun nsubst-if-not (new test tree &key key)
 723   #!+sb-doc
 724   "Substitute NEW for subtrees of TREE for which TEST is false."
 725   (let ((test (%coerce-callable-to-fun test))
 726         (key (and key (%coerce-callable-to-fun key))))
 727     (labels ((s (subtree)
 728                (cond ((not (funcall test (apply-key key subtree))) new)
 729                      ((atom subtree) subtree)
 730                      (t (do* ((last nil subtree)
 731                               (subtree subtree (cdr subtree)))
 732                              ((atom subtree)
 733                               (if (not (funcall test (apply-key key subtree)))
 734                                   (setf (cdr last) new)))
 735                           (if (not (funcall test (apply-key key subtree)))
 736                               (return (setf (cdr last) new))
 737                               (setf (car subtree) (s (car subtree)))))
 738                         subtree))))
 739       (s tree))))
 740 \f
 741 (defun sublis (alist tree &key key (test #'eql testp) (test-not #'eql notp))
 742   #!+sb-doc
 743   "Substitute from ALIST into TREE nondestructively."
 744   (when (and testp notp)
 745     (error ":TEST and :TEST-NOT were both supplied."))
 746   (let ((key (and key (%coerce-callable-to-fun key)))
 747         (test (if testp (%coerce-callable-to-fun test) test))
 748         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 749     (declare (type function test test-not))
 750     (declare (inline assoc))
 751     (labels ((s (subtree)
 752                (let* ((key-val (apply-key key subtree))
 753                       (assoc (if notp
 754                                  (assoc key-val alist :test-not test-not)
 755                                  (assoc key-val alist :test test))))
 756                  (cond (assoc (cdr assoc))
 757                        ((atom subtree) subtree)
 758                        (t (let ((car (s (car subtree)))
 759                                 (cdr (s (cdr subtree))))
 760                             (if (and (eq car (car subtree))
 761                                      (eq cdr (cdr subtree)))
 762                                 subtree
 763                                 (cons car cdr))))))))
 764       (s tree))))
 765
 766 ;;; This is in run-time env (i.e. not wrapped in EVAL-WHEN (COMPILE EVAL))
 767 ;;; because it can be referenced in inline expansions.
 768 (defmacro nsublis-macro ()
 769   (let ((key-tmp (gensym)))
 770     `(let ((,key-tmp (apply-key key subtree)))
 771       (if notp
 772           (assoc ,key-tmp alist :test-not test-not)
 773           (assoc ,key-tmp alist :test test)))))
 774
 775 (defun nsublis (alist tree &key key (test #'eql testp) (test-not #'eql notp))
 776   #!+sb-doc
 777   "Substitute from ALIST into TRUE destructively."
 778   (when (and testp notp)
 779     (error ":TEST and :TEST-NOT were both supplied."))
 780   (let ((key (and key (%coerce-callable-to-fun key)))
 781         (test (if testp (%coerce-callable-to-fun test) test))
 782         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 783     (declare (inline assoc))
 784     (let (temp)
 785       (labels ((s (subtree)
 786                  (cond ((setq temp (nsublis-macro))
 787                         (cdr temp))
 788                        ((atom subtree) subtree)
 789                        (t (do* ((last nil subtree)
 790                                 (subtree subtree (cdr subtree)))
 791                                ((atom subtree)
 792                                 (if (setq temp (nsublis-macro))
 793                                     (setf (cdr last) (cdr temp))))
 794                             (if (setq temp (nsublis-macro))
 795                                 (return (setf (cdr last) (cdr temp)))
 796                                 (setf (car subtree) (s (car subtree)))))
 797                           subtree))))
 798         (s tree)))))
 799 \f
 800 ;;;; functions for using lists as sets
 801
 802 (defun member (item list &key key (test #'eql testp) (test-not #'eql notp))
 803   #!+sb-doc
 804   "Return the tail of LIST beginning with first element satisfying EQLity,
 805    :TEST, or :TEST-NOT with the given ITEM."
 806   (when (and testp notp)
 807     (error ":TEST and :TEST-NOT were both supplied."))
 808   (let ((key (and key (%coerce-callable-to-fun key)))
 809         (test (if testp (%coerce-callable-to-fun test) test))
 810         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 811     (declare (type function test test-not))
 812     (do ((list list (cdr list)))
 813         ((null list) nil)
 814       (let ((car (car list)))
 815         (when (satisfies-the-test item car)
 816           (return list))))))
 817
 818 (defun member-if (test list &key key)
 819   #!+sb-doc
 820   "Return tail of LIST beginning with first element satisfying TEST."
 821   (let ((test (%coerce-callable-to-fun test))
 822         (key (and key (%coerce-callable-to-fun key))))
 823     (do ((list list (cdr list)))
 824         ((endp list) nil)
 825       (if (funcall test (apply-key key (car list)))
 826           (return list)))))
 827
 828 (defun member-if-not (test list &key key)
 829   #!+sb-doc
 830   "Return tail of LIST beginning with first element not satisfying TEST."
 831   (let ((test (%coerce-callable-to-fun test))
 832         (key (and key (%coerce-callable-to-fun key))))
 833     (do ((list list (cdr list)))
 834         ((endp list) ())
 835       (if (not (funcall test (apply-key key (car list))))
 836           (return list)))))
 837
 838 (defun tailp (object list)
 839   #!+sb-doc
 840   "Return true if OBJECT is the same as some tail of LIST, otherwise
 841    returns false. LIST must be a proper list or a dotted list."
 842   (do ((list list (cdr list)))
 843       ((atom list) (eql list object))
 844     (if (eql object list)
 845         (return t))))
 846
 847 (defun adjoin (item list &key key (test #'eql testp) (test-not nil notp))
 848   #!+sb-doc
 849   "Add ITEM to LIST unless it is already a member"
 850   (when (and testp notp)
 851     (error ":TEST and :TEST-NOT were both supplied."))
 852   (let ((key (and key (%coerce-callable-to-fun key))))
 853     (if (let ((key-val (apply-key key item)))
 854           (if notp
 855               (member key-val list :test-not test-not :key key)
 856               (member key-val list :test test :key key)))
 857         list
 858         (cons item list))))
 859
 860 (defconstant +list-based-union-limit+ 80)
 861
 862 (defun union (list1 list2 &key key (test #'eql testp) (test-not nil notp))
 863   #!+sb-doc
 864   "Return the union of LIST1 and LIST2."
 865   (declare (inline member))
 866   (when (and testp notp)
 867     (error ":TEST and :TEST-NOT were both supplied."))
 868   ;; We have to possibilities here: for shortish lists we pick up the
 869   ;; shorter one as the result, and add the other one to it. For long
 870   ;; lists we use a hash-table when possible.
 871   (let ((n1 (length list1))
 872         (n2 (length list2))
 873         (key (and key (%coerce-callable-to-fun key)))
 874         (test (if notp
 875                   (let ((test-not-fun (%coerce-callable-to-fun test-not)))
 876                     (lambda (x) (not (funcall test-not-fun x))))
 877                   (%coerce-callable-to-fun test))))
 878     (multiple-value-bind (short long n-short)
 879         (if (< n1 n2)
 880             (values list1 list2 n1)
 881             (values list2 list1 n2))
 882       (if (or (< n-short +list-based-union-limit+)
 883               (not (member test (list #'eq #'eql #'equal #'equalp))))
 884           (let ((orig short))
 885             (dolist (elt long)
 886               (unless (member (apply-key key elt) orig :key key :test test)
 887                 (push elt short)))
 888             short)
 889           (let ((table (make-hash-table :test test :size (+ n1 n2)))
 890                 (union nil))
 891             (dolist (elt long)
 892               (setf (gethash (apply-key key elt) table) elt))
 893             (dolist (elt short)
 894               (setf (gethash (apply-key key elt) table) elt))
 895             (maphash (lambda (k v)
 896                        (declare (ignore k))
 897                        (push v union))
 898                      table)
 899             union)))))
 900
 901 ;;; Destination and source are SETF-able and many-evaluable. Set the
 902 ;;; SOURCE to the CDR, and "cons" the 1st elt of source to DESTINATION.
 903 ;;;
 904 ;;; FIXME: needs a more mnemonic name
 905 (defmacro steve-splice (source destination)
 906   `(let ((temp ,source))
 907      (setf ,source (cdr ,source)
 908            (cdr temp) ,destination
 909            ,destination temp)))
 910
 911 (defun nunion (list1 list2 &key key (test #'eql testp) (test-not nil notp))
 912   #!+sb-doc
 913   "Destructively return the union of LIST1 and LIST2."
 914   (declare (inline member))
 915   (when (and testp notp)
 916     (error ":TEST and :TEST-NOT were both supplied."))
 917   ;; We have to possibilities here: for shortish lists we pick up the
 918   ;; shorter one as the result, and add the other one to it. For long
 919   ;; lists we use a hash-table when possible.
 920   (let ((n1 (length list1))
 921         (n2 (length list2))
 922         (key (and key (%coerce-callable-to-fun key)))
 923         (test (if notp
 924                   (let ((test-not-fun (%coerce-callable-to-fun test-not)))
 925                     (lambda (x) (not (funcall test-not-fun x))))
 926                   (%coerce-callable-to-fun test))))
 927     (multiple-value-bind (short long n-short)
 928         (if (< n1 n2)
 929             (values list1 list2 n1)
 930             (values list2 list1 n2))
 931       (if (or (< n-short +list-based-union-limit+)
 932               (not (member test (list #'eq #'eql #'equal #'equalp))))
 933           (let ((orig short))
 934             (do ((elt (car long) (car long)))
 935                 ((endp long))
 936               (if (not (member (apply-key key elt) orig :key key :test test))
 937                   (steve-splice long short)
 938                   (setf long (cdr long))))
 939             short)
 940           (let ((table (make-hash-table :test test :size (+ n1 n2))))
 941             (dolist (elt long)
 942               (setf (gethash (apply-key key elt) table) elt))
 943             (dolist (elt short)
 944               (setf (gethash (apply-key key elt) table) elt))
 945             (let ((union long)
 946                   (head long))
 947               (maphash (lambda (k v)
 948                          (declare (ignore k))
 949                          (if head
 950                              (setf (car head) v
 951                                    head (cdr head))
 952                              (push v union)))
 953                       table)
 954               union))))))
 955
 956 (defun intersection (list1 list2
 957                      &key key (test #'eql testp) (test-not nil notp))
 958   #!+sb-doc
 959   "Return the intersection of LIST1 and LIST2."
 960   (declare (inline member))
 961   (when (and testp notp)
 962     (error ":TEST and :TEST-NOT were both supplied."))
 963   (let ((key (and key (%coerce-callable-to-fun key))))
 964     (let ((res nil))
 965       (dolist (elt list1)
 966         (if (with-set-keys (member (apply-key key elt) list2))
 967             (push elt res)))
 968       res)))
 969
 970 (defun nintersection (list1 list2
 971                       &key key (test #'eql testp) (test-not nil notp))
 972   #!+sb-doc
 973   "Destructively return the intersection of LIST1 and LIST2."
 974   (declare (inline member))
 975   (when (and testp notp)
 976     (error ":TEST and :TEST-NOT were both supplied."))
 977   (let ((key (and key (%coerce-callable-to-fun key))))
 978     (let ((res nil)
 979           (list1 list1))
 980       (do () ((endp list1))
 981         (if (with-set-keys (member (apply-key key (car list1)) list2))
 982             (steve-splice list1 res)
 983             (setq list1 (cdr list1))))
 984       res)))
 985
 986 (defun set-difference (list1 list2
 987                        &key key (test #'eql testp) (test-not nil notp))
 988   #!+sb-doc
 989   "Return the elements of LIST1 which are not in LIST2."
 990   (declare (inline member))
 991   (when (and testp notp)
 992     (error ":TEST and :TEST-NOT were both supplied."))
 993   (let ((key (and key (%coerce-callable-to-fun key))))
 994     (if (null list2)
 995         list1
 996         (let ((res nil))
 997           (dolist (elt list1)
 998             (if (not (with-set-keys (member (apply-key key elt) list2)))
 999                 (push elt res)))
1000           res))))
1001
1002 (defun nset-difference (list1 list2
1003                         &key key (test #'eql testp) (test-not nil notp))
1004   #!+sb-doc
1005   "Destructively return the elements of LIST1 which are not in LIST2."
1006   (declare (inline member))
1007   (when (and testp notp)
1008     (error ":TEST and :TEST-NOT were both supplied."))
1009   (let ((key (and key (%coerce-callable-to-fun key))))
1010     (let ((res nil)
1011           (list1 list1))
1012       (do () ((endp list1))
1013         (if (not (with-set-keys (member (apply-key key (car list1)) list2)))
1014             (steve-splice list1 res)
1015             (setq list1 (cdr list1))))
1016       res)))
1017
1018 (defun set-exclusive-or (list1 list2
1019                          &key key (test #'eql testp) (test-not #'eql notp))
1020   #!+sb-doc
1021   "Return new list of elements appearing exactly once in LIST1 and LIST2."
1022   (declare (inline member))
1023   (when (and testp notp)
1024     (error ":TEST and :TEST-NOT were both supplied."))
1025   (let ((result nil)
1026         (key (and key (%coerce-callable-to-fun key)))
1027         (test (if testp (%coerce-callable-to-fun test) test))
1028         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
1029     (declare (type function test test-not))
1030     (dolist (elt list1)
1031       (unless (with-set-keys (member (apply-key key elt) list2))
1032         (setq result (cons elt result))))
1033     (let ((test (if testp
1034                     (lambda (x y) (funcall test y x))
1035                     test))
1036           (test-not (if notp
1037                         (lambda (x y) (funcall test-not y x))
1038                         test-not)))
1039       (dolist (elt list2)
1040         (unless (with-set-keys (member (apply-key key elt) list1))
1041           (setq result (cons elt result)))))
1042     result))
1043
1044 (defun nset-exclusive-or (list1 list2
1045                           &key key (test #'eql testp) (test-not #'eql notp))
1046   #!+sb-doc
1047   "Destructively return a list with elements which appear but once in LIST1
1048    and LIST2."
1049   (when (and testp notp)
1050     (error ":TEST and :TEST-NOT were both supplied."))
1051   (let ((key (and key (%coerce-callable-to-fun key)))
1052         (test (if testp (%coerce-callable-to-fun test) test))
1053         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
1054     (declare (type function test test-not))
1055     ;; The outer loop examines LIST1 while the inner loop examines
1056     ;; LIST2. If an element is found in LIST2 "equal" to the element
1057     ;; in LIST1, both are spliced out. When the end of LIST1 is
1058     ;; reached, what is left of LIST2 is tacked onto what is left of
1059     ;; LIST1. The splicing operation ensures that the correct
1060     ;; operation is performed depending on whether splice is at the
1061     ;; top of the list or not.
1062     (do ((list1 list1)
1063          (list2 list2)
1064          (x list1 (cdr x))
1065          (splicex ())
1066          (deleted-y ())
1067          ;; elements of LIST2, which are "equal" to some processed
1068          ;; earlier elements of LIST1
1069          )
1070         ((endp x)
1071          (if (null splicex)
1072              (setq list1 list2)
1073              (rplacd splicex list2))
1074          list1)
1075       (let ((key-val-x (apply-key key (car x)))
1076             (found-duplicate nil))
1077
1078         ;; Move all elements from LIST2, which are "equal" to (CAR X),
1079         ;; to DELETED-Y.
1080         (do* ((y list2 next-y)
1081               (next-y (cdr y) (cdr y))
1082               (splicey ()))
1083              ((endp y))
1084           (cond ((let ((key-val-y (apply-key key (car y))))
1085                    (if notp
1086                        (not (funcall test-not key-val-x key-val-y))
1087                        (funcall test key-val-x key-val-y)))
1088                  (if (null splicey)
1089                      (setq list2 (cdr y))
1090                      (rplacd splicey (cdr y)))
1091                  (setq deleted-y (rplacd y deleted-y))
1092                  (setq found-duplicate t))
1093                 (t (setq splicey y))))
1094
1095         (unless found-duplicate
1096           (setq found-duplicate (with-set-keys (member key-val-x deleted-y))))
1097
1098         (if found-duplicate
1099             (if (null splicex)
1100                 (setq list1 (cdr x))
1101                 (rplacd splicex (cdr x)))
1102             (setq splicex x))))))
1103
1104 (defun subsetp (list1 list2 &key key (test #'eql testp) (test-not nil notp))
1105   #!+sb-doc
1106   "Return T if every element in LIST1 is also in LIST2."
1107   (declare (inline member))
1108   (when (and testp notp)
1109     (error ":TEST and :TEST-NOT were both supplied."))
1110   (let ((key (and key (%coerce-callable-to-fun key))))
1111     (dolist (elt list1)
1112       (unless (with-set-keys (member (apply-key key elt) list2))
1113         (return-from subsetp nil)))
1114     t))
1115 \f
1116 ;;;; functions that operate on association lists
1117
1118 (defun acons (key datum alist)
1119   #!+sb-doc
1120   "Construct a new alist by adding the pair (KEY . DATUM) to ALIST."
1121   (cons (cons key datum) alist))
1122
1123 (defun pairlis (keys data &optional (alist '()))
1124   #!+sb-doc
1125   "Construct an association list from KEYS and DATA (adding to ALIST)."
1126   (do ((x keys (cdr x))
1127        (y data (cdr y)))
1128       ((and (endp x) (endp y)) alist)
1129     (if (or (endp x) (endp y))
1130         (error "The lists of keys and data are of unequal length."))
1131     (setq alist (acons (car x) (car y) alist))))
1132
1133 ;;; This is defined in the run-time environment, not just the compile-time
1134 ;;; environment (i.e. not wrapped in EVAL-WHEN (COMPILE EVAL)) because it
1135 ;;; can appear in inline expansions.
1136 (defmacro assoc-guts (test-expr)
1137   `(do ((alist alist (cdr alist)))
1138        ((endp alist))
1139     (when (and (car alist) ,test-expr)
1140       (return (car alist)))))
1141
1142 (defun assoc (item alist &key key (test nil testp) (test-not nil notp))
1143   #!+sb-doc
1144   "Return the cons in ALIST whose car is equal (by a given test or EQL) to
1145    the ITEM."
1146   (when (and testp notp)
1147     (error ":TEST and :TEST-NOT were both supplied."))
1148   (let ((key (and key (%coerce-callable-to-fun key)))
1149         (test (and testp (%coerce-callable-to-fun test)))
1150         (test-not (and notp (%coerce-callable-to-fun test-not))))
1151     (cond (test
1152            (if key
1153                (assoc-guts (funcall test item (funcall key (caar alist))))
1154                (assoc-guts (funcall test item (caar alist)))))
1155           (test-not
1156            (if key
1157                (assoc-guts (not (funcall test-not item
1158                                          (funcall key (caar alist)))))
1159                (assoc-guts (not (funcall test-not item (caar alist))))))
1160           (t
1161            (if key
1162                (assoc-guts (eql item (funcall key (caar alist))))
1163                (assoc-guts (eql item (caar alist))))))))
1164
1165 (defun assoc-if (predicate alist &key key)
1166   #!+sb-doc
1167   "Return the first cons in ALIST whose CAR satisfies PREDICATE. If
1168    KEY is supplied, apply it to the CAR of each cons before testing."
1169   (let ((predicate (%coerce-callable-to-fun predicate))
1170         (key (and key (%coerce-callable-to-fun key))))
1171     (if key
1172         (assoc-guts (funcall predicate (funcall key (caar alist))))
1173         (assoc-guts (funcall predicate (caar alist))))))
1174
1175 (defun assoc-if-not (predicate alist &key key)
1176   #!+sb-doc
1177   "Return the first cons in ALIST whose CAR does not satisfy PREDICATE.
1178   If KEY is supplied, apply it to the CAR of each cons before testing."
1179   (let ((predicate (%coerce-callable-to-fun predicate))
1180         (key (and key (%coerce-callable-to-fun key))))
1181     (if key
1182         (assoc-guts (not (funcall predicate (funcall key (caar alist)))))
1183         (assoc-guts (not (funcall predicate (caar alist)))))))
1184
1185 (defun rassoc (item alist &key key (test nil testp) (test-not nil notp))
1186   (declare (list alist))
1187   #!+sb-doc
1188   "Return the cons in ALIST whose CDR is equal (by a given test or EQL) to
1189    the ITEM."
1190   (when (and testp notp)
1191     (error ":TEST and :TEST-NOT were both supplied."))
1192   (let ((key (and key (%coerce-callable-to-fun key)))
1193         (test (and testp (%coerce-callable-to-fun test)))
1194         (test-not (and notp (%coerce-callable-to-fun test-not))))
1195     (cond (test
1196            (if key
1197                (assoc-guts (funcall test item (funcall key (cdar alist))))
1198                (assoc-guts (funcall test item (cdar alist)))))
1199           (test-not
1200            (if key
1201                (assoc-guts (not (funcall test-not item
1202                                          (funcall key (cdar alist)))))
1203                (assoc-guts (not (funcall test-not item (cdar alist))))))
1204           (t
1205            (if key
1206                (assoc-guts (eql item (funcall key (cdar alist))))
1207                (assoc-guts (eql item (cdar alist))))))))
1208
1209 (defun rassoc-if (predicate alist &key key)
1210   #!+sb-doc
1211   "Return the first cons in ALIST whose CDR satisfies PREDICATE. If KEY
1212   is supplied, apply it to the CDR of each cons before testing."
1213   (let ((predicate (%coerce-callable-to-fun predicate))
1214         (key (and key (%coerce-callable-to-fun key))))
1215     (if key
1216         (assoc-guts (funcall predicate (funcall key (cdar alist))))
1217         (assoc-guts (funcall predicate (cdar alist))))))
1218
1219 (defun rassoc-if-not (predicate alist &key key)
1220   #!+sb-doc
1221   "Return the first cons in ALIST whose CDR does not satisfy PREDICATE.
1222   If KEY is supplied, apply it to the CDR of each cons before testing."
1223   (let ((predicate (%coerce-callable-to-fun predicate))
1224         (key (and key (%coerce-callable-to-fun key))))
1225     (if key
1226         (assoc-guts (not (funcall predicate (funcall key (cdar alist)))))
1227         (assoc-guts (not (funcall predicate (cdar alist)))))))
1228 \f
1229 ;;;; mapping functions
1230
1231 ;;; a helper function for implementation of MAPC, MAPCAR, MAPCAN,
1232 ;;; MAPL, MAPLIST, and MAPCON
1233 ;;;
1234 ;;; Map the designated function over the arglists in the appropriate
1235 ;;; way. It is done when any of the arglists runs out. Until then, it
1236 ;;; CDRs down the arglists calling the function and accumulating
1237 ;;; results as desired.
1238 (defun map1 (fun-designator original-arglists accumulate take-car)
1239   (let ((fun (%coerce-callable-to-fun fun-designator)))
1240     (let* ((arglists (copy-list original-arglists))
1241            (ret-list (list nil))
1242            (temp ret-list))
1243       (do ((res nil)
1244            (args '() '()))
1245           ((dolist (x arglists nil) (if (null x) (return t)))
1246            (if accumulate
1247                (cdr ret-list)
1248                (car original-arglists)))
1249         (do ((l arglists (cdr l)))
1250             ((null l))
1251           (push (if take-car (caar l) (car l)) args)
1252           (setf (car l) (cdar l)))
1253         (setq res (apply fun (nreverse args)))
1254         (case accumulate
1255           (:nconc (setq temp (last (nconc temp res))))
1256           (:list (rplacd temp (list res))
1257                  (setq temp (cdr temp))))))))
1258
1259 (defun mapc (function list &rest more-lists)
1260   #!+sb-doc
1261   "Apply FUNCTION to successive elements of lists. Return the second argument."
1262   (map1 function (cons list more-lists) nil t))
1263
1264 (defun mapcar (function list &rest more-lists)
1265   #!+sb-doc
1266   "Apply FUNCTION to successive elements of LIST. Return list of FUNCTION
1267    return values."
1268   (map1 function (cons list more-lists) :list t))
1269
1270 (defun mapcan (function list &rest more-lists)
1271   #!+sb-doc
1272   "Apply FUNCTION to successive elements of LIST. Return NCONC of FUNCTION
1273    results."
1274   (map1 function (cons list more-lists) :nconc t))
1275
1276 (defun mapl (function list &rest more-lists)
1277   #!+sb-doc
1278   "Apply FUNCTION to successive CDRs of list. Return NIL."
1279   (map1 function (cons list more-lists) nil nil))
1280
1281 (defun maplist (function list &rest more-lists)
1282   #!+sb-doc
1283   "Apply FUNCTION to successive CDRs of list. Return list of results."
1284   (map1 function (cons list more-lists) :list nil))
1285
1286 (defun mapcon (function list &rest more-lists)
1287   #!+sb-doc
1288   "Apply FUNCTION to successive CDRs of lists. Return NCONC of results."
1289   (map1 function (cons list more-lists) :nconc nil))
1290
1291 ;;;; Specialized versions
1292
1293 ;;; %MEMBER-* and %ASSOC-* functions. The transforms for MEMBER and
1294 ;;; ASSOC pick the appropriate version. These win because they have
1295 ;;; only positional arguments, the TEST, TEST-NOT & KEY functions are
1296 ;;; known to exist (or not), and are known to be functions instead of
1297 ;;; function designators. We are also able to transform many common
1298 ;;; cases to -EQ versions, which are substantially faster then EQL
1299 ;;; using ones.
1300 (macrolet
1301     ((def (funs form &optional variant)
1302        (flet ((%def (name)
1303                 `(defun ,(intern (format nil "%~A~{-~A~}~@[-~A~]" name funs variant))
1304                      (item list ,@funs)
1305                    (declare (optimize speed))
1306                    ,@(when funs `((declare (function ,@funs))))
1307                    (do ((list list (cdr list)))
1308                        ((null list) nil)
1309                      (declare (list list))
1310                      (let ((this (car list)))
1311                        ,(ecase name
1312                                (assoc
1313                                 (if funs
1314                                     `(when this
1315                                        (let ((target (car this)))
1316                                          (when ,form
1317                                            (return this))))
1318                                     ;; If there is no TEST/TEST-NOT or
1319                                     ;; KEY, do the EQ/EQL test first,
1320                                     ;; before checking for NIL.
1321                                     `(let ((target (car this)))
1322                                        (when (and ,form this)
1323                                          (return this)))))
1324                                (member
1325                                 `(let ((target this))
1326                                    (when ,form
1327                                      (return list))))))))))
1328          `(progn
1329             ,(%def 'member)
1330             ,(%def 'assoc)))))
1331   (def ()
1332       (eql item target))
1333   (def ()
1334       (eq item target)
1335     eq)
1336   (def (key)
1337       (eql item (funcall key target)))
1338   (def (key)
1339       (eq item (funcall key target))
1340     eq)
1341   (def (key test)
1342       (funcall test item (funcall key target)))
1343   (def (key test-not)
1344       (not (funcall test-not item (funcall key target))))
1345   (def (test)
1346       (funcall test item target))
1347   (def (test-not)
1348     (not (funcall test-not item target))))