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           tree-equal nth %setnth nthcdr make-list
  22           tailp union
  23           nunion intersection nintersection set-difference nset-difference
  24           set-exclusive-or nset-exclusive-or subsetp acons
  25           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   #!+sb-doc
 177   "Return the 2nd object in a list or NIL if there is no 2nd object."
 178   (cadr list))
 179 (defun third (list)
 180   #!+sb-doc
 181   "Return the 3rd object in a list or NIL if there is no 3rd object."
 182   (caddr list))
 183 (defun fourth (list)
 184   #!+sb-doc
 185   "Return the 4th object in a list or NIL if there is no 4th object."
 186   (cadddr list))
 187 (defun fifth (list)
 188   #!+sb-doc
 189   "Return the 5th object in a list or NIL if there is no 5th object."
 190   (car (cddddr list)))
 191 (defun sixth (list)
 192   #!+sb-doc
 193   "Return the 6th object in a list or NIL if there is no 6th object."
 194   (cadr (cddddr list)))
 195 (defun seventh (list)
 196   #!+sb-doc
 197   "Return the 7th object in a list or NIL if there is no 7th object."
 198   (caddr (cddddr list)))
 199 (defun eighth (list)
 200   #!+sb-doc
 201   "Return the 8th object in a list or NIL if there is no 8th object."
 202   (cadddr (cddddr list)))
 203 (defun ninth (list)
 204   #!+sb-doc
 205   "Return the 9th object in a list or NIL if there is no 9th object."
 206   (car (cddddr (cddddr list))))
 207 (defun tenth (list)
 208   #!+sb-doc
 209   "Return the 10th object in a list or NIL if there is no 10th object."
 210   (cadr (cddddr (cddddr list))))
 211 (defun rest (list)
 212   #!+sb-doc
 213   "Means the same as the cdr of a list."
 214   (cdr list))
 215
 216 (defun nthcdr (n list)
 217   #!+sb-doc
 218   "Performs the cdr function n times on a list."
 219   (flet ((fast-nthcdr (n list)
 220            (declare (type index n))
 221            (do ((i n (1- i))
 222                 (result list (cdr result)))
 223                ((not (plusp i)) result)
 224              (declare (type index i)))))
 225     (typecase n
 226       (index (fast-nthcdr n list))
 227       (t (do ((i 0 (1+ i))
 228               (r-i list (cdr r-i))
 229               (r-2i list (cddr r-2i)))
 230              ((and (eq r-i r-2i) (not (zerop i)))
 231               (fast-nthcdr (mod n i) r-i))
 232            (declare (type index i)))))))
 233
 234 ;;; LAST
 235 ;;;
 236 ;;; Transforms in src/compiler/srctran.lisp pick the most specific
 237 ;;; version possible. %LAST/BIGNUM is admittedly somewhat academic...
 238 (macrolet ((last0-macro ()
 239              `(let ((rest list)
 240                     (list list))
 241                 (loop (unless (consp rest)
 242                         (return rest))
 243                   (shiftf list rest (cdr rest)))))
 244            (last1-macro ()
 245              `(let ((rest list)
 246                     (list list))
 247                 (loop (unless (consp rest)
 248                         (return list))
 249                   (shiftf list rest (cdr rest)))))
 250            (lastn-macro (type)
 251              `(let ((returned-list list)
 252                     (checked-list list)
 253                     (n (truly-the ,type n)))
 254                 (declare (,type n))
 255                 (tagbody
 256                  :scan
 257                    (pop checked-list)
 258                    (when (atom checked-list)
 259                      (go :done))
 260                    (if (zerop (truly-the ,type (decf n)))
 261                        (go :pop)
 262                        (go :scan))
 263                  :pop
 264                    (pop returned-list)
 265                    (pop checked-list)
 266                    (if (atom checked-list)
 267                        (go :done)
 268                        (go :pop))
 269                  :done)
 270                 returned-list)))
 271
 272   (defun %last0 (list)
 273     (declare (optimize speed (sb!c::verify-arg-count 0)))
 274     (last0-macro))
 275
 276   (defun %last1 (list)
 277     (declare (optimize speed (sb!c::verify-arg-count 0)))
 278     (last1-macro))
 279
 280   (defun %lastn/fixnum (list n)
 281     (declare (optimize speed (sb!c::verify-arg-count 0))
 282              (type (and unsigned-byte fixnum) n))
 283     (case n
 284       (1 (last1-macro))
 285       (0 (last0-macro))
 286       (t (lastn-macro fixnum))))
 287
 288   (defun %lastn/bignum (list n)
 289     (declare (optimize speed (sb!c::verify-arg-count 0))
 290              (type (and unsigned-byte bignum) n))
 291     (lastn-macro unsigned-byte))
 292
 293   (defun last (list &optional (n 1))
 294     #!+sb-doc
 295     "Return the last N conses (not the last element!) of a list."
 296     (case n
 297       (1 (last1-macro))
 298       (0 (last0-macro))
 299       (t
 300        (typecase n
 301          (fixnum
 302           (lastn-macro fixnum))
 303          (bignum
 304           (lastn-macro unsigned-byte)))))))
 305
 306 (define-compiler-macro last (&whole form list &optional (n 1) &environment env)
 307   (if (sb!xc:constantp n env)
 308       (case (constant-form-value n env)
 309         (0 `(%last0 ,list))
 310         (1 `(%last1 ,list))
 311         (t form))
 312       form))
 313
 314 (defun list (&rest args)
 315   #!+sb-doc
 316   "Return constructs and returns a list of its arguments."
 317   args)
 318
 319 ;;; LIST* is done the same as LIST, except that the last cons is made
 320 ;;; a dotted pair.
 321
 322 (defun list* (arg &rest others)
 323   #!+sb-doc
 324   "Return a list of the arguments with last cons a dotted pair."
 325   ;; We know the &REST is a proper list.
 326   (declare (optimize (sb!c::type-check 0)))
 327   (cond ((atom others) arg)
 328         ((atom (cdr others)) (cons arg (car others)))
 329         (t (do ((x others (cdr x)))
 330                ((null (cddr x)) (rplacd x (cadr x))))
 331            (cons arg others))))
 332
 333 (defun make-list (size &key initial-element)
 334   #!+sb-doc
 335   "Constructs a list with size elements each set to value"
 336   (declare (type index size))
 337   (do ((count size (1- count))
 338        (result '() (cons initial-element result)))
 339       ((<= count 0) result)
 340     (declare (type index count))))
 341 \f
 342 (defun append (&rest lists)
 343   #!+sb-doc
 344   "Construct a new list by concatenating the list arguments"
 345   (declare (truly-dynamic-extent lists) (optimize speed))
 346   (labels ((fail (object)
 347              (error 'type-error
 348                     :datum object
 349                     :expected-type 'list))
 350            (append-into (last-cons current rest)
 351              ;; Set (CDR LAST-CONS) to (APPLY #'APPEND CURRENT REST).
 352              (declare (cons last-cons rest))
 353              (if (listp current)
 354                  (if (consp current)
 355                      ;; normal case, cdr down the list
 356                      (append-into (setf (cdr last-cons) (list (car current)))
 357                                   (cdr current)
 358                                   rest)
 359                      ;; empty list
 360                      (let ((more (cdr rest)))
 361                        (if (null more)
 362                            (setf (cdr last-cons) (car rest))
 363                            (append-into last-cons (car rest) more))))
 364                  (fail current)))
 365            (append1 (lists)
 366              (let ((current (car lists))
 367                    (rest (cdr lists)))
 368                (cond ((null rest)
 369                       current)
 370                      ((consp current)
 371                       (let ((result (truly-the cons (list (car current)))))
 372                         (append-into result
 373                                      (cdr current)
 374                                      rest)
 375                         result))
 376                      ((null current)
 377                       (append1 rest))
 378                      (t
 379                       (fail current))))))
 380     (append1 lists)))
 381
 382 (defun append2 (x y)
 383   (declare (optimize speed (sb!c::verify-arg-count 0)))
 384   (if (null x)
 385       y
 386       (let ((result (list (car x))))
 387         (do ((more (cdr x) (cdr more))
 388              (tail result (cdr tail)))
 389             ((null more)
 390              (rplacd tail y)
 391              result)
 392           (rplacd tail (list (car more)))))))
 393
 394 \f
 395 ;;;; list copying functions
 396
 397 (eval-when (:compile-toplevel :load-toplevel :execute)
 398   (sb!xc:defmacro !copy-list-macro (list &key check-proper-list)
 399     ;; Unless CHECK-PROPER-LIST is true, the list is copied correctly
 400     ;; even if the list is not terminated by NIL. The new list is built
 401     ;; by CDR'ing SPLICE which is always at the tail of the new list.
 402     `(when ,list
 403        (let ((copy (list (car ,list))))
 404          (do ((orig (cdr ,list) (cdr orig))
 405               (splice copy (cdr (rplacd splice (cons (car orig) nil)))))
 406              (,@(if check-proper-list
 407                     '((endp orig))
 408                     '((atom orig)
 409                       (unless (null orig)
 410                         (rplacd splice orig))))
 411               copy))))))
 412
 413 (defun copy-list (list)
 414   #!+sb-doc
 415   "Return a new list which is EQUAL to LIST. LIST may be improper."
 416   (!copy-list-macro list))
 417
 418 (defun copy-alist (alist)
 419   #!+sb-doc
 420   "Return a new association list which is EQUAL to ALIST."
 421   (if (endp alist)
 422       alist
 423       (let ((result
 424              (cons (if (atom (car alist))
 425                        (car alist)
 426                        (cons (caar alist) (cdar alist)))
 427                    nil)))
 428         (do ((x (cdr alist) (cdr x))
 429              (splice result
 430                      (cdr (rplacd splice
 431                                   (cons
 432                                    (if (atom (car x))
 433                                        (car x)
 434                                        (cons (caar x) (cdar x)))
 435                                    nil)))))
 436             ((endp x)))
 437         result)))
 438
 439 (defun copy-tree (object)
 440   #!+sb-doc
 441   "Recursively copy trees of conses."
 442   (if (consp object)
 443       (let ((result (list (if (consp (car object))
 444                               (copy-tree (car object))
 445                               (car object)))))
 446         (loop for last-cons = result then new-cons
 447               for cdr = (cdr object) then (cdr cdr)
 448               for car = (if (consp cdr)
 449                             (car cdr)
 450                             (return (setf (cdr last-cons) cdr)))
 451               for new-cons = (list (if (consp car)
 452                                        (copy-tree car)
 453                                        car))
 454               do (setf (cdr last-cons) new-cons))
 455         result)
 456       object))
 457
 458 \f
 459 ;;;; more commonly-used list functions
 460
 461 (defun revappend (x y)
 462   #!+sb-doc
 463   "Return (append (reverse x) y)."
 464   (do ((top x (cdr top))
 465        (result y (cons (car top) result)))
 466       ((endp top) result)))
 467
 468 ;;; NCONC finds the first non-null list, so it can make splice point
 469 ;;; to a cons. After finding the first cons element, it holds it in a
 470 ;;; result variable while running down successive elements tacking
 471 ;;; them together. While tacking lists together, if we encounter a
 472 ;;; null list, we set the previous list's last cdr to nil just in case
 473 ;;; it wasn't already nil, and it could have been dotted while the
 474 ;;; null list was the last argument to NCONC. The manipulation of
 475 ;;; splice (that is starting it out on a first cons, setting LAST of
 476 ;;; splice, and setting splice to ele) inherently handles (nconc x x),
 477 ;;; and it avoids running down the last argument to NCONC which allows
 478 ;;; the last argument to be circular.
 479 (defun nconc (&rest lists)
 480    #!+sb-doc
 481    "Concatenates the lists given as arguments (by changing them)"
 482    (declare (optimize speed))
 483    (flet ((fail (object)
 484             (error 'type-error
 485                    :datum object
 486                    :expected-type 'list)))
 487      (do-rest-arg ((result index) lists)
 488          (typecase result
 489            (cons
 490             (let ((splice result))
 491               (do-rest-arg ((ele index) lists (1+ index))
 492                   (typecase ele
 493                     (cons (rplacd (last splice) ele)
 494                           (setf splice ele))
 495                     (null (rplacd (last splice) nil))
 496                     (atom (if (< (1+ index) (length lists))
 497                               (fail ele)
 498                               (rplacd (last splice) ele)))))
 499               (return result)))
 500            (null)
 501            (atom
 502             (if (< (1+ index) (length lists))
 503                 (fail result)
 504                 (return result)))))))
 505
 506 (defun nreconc (x y)
 507   #!+sb-doc
 508   "Return (NCONC (NREVERSE X) Y)."
 509   (do ((1st (cdr x) (if (endp 1st) 1st (cdr 1st)))
 510        (2nd x 1st)              ;2nd follows first down the list.
 511        (3rd y 2nd))             ;3rd follows 2nd down the list.
 512       ((atom 2nd) 3rd)
 513     (rplacd 2nd 3rd)))
 514 \f
 515 (defun butlast (list &optional (n 1))
 516   (cond ((zerop n)
 517          (copy-list list))
 518         ((not (typep n 'index))
 519          nil)
 520         (t
 521          (let ((head (nthcdr (1- n) list)))
 522            (and (consp head)      ; there are at least n
 523                 (collect ((copy)) ; conses; copy!
 524                   (do ((trail list (cdr trail))
 525                        (head head (cdr head)))
 526                       ;; HEAD is n-1 conses ahead of TRAIL;
 527                       ;; when HEAD is at the last cons, return
 528                       ;; the data copied so far.
 529                       ((atom (cdr head))
 530                        (copy))
 531                     (copy (car trail)))))))))
 532
 533 (defun nbutlast (list &optional (n 1))
 534   (cond ((zerop n)
 535          list)
 536         ((not (typep n 'index))
 537          nil)
 538         (t
 539          (let ((head (nthcdr (1- n) list)))
 540            (and (consp head)       ; there are more than n
 541                 (consp (cdr head)) ; conses.
 542                 ;; TRAIL trails by n cons to be able to
 543                 ;; cut the list at the cons just before.
 544                 (do ((trail list (cdr trail))
 545                      (head (cdr head) (cdr head)))
 546                     ((atom (cdr head))
 547                      (setf (cdr trail) nil)
 548                      list)))))))
 549
 550 (defun ldiff (list object)
 551   #!+sb-doc
 552   "Return a new list, whose elements are those of LIST that appear before
 553    OBJECT. If OBJECT is not a tail of LIST, a copy of LIST is returned.
 554    LIST must be a proper list or a dotted list."
 555   (do* ((list list (cdr list))
 556         (result (list ()))
 557         (splice result))
 558        ((atom list)
 559         (if (eql list object)
 560             (cdr result)
 561             (progn (rplacd splice list) (cdr result))))
 562     (if (eql list object)
 563         (return (cdr result))
 564         (setq splice (cdr (rplacd splice (list (car list))))))))
 565 \f
 566 ;;;; functions to alter list structure
 567
 568 (defun rplaca (cons x)
 569   #!+sb-doc
 570   "Change the CAR of CONS to X and return the CONS."
 571   (rplaca cons x))
 572
 573 (defun rplacd (cons x)
 574   #!+sb-doc
 575   "Change the CDR of CONS to X and return the CONS."
 576   (rplacd cons x))
 577
 578 ;;; The following are for use by SETF.
 579
 580 (defun %rplaca (x val) (rplaca x val) val)
 581
 582 (defun %rplacd (x val) (rplacd x val) val)
 583
 584 ;;; Set the Nth element of LIST to NEWVAL.
 585 (defun %setnth (n list newval)
 586   (typecase n
 587     (index
 588      (do ((count n (1- count))
 589           (list list (cdr list)))
 590          ((endp list)
 591           (error "~S is too large an index for SETF of NTH." n))
 592        (declare (type fixnum count))
 593        (when (<= count 0)
 594          (rplaca list newval)
 595          (return newval))))
 596     (t (let ((cons (nthcdr n list)))
 597          (when (endp cons)
 598            (error "~S is too large an index for SETF of NTH." n))
 599          (rplaca cons newval)
 600          newval))))
 601 \f
 602 ;;;; :KEY arg optimization to save funcall of IDENTITY
 603
 604 ;;; APPLY-KEY saves us a function call sometimes.
 605 ;;;    This isn't wrapped in an (EVAL-WHEN (COMPILE EVAL) ..)
 606 ;;;    because it's used in seq.lisp and sort.lisp.
 607 (defmacro apply-key (key element)
 608   `(if ,key
 609        (funcall ,key ,element)
 610        ,element))
 611 \f
 612 ;;;; macros for (&KEY (KEY #'IDENTITY) (TEST #'EQL TESTP) (TEST-NOT NIL NOTP))
 613
 614 ;;; Use these with the following &KEY args:
 615 (defmacro with-set-keys (funcall)
 616   `(if notp
 617        ,(append funcall '(:key key :test-not test-not))
 618        ,(append funcall '(:key key :test test))))
 619
 620 (defmacro satisfies-the-test (item elt)
 621   (let ((key-tmp (gensym)))
 622     `(let ((,key-tmp (apply-key key ,elt)))
 623       (cond (testp (funcall test ,item ,key-tmp))
 624             (notp (not (funcall test-not ,item ,key-tmp)))
 625             (t (funcall test ,item ,key-tmp))))))
 626 \f
 627 ;;;; substitution of expressions
 628
 629 (defun subst (new old tree &key key (test #'eql testp) (test-not #'eql notp))
 630   #!+sb-doc
 631   "Substitutes new for subtrees matching old."
 632   (when (and testp notp)
 633     (error ":TEST and :TEST-NOT were both supplied."))
 634   (let ((key (and key (%coerce-callable-to-fun key)))
 635         (test (if testp (%coerce-callable-to-fun test) test))
 636         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 637     (declare (type function test test-not))
 638     (labels ((s (subtree)
 639                (cond ((satisfies-the-test old subtree) new)
 640                      ((atom subtree) subtree)
 641                      (t (let ((car (s (car subtree)))
 642                               (cdr (s (cdr subtree))))
 643                           (if (and (eq car (car subtree))
 644                                    (eq cdr (cdr subtree)))
 645                               subtree
 646                               (cons car cdr)))))))
 647       (s tree))))
 648
 649 (defun subst-if (new test tree &key key)
 650   #!+sb-doc
 651   "Substitutes new for subtrees for which test is true."
 652   (let ((test (%coerce-callable-to-fun test))
 653         (key (and key (%coerce-callable-to-fun key))))
 654     (labels ((s (subtree)
 655                (cond ((funcall test (apply-key key subtree)) new)
 656                      ((atom subtree) subtree)
 657                      (t (let ((car (s (car subtree)))
 658                               (cdr (s (cdr subtree))))
 659                           (if (and (eq car (car subtree))
 660                                    (eq cdr (cdr subtree)))
 661                               subtree
 662                               (cons car cdr)))))))
 663       (s tree))))
 664
 665 (defun subst-if-not (new test tree &key key)
 666   #!+sb-doc
 667   "Substitutes new for subtrees for which test is false."
 668   (let ((test (%coerce-callable-to-fun test))
 669         (key (and key (%coerce-callable-to-fun key))))
 670     (labels ((s (subtree)
 671                (cond ((not (funcall test (apply-key key subtree))) new)
 672                      ((atom subtree) subtree)
 673                      (t (let ((car (s (car subtree)))
 674                               (cdr (s (cdr subtree))))
 675                           (if (and (eq car (car subtree))
 676                                    (eq cdr (cdr subtree)))
 677                               subtree
 678                               (cons car cdr)))))))
 679       (s tree))))
 680
 681 (defun nsubst (new old tree &key key (test #'eql testp) (test-not #'eql notp))
 682   #!+sb-doc
 683   "Substitute NEW for subtrees matching OLD."
 684   (when (and testp notp)
 685     (error ":TEST and :TEST-NOT were both supplied."))
 686   (let ((key (and key (%coerce-callable-to-fun key)))
 687         (test (if testp (%coerce-callable-to-fun test) test))
 688         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 689     (declare (type function test test-not))
 690     (labels ((s (subtree)
 691                (cond ((satisfies-the-test old subtree) new)
 692                      ((atom subtree) subtree)
 693                      (t (do* ((last nil subtree)
 694                               (subtree subtree (cdr subtree)))
 695                              ((atom subtree)
 696                               (if (satisfies-the-test old subtree)
 697                                   (setf (cdr last) new)))
 698                           (if (satisfies-the-test old subtree)
 699                               (return (setf (cdr last) new))
 700                               (setf (car subtree) (s (car subtree)))))
 701                         subtree))))
 702       (s tree))))
 703
 704 (defun nsubst-if (new test tree &key key)
 705   #!+sb-doc
 706   "Substitute NEW for subtrees of TREE for which TEST is true."
 707   (let ((test (%coerce-callable-to-fun test))
 708         (key (and key (%coerce-callable-to-fun key))))
 709     (labels ((s (subtree)
 710                (cond ((funcall test (apply-key key subtree)) new)
 711                      ((atom subtree) subtree)
 712                      (t (do* ((last nil subtree)
 713                               (subtree subtree (cdr subtree)))
 714                              ((atom subtree)
 715                               (if (funcall test (apply-key key subtree))
 716                                   (setf (cdr last) new)))
 717                           (if (funcall test (apply-key key subtree))
 718                               (return (setf (cdr last) new))
 719                               (setf (car subtree) (s (car subtree)))))
 720                         subtree))))
 721       (s tree))))
 722
 723 (defun nsubst-if-not (new test tree &key key)
 724   #!+sb-doc
 725   "Substitute NEW for subtrees of TREE for which TEST is false."
 726   (let ((test (%coerce-callable-to-fun test))
 727         (key (and key (%coerce-callable-to-fun key))))
 728     (labels ((s (subtree)
 729                (cond ((not (funcall test (apply-key key subtree))) new)
 730                      ((atom subtree) subtree)
 731                      (t (do* ((last nil subtree)
 732                               (subtree subtree (cdr subtree)))
 733                              ((atom subtree)
 734                               (if (not (funcall test (apply-key key subtree)))
 735                                   (setf (cdr last) new)))
 736                           (if (not (funcall test (apply-key key subtree)))
 737                               (return (setf (cdr last) new))
 738                               (setf (car subtree) (s (car subtree)))))
 739                         subtree))))
 740       (s tree))))
 741 \f
 742 (defun sublis (alist tree &key key (test #'eql testp) (test-not #'eql notp))
 743   #!+sb-doc
 744   "Substitute from ALIST into TREE nondestructively."
 745   (when (and testp notp)
 746     (error ":TEST and :TEST-NOT were both supplied."))
 747   (let ((key (and key (%coerce-callable-to-fun key)))
 748         (test (if testp (%coerce-callable-to-fun test) test))
 749         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 750     (declare (type function test test-not))
 751     (declare (inline assoc))
 752     (labels ((s (subtree)
 753                (let* ((key-val (apply-key key subtree))
 754                       (assoc (if notp
 755                                  (assoc key-val alist :test-not test-not)
 756                                  (assoc key-val alist :test test))))
 757                  (cond (assoc (cdr assoc))
 758                        ((atom subtree) subtree)
 759                        (t (let ((car (s (car subtree)))
 760                                 (cdr (s (cdr subtree))))
 761                             (if (and (eq car (car subtree))
 762                                      (eq cdr (cdr subtree)))
 763                                 subtree
 764                                 (cons car cdr))))))))
 765       (s tree))))
 766
 767 ;;; This is in run-time env (i.e. not wrapped in EVAL-WHEN (COMPILE EVAL))
 768 ;;; because it can be referenced in inline expansions.
 769 (defmacro nsublis-macro ()
 770   (let ((key-tmp (gensym)))
 771     `(let ((,key-tmp (apply-key key subtree)))
 772       (if notp
 773           (assoc ,key-tmp alist :test-not test-not)
 774           (assoc ,key-tmp alist :test test)))))
 775
 776 (defun nsublis (alist tree &key key (test #'eql testp) (test-not #'eql notp))
 777   #!+sb-doc
 778   "Substitute from ALIST into TRUE destructively."
 779   (when (and testp notp)
 780     (error ":TEST and :TEST-NOT were both supplied."))
 781   (let ((key (and key (%coerce-callable-to-fun key)))
 782         (test (if testp (%coerce-callable-to-fun test) test))
 783         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
 784     (declare (inline assoc))
 785     (let (temp)
 786       (labels ((s (subtree)
 787                  (cond ((setq temp (nsublis-macro))
 788                         (cdr temp))
 789                        ((atom subtree) subtree)
 790                        (t (do* ((last nil subtree)
 791                                 (subtree subtree (cdr subtree)))
 792                                ((atom subtree)
 793                                 (if (setq temp (nsublis-macro))
 794                                     (setf (cdr last) (cdr temp))))
 795                             (if (setq temp (nsublis-macro))
 796                                 (return (setf (cdr last) (cdr temp)))
 797                                 (setf (car subtree) (s (car subtree)))))
 798                           subtree))))
 799         (s tree)))))
 800 \f
 801 ;;;; functions for using lists as sets
 802
 803 (defun member (item list &key key (test nil testp) (test-not nil notp))
 804   #!+sb-doc
 805   "Return the tail of LIST beginning with first element satisfying EQLity,
 806    :TEST, or :TEST-NOT with the given ITEM."
 807   (when (and testp notp)
 808     (error ":TEST and :TEST-NOT were both supplied."))
 809   (let ((key (and key (%coerce-callable-to-fun key)))
 810         (test (and testp (%coerce-callable-to-fun test)))
 811         (test-not (and notp (%coerce-callable-to-fun test-not))))
 812     (cond (test
 813            (if key
 814                (%member-key-test item list key test)
 815                (%member-test item list test)))
 816           (test-not
 817            (if key
 818                (%member-key-test-not item list key test-not)
 819                (%member-test-not item list test-not)))
 820           (t
 821            (if key
 822                (%member-key item list key)
 823                (%member item list))))))
 824
 825 (defun member-if (test list &key key)
 826   #!+sb-doc
 827   "Return tail of LIST beginning with first element satisfying TEST."
 828   (let ((test (%coerce-callable-to-fun test))
 829         (key (and key (%coerce-callable-to-fun key))))
 830     (if key
 831         (%member-if-key test list key)
 832         (%member-if test list))))
 833
 834 (defun member-if-not (test list &key key)
 835   #!+sb-doc
 836   "Return tail of LIST beginning with first element not satisfying TEST."
 837   (let ((test (%coerce-callable-to-fun test))
 838         (key (and key (%coerce-callable-to-fun key))))
 839     (if key
 840         (%member-if-not-key test list key)
 841         (%member-if-not test list))))
 842
 843 (defun tailp (object list)
 844   #!+sb-doc
 845   "Return true if OBJECT is the same as some tail of LIST, otherwise
 846    returns false. LIST must be a proper list or a dotted list."
 847   (do ((list list (cdr list)))
 848       ((atom list) (eql list object))
 849     (if (eql object list)
 850         (return t))))
 851
 852 (defun adjoin (item list &key key (test #'eql testp) (test-not nil notp))
 853   #!+sb-doc
 854   "Add ITEM to LIST unless it is already a member"
 855   (when (and testp notp)
 856     (error ":TEST and :TEST-NOT were both supplied."))
 857   (let ((key (and key (%coerce-callable-to-fun key)))
 858         (test (and testp (%coerce-callable-to-fun test)))
 859         (test-not (and notp (%coerce-callable-to-fun test-not))))
 860     (cond (test
 861            (if key
 862                (%adjoin-key-test item list key test)
 863                (%adjoin-test item list test)))
 864           (test-not
 865            (if key
 866                (%adjoin-key-test-not item list key test-not)
 867                (%adjoin-test-not item list test-not)))
 868           (t
 869            (if key
 870                (%adjoin-key item list key)
 871                (%adjoin item list))))))
 872
 873 (defconstant +list-based-union-limit+ 80)
 874
 875 (defun union (list1 list2 &key key (test #'eql testp) (test-not nil notp))
 876   #!+sb-doc
 877   "Return the union of LIST1 and LIST2."
 878   (declare (inline member))
 879   (when (and testp notp)
 880     (error ":TEST and :TEST-NOT were both supplied."))
 881   ;; We have two possibilities here: for shortish lists we pick up the
 882   ;; shorter one as the result, and add the other one to it. For long
 883   ;; lists we use a hash-table when possible.
 884   (let ((n1 (length list1))
 885         (n2 (length list2))
 886         (key (and key (%coerce-callable-to-fun key)))
 887         (test (if notp
 888                   (let ((test-not-fun (%coerce-callable-to-fun test-not)))
 889                     (lambda (x y) (not (funcall test-not-fun x y))))
 890                   (%coerce-callable-to-fun test))))
 891     (multiple-value-bind (short long n-short)
 892         (if (< n1 n2)
 893             (values list1 list2 n1)
 894             (values list2 list1 n2))
 895       (if (or (< n-short +list-based-union-limit+)
 896               (not (member test (list #'eq #'eql #'equal #'equalp))))
 897           (let ((orig short))
 898             (dolist (elt long)
 899               (unless (member (apply-key key elt) orig :key key :test test)
 900                 (push elt short)))
 901             short)
 902           (let ((table (make-hash-table :test test :size (+ n1 n2)))
 903                 (union nil))
 904             (dolist (elt long)
 905               (setf (gethash (apply-key key elt) table) elt))
 906             (dolist (elt short)
 907               (setf (gethash (apply-key key elt) table) elt))
 908             (maphash (lambda (k v)
 909                        (declare (ignore k))
 910                        (push v union))
 911                      table)
 912             union)))))
 913
 914 ;;; Destination and source are SETF-able and many-evaluable. Set the
 915 ;;; SOURCE to the CDR, and "cons" the 1st elt of source to DESTINATION.
 916 ;;;
 917 ;;; FIXME: needs a more mnemonic name
 918 (defmacro steve-splice (source destination)
 919   `(let ((temp ,source))
 920      (setf ,source (cdr ,source)
 921            (cdr temp) ,destination
 922            ,destination temp)))
 923
 924 (defun nunion (list1 list2 &key key (test #'eql testp) (test-not nil notp))
 925   #!+sb-doc
 926   "Destructively return the union of LIST1 and LIST2."
 927   (declare (inline member))
 928   (when (and testp notp)
 929     (error ":TEST and :TEST-NOT were both supplied."))
 930   ;; We have two possibilities here: for shortish lists we pick up the
 931   ;; shorter one as the result, and add the other one to it. For long
 932   ;; lists we use a hash-table when possible.
 933   (let ((n1 (length list1))
 934         (n2 (length list2))
 935         (key (and key (%coerce-callable-to-fun key)))
 936         (test (if notp
 937                   (let ((test-not-fun (%coerce-callable-to-fun test-not)))
 938                     (lambda (x y) (not (funcall test-not-fun x y))))
 939                   (%coerce-callable-to-fun test))))
 940     (multiple-value-bind (short long n-short)
 941         (if (< n1 n2)
 942             (values list1 list2 n1)
 943             (values list2 list1 n2))
 944       (if (or (< n-short +list-based-union-limit+)
 945               (not (member test (list #'eq #'eql #'equal #'equalp))))
 946           (let ((orig short))
 947             (do ((elt (car long) (car long)))
 948                 ((endp long))
 949               (if (not (member (apply-key key elt) orig :key key :test test))
 950                   (steve-splice long short)
 951                   (setf long (cdr long))))
 952             short)
 953           (let ((table (make-hash-table :test test :size (+ n1 n2))))
 954             (dolist (elt long)
 955               (setf (gethash (apply-key key elt) table) elt))
 956             (dolist (elt short)
 957               (setf (gethash (apply-key key elt) table) elt))
 958             (let ((union long)
 959                   (head long))
 960               (maphash (lambda (k v)
 961                          (declare (ignore k))
 962                          (if head
 963                              (setf (car head) v
 964                                    head (cdr head))
 965                              (push v union)))
 966                       table)
 967               union))))))
 968
 969 (defun intersection (list1 list2
 970                      &key key (test #'eql testp) (test-not nil notp))
 971   #!+sb-doc
 972   "Return the intersection of LIST1 and LIST2."
 973   (declare (inline member))
 974   (when (and testp notp)
 975     (error ":TEST and :TEST-NOT were both supplied."))
 976   (let ((key (and key (%coerce-callable-to-fun key))))
 977     (let ((res nil))
 978       (dolist (elt list1)
 979         (if (with-set-keys (member (apply-key key elt) list2))
 980             (push elt res)))
 981       res)))
 982
 983 (defun nintersection (list1 list2
 984                       &key key (test #'eql testp) (test-not nil notp))
 985   #!+sb-doc
 986   "Destructively return the intersection of LIST1 and LIST2."
 987   (declare (inline member))
 988   (when (and testp notp)
 989     (error ":TEST and :TEST-NOT were both supplied."))
 990   (let ((key (and key (%coerce-callable-to-fun key))))
 991     (let ((res nil)
 992           (list1 list1))
 993       (do () ((endp list1))
 994         (if (with-set-keys (member (apply-key key (car list1)) list2))
 995             (steve-splice list1 res)
 996             (setq list1 (cdr list1))))
 997       res)))
 998
 999 (defun set-difference (list1 list2
1000                        &key key (test #'eql testp) (test-not nil notp))
1001   #!+sb-doc
1002   "Return the elements of LIST1 which are not in LIST2."
1003   (declare (inline member))
1004   (when (and testp notp)
1005     (error ":TEST and :TEST-NOT were both supplied."))
1006   (let ((key (and key (%coerce-callable-to-fun key))))
1007     (if (null list2)
1008         list1
1009         (let ((res nil))
1010           (dolist (elt list1)
1011             (if (not (with-set-keys (member (apply-key key elt) list2)))
1012                 (push elt res)))
1013           res))))
1014
1015 (defun nset-difference (list1 list2
1016                         &key key (test #'eql testp) (test-not nil notp))
1017   #!+sb-doc
1018   "Destructively return the elements of LIST1 which are not in LIST2."
1019   (declare (inline member))
1020   (when (and testp notp)
1021     (error ":TEST and :TEST-NOT were both supplied."))
1022   (let ((key (and key (%coerce-callable-to-fun key))))
1023     (let ((res nil)
1024           (list1 list1))
1025       (do () ((endp list1))
1026         (if (not (with-set-keys (member (apply-key key (car list1)) list2)))
1027             (steve-splice list1 res)
1028             (setq list1 (cdr list1))))
1029       res)))
1030
1031 (defun set-exclusive-or (list1 list2
1032                          &key key (test #'eql testp) (test-not #'eql notp))
1033   #!+sb-doc
1034   "Return new list of elements appearing exactly once in LIST1 and LIST2."
1035   (declare (inline member))
1036   (when (and testp notp)
1037     (error ":TEST and :TEST-NOT were both supplied."))
1038   (let ((result nil)
1039         (key (and key (%coerce-callable-to-fun key)))
1040         (test (if testp (%coerce-callable-to-fun test) test))
1041         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
1042     (declare (type function test test-not))
1043     (dolist (elt list1)
1044       (unless (with-set-keys (member (apply-key key elt) list2))
1045         (setq result (cons elt result))))
1046     (let ((test (if testp
1047                     (lambda (x y) (funcall test y x))
1048                     test))
1049           (test-not (if notp
1050                         (lambda (x y) (funcall test-not y x))
1051                         test-not)))
1052       (dolist (elt list2)
1053         (unless (with-set-keys (member (apply-key key elt) list1))
1054           (setq result (cons elt result)))))
1055     result))
1056
1057 (defun nset-exclusive-or (list1 list2
1058                           &key key (test #'eql testp) (test-not #'eql notp))
1059   #!+sb-doc
1060   "Destructively return a list with elements which appear but once in LIST1
1061    and LIST2."
1062   (when (and testp notp)
1063     (error ":TEST and :TEST-NOT were both supplied."))
1064   (let ((key (and key (%coerce-callable-to-fun key)))
1065         (test (if testp (%coerce-callable-to-fun test) test))
1066         (test-not (if notp (%coerce-callable-to-fun test-not) test-not)))
1067     (declare (type function test test-not))
1068     ;; The outer loop examines LIST1 while the inner loop examines
1069     ;; LIST2. If an element is found in LIST2 "equal" to the element
1070     ;; in LIST1, both are spliced out. When the end of LIST1 is
1071     ;; reached, what is left of LIST2 is tacked onto what is left of
1072     ;; LIST1. The splicing operation ensures that the correct
1073     ;; operation is performed depending on whether splice is at the
1074     ;; top of the list or not.
1075     (do ((list1 list1)
1076          (list2 list2)
1077          (x list1 (cdr x))
1078          (splicex ())
1079          (deleted-y ())
1080          ;; elements of LIST2, which are "equal" to some processed
1081          ;; earlier elements of LIST1
1082          )
1083         ((endp x)
1084          (if (null splicex)
1085              (setq list1 list2)
1086              (rplacd splicex list2))
1087          list1)
1088       (let ((key-val-x (apply-key key (car x)))
1089             (found-duplicate nil))
1090
1091         ;; Move all elements from LIST2, which are "equal" to (CAR X),
1092         ;; to DELETED-Y.
1093         (do* ((y list2 next-y)
1094               (next-y (cdr y) (cdr y))
1095               (splicey ()))
1096              ((endp y))
1097           (cond ((let ((key-val-y (apply-key key (car y))))
1098                    (if notp
1099                        (not (funcall test-not key-val-x key-val-y))
1100                        (funcall test key-val-x key-val-y)))
1101                  (if (null splicey)
1102                      (setq list2 (cdr y))
1103                      (rplacd splicey (cdr y)))
1104                  (setq deleted-y (rplacd y deleted-y))
1105                  (setq found-duplicate t))
1106                 (t (setq splicey y))))
1107
1108         (unless found-duplicate
1109           (setq found-duplicate (with-set-keys (member key-val-x deleted-y))))
1110
1111         (if found-duplicate
1112             (if (null splicex)
1113                 (setq list1 (cdr x))
1114                 (rplacd splicex (cdr x)))
1115             (setq splicex x))))))
1116
1117 (defun subsetp (list1 list2 &key key (test #'eql testp) (test-not nil notp))
1118   #!+sb-doc
1119   "Return T if every element in LIST1 is also in LIST2."
1120   (declare (inline member))
1121   (when (and testp notp)
1122     (error ":TEST and :TEST-NOT were both supplied."))
1123   (let ((key (and key (%coerce-callable-to-fun key))))
1124     (dolist (elt list1)
1125       (unless (with-set-keys (member (apply-key key elt) list2))
1126         (return-from subsetp nil)))
1127     t))
1128 \f
1129 ;;;; functions that operate on association lists
1130
1131 (defun acons (key datum alist)
1132   #!+sb-doc
1133   "Construct a new alist by adding the pair (KEY . DATUM) to ALIST."
1134   (cons (cons key datum) alist))
1135
1136 (defun pairlis (keys data &optional (alist '()))
1137   #!+sb-doc
1138   "Construct an association list from KEYS and DATA (adding to ALIST)."
1139   (do ((x keys (cdr x))
1140        (y data (cdr y)))
1141       ((and (endp x) (endp y)) alist)
1142     (if (or (endp x) (endp y))
1143         (error "The lists of keys and data are of unequal length."))
1144     (setq alist (acons (car x) (car y) alist))))
1145
1146 (defun assoc (item alist &key key (test nil testp) (test-not nil notp))
1147   #!+sb-doc
1148   "Return the cons in ALIST whose car is equal (by a given test or EQL) to
1149    the ITEM."
1150   (when (and testp notp)
1151     (error ":TEST and :TEST-NOT were both supplied."))
1152   (let ((key (and key (%coerce-callable-to-fun key)))
1153         (test (and testp (%coerce-callable-to-fun test)))
1154         (test-not (and notp (%coerce-callable-to-fun test-not))))
1155     (cond (test
1156            (if key
1157                (%assoc-key-test item alist key test)
1158                (%assoc-test item alist test)))
1159           (test-not
1160            (if key
1161                (%assoc-key-test-not item alist key test-not)
1162                (%assoc-test-not item alist test-not)))
1163           (t
1164            (if key
1165                (%assoc-key item alist key)
1166                (%assoc item alist))))))
1167
1168 (defun assoc-if (predicate alist &key key)
1169   #!+sb-doc
1170   "Return the first cons in ALIST whose CAR satisfies PREDICATE. If
1171    KEY is supplied, apply it to the CAR of each cons before testing."
1172   (let ((predicate (%coerce-callable-to-fun predicate))
1173         (key (and key (%coerce-callable-to-fun key))))
1174     (if key
1175         (%assoc-if-key predicate alist key)
1176         (%assoc-if predicate alist))))
1177
1178 (defun assoc-if-not (predicate alist &key key)
1179   #!+sb-doc
1180   "Return the first cons in ALIST whose CAR does not satisfy PREDICATE.
1181   If KEY is supplied, apply it to the CAR of each cons before testing."
1182   (let ((predicate (%coerce-callable-to-fun predicate))
1183         (key (and key (%coerce-callable-to-fun key))))
1184     (if key
1185         (%assoc-if-not-key predicate alist key)
1186         (%assoc-if-not predicate alist))))
1187
1188 (defun rassoc (item alist &key key (test nil testp) (test-not nil notp))
1189   (declare (list alist))
1190   #!+sb-doc
1191   "Return the cons in ALIST whose CDR is equal (by a given test or EQL) to
1192    the ITEM."
1193   (when (and testp notp)
1194     (error ":TEST and :TEST-NOT were both supplied."))
1195   (let ((key (and key (%coerce-callable-to-fun key)))
1196         (test (and testp (%coerce-callable-to-fun test)))
1197         (test-not (and notp (%coerce-callable-to-fun test-not))))
1198     (cond (test
1199            (if key
1200                (%rassoc-key-test item alist key test)
1201                (%rassoc-test item alist test)))
1202           (test-not
1203            (if key
1204                (%rassoc-key-test-not item alist key test-not)
1205                (%rassoc-test-not item alist test-not)))
1206           (t
1207            (if key
1208                (%rassoc-key item alist key)
1209                (%rassoc item alist))))))
1210
1211 (defun rassoc-if (predicate alist &key key)
1212   #!+sb-doc
1213   "Return the first cons in ALIST whose CDR satisfies PREDICATE. If KEY
1214   is supplied, apply it to the CDR of each cons before testing."
1215   (let ((predicate (%coerce-callable-to-fun predicate))
1216         (key (and key (%coerce-callable-to-fun key))))
1217     (if key
1218         (%rassoc-if-key predicate alist key)
1219         (%rassoc-if predicate alist))))
1220
1221 (defun rassoc-if-not (predicate alist &key key)
1222   #!+sb-doc
1223   "Return the first cons in ALIST whose CDR does not satisfy PREDICATE.
1224   If KEY is supplied, apply it to the CDR of each cons before testing."
1225   (let ((predicate (%coerce-callable-to-fun predicate))
1226         (key (and key (%coerce-callable-to-fun key))))
1227     (if key
1228         (%rassoc-if-not-key predicate alist key)
1229         (%rassoc-if-not predicate alist))))
1230 \f
1231 ;;;; mapping functions
1232
1233 ;;; a helper function for implementation of MAPC, MAPCAR, MAPCAN,
1234 ;;; MAPL, MAPLIST, and MAPCON
1235 ;;;
1236 ;;; Map the designated function over the arglists in the appropriate
1237 ;;; way. It is done when any of the arglists runs out. Until then, it
1238 ;;; CDRs down the arglists calling the function and accumulating
1239 ;;; results as desired.
1240 (defun map1 (fun-designator arglists accumulate take-car)
1241   (do* ((fun (%coerce-callable-to-fun fun-designator))
1242         (non-acc-result (car arglists))
1243         (ret-list (list nil))
1244         (temp ret-list)
1245         (res nil)
1246         (args (make-list (length arglists))))
1247        ((dolist (x arglists) (or x (return t)))
1248         (if accumulate
1249             (cdr ret-list)
1250             non-acc-result))
1251     (do ((l arglists (cdr l))
1252          (arg args (cdr arg)))
1253         ((null l))
1254       (setf (car arg) (if take-car (caar l) (car l)))
1255       (setf (car l) (cdar l)))
1256     (setq res (apply fun args))
1257     (case accumulate
1258       (:nconc
1259        (when res
1260          (setf (cdr temp) res)
1261          ;; KLUDGE: it is said that MAPCON is equivalent to
1262          ;; (apply #'nconc (maplist ...)) which means (nconc 1) would
1263          ;; return 1, but (nconc 1 1) should signal an error.
1264          ;; The transformed MAP code returns the last result, do that
1265          ;; here as well for consistency and simplicity.
1266          (when (consp res)
1267            (setf temp (last res)))))
1268       (:list (setf (cdr temp) (list res)
1269                    temp (cdr temp))))))
1270
1271 (defun mapc (function list &rest more-lists)
1272   #!+sb-doc
1273   "Apply FUNCTION to successive elements of lists. Return the second argument."
1274   (map1 function (cons list more-lists) nil t))
1275
1276 (defun mapcar (function list &rest more-lists)
1277   #!+sb-doc
1278   "Apply FUNCTION to successive elements of LIST. Return list of FUNCTION
1279    return values."
1280   (map1 function (cons list more-lists) :list t))
1281
1282 (defun mapcan (function list &rest more-lists)
1283   #!+sb-doc
1284   "Apply FUNCTION to successive elements of LIST. Return NCONC of FUNCTION
1285    results."
1286   (map1 function (cons list more-lists) :nconc t))
1287
1288 (defun mapl (function list &rest more-lists)
1289   #!+sb-doc
1290   "Apply FUNCTION to successive CDRs of list. Return NIL."
1291   (map1 function (cons list more-lists) nil nil))
1292
1293 (defun maplist (function list &rest more-lists)
1294   #!+sb-doc
1295   "Apply FUNCTION to successive CDRs of list. Return list of results."
1296   (map1 function (cons list more-lists) :list nil))
1297
1298 (defun mapcon (function list &rest more-lists)
1299   #!+sb-doc
1300   "Apply FUNCTION to successive CDRs of lists. Return NCONC of results."
1301   (map1 function (cons list more-lists) :nconc nil))
1302
1303 ;;;; Specialized versions
1304
1305 ;;; %ADJOIN-*, %ASSOC-*, %MEMBER-*, and %RASSOC-* functions. Deftransforms
1306 ;;; delegate to TRANSFORM-LIST-PRED-SEEK and TRANSFORM-LIST-ITEM-SEEK which
1307 ;;; pick the appropriate versions. These win because they have only positional
1308 ;;; arguments, the TEST, TEST-NOT & KEY functions are known to exist (or not),
1309 ;;; and are known to be functions instead of function designators. We are also
1310 ;;; able to transform many common cases to -EQ versions, which are
1311 ;;; substantially faster then EQL using ones.
1312 (macrolet
1313     ((def (funs form &optional variant)
1314        (flet ((%def (name &optional conditional)
1315                 (let* ((body-loop
1316                         `(do ((list list (cdr list)))
1317                              ((null list) nil)
1318                            (declare (list list))
1319                            (let ((this (car list)))
1320                              ,(let ((cxx (if (char= #\A (char (string name) 0))
1321                                              'car    ; assoc, assoc-if, assoc-if-not
1322                                              'cdr))) ; rassoc, rassoc-if, rassoc-if-not
1323                                    (ecase name
1324                                       ((assoc rassoc)
1325                                        (if funs
1326                                            `(when this
1327                                               (let ((target (,cxx this)))
1328                                                 (when ,form
1329                                                   (return this))))
1330                                            ;; If there is no TEST/TEST-NOT or
1331                                            ;; KEY, do the EQ/EQL test first,
1332                                            ;; before checking for NIL.
1333                                            `(let ((target (,cxx this)))
1334                                               (when (and ,form this)
1335                                                 (return this)))))
1336                                  ((assoc-if assoc-if-not rassoc-if rassoc-if-not)
1337                                   (aver (equal '(eql x) (subseq form 0 2)))
1338                                   `(when this
1339                                      (let ((target (,cxx this)))
1340                                        (,conditional (funcall ,@(cdr form))
1341                                                      (return this)))))
1342                                  (member
1343                                   `(let ((target this))
1344                                      (when ,form
1345                                        (return list))))
1346                                  ((member-if member-if-not)
1347                                   (aver (equal '(eql x) (subseq form 0 2)))
1348                                   `(let ((target this))
1349                                      (,conditional (funcall ,@(cdr form))
1350                                                    (return list))))
1351                                  (adjoin
1352                                   `(let ((target this))
1353                                      (when ,form
1354                                        (return t)))))))))
1355                        (body (if (eq 'adjoin name)
1356                                  `(if (let ,(when (member 'key funs)
1357                                                   `((x (funcall key x))))
1358                                         ,body-loop)
1359                                       list
1360                                       (cons x list))
1361                                  body-loop)))
1362                   `(defun ,(intern (format nil "%~A~{-~A~}~@[-~A~]" name funs variant))
1363                        (x list ,@funs)
1364                      (declare (optimize speed (sb!c::verify-arg-count 0)))
1365                      ,@(when funs `((declare (function ,@funs))))
1366                      ,@(unless (member name '(member assoc adjoin rassoc)) `((declare (function x))))
1367                      ,body))))
1368          `(progn
1369             ,(%def 'adjoin)
1370             ,(%def 'assoc)
1371             ,(%def 'member)
1372             ,(%def 'rassoc)
1373             ,@(when (and (not variant) (member funs '(() (key)) :test #'equal))
1374                     (list (%def 'member-if 'when)
1375                           (%def 'member-if-not 'unless)
1376                           (%def 'assoc-if 'when)
1377                           (%def 'assoc-if-not 'unless)
1378                           (%def 'rassoc-if 'when)
1379                           (%def 'rassoc-if-not 'unless)))))))
1380   (def ()
1381       (eql x target))
1382   (def ()
1383       (eq x target)
1384     eq)
1385   (def (key)
1386       (eql x (funcall key target)))
1387   (def (key)
1388       (eq x (funcall key target))
1389     eq)
1390   (def (key test)
1391       (funcall test x (funcall key target)))
1392   (def (key test-not)
1393       (not (funcall test-not x (funcall key target))))
1394   (def (test)
1395       (funcall test x target))
1396   (def (test-not)
1397       (not (funcall test-not x target))))