src/code/seq.lisp

   1 ;;;; generic SEQUENCEs
   2 ;;;;
   3 ;;;; KLUDGE: comment from original CMU CL source:
   4 ;;;;   Be careful when modifying code. A lot of the structure of the
   5 ;;;;   code is affected by the fact that compiler transforms use the
   6 ;;;;   lower level support functions. If transforms are written for
   7 ;;;;   some sequence operation, note how the END argument is handled
   8 ;;;;   in other operations with transforms.
   9
  10 ;;;; This software is part of the SBCL system. See the README file for
  11 ;;;; more information.
  12 ;;;;
  13 ;;;; This software is derived from the CMU CL system, which was
  14 ;;;; written at Carnegie Mellon University and released into the
  15 ;;;; public domain. The software is in the public domain and is
  16 ;;;; provided with absolutely no warranty. See the COPYING and CREDITS
  17 ;;;; files for more information.
  18
  19 (in-package "SB!IMPL")
  20 \f
  21 ;;;; utilities
  22
  23 (defun %check-generic-sequence-bounds (seq start end)
  24   (let ((length (sb!sequence:length seq)))
  25     (if (<= 0 start (or end length) length)
  26         (or end length)
  27         (sequence-bounding-indices-bad-error seq start end))))
  28
  29 (eval-when (:compile-toplevel :load-toplevel :execute)
  30   (defparameter *sequence-keyword-info*
  31     ;; (name default supplied-p adjustment new-type)
  32     `((count nil
  33              nil
  34              (etypecase count
  35                (null (1- most-positive-fixnum))
  36                (fixnum (max 0 count))
  37                (integer (if (minusp count)
  38                             0
  39                             (1- most-positive-fixnum))))
  40              (mod #.sb!xc:most-positive-fixnum))
  41       ;; Entries for {start,end}{,1,2}
  42       ,@(mapcan (lambda (names)
  43                   (destructuring-bind (start end length sequence) names
  44                     (list
  45                      `(,start
  46                        0
  47                        nil
  48                        ;; Only evaluate LENGTH (which may be expensive)
  49                        ;; if START is non-NIL.
  50                        (if (or (zerop ,start) (<= 0 ,start ,length))
  51                            ,start
  52                            (sequence-bounding-indices-bad-error ,sequence ,start ,end))
  53                        index)
  54                      `(,end
  55                        nil
  56                        nil
  57                        ;; Only evaluate LENGTH (which may be expensive)
  58                        ;; if END is non-NIL.
  59                        (if (or (null ,end) (<= ,start ,end ,length))
  60                            ;; Defaulting of NIL is done inside the
  61                            ;; bodies, for ease of sharing with compiler
  62                            ;; transforms.
  63                            ;;
  64                            ;; FIXME: defend against non-number non-NIL
  65                            ;; stuff?
  66                            ,end
  67                            (sequence-bounding-indices-bad-error ,sequence ,start ,end))
  68                        (or null index)))))
  69                 '((start end length sequence)
  70                   (start1 end1 length1 sequence1)
  71                   (start2 end2 length2 sequence2)))
  72       (key nil
  73            nil
  74            (and key (%coerce-callable-to-fun key))
  75            (or null function))
  76       (test #'eql
  77             nil
  78             (%coerce-callable-to-fun test)
  79             function)
  80       (test-not nil
  81                 nil
  82                 (and test-not (%coerce-callable-to-fun test-not))
  83                 (or null function)))))
  84
  85 (sb!xc:defmacro define-sequence-traverser (name args &body body)
  86   (multiple-value-bind (body declarations docstring) (parse-body body t)
  87     (collect ((new-args)
  88               (new-declarations)
  89               ;; Things which are definitely used in any code path.
  90               (rebindings/eager)
  91               ;; Things which may be used/are only used in certain
  92               ;; code paths (e.g. length).
  93               (rebindings/lazy))
  94       (dolist (arg args)
  95         (case arg
  96           ;; FIXME: make this robust.  And clean.
  97           ((sequence sequence1 sequence2)
  98            (let* ((length-var (ecase arg
  99                                 (sequence  'length)
 100                                 (sequence1 'length1)
 101                                 (sequence2 'length2)))
 102                   (cache-var (symbolicate length-var '#:-cache)))
 103              (new-args arg)
 104              (rebindings/eager `(,cache-var nil))
 105              (rebindings/lazy
 106               `(,length-var (truly-the
 107                              index
 108                              (or ,cache-var (setf ,cache-var (length ,arg))))))))
 109           ((function predicate)
 110            (new-args arg)
 111            (rebindings/eager `(,arg (%coerce-callable-to-fun ,arg))))
 112           (t
 113            (let ((info (cdr (assoc arg *sequence-keyword-info*))))
 114              (cond (info
 115                     (destructuring-bind (default supplied-p adjuster type) info
 116                       (new-args `(,arg ,default ,@(when supplied-p (list supplied-p))))
 117                       (rebindings/eager `(,arg ,adjuster))
 118                       (new-declarations `(type ,type ,arg))))
 119                    (t (new-args arg)))))))
 120       `(defun ,name ,(new-args)
 121          ,@(when docstring (list docstring))
 122          ,@declarations
 123          (symbol-macrolet (,@(rebindings/lazy))
 124            (let* (,@(rebindings/eager))
 125              (declare ,@(new-declarations))
 126              ,@body))))))
 127
 128 ;;; SEQ-DISPATCH does an efficient type-dispatch on the given SEQUENCE.
 129 ;;;
 130 ;;; FIXME: It might be worth making three cases here, LIST,
 131 ;;; SIMPLE-VECTOR, and VECTOR, instead of the current LIST and VECTOR.
 132 ;;; It tends to make code run faster but be bigger; some benchmarking
 133 ;;; is needed to decide.
 134 (sb!xc:defmacro seq-dispatch
 135     (sequence list-form array-form &optional other-form)
 136   `(if (listp ,sequence)
 137        (let ((,sequence (truly-the list ,sequence)))
 138          (declare (ignorable ,sequence))
 139          ,list-form)
 140        ,@(if other-form
 141              `((if (arrayp ,sequence)
 142                    (let ((,sequence (truly-the vector ,sequence)))
 143                      (declare (ignorable ,sequence))
 144                      ,array-form)
 145                    ,other-form))
 146              `((let ((,sequence (truly-the vector ,sequence)))
 147                  (declare (ignorable ,sequence))
 148                  ,array-form)))))
 149
 150 ;; Same as above, but don't assume that ARRAYP implies VECTORP,
 151 ;; and test EXTENDED-SEQUENCE-P if three cases are allowed.
 152 ;; Signal a type error for non-sequences.
 153 ;; This is for dispatching within sequence functions that have
 154 ;; the EXPLICIT-CHECK attribute on at least their sequence arg(s).
 155 (eval-when (:compile-toplevel)
 156 (sb!xc:defmacro seq-dispatch-checking
 157     (sequence list-form vector-form &optional (other-form nil other-form-p))
 158   `(cond ((listp ,sequence)
 159           (let ((,sequence (truly-the list ,sequence)))
 160             (declare (ignorable ,sequence))
 161             ,list-form))
 162          ((vectorp ,sequence)
 163           (let ((,sequence (truly-the vector ,sequence)))
 164             (declare (ignorable ,sequence))
 165             ,vector-form))
 166          ,@(cond ((not other-form-p)
 167                   `((t
 168                      (sb!c::%type-check-error
 169                       ,sequence '(or list vector)))))
 170                  (other-form
 171                   `(((extended-sequence-p ,sequence)
 172                      (let ((,sequence (truly-the extended-sequence ,sequence)))
 173                        (declare (ignorable ,sequence))
 174                        ,other-form))
 175                     (t
 176                      (sb!c::%type-check-error/c
 177                       ,sequence 'sb!kernel::object-not-sequence-error)))))))
 178
 179 ;;; Like SEQ-DISPATCH-CHECKING, but also assert that OTHER-FORM produces
 180 ;;; a sequence. This assumes that the containing function declares its
 181 ;;; result to be explicitly checked,
 182 ;;; and that the LIST and VECTOR cases never fail to return a sequence.
 183 (sb!xc:defmacro seq-dispatch-checking=>seq
 184     (sequence list-form vector-form other-form)
 185   `(seq-dispatch-checking ,sequence ,list-form ,vector-form
 186                           (the sequence (values ,other-form)))))
 187
 188 (sb!xc:defmacro %make-sequence-like (sequence length)
 189   #!+sb-doc
 190   "Return a sequence of the same type as SEQUENCE and the given LENGTH."
 191   `(seq-dispatch ,sequence
 192      (make-list ,length)
 193      (make-vector-like ,sequence ,length)
 194      (sb!sequence:make-sequence-like ,sequence ,length)))
 195
 196 (defun bad-sequence-type-error (type-spec)
 197   (declare (optimize allow-non-returning-tail-call))
 198   (error 'simple-type-error
 199          :datum type-spec
 200          :expected-type '(satisfies is-a-valid-sequence-type-specifier-p)
 201          :format-control "~S is a bad type specifier for sequences."
 202          :format-arguments (list type-spec)))
 203
 204 (defun sequence-type-length-mismatch-error (type length)
 205   (declare (optimize allow-non-returning-tail-call))
 206   (error 'simple-type-error
 207          :datum length
 208          :expected-type (cond ((array-type-p type)
 209                                `(eql ,(car (array-type-dimensions type))))
 210                               ((type= type (specifier-type 'null))
 211                                '(eql 0))
 212                               ((cons-type-p type)
 213                                '(integer 1))
 214                               (t (bug "weird type in S-T-L-M-ERROR")))
 215          ;; FIXME: this format control causes ugly printing.  There's
 216          ;; probably some ~<~@:_~> incantation that would make it
 217          ;; nicer. -- CSR, 2002-10-18
 218          :format-control "The length requested (~S) does not match the type restriction in ~S."
 219          :format-arguments (list length (type-specifier type))))
 220
 221 (defun sequence-type-too-hairy (type-spec)
 222   ;; FIXME: Should this be a BUG? I'm inclined to think not; there are
 223   ;; words that give some but not total support to this position in
 224   ;; ANSI.  Essentially, we are justified in throwing this on
 225   ;; e.g. '(OR SIMPLE-VECTOR (VECTOR FIXNUM)), but maybe not (by ANSI)
 226   ;; on '(CONS * (CONS * NULL)) -- CSR, 2002-10-18
 227
 228   ;; On the other hand, I'm not sure it deserves to be a type-error,
 229   ;; either. -- bem, 2005-08-10
 230   (declare (optimize allow-non-returning-tail-call))
 231   (error 'simple-program-error
 232          :format-control "~S is too hairy for sequence functions."
 233          :format-arguments (list type-spec)))
 234
 235 (sb!xc:defmacro when-extended-sequence-type
 236     ((type-specifier type
 237       &key
 238       expandedp
 239       (expanded (gensym "EXPANDED"))
 240       (class (gensym "CLASS"))
 241       (prototype (gensym "PROTOTYPE") prototypep))
 242      &body body)
 243   (once-only ((type-specifier type-specifier) (type type))
 244     `(when (csubtypep ,type (specifier-type 'sequence))
 245        (binding* ((,expanded ,(if expandedp
 246                                   type-specifier
 247                                   `(typexpand ,type-specifier)))
 248                   (,class (if (typep ,expanded 'class)
 249                               ,expanded
 250                               (find-class ,expanded nil))
 251                           :exit-if-null)
 252                   (,prototype (sb!mop:class-prototype
 253                                (sb!pcl:ensure-class-finalized ,class))))
 254          ,@(unless prototypep `((ignore ,prototype)))
 255          ,@body))))
 256
 257 (defun is-a-valid-sequence-type-specifier-p (type)
 258   (let ((type (specifier-type type)))
 259     (or (csubtypep type (specifier-type 'list))
 260         (csubtypep type (specifier-type 'vector)))))
 261
 262 ;;; It's possible with some sequence operations to declare the length
 263 ;;; of a result vector, and to be safe, we really ought to verify that
 264 ;;; the actual result has the declared length.
 265 (defun vector-of-checked-length-given-length (vector declared-length)
 266   (declare (type vector vector))
 267   (declare (type index declared-length))
 268   (let ((actual-length (length vector)))
 269     (unless (= actual-length declared-length)
 270       (error 'simple-type-error
 271              :datum vector
 272              :expected-type `(vector ,declared-length)
 273              :format-control
 274              "Vector length (~W) doesn't match declared length (~W)."
 275              :format-arguments (list actual-length declared-length))))
 276   vector)
 277
 278 (defun sequence-of-checked-length-given-type (sequence result-type)
 279   (let ((ctype (specifier-type result-type)))
 280     (if (not (array-type-p ctype))
 281         sequence
 282         (let ((declared-length (first (array-type-dimensions ctype))))
 283           (if (eq declared-length '*)
 284               sequence
 285               (vector-of-checked-length-given-length sequence
 286                                                      declared-length))))))
 287
 288 (declaim (ftype (function (sequence index) nil) signal-index-too-large-error))
 289 (defun signal-index-too-large-error (sequence index)
 290   (declare (optimize allow-non-returning-tail-call))
 291   (let* ((length (length sequence))
 292          (max-index (and (plusp length)
 293                          (1- length))))
 294     (error 'index-too-large-error
 295            :datum index
 296            :expected-type (if max-index
 297                               `(integer 0 ,max-index)
 298                               ;; This seems silly, is there something better?
 299                               '(integer 0 (0))))))
 300
 301 (declaim (ftype (function (t t t) nil) sequence-bounding-indices-bad-error))
 302 (defun sequence-bounding-indices-bad-error (sequence start end)
 303   (declare (optimize allow-non-returning-tail-call))
 304   (let ((size (length sequence)))
 305     (error 'bounding-indices-bad-error
 306            :datum (cons start end)
 307            :expected-type `(cons (integer 0 ,size)
 308                                  (integer ,start ,size))
 309            :object sequence)))
 310
 311 (declaim (ftype (function (t t t) nil) array-bounding-indices-bad-error))
 312 (defun array-bounding-indices-bad-error (array start end)
 313   (declare (optimize allow-non-returning-tail-call))
 314   (let ((size (array-total-size array)))
 315     (error 'bounding-indices-bad-error
 316            :datum (cons start end)
 317            :expected-type `(cons (integer 0 ,size)
 318                                  (integer ,start ,size))
 319            :object array)))
 320
 321 (declaim (ftype (function (t) nil) circular-list-error))
 322 (defun circular-list-error (list)
 323   (declare (optimize allow-non-returning-tail-call))
 324   (error 'simple-type-error
 325          :format-control "List is circular:~%  ~S"
 326          :format-arguments (list list)
 327          :datum list
 328          :type '(and list (satisfies list-length))))
 329
 330 \f
 331
 332 (defun emptyp (sequence)
 333   #!+sb-doc
 334   "Returns T if SEQUENCE is an empty sequence and NIL
 335    otherwise. Signals an error if SEQUENCE is not a sequence."
 336   (declare (explicit-check sequence))
 337   (seq-dispatch-checking sequence
 338                 (null sequence)
 339                 (zerop (length sequence))
 340                 (sb!sequence:emptyp sequence)))
 341
 342 (defun elt (sequence index)
 343   #!+sb-doc "Return the element of SEQUENCE specified by INDEX."
 344   (declare (explicit-check sequence))
 345   (seq-dispatch-checking sequence
 346                 (do ((count index (1- count))
 347                      (list sequence (cdr list)))
 348                     ((= count 0)
 349                      (if (endp list)
 350                          (signal-index-too-large-error sequence index)
 351                          (car list)))
 352                   (declare (type index count)))
 353                 (progn
 354                   (when (>= index (length sequence))
 355                     (signal-index-too-large-error sequence index))
 356                   (aref sequence index))
 357                 (sb!sequence:elt sequence index)))
 358
 359 (defun %setelt (sequence index newval)
 360   #!+sb-doc "Store NEWVAL as the component of SEQUENCE specified by INDEX."
 361   (declare (explicit-check sequence))
 362   (seq-dispatch-checking sequence
 363                 (do ((count index (1- count))
 364                      (seq sequence))
 365                     ((= count 0) (rplaca seq newval) newval)
 366                   (declare (fixnum count))
 367                   (if (atom (cdr seq))
 368                       (signal-index-too-large-error sequence index)
 369                       (setq seq (cdr seq))))
 370                 (progn
 371                   (when (>= index (length sequence))
 372                     (signal-index-too-large-error sequence index))
 373                   (setf (aref sequence index) newval))
 374                 (setf (sb!sequence:elt sequence index) newval)))
 375
 376 (defun length (sequence)
 377   #!+sb-doc "Return an integer that is the length of SEQUENCE."
 378   (declare (explicit-check))
 379   (seq-dispatch-checking sequence
 380                 (length sequence)
 381                 (length sequence)
 382                 (sb!sequence:length sequence)))
 383
 384 (defun make-sequence (result-type length &key (initial-element nil iep))
 385   #!+sb-doc
 386   "Return a sequence of the given RESULT-TYPE and LENGTH, with
 387   elements initialized to INITIAL-ELEMENT."
 388   (declare (index length) (explicit-check))
 389   (let* ((expanded-type (typexpand result-type))
 390          (adjusted-type
 391           (typecase expanded-type
 392             (atom (cond
 393                     ((eq expanded-type 'string) '(vector character))
 394                     ((eq expanded-type 'simple-string)
 395                      '(simple-array character (*)))
 396                     (t expanded-type)))
 397             (cons (cond
 398                     ((eq (car expanded-type) 'string)
 399                      `(vector character ,@(cdr expanded-type)))
 400                     ((eq (car expanded-type) 'simple-string)
 401                      `(simple-array character ,(if (cdr expanded-type)
 402                                                    (cdr expanded-type)
 403                                                    '(*))))
 404                     (t expanded-type)))))
 405          (type (specifier-type adjusted-type))
 406          (list-type (specifier-type 'list)))
 407     (cond ((csubtypep type list-type)
 408            (cond
 409              ((type= type list-type)
 410               (make-list length :initial-element initial-element))
 411              ((eq type *empty-type*)
 412               (bad-sequence-type-error nil))
 413              ((type= type (specifier-type 'null))
 414               (if (= length 0)
 415                   'nil
 416                   (sequence-type-length-mismatch-error type length)))
 417              ((cons-type-p type)
 418               (multiple-value-bind (min exactp)
 419                   (sb!kernel::cons-type-length-info type)
 420                 (if exactp
 421                     (unless (= length min)
 422                       (sequence-type-length-mismatch-error type length))
 423                     (unless (>= length min)
 424                       (sequence-type-length-mismatch-error type length)))
 425                 (make-list length :initial-element initial-element)))
 426              ;; We'll get here for e.g. (OR NULL (CONS INTEGER *)),
 427              ;; which may seem strange and non-ideal, but then I'd say
 428              ;; it was stranger to feed that type in to MAKE-SEQUENCE.
 429              (t (sequence-type-too-hairy (type-specifier type)))))
 430           ((csubtypep type (specifier-type 'vector))
 431            (cond
 432              (;; is it immediately obvious what the result type is?
 433               (typep type 'array-type)
 434               (aver (= (length (array-type-dimensions type)) 1))
 435               (let* ((etype (type-specifier
 436                              (array-type-specialized-element-type type)))
 437                      (etype (if (eq etype '*) t etype))
 438                      (type-length (car (array-type-dimensions type))))
 439                 (unless (or (eq type-length '*)
 440                             (= type-length length))
 441                   (sequence-type-length-mismatch-error type length))
 442                 (if iep
 443                     (make-array length :element-type etype
 444                                 :initial-element initial-element)
 445                     (make-array length :element-type etype))))
 446              (t (sequence-type-too-hairy (type-specifier type)))))
 447           ((when-extended-sequence-type
 448                (expanded-type type :expandedp t :prototype prototype)
 449              ;; This function has the EXPLICIT-CHECK declaration, so
 450              ;; we manually assert that it returns a SEQUENCE.
 451              (the extended-sequence
 452                   (if iep
 453                       (sb!sequence:make-sequence-like
 454                        prototype length :initial-element initial-element)
 455                       (sb!sequence:make-sequence-like
 456                        prototype length)))))
 457           (t (bad-sequence-type-error (type-specifier type))))))
 458 \f
 459 ;;;; SUBSEQ
 460 ;;;;
 461
 462 (!define-array-dispatch vector-subseq-dispatch (array start end)
 463   (declare (optimize speed (safety 0)))
 464   (declare (type index start end))
 465   (subseq array start end))
 466
 467 ;;;; The support routines for SUBSEQ are used by compiler transforms,
 468 ;;;; so we worry about dealing with END being supplied or defaulting
 469 ;;;; to NIL at this level.
 470
 471 (defun vector-subseq* (sequence start end)
 472   (declare (type vector sequence))
 473   (declare (type index start)
 474            (type (or null index) end)
 475            (optimize speed))
 476   (with-array-data ((data sequence)
 477                     (start start)
 478                     (end end)
 479                     :check-fill-pointer t
 480                     :force-inline t)
 481     (vector-subseq-dispatch data start end)))
 482
 483 (defun list-subseq* (sequence start end)
 484   (declare (type list sequence)
 485            (type unsigned-byte start)
 486            (type (or null unsigned-byte) end))
 487   (flet ((oops ()
 488            (sequence-bounding-indices-bad-error sequence start end)))
 489     (let ((pointer sequence))
 490       (unless (zerop start)
 491         ;; If START > 0 the list cannot be empty. So CDR down to
 492         ;; it START-1 times, check that we still have something, then
 493         ;; CDR the final time.
 494         ;;
 495         ;; If START was zero, the list may be empty if END is NIL or
 496         ;; also zero.
 497         (when (> start 1)
 498           (setf pointer (nthcdr (1- start) pointer)))
 499         (if pointer
 500             (pop pointer)
 501             (oops)))
 502       (if end
 503           (let ((n (- end start)))
 504             (declare (integer n))
 505             (when (minusp n)
 506               (oops))
 507             (when (plusp n)
 508               (let* ((head (list nil))
 509                      (tail head))
 510                 (macrolet ((pop-one ()
 511                              `(let ((tmp (list (pop pointer))))
 512                                 (setf (cdr tail) tmp
 513                                       tail tmp))))
 514                   ;; Bignum case
 515                   (loop until (fixnump n)
 516                         do (pop-one)
 517                            (decf n))
 518                   ;; Fixnum case, but leave last element, so we should
 519                   ;; still have something left in the sequence.
 520                   (let ((m (1- n)))
 521                     (declare (fixnum m))
 522                     (loop repeat m
 523                           do (pop-one)))
 524                   (unless pointer
 525                     (oops))
 526                   ;; OK, pop the last one.
 527                   (pop-one)
 528                   (cdr head)))))
 529             (loop while pointer
 530                   collect (pop pointer))))))
 531
 532 (defun subseq (sequence start &optional end)
 533   #!+sb-doc
 534   "Return a copy of a subsequence of SEQUENCE starting with element number
 535    START and continuing to the end of SEQUENCE or the optional END."
 536   (declare (explicit-check sequence :result))
 537   (seq-dispatch-checking=>seq sequence
 538     (list-subseq* sequence start end)
 539     (vector-subseq* sequence start end)
 540     (sb!sequence:subseq sequence start end)))
 541 \f
 542 ;;;; COPY-SEQ
 543
 544 (defun copy-seq (sequence)
 545   #!+sb-doc "Return a copy of SEQUENCE which is EQUAL to SEQUENCE but not EQ."
 546   (declare (explicit-check sequence :result))
 547   (seq-dispatch-checking sequence
 548     (list-copy-seq* sequence)
 549     (vector-subseq* sequence 0 nil)
 550     ;; Copying an extended sequence has to return an extended-sequence
 551     ;; and not just any SEQUENCE.
 552     (the extended-sequence (values (sb!sequence:copy-seq sequence)))))
 553
 554 (defun list-copy-seq* (sequence)
 555   (!copy-list-macro sequence :check-proper-list t))
 556 \f
 557 ;;;; FILL
 558
 559 (defun list-fill* (sequence item start end)
 560   (declare (type list sequence)
 561            (type unsigned-byte start)
 562            (type (or null unsigned-byte) end))
 563   (flet ((oops ()
 564            (sequence-bounding-indices-bad-error sequence start end)))
 565     (let ((pointer sequence))
 566       (unless (zerop start)
 567         ;; If START > 0 the list cannot be empty. So CDR down to it
 568         ;; START-1 times, check that we still have something, then CDR
 569         ;; the final time.
 570         ;;
 571         ;; If START was zero, the list may be empty if END is NIL or
 572         ;; also zero.
 573         (unless (= start 1)
 574           (setf pointer (nthcdr (1- start) pointer)))
 575         (if pointer
 576             (pop pointer)
 577             (oops)))
 578       (if end
 579           (let ((n (- end start)))
 580             (declare (integer n))
 581             (when (minusp n)
 582               (oops))
 583             (when (plusp n)
 584               (loop repeat n
 585                     do (setf pointer (cdr (rplaca pointer item))))))
 586           (loop while pointer
 587                 do (setf pointer (cdr (rplaca pointer item)))))))
 588   sequence)
 589
 590 (defun vector-fill* (sequence item start end)
 591   (with-array-data ((data sequence)
 592                     (start start)
 593                     (end end)
 594                     :force-inline t
 595                     :check-fill-pointer t)
 596     (let ((setter (!find-data-vector-setter data)))
 597       (declare (optimize (speed 3) (safety 0)))
 598       (do ((index start (1+ index)))
 599           ((= index end) sequence)
 600         (declare (index index))
 601         (funcall setter data index item)))))
 602
 603 (defun string-fill* (sequence item start end)
 604   (declare (string sequence))
 605   (with-array-data ((data sequence)
 606                     (start start)
 607                     (end end)
 608                     :force-inline t
 609                     :check-fill-pointer t)
 610     ;; DEFTRANSFORM for FILL will turn these into
 611     ;; calls to UB*-BASH-FILL.
 612     (etypecase data
 613       #!+sb-unicode
 614       ((simple-array character (*))
 615        (let ((item (locally (declare (optimize (safety 3)))
 616                      (the character item))))
 617          (fill data item :start start :end end)))
 618       ((simple-array base-char (*))
 619        (let ((item (locally (declare (optimize (safety 3)))
 620                      (the base-char item))))
 621          (fill data item :start start :end end))))))
 622
 623 (defun fill (sequence item &key (start 0) end)
 624   #!+sb-doc
 625   "Replace the specified elements of SEQUENCE with ITEM."
 626   (declare (explicit-check sequence :result))
 627   (seq-dispatch-checking=>seq sequence
 628    (list-fill* sequence item start end)
 629    (vector-fill* sequence item start end)
 630    (sb!sequence:fill sequence item
 631                      :start start
 632                      :end (%check-generic-sequence-bounds sequence start end))))
 633 \f
 634 ;;;; REPLACE
 635
 636 (eval-when (:compile-toplevel :execute)
 637
 638 ;;; If we are copying around in the same vector, be careful not to copy the
 639 ;;; same elements over repeatedly. We do this by copying backwards.
 640 (sb!xc:defmacro mumble-replace-from-mumble ()
 641   `(if (and (eq target-sequence source-sequence) (> target-start source-start))
 642        (let ((nelts (min (- target-end target-start)
 643                          (- source-end source-start))))
 644          (do ((target-index (+ (the fixnum target-start) (the fixnum nelts) -1)
 645                             (1- target-index))
 646               (source-index (+ (the fixnum source-start) (the fixnum nelts) -1)
 647                             (1- source-index)))
 648              ((= target-index (the fixnum (1- target-start))) target-sequence)
 649            (declare (fixnum target-index source-index))
 650            ;; disable bounds checking
 651            (declare (optimize (safety 0)))
 652            (setf (aref target-sequence target-index)
 653                  (aref source-sequence source-index))))
 654        (do ((target-index target-start (1+ target-index))
 655             (source-index source-start (1+ source-index)))
 656            ((or (= target-index (the fixnum target-end))
 657                 (= source-index (the fixnum source-end)))
 658             target-sequence)
 659          (declare (fixnum target-index source-index))
 660          ;; disable bounds checking
 661          (declare (optimize (safety 0)))
 662          (setf (aref target-sequence target-index)
 663                (aref source-sequence source-index)))))
 664
 665 (sb!xc:defmacro list-replace-from-list ()
 666   `(if (and (eq target-sequence source-sequence) (> target-start source-start))
 667        (let ((new-elts (subseq source-sequence source-start
 668                                (+ (the fixnum source-start)
 669                                   (the fixnum
 670                                        (min (- (the fixnum target-end)
 671                                                (the fixnum target-start))
 672                                             (- (the fixnum source-end)
 673                                                (the fixnum source-start))))))))
 674          (do ((n new-elts (cdr n))
 675               (o (nthcdr target-start target-sequence) (cdr o)))
 676              ((null n) target-sequence)
 677            (rplaca o (car n))))
 678        (do ((target-index target-start (1+ target-index))
 679             (source-index source-start (1+ source-index))
 680             (target-sequence-ref (nthcdr target-start target-sequence)
 681                                  (cdr target-sequence-ref))
 682             (source-sequence-ref (nthcdr source-start source-sequence)
 683                                  (cdr source-sequence-ref)))
 684            ((or (= target-index (the fixnum target-end))
 685                 (= source-index (the fixnum source-end))
 686                 (null target-sequence-ref) (null source-sequence-ref))
 687             target-sequence)
 688          (declare (fixnum target-index source-index))
 689          (rplaca target-sequence-ref (car source-sequence-ref)))))
 690
 691 (sb!xc:defmacro list-replace-from-mumble ()
 692   `(do ((target-index target-start (1+ target-index))
 693         (source-index source-start (1+ source-index))
 694         (target-sequence-ref (nthcdr target-start target-sequence)
 695                              (cdr target-sequence-ref)))
 696        ((or (= target-index (the fixnum target-end))
 697             (= source-index (the fixnum source-end))
 698             (null target-sequence-ref))
 699         target-sequence)
 700      (declare (fixnum source-index target-index))
 701      (rplaca target-sequence-ref (aref source-sequence source-index))))
 702
 703 (sb!xc:defmacro mumble-replace-from-list ()
 704   `(do ((target-index target-start (1+ target-index))
 705         (source-index source-start (1+ source-index))
 706         (source-sequence (nthcdr source-start source-sequence)
 707                          (cdr source-sequence)))
 708        ((or (= target-index (the fixnum target-end))
 709             (= source-index (the fixnum source-end))
 710             (null source-sequence))
 711         target-sequence)
 712      (declare (fixnum target-index source-index))
 713      (setf (aref target-sequence target-index) (car source-sequence))))
 714
 715 ) ; EVAL-WHEN
 716
 717 ;;;; The support routines for REPLACE are used by compiler transforms, so we
 718 ;;;; worry about dealing with END being supplied or defaulting to NIL
 719 ;;;; at this level.
 720
 721 (defun list-replace-from-list* (target-sequence source-sequence target-start
 722                                 target-end source-start source-end)
 723   (when (null target-end) (setq target-end (length target-sequence)))
 724   (when (null source-end) (setq source-end (length source-sequence)))
 725   (list-replace-from-list))
 726
 727 (defun list-replace-from-vector* (target-sequence source-sequence target-start
 728                                   target-end source-start source-end)
 729   (when (null target-end) (setq target-end (length target-sequence)))
 730   (when (null source-end) (setq source-end (length source-sequence)))
 731   (list-replace-from-mumble))
 732
 733 (defun vector-replace-from-list* (target-sequence source-sequence target-start
 734                                   target-end source-start source-end)
 735   (when (null target-end) (setq target-end (length target-sequence)))
 736   (when (null source-end) (setq source-end (length source-sequence)))
 737   (mumble-replace-from-list))
 738
 739 (defun vector-replace-from-vector* (target-sequence source-sequence
 740                                     target-start target-end source-start
 741                                     source-end)
 742   (when (null target-end) (setq target-end (length target-sequence)))
 743   (when (null source-end) (setq source-end (length source-sequence)))
 744   (mumble-replace-from-mumble))
 745
 746 #!+sb-unicode
 747 (defun simple-character-string-replace-from-simple-character-string*
 748     (target-sequence source-sequence
 749      target-start target-end source-start source-end)
 750   (declare (type (simple-array character (*)) target-sequence source-sequence))
 751   (when (null target-end) (setq target-end (length target-sequence)))
 752   (when (null source-end) (setq source-end (length source-sequence)))
 753   (mumble-replace-from-mumble))
 754
 755 (define-sequence-traverser replace
 756     (sequence1 sequence2 &rest args &key start1 end1 start2 end2)
 757   #!+sb-doc
 758   "Destructively modifies SEQUENCE1 by copying successive elements
 759 into it from the SEQUENCE2.
 760
 761 Elements are copied to the subseqeuence bounded by START1 and END1,
 762 from the subsequence bounded by START2 and END2. If these subsequences
 763 are not of the same length, then the shorter length determines how
 764 many elements are copied."
 765   (declare (truly-dynamic-extent args))
 766   (declare (explicit-check sequence1 sequence2 :result))
 767   (let* (;; KLUDGE: absent either rewriting FOO-REPLACE-FROM-BAR, or
 768          ;; excessively polluting DEFINE-SEQUENCE-TRAVERSER, we rebind
 769          ;; these things here so that legacy code gets the names it's
 770          ;; expecting.  We could use &AUX instead :-/.
 771          (target-sequence sequence1)
 772          (source-sequence sequence2)
 773          (target-start start1)
 774          (source-start start2)
 775          (target-end (or end1 length1))
 776          (source-end (or end2 length2)))
 777     (seq-dispatch-checking target-sequence
 778       (seq-dispatch-checking source-sequence
 779         (return-from replace (list-replace-from-list))
 780         (return-from replace (list-replace-from-mumble))
 781         nil)
 782       (seq-dispatch-checking source-sequence
 783         (return-from replace (mumble-replace-from-list))
 784         (return-from replace (mumble-replace-from-mumble))
 785         nil)
 786       t)
 787     ;; If sequence1 is an extended-sequence, we know nothing about sequence2.
 788     ;; If sequence1 was a list or vector, then sequence2 is an extended-sequence
 789     ;; or not a sequence. Either way, check it.
 790     (the sequence
 791       (values (apply #'sb!sequence:replace sequence1
 792                      (the sequence sequence2) args)))))
 793 \f
 794 ;;;; REVERSE
 795 (defun reverse (sequence)
 796   #!+sb-doc
 797   "Return a new sequence containing the same elements but in reverse order."
 798   (declare (explicit-check))
 799   (seq-dispatch-checking sequence
 800     (list-reverse sequence)
 801     (vector-reverse sequence)
 802     ;; The type deriver says that LIST => LIST and VECTOR => VECTOR
 803     ;; but does not claim to know anything about extended-sequences.
 804     ;; So this could theoretically return any subtype of SEQUENCE
 805     ;; given an EXTENDED-SEQUENCE as input. But fndb says this returns
 806     ;; a CONSED-SEQUENCE, which precludes non-simple vectors.
 807     ;; But a CLOS sequence can apparently decide to return a LIST when
 808     ;; reversed. [Is that too weird? Make this EXTENDED-SEQUENCE maybe?]
 809     (the consed-sequence (values (sb!sequence:reverse sequence)))))
 810
 811 (defun list-reverse (list)
 812   (do ((new-list ()))
 813       ((endp list) new-list)
 814     (push (pop list) new-list)))
 815
 816 (defmacro word-specialized-vector-tag-p (tag)
 817   `(or
 818     ,@(loop for saetp across sb!vm:*specialized-array-element-type-properties*
 819            when (and (eq (sb!vm:saetp-n-bits saetp) sb!vm:n-word-bits)
 820                      (not (eq (sb!vm:saetp-specifier saetp) t)))
 821            collect `(eq ,tag ,(sb!vm:saetp-typecode saetp)))))
 822
 823 (defun reverse-word-specialized-vector (from to end)
 824   (declare (vector from))
 825   (do ((length (length to))
 826        (left-index 0 (1+ left-index))
 827        (right-index end))
 828       ((= left-index length))
 829     (declare (type index left-index right-index))
 830     (decf right-index)
 831     (setf (%vector-raw-bits to left-index)
 832           (%vector-raw-bits from right-index)))
 833   to)
 834
 835 (defun vector-reverse (vector)
 836   (declare (vector vector))
 837   (let ((length (length vector)))
 838     (with-array-data ((vector vector) (start) (end)
 839                       :check-fill-pointer t)
 840       (declare (ignore start))
 841       (let* ((tag (%other-pointer-widetag vector))
 842              (new-vector (allocate-vector-with-widetag tag length)))
 843         (cond ((= tag sb!vm:simple-vector-widetag)
 844                (do ((left-index 0 (1+ left-index))
 845                     (right-index end))
 846                    ((= left-index length))
 847                  (declare (type index left-index right-index))
 848                  (decf right-index)
 849                  (setf (svref new-vector left-index)
 850                        (svref vector right-index))))
 851               ((word-specialized-vector-tag-p tag)
 852                (reverse-word-specialized-vector vector new-vector end))
 853               (t
 854                (let ((getter (the function (svref %%data-vector-reffers%% tag)))
 855                      (setter (the function (svref %%data-vector-setters%% tag))))
 856                  (declare (fixnum length))
 857                  (do ((forward-index 0 (1+ forward-index))
 858                       (backward-index (1- end) (1- backward-index)))
 859                      ((= forward-index length))
 860                    (declare (fixnum forward-index backward-index))
 861                    (funcall setter new-vector forward-index
 862                             (funcall getter vector backward-index))))))
 863         new-vector))))
 864 \f
 865 ;;;; NREVERSE
 866
 867 (defun list-nreverse (list)
 868   (do ((1st (cdr list) (if (endp 1st) 1st (cdr 1st)))
 869        (2nd list 1st)
 870        (3rd '() 2nd))
 871       ((atom 2nd) 3rd)
 872     (rplacd 2nd 3rd)))
 873
 874 (defun nreverse-word-specialized-vector (vector start end)
 875   (do ((left-index start (1+ left-index))
 876        (right-index (1- end) (1- right-index)))
 877       ((<= right-index left-index))
 878     (declare (type index left-index right-index))
 879     (let ((left (%vector-raw-bits vector left-index))
 880           (right (%vector-raw-bits vector right-index)))
 881       (setf (%vector-raw-bits vector left-index) right
 882             (%vector-raw-bits vector right-index) left)))
 883   vector)
 884
 885 (defun vector-nreverse (vector)
 886   (declare (vector vector))
 887   (when (> (length vector) 1)
 888     (with-array-data ((vector vector) (start) (end)
 889                       :check-fill-pointer t)
 890       (let ((tag (%other-pointer-widetag vector)))
 891         (cond ((= tag sb!vm:simple-vector-widetag)
 892                (do ((left-index start (1+ left-index))
 893                     (right-index (1- end) (1- right-index)))
 894                    ((<= right-index left-index))
 895                  (declare (type index left-index right-index))
 896                  (let ((left (svref vector left-index))
 897                        (right (svref vector right-index)))
 898                    (setf (svref vector left-index) right
 899                          (svref vector right-index) left))))
 900               ((word-specialized-vector-tag-p tag)
 901                (nreverse-word-specialized-vector vector start end))
 902               (t
 903                (let* ((getter (the function (svref %%data-vector-reffers%% tag)))
 904                       (setter (the function (svref %%data-vector-setters%% tag))))
 905                  (do ((left-index start (1+ left-index))
 906                       (right-index (1- end) (1- right-index)))
 907                      ((<= right-index left-index))
 908                    (declare (type index left-index right-index))
 909                    (let ((left (funcall getter vector left-index))
 910                          (right (funcall getter vector right-index)))
 911                      (funcall setter vector left-index right)
 912                      (funcall setter vector right-index left)))))))))
 913   vector)
 914
 915 (defun nreverse (sequence)
 916   #!+sb-doc
 917   "Return a sequence of the same elements in reverse order; the argument
 918    is destroyed."
 919   (declare (explicit-check))
 920   (seq-dispatch-checking sequence
 921     (list-nreverse sequence)
 922     (vector-nreverse sequence)
 923     ;; The type deriver for this is 'result-type-first-arg',
 924     ;; meaning it should return definitely an EXTENDED-SEQUENCE
 925     ;; and not a list or vector.
 926     (the extended-sequence (values (sb!sequence:nreverse sequence)))))
 927 \f
 928
 929 (defmacro sb!sequence:dosequence ((element sequence &optional return) &body body)
 930   #!+sb-doc
 931   "Executes BODY with ELEMENT subsequently bound to each element of
 932   SEQUENCE, then returns RETURN."
 933   (multiple-value-bind (forms decls) (parse-body body nil)
 934     (once-only ((sequence sequence))
 935       (with-unique-names (state limit from-end step endp elt)
 936         `(block nil
 937            (seq-dispatch ,sequence
 938              (dolist (,element ,sequence ,return) ,@body)
 939              (do-vector-data (,element ,sequence ,return) ,@body)
 940              (multiple-value-bind (,state ,limit ,from-end ,step ,endp ,elt)
 941                  (sb!sequence:make-sequence-iterator ,sequence)
 942                (declare (function ,step ,endp ,elt))
 943                (do ((,state ,state (funcall ,step ,sequence ,state ,from-end)))
 944                    ((funcall ,endp ,sequence ,state ,limit ,from-end)
 945                     (let ((,element nil))
 946                       ,@(filter-dolist-declarations decls)
 947                       (declare (ignorable ,element))
 948                       ,return))
 949                  (let ((,element (funcall ,elt ,sequence ,state)))
 950                    ,@decls
 951                    (tagbody
 952                       ,@forms))))))))))
 953
 954 \f
 955 ;;;; CONCATENATE
 956
 957 (defun concatenate (result-type &rest sequences)
 958   #!+sb-doc
 959   "Return a new sequence of all the argument sequences concatenated together
 960   which shares no structure with the original argument sequences of the
 961   specified RESULT-TYPE."
 962   (declare (explicit-check)
 963            (dynamic-extent sequences))
 964   (flet ((concat-to-simple* (type-spec sequences)
 965            (do ((seqs sequences (cdr seqs))
 966                 (total-length 0)
 967                 (lengths ()))
 968                ((null seqs)
 969                 (do ((sequences sequences (cdr sequences))
 970                      (lengths lengths (cdr lengths))
 971                      (index 0)
 972                      (result (make-sequence type-spec total-length)))
 973                     ((= index total-length) result)
 974                   (declare (fixnum index))
 975                   (let ((sequence (car sequences)))
 976                     (sb!sequence:dosequence (e sequence)
 977                       (setf (aref result index) e)
 978                       (incf index)))))
 979              (let ((length (length (car seqs))))
 980                (declare (fixnum length))
 981                (setq lengths (nconc lengths (list length)))
 982                (setq total-length (+ total-length length))))))
 983     (case result-type
 984       ;; Pick up some common cases first
 985       (list
 986        (apply #'%concatenate-to-list sequences))
 987       ((vector simple-vector)
 988        (apply #'%concatenate-to-simple-vector sequences))
 989       #!+sb-unicode
 990       ((string simple-string)
 991        (apply #'%concatenate-to-string sequences))
 992       ((simple-base-string #!-sb-unicode string #!-sb-unicode simple-string)
 993        (apply #'%concatenate-to-base-string sequences))
 994       (t
 995        (let ((type (specifier-type result-type)))
 996          (cond
 997            ((csubtypep type (specifier-type 'list))
 998             (cond
 999               ((type= type (specifier-type 'list))
1000                (apply #'%concatenate-to-list sequences))
1001               ((eq type *empty-type*)
1002                (bad-sequence-type-error nil))
1003               ((type= type (specifier-type 'null))
1004                (unless (every #'emptyp sequences)
1005                  (sequence-type-length-mismatch-error
1006                   type (reduce #'+ sequences :key #'length))) ; FIXME: circular list issues.
1007                '())
1008               ((cons-type-p type)
1009                (multiple-value-bind (min exactp)
1010                    (sb!kernel::cons-type-length-info type)
1011                  (let ((length (reduce #'+ sequences :key #'length)))
1012                    (if exactp
1013                        (unless (= length min)
1014                          (sequence-type-length-mismatch-error type length))
1015                        (unless (>= length min)
1016                          (sequence-type-length-mismatch-error type length)))
1017                    (apply #'%concatenate-to-list sequences))))
1018               (t (sequence-type-too-hairy (type-specifier type)))))
1019            ((csubtypep type (specifier-type 'vector))
1020             (concat-to-simple* result-type sequences))
1021            ((when-extended-sequence-type
1022                 (result-type type :expandedp nil :prototype prototype)
1023               ;; This function has the EXPLICIT-CHECK declaration,
1024               ;; so we manually assert that it returns a SEQUENCE.
1025               (the extended-sequence
1026                    (apply #'sb!sequence:concatenate prototype sequences))))
1027            (t
1028             (bad-sequence-type-error result-type))))))))
1029
1030 ;;; Efficient out-of-line concatenate for strings. Compiler transforms
1031 ;;; CONCATENATE 'STRING &co into these.
1032 (macrolet ((def (name element-type &rest dispatch)
1033              `(defun ,name (&rest sequences)
1034                 (declare (explicit-check)
1035                          (optimize (sb!c::insert-array-bounds-checks 0)))
1036                 (let ((length 0))
1037                   (declare (index length))
1038                   (do-rest-arg ((seq) sequences)
1039                     (incf length (length seq)))
1040                   (let ((result (make-array length :element-type ',element-type))
1041                         (start 0))
1042                     (declare (index start))
1043                     (do-rest-arg ((seq) sequences)
1044                       (string-dispatch (,@dispatch t)
1045                                        seq
1046                         (let ((length (length seq)))
1047                           (replace result seq :start1 start)
1048                           (incf start length))))
1049                     result)))))
1050   #!+sb-unicode
1051   (def %concatenate-to-string character
1052     (simple-array character (*)) (simple-array base-char (*)))
1053   (def %concatenate-to-base-string base-char
1054     (simple-array base-char (*)) #!+sb-unicode (simple-array character (*)))
1055   (def %concatenate-to-simple-vector t simple-vector))
1056
1057 (defun %concatenate-to-list (&rest sequences)
1058   (declare (explicit-check))
1059   (let* ((result (list nil))
1060          (splice result))
1061     (do-rest-arg ((sequence) sequences)
1062       (sb!sequence:dosequence (e sequence)
1063         (setf splice (cdr (rplacd splice (list e))))))
1064     (cdr result)))
1065
1066 (defun %concatenate-to-vector (widetag &rest sequences)
1067   (declare (explicit-check))
1068   (let ((length 0))
1069     (declare (index length))
1070     (do-rest-arg ((seq) sequences)
1071       (incf length (length seq)))
1072     (let ((result (allocate-vector-with-widetag widetag length))
1073           (setter (the function (svref %%data-vector-setters%% widetag)))
1074           (index 0))
1075       (declare (index index))
1076       (do-rest-arg ((seq) sequences)
1077         (sb!sequence:dosequence (e seq)
1078           (funcall setter result index e)
1079           (incf index)))
1080       result)))
1081 \f
1082 ;;;; MAP
1083
1084 ;;; helper functions to handle arity-1 subcases of MAP
1085 (defun %map-to-list-arity-1 (fun sequence)
1086   (declare (explicit-check))
1087   (let ((reversed-result nil)
1088         (really-fun (%coerce-callable-to-fun fun)))
1089     (sb!sequence:dosequence (element sequence)
1090       (push (funcall really-fun element)
1091             reversed-result))
1092     (nreverse reversed-result)))
1093 (defun %map-to-simple-vector-arity-1 (fun sequence)
1094   (declare (explicit-check))
1095   (let ((result (make-array (length sequence)))
1096         (index 0)
1097         (really-fun (%coerce-callable-to-fun fun)))
1098     (declare (type index index))
1099     (sb!sequence:dosequence (element sequence)
1100       (setf (aref result index)
1101             (funcall really-fun element))
1102       (incf index))
1103     result))
1104 (defun %map-for-effect-arity-1 (fun sequence)
1105   (declare (explicit-check))
1106   (let ((really-fun (%coerce-callable-to-fun fun)))
1107     (sb!sequence:dosequence (element sequence)
1108       (funcall really-fun element)))
1109   nil)
1110
1111 (declaim (maybe-inline %map-for-effect))
1112 (defun %map-for-effect (fun sequences)
1113   (declare (type function fun) (type list sequences))
1114   (let ((%sequences sequences)
1115         (%iters (mapcar (lambda (s)
1116                           (seq-dispatch s
1117                             s
1118                             0
1119                             (multiple-value-list
1120                              (sb!sequence:make-sequence-iterator s))))
1121                         sequences))
1122         (%apply-args (make-list (length sequences))))
1123     ;; this is almost efficient (except in the general case where we
1124     ;; trampoline to MAKE-SEQUENCE-ITERATOR; if we had DX allocation
1125     ;; of MAKE-LIST, the whole of %MAP would be cons-free.
1126     ;; TODO: on x86-64, we do have. Now see if the above remark is true.
1127     (declare (type list %sequences %iters %apply-args))
1128     (loop
1129      (do ((in-sequences  %sequences  (cdr in-sequences))
1130           (in-iters      %iters      (cdr in-iters))
1131           (in-apply-args %apply-args (cdr in-apply-args)))
1132          ((null in-sequences) (apply fun %apply-args))
1133        (let ((i (car in-iters)))
1134          (declare (type (or list index) i))
1135          (cond
1136            ((listp (car in-sequences))
1137             (if (null i)
1138                 (return-from %map-for-effect nil)
1139                 (setf (car in-apply-args) (car i)
1140                       (car in-iters) (cdr i))))
1141            ((typep i 'index)
1142             (let ((v (the vector (car in-sequences))))
1143               (if (>= i (length v))
1144                   (return-from %map-for-effect nil)
1145                   (setf (car in-apply-args) (aref v i)
1146                         (car in-iters) (1+ i)))))
1147            (t
1148             ;; While on one hand this could benefit from a zero-safety ds-bind,
1149             ;; on the other, why not coerce these tuples to vectors or structs?
1150             (destructuring-bind (state limit from-end step endp elt &rest ignore)
1151                 i
1152               (declare (type function step endp elt)
1153                        (ignore ignore))
1154               (let ((s (car in-sequences)))
1155                 (if (funcall endp s state limit from-end)
1156                     (return-from %map-for-effect nil)
1157                     (progn
1158                       (setf (car in-apply-args) (funcall elt s state))
1159                       (setf (caar in-iters) (funcall step s state from-end)))))))))))))
1160 (defun %map-to-list (fun sequences)
1161   (declare (type function fun)
1162            (type list sequences))
1163   (let ((result nil))
1164     (flet ((f (&rest args)
1165              (declare (truly-dynamic-extent args))
1166              (push (apply fun args) result)))
1167       (declare (truly-dynamic-extent #'f))
1168       (%map-for-effect #'f sequences))
1169     (nreverse result)))
1170 (defun %map-to-vector (output-type-spec fun sequences)
1171   (declare (type function fun)
1172            (type list sequences))
1173   (let ((min-len 0))
1174     (flet ((f (&rest args)
1175              (declare (truly-dynamic-extent args))
1176              (declare (ignore args))
1177              (incf min-len)))
1178       (declare (truly-dynamic-extent #'f))
1179       (%map-for-effect #'f sequences))
1180     (let ((result (make-sequence output-type-spec min-len))
1181           (i 0))
1182       (declare (type (simple-array * (*)) result))
1183       (flet ((f (&rest args)
1184                (declare (truly-dynamic-extent args))
1185                (setf (aref result i) (apply fun args))
1186                (incf i)))
1187         (declare (truly-dynamic-extent #'f))
1188         (%map-for-effect #'f sequences))
1189       result)))
1190
1191 ;;; %MAP is just MAP without the final just-to-be-sure check that
1192 ;;; length of the output sequence matches any length specified
1193 ;;; in RESULT-TYPE.
1194 (defun %map (result-type function &rest sequences)
1195   (declare (explicit-check))
1196   (declare (dynamic-extent sequences))
1197   ;; Everything that we end up calling uses %COERCE-TO-CALLABLE
1198   ;; on FUNCTION so we don't need to declare it of type CALLABLE here.
1199   ;; Additionally all the arity-1 mappers use SEQ-DISPATCH which asserts
1200   ;; that the input is a SEQUENCE. Despite SEQ-DISPATCH being "less safe"
1201   ;; than SEQ-DISPATCH-CHECKING, both are in fact equally safe, because
1202   ;; the ARRAY case (which assumes that all arrays are vectors) utilizes
1203   ;; %WITH-ARRAY-DATA/FP which asserts that its input is a vector.
1204   (labels ((slower-map (type)
1205              (let ((really-fun (%coerce-callable-to-fun function)))
1206                (cond
1207                  ((eq type *empty-type*)
1208                   (%map-for-effect really-fun sequences))
1209                  ((csubtypep type (specifier-type 'list))
1210                   (%map-to-list really-fun sequences))
1211                  ((csubtypep type (specifier-type 'vector))
1212                   (%map-to-vector result-type really-fun sequences))
1213                  ((when-extended-sequence-type
1214                       (result-type type :expandedp nil :prototype prototype)
1215                     ;; This function has the EXPLICIT-CHECK
1216                     ;; declaration, so we manually assert that it
1217                     ;; returns a SEQUENCE.
1218                     (the extended-sequence
1219                          (apply #'sb!sequence:map
1220                                 prototype really-fun sequences))))
1221                  (t
1222                   (bad-sequence-type-error result-type))))))
1223     ;; Handle some easy cases faster
1224     (if (/= (length sequences) 1)
1225         (slower-map (specifier-type result-type))
1226         (let ((first-sequence (fast-&rest-nth 0 sequences)))
1227           (case result-type
1228            ((nil)
1229             (%map-for-effect-arity-1 function first-sequence))
1230            ((list cons)
1231             (%map-to-list-arity-1 function first-sequence))
1232            ((vector simple-vector)
1233             (%map-to-simple-vector-arity-1 function first-sequence))
1234            (t
1235             (let ((type (specifier-type result-type)))
1236               (cond ((eq type *empty-type*)
1237                      (%map-for-effect-arity-1 function first-sequence))
1238                     ((csubtypep type (specifier-type 'list))
1239                      (%map-to-list-arity-1 function first-sequence))
1240                     ((csubtypep type (specifier-type '(vector t)))
1241                      (%map-to-simple-vector-arity-1 function first-sequence))
1242                     (t
1243                      (slower-map type))))))))))
1244
1245 (defun map (result-type function first-sequence &rest more-sequences)
1246   (declare (explicit-check))
1247   (let ((result
1248          (apply #'%map result-type function first-sequence more-sequences)))
1249     (if (or (eq result-type 'nil) (typep result result-type))
1250         result
1251         (error 'simple-type-error
1252                :format-control "MAP result ~S is not a sequence of type ~S"
1253                :datum result
1254                :expected-type result-type
1255                :format-arguments (list result result-type)))))
1256
1257 ;;;; MAP-INTO
1258
1259 (defmacro map-into-lambda (sequences params &body body)
1260   (check-type sequences symbol)
1261   `(flet ((f ,params ,@body))
1262      (declare (truly-dynamic-extent #'f))
1263      ;; Note (MAP-INTO SEQ (LAMBDA () ...)) is a different animal,
1264      ;; hence the awkward flip between MAP and LOOP.
1265      (if ,sequences
1266          (apply #'%map nil #'f ,sequences)
1267          (loop (f)))))
1268
1269 (!define-array-dispatch vector-map-into (data start end fun sequences)
1270   (declare (type index start end)
1271            (type function fun)
1272            (type list sequences))
1273   (declare (explicit-check))
1274   (let ((index start))
1275     (declare (type index index))
1276     (block mapping
1277       (map-into-lambda sequences (&rest args)
1278         (declare (truly-dynamic-extent args))
1279         (when (eql index end)
1280           (return-from mapping))
1281         (setf (aref data index) (apply fun args))
1282         (incf index)))
1283     index))
1284
1285 ;;; Uses the machinery of (MAP NIL ...). For non-vectors we avoid
1286 ;;; computing the length of the result sequence since we can detect
1287 ;;; the end during mapping (if MAP even gets that far).
1288 ;;;
1289 ;;; For each result type, define a mapping function which is
1290 ;;; responsible for replacing RESULT-SEQUENCE elements and for
1291 ;;; terminating itself if the end of RESULT-SEQUENCE is reached.
1292 ;;; The mapping function is defined with MAP-INTO-LAMBDA.
1293 ;;;
1294 ;;; MAP-INTO-LAMBDAs are optimized since they are the inner loops.
1295 ;;; Because we are manually doing bounds checking with known types,
1296 ;;; safety is turned off for vectors and lists but kept for generic
1297 ;;; sequences.
1298 (defun map-into (result-sequence function &rest sequences)
1299   (declare (optimize (sb!c::check-tag-existence 0)))
1300   (let ((really-fun (%coerce-callable-to-fun function)))
1301     (etypecase result-sequence
1302       (vector
1303        (with-array-data ((data result-sequence) (start) (end)
1304                          ;; MAP-INTO ignores fill pointer when mapping
1305                          :check-fill-pointer nil)
1306          (let ((new-end (vector-map-into data start end really-fun sequences)))
1307            (when (array-has-fill-pointer-p result-sequence)
1308              (setf (fill-pointer result-sequence) (- new-end start))))))
1309       (list
1310        (let ((node result-sequence))
1311          (declare (type list node))
1312          (map-into-lambda sequences (&rest args)
1313            (declare (truly-dynamic-extent args))
1314            (cond ((null node)
1315                   (return-from map-into result-sequence))
1316                  ((not (listp (cdr node)))
1317                   (error 'simple-type-error
1318                          :format-control "~a is not a proper list"
1319                          :format-arguments (list result-sequence)
1320                          :expected-type 'list
1321                          :datum result-sequence)))
1322            (setf (car node) (apply really-fun args))
1323            (setf node (cdr node)))))
1324       (sequence
1325        (multiple-value-bind (iter limit from-end)
1326            (sb!sequence:make-sequence-iterator result-sequence)
1327          (map-into-lambda sequences (&rest args)
1328            (declare (truly-dynamic-extent args) (optimize speed))
1329            (when (sb!sequence:iterator-endp result-sequence
1330                                             iter limit from-end)
1331              (return-from map-into result-sequence))
1332            (setf (sb!sequence:iterator-element result-sequence iter)
1333                  (apply really-fun args))
1334            (setf iter (sb!sequence:iterator-step result-sequence
1335                                                            iter from-end)))))))
1336   result-sequence)
1337 \f
1338 ;;;; REDUCE
1339
1340 (eval-when (:compile-toplevel :execute)
1341
1342 (sb!xc:defmacro mumble-reduce (function
1343                                sequence
1344                                key
1345                                start
1346                                end
1347                                initial-value
1348                                ref)
1349   `(do ((index ,start (1+ index))
1350         (value ,initial-value))
1351        ((>= index ,end) value)
1352      (setq value (funcall ,function value
1353                           (apply-key ,key (,ref ,sequence index))))))
1354
1355 (sb!xc:defmacro mumble-reduce-from-end (function
1356                                         sequence
1357                                         key
1358                                         start
1359                                         end
1360                                         initial-value
1361                                         ref)
1362   `(do ((index (1- ,end) (1- index))
1363         (value ,initial-value)
1364         (terminus (1- ,start)))
1365        ((<= index terminus) value)
1366      (setq value (funcall ,function
1367                           (apply-key ,key (,ref ,sequence index))
1368                           value))))
1369
1370 (sb!xc:defmacro list-reduce (function
1371                              sequence
1372                              key
1373                              start
1374                              end
1375                              initial-value
1376                              ivp)
1377   `(let ((sequence (nthcdr ,start ,sequence)))
1378      (do ((count (if ,ivp ,start (1+ ,start))
1379                  (1+ count))
1380           (sequence (if ,ivp sequence (cdr sequence))
1381                     (cdr sequence))
1382           (value (if ,ivp ,initial-value (apply-key ,key (car sequence)))
1383                  (funcall ,function value (apply-key ,key (car sequence)))))
1384          ((>= count ,end) value))))
1385
1386 (sb!xc:defmacro list-reduce-from-end (function
1387                                       sequence
1388                                       key
1389                                       start
1390                                       end
1391                                       initial-value
1392                                       ivp)
1393   `(let ((sequence (nthcdr (- (length ,sequence) ,end)
1394                            (reverse ,sequence))))
1395      (do ((count (if ,ivp ,start (1+ ,start))
1396                  (1+ count))
1397           (sequence (if ,ivp sequence (cdr sequence))
1398                     (cdr sequence))
1399           (value (if ,ivp ,initial-value (apply-key ,key (car sequence)))
1400                  (funcall ,function (apply-key ,key (car sequence)) value)))
1401          ((>= count ,end) value))))
1402
1403 ) ; EVAL-WHEN
1404
1405 (define-sequence-traverser reduce (function sequence &rest args &key key
1406                                    from-end start end (initial-value nil ivp))
1407   (declare (type index start)
1408            (truly-dynamic-extent args))
1409   (declare (explicit-check sequence))
1410   (seq-dispatch-checking sequence
1411     (let ((end (or end length)))
1412       (declare (type index end))
1413       (if (= end start)
1414           (if ivp initial-value (funcall function))
1415           (if from-end
1416               (list-reduce-from-end function sequence key start end
1417                                     initial-value ivp)
1418               (list-reduce function sequence key start end
1419                            initial-value ivp))))
1420     (let ((end (or end length)))
1421       (declare (type index end))
1422       (if (= end start)
1423           (if ivp initial-value (funcall function))
1424           (if from-end
1425               (progn
1426                 (when (not ivp)
1427                   (setq end (1- (the fixnum end)))
1428                   (setq initial-value (apply-key key (aref sequence end))))
1429                 (mumble-reduce-from-end function sequence key start end
1430                                         initial-value aref))
1431               (progn
1432                 (when (not ivp)
1433                   (setq initial-value (apply-key key (aref sequence start)))
1434                   (setq start (1+ start)))
1435                 (mumble-reduce function sequence key start end
1436                                initial-value aref)))))
1437     (apply #'sb!sequence:reduce function sequence args)))
1438 \f
1439 ;;;; DELETE
1440
1441 (eval-when (:compile-toplevel :execute)
1442
1443 (sb!xc:defmacro mumble-delete (pred)
1444   `(do ((index start (1+ index))
1445         (jndex start)
1446         (number-zapped 0))
1447        ((or (= index (the fixnum end)) (= number-zapped count))
1448         (do ((index index (1+ index))           ; Copy the rest of the vector.
1449              (jndex jndex (1+ jndex)))
1450             ((= index (the fixnum length))
1451              (shrink-vector sequence jndex))
1452           (declare (fixnum index jndex))
1453           (setf (aref sequence jndex) (aref sequence index))))
1454      (declare (fixnum index jndex number-zapped))
1455      (setf (aref sequence jndex) (aref sequence index))
1456      (if ,pred
1457          (incf number-zapped)
1458          (incf jndex))))
1459
1460 (sb!xc:defmacro mumble-delete-from-end (pred)
1461   `(do ((index (1- (the fixnum end)) (1- index)) ; Find the losers.
1462         (number-zapped 0)
1463         (losers ())
1464         this-element
1465         (terminus (1- start)))
1466        ((or (= index terminus) (= number-zapped count))
1467         (do ((losers losers)                     ; Delete the losers.
1468              (index start (1+ index))
1469              (jndex start))
1470             ((or (null losers) (= index (the fixnum end)))
1471              (do ((index index (1+ index))       ; Copy the rest of the vector.
1472                   (jndex jndex (1+ jndex)))
1473                  ((= index (the fixnum length))
1474                   (shrink-vector sequence jndex))
1475                (declare (fixnum index jndex))
1476                (setf (aref sequence jndex) (aref sequence index))))
1477           (declare (fixnum index jndex))
1478           (setf (aref sequence jndex) (aref sequence index))
1479           (if (= index (the fixnum (car losers)))
1480               (pop losers)
1481               (incf jndex))))
1482      (declare (fixnum index number-zapped terminus))
1483      (setq this-element (aref sequence index))
1484      (when ,pred
1485        (incf number-zapped)
1486        (push index losers))))
1487
1488 (sb!xc:defmacro normal-mumble-delete ()
1489   `(mumble-delete
1490     (if test-not
1491         (not (funcall test-not item (apply-key key (aref sequence index))))
1492         (funcall test item (apply-key key (aref sequence index))))))
1493
1494 (sb!xc:defmacro normal-mumble-delete-from-end ()
1495   `(mumble-delete-from-end
1496     (if test-not
1497         (not (funcall test-not item (apply-key key this-element)))
1498         (funcall test item (apply-key key this-element)))))
1499
1500 (sb!xc:defmacro list-delete (pred)
1501   `(let ((handle (cons nil sequence)))
1502      (declare (truly-dynamic-extent handle))
1503      (do* ((previous (nthcdr start handle))
1504            (current (cdr previous) (cdr current))
1505            (index start (1+ index))
1506            (number-zapped 0))
1507           ((or (= index end) (= number-zapped count))
1508            (cdr handle))
1509        (declare (index index number-zapped))
1510        (cond (,pred
1511               (rplacd previous (cdr current))
1512               (incf number-zapped))
1513              (t
1514               (pop previous))))))
1515
1516 (sb!xc:defmacro list-delete-from-end (pred)
1517   `(let* ((reverse (nreverse sequence))
1518           (handle (cons nil reverse)))
1519      (declare (truly-dynamic-extent handle))
1520      (do* ((previous (nthcdr (- length end) handle))
1521            (current (cdr previous) (cdr current))
1522            (index start (1+ index))
1523            (number-zapped 0))
1524           ((or (= index end) (= number-zapped count))
1525            (nreverse (cdr handle)))
1526        (declare (index index number-zapped))
1527        (cond (,pred
1528               (rplacd previous (cdr current))
1529               (incf number-zapped))
1530              (t
1531               (pop previous))))))
1532
1533 (sb!xc:defmacro normal-list-delete ()
1534   '(list-delete
1535     (if test-not
1536         (not (funcall test-not item (apply-key key (car current))))
1537         (funcall test item (apply-key key (car current))))))
1538
1539 (sb!xc:defmacro normal-list-delete-from-end ()
1540   '(list-delete-from-end
1541     (if test-not
1542         (not (funcall test-not item (apply-key key (car current))))
1543         (funcall test item (apply-key key (car current))))))
1544
1545 ) ; EVAL-WHEN
1546
1547 (define-sequence-traverser delete
1548     (item sequence &rest args &key from-end test test-not start
1549      end count key)
1550   #!+sb-doc
1551   "Return a sequence formed by destructively removing the specified ITEM from
1552   the given SEQUENCE."
1553   (declare (type fixnum start)
1554            (truly-dynamic-extent args))
1555   (declare (explicit-check sequence :result))
1556   (seq-dispatch-checking=>seq sequence
1557     (let ((end (or end length)))
1558       (declare (type index end))
1559       (if from-end
1560           (normal-list-delete-from-end)
1561           (normal-list-delete)))
1562     (let ((end (or end length)))
1563       (declare (type index end))
1564       (if from-end
1565           (normal-mumble-delete-from-end)
1566           (normal-mumble-delete)))
1567     (apply #'sb!sequence:delete item sequence args)))
1568
1569 (eval-when (:compile-toplevel :execute)
1570
1571 (sb!xc:defmacro if-mumble-delete ()
1572   `(mumble-delete
1573     (funcall predicate (apply-key key (aref sequence index)))))
1574
1575 (sb!xc:defmacro if-mumble-delete-from-end ()
1576   `(mumble-delete-from-end
1577     (funcall predicate (apply-key key this-element))))
1578
1579 (sb!xc:defmacro if-list-delete ()
1580   '(list-delete
1581     (funcall predicate (apply-key key (car current)))))
1582
1583 (sb!xc:defmacro if-list-delete-from-end ()
1584   '(list-delete-from-end
1585     (funcall predicate (apply-key key (car current)))))
1586
1587 ) ; EVAL-WHEN
1588
1589 (define-sequence-traverser delete-if
1590     (predicate sequence &rest args &key from-end start key end count)
1591   #!+sb-doc
1592   "Return a sequence formed by destructively removing the elements satisfying
1593   the specified PREDICATE from the given SEQUENCE."
1594   (declare (type fixnum start)
1595            (truly-dynamic-extent args))
1596   (declare (explicit-check sequence :result))
1597   (seq-dispatch-checking=>seq sequence
1598     (let ((end (or end length)))
1599       (declare (type index end))
1600       (if from-end
1601           (if-list-delete-from-end)
1602           (if-list-delete)))
1603     (let ((end (or end length)))
1604       (declare (type index end))
1605       (if from-end
1606           (if-mumble-delete-from-end)
1607           (if-mumble-delete)))
1608     (apply #'sb!sequence:delete-if predicate sequence args)))
1609
1610 (eval-when (:compile-toplevel :execute)
1611
1612 (sb!xc:defmacro if-not-mumble-delete ()
1613   `(mumble-delete
1614     (not (funcall predicate (apply-key key (aref sequence index))))))
1615
1616 (sb!xc:defmacro if-not-mumble-delete-from-end ()
1617   `(mumble-delete-from-end
1618     (not (funcall predicate (apply-key key this-element)))))
1619
1620 (sb!xc:defmacro if-not-list-delete ()
1621   '(list-delete
1622     (not (funcall predicate (apply-key key (car current))))))
1623
1624 (sb!xc:defmacro if-not-list-delete-from-end ()
1625   '(list-delete-from-end
1626     (not (funcall predicate (apply-key key (car current))))))
1627
1628 ) ; EVAL-WHEN
1629
1630 (define-sequence-traverser delete-if-not
1631     (predicate sequence &rest args &key from-end start end key count)
1632   #!+sb-doc
1633   "Return a sequence formed by destructively removing the elements not
1634   satisfying the specified PREDICATE from the given SEQUENCE."
1635   (declare (type fixnum start)
1636            (truly-dynamic-extent args))
1637   (declare (explicit-check sequence :result))
1638   (seq-dispatch-checking=>seq sequence
1639     (let ((end (or end length)))
1640       (declare (type index end))
1641       (if from-end
1642           (if-not-list-delete-from-end)
1643           (if-not-list-delete)))
1644     (let ((end (or end length)))
1645       (declare (type index end))
1646       (if from-end
1647           (if-not-mumble-delete-from-end)
1648           (if-not-mumble-delete)))
1649     (apply #'sb!sequence:delete-if-not predicate sequence args)))
1650 \f
1651 ;;;; REMOVE
1652
1653 (eval-when (:compile-toplevel :execute)
1654
1655 ;;; MUMBLE-REMOVE-MACRO does not include (removes) each element that
1656 ;;; satisfies the predicate.
1657 (sb!xc:defmacro mumble-remove-macro (bump left begin finish right pred)
1658   `(do ((index ,begin (,bump index))
1659         (result
1660          (do ((index ,left (,bump index))
1661               (result (%make-sequence-like sequence length)))
1662              ((= index (the fixnum ,begin)) result)
1663            (declare (fixnum index))
1664            (setf (aref result index) (aref sequence index))))
1665         (new-index ,begin)
1666         (number-zapped 0)
1667         (this-element))
1668        ((or (= index (the fixnum ,finish))
1669             (= number-zapped count))
1670         (do ((index index (,bump index))
1671              (new-index new-index (,bump new-index)))
1672             ((= index (the fixnum ,right)) (%shrink-vector result new-index))
1673           (declare (fixnum index new-index))
1674           (setf (aref result new-index) (aref sequence index))))
1675      (declare (fixnum index new-index number-zapped))
1676      (setq this-element (aref sequence index))
1677      (cond (,pred (incf number-zapped))
1678            (t (setf (aref result new-index) this-element)
1679               (setq new-index (,bump new-index))))))
1680
1681 (sb!xc:defmacro mumble-remove (pred)
1682   `(mumble-remove-macro 1+ 0 start end length ,pred))
1683
1684 (sb!xc:defmacro mumble-remove-from-end (pred)
1685   `(let ((sequence (copy-seq sequence)))
1686      (mumble-delete-from-end ,pred)))
1687
1688 (sb!xc:defmacro normal-mumble-remove ()
1689   `(mumble-remove
1690     (if test-not
1691         (not (funcall test-not item (apply-key key this-element)))
1692         (funcall test item (apply-key key this-element)))))
1693
1694 (sb!xc:defmacro normal-mumble-remove-from-end ()
1695   `(mumble-remove-from-end
1696     (if test-not
1697         (not (funcall test-not item (apply-key key this-element)))
1698         (funcall test item (apply-key key this-element)))))
1699
1700 (sb!xc:defmacro if-mumble-remove ()
1701   `(mumble-remove (funcall predicate (apply-key key this-element))))
1702
1703 (sb!xc:defmacro if-mumble-remove-from-end ()
1704   `(mumble-remove-from-end (funcall predicate (apply-key key this-element))))
1705
1706 (sb!xc:defmacro if-not-mumble-remove ()
1707   `(mumble-remove (not (funcall predicate (apply-key key this-element)))))
1708
1709 (sb!xc:defmacro if-not-mumble-remove-from-end ()
1710   `(mumble-remove-from-end
1711     (not (funcall predicate (apply-key key this-element)))))
1712
1713 ;;; LIST-REMOVE-MACRO does not include (removes) each element that satisfies
1714 ;;; the predicate.
1715 (sb!xc:defmacro list-remove-macro (pred reverse?)
1716   `(let* ((sequence ,(if reverse?
1717                          '(reverse (the list sequence))
1718                          'sequence))
1719           (%start ,(if reverse? '(- length end) 'start))
1720           (%end ,(if reverse? '(- length start) 'end))
1721           (splice (list nil))
1722           (tail (and (/= %end length)
1723                      (nthcdr %end sequence)))
1724           (results ,(if reverse?
1725                           ;; It's already copied by REVERSE, so it can
1726                           ;; be modified here
1727                           `(if (plusp %start)
1728                                (let* ((tail (nthcdr (1- %start) sequence))
1729                                       (remaining (cdr tail)))
1730                                  (setf (cdr tail) nil)
1731                                  (prog1 splice
1732                                    (rplacd splice sequence)
1733                                    (setf splice tail
1734                                          sequence remaining)))
1735                                splice)
1736                           `(do ((index 0 (1+ index))
1737                                 (before-start splice))
1738                                ((= index (the fixnum %start)) before-start)
1739                              (declare (fixnum index))
1740                              (setf splice
1741                                    (cdr (rplacd splice (list (pop sequence)))))))))
1742      (declare (truly-dynamic-extent splice))
1743      (do ((this-element)
1744           (number-zapped 0))
1745          ((cond ((eq tail sequence)
1746                  (rplacd splice tail)
1747                  t)
1748                 ((= number-zapped count)
1749                  (rplacd splice sequence)
1750                  t))
1751           ,(if reverse?
1752                '(nreverse (the list (cdr results)))
1753                '(cdr results)))
1754        (declare (index number-zapped))
1755        (setf this-element (pop sequence))
1756        (if ,pred
1757            (incf number-zapped)
1758            (setf splice (cdr (rplacd splice (list this-element))))))))
1759
1760 (sb!xc:defmacro list-remove (pred)
1761   `(list-remove-macro ,pred nil))
1762
1763 (sb!xc:defmacro list-remove-from-end (pred)
1764   `(list-remove-macro ,pred t))
1765
1766 (sb!xc:defmacro normal-list-remove ()
1767   `(list-remove
1768     (if test-not
1769         (not (funcall test-not item (apply-key key this-element)))
1770         (funcall test item (apply-key key this-element)))))
1771
1772 (sb!xc:defmacro normal-list-remove-from-end ()
1773   `(list-remove-from-end
1774     (if test-not
1775         (not (funcall test-not item (apply-key key this-element)))
1776         (funcall test item (apply-key key this-element)))))
1777
1778 (sb!xc:defmacro if-list-remove ()
1779   `(list-remove
1780     (funcall predicate (apply-key key this-element))))
1781
1782 (sb!xc:defmacro if-list-remove-from-end ()
1783   `(list-remove-from-end
1784     (funcall predicate (apply-key key this-element))))
1785
1786 (sb!xc:defmacro if-not-list-remove ()
1787   `(list-remove
1788     (not (funcall predicate (apply-key key this-element)))))
1789
1790 (sb!xc:defmacro if-not-list-remove-from-end ()
1791   `(list-remove-from-end
1792     (not (funcall predicate (apply-key key this-element)))))
1793
1794 ) ; EVAL-WHEN
1795
1796 (define-sequence-traverser remove
1797     (item sequence &rest args &key from-end test test-not start
1798      end count key)
1799   #!+sb-doc
1800   "Return a copy of SEQUENCE with elements satisfying the test (default is
1801    EQL) with ITEM removed."
1802   (declare (type fixnum start)
1803            (truly-dynamic-extent args))
1804   (declare (explicit-check sequence :result))
1805   (seq-dispatch-checking=>seq sequence
1806     (let ((end (or end length)))
1807       (declare (type index end))
1808       (if from-end
1809           (normal-list-remove-from-end)
1810           (normal-list-remove)))
1811     (let ((end (or end length)))
1812       (declare (type index end))
1813       (if from-end
1814           (normal-mumble-remove-from-end)
1815           (normal-mumble-remove)))
1816     (apply #'sb!sequence:remove item sequence args)))
1817
1818 (define-sequence-traverser remove-if
1819     (predicate sequence &rest args &key from-end start end count key)
1820   #!+sb-doc
1821   "Return a copy of sequence with elements satisfying PREDICATE removed."
1822   (declare (type fixnum start)
1823            (truly-dynamic-extent args))
1824   (declare (explicit-check sequence :result))
1825   (seq-dispatch-checking=>seq sequence
1826     (let ((end (or end length)))
1827       (declare (type index end))
1828       (if from-end
1829           (if-list-remove-from-end)
1830           (if-list-remove)))
1831     (let ((end (or end length)))
1832       (declare (type index end))
1833       (if from-end
1834           (if-mumble-remove-from-end)
1835           (if-mumble-remove)))
1836     (apply #'sb!sequence:remove-if predicate sequence args)))
1837
1838 (define-sequence-traverser remove-if-not
1839     (predicate sequence &rest args &key from-end start end count key)
1840   #!+sb-doc
1841   "Return a copy of sequence with elements not satisfying PREDICATE removed."
1842   (declare (type fixnum start)
1843            (truly-dynamic-extent args))
1844   (declare (explicit-check sequence :result))
1845   (seq-dispatch-checking=>seq sequence
1846     (let ((end (or end length)))
1847       (declare (type index end))
1848       (if from-end
1849           (if-not-list-remove-from-end)
1850           (if-not-list-remove)))
1851     (let ((end (or end length)))
1852       (declare (type index end))
1853       (if from-end
1854           (if-not-mumble-remove-from-end)
1855           (if-not-mumble-remove)))
1856     (apply #'sb!sequence:remove-if-not predicate sequence args)))
1857 \f
1858 ;;;; REMOVE-DUPLICATES
1859
1860 ;;; Remove duplicates from a list. If from-end, remove the later duplicates,
1861 ;;; not the earlier ones. Thus if we check from-end we don't copy an item
1862 ;;; if we look into the already copied structure (from after :start) and see
1863 ;;; the item. If we check from beginning we check into the rest of the
1864 ;;; original list up to the :end marker (this we have to do by running a
1865 ;;; do loop down the list that far and using our test.
1866 (defun list-remove-duplicates* (list test test-not start end key from-end)
1867   (declare (fixnum start)
1868            (list list))
1869   (let* ((result (list ())) ; Put a marker on the beginning to splice with.
1870          (splice result)
1871          (current list)
1872          (length (length list))
1873          (end (or end length))
1874          (whole (= end length))
1875          (hash (and (> (- end start) 20)
1876                     (not key)
1877                     (not test-not)
1878                     (hash-table-test-p test)
1879                     (make-hash-table :test test :size (- end start))))
1880          (tail (and (not whole)
1881                     (nthcdr end list))))
1882     (declare (truly-dynamic-extent result))
1883     (do ((index 0 (1+ index)))
1884         ((= index start))
1885       (declare (fixnum index))
1886       (setq splice (cdr (rplacd splice (list (car current)))))
1887       (setq current (cdr current)))
1888     (if hash
1889         (do ()
1890             ((eq current tail))
1891           ;; The hash table contains links from values that are
1892           ;; already in result to the cons cell *preceding* theirs
1893           ;; in the list.  That is, for each value v in the list,
1894           ;; v and (cadr (gethash v hash)) are equal under TEST.
1895           (let ((prev (gethash (car current) hash)))
1896             (cond
1897               ((not prev)
1898                (setf (gethash (car current) hash) splice)
1899                (setq splice (cdr (rplacd splice (list (car current))))))
1900               ((not from-end)
1901                (let* ((old (cdr prev))
1902                       (next (cdr old)))
1903                  (if next
1904                      (let ((next-val (car next)))
1905                        ;; (assert (eq (gethash next-val hash) old))
1906                        (setf (cdr prev) next
1907                              (gethash next-val hash) prev
1908                              (gethash (car current) hash) splice
1909                              splice (cdr (rplacd splice (list (car current))))))
1910                      (setf (car old) (car current)))))))
1911           (setq current (cdr current)))
1912         (let ((testp test) ;; for with-member-test
1913               (notp test-not))
1914           (with-member-test (member-test
1915                              ((and (not from-end)
1916                                    (not whole))
1917                               (if notp
1918                                   (if key
1919                                       (lambda (x y key test)
1920                                         (not (funcall (truly-the function test) x
1921                                                       (funcall (truly-the function key) y))))
1922                                       (lambda (x y key test)
1923                                         (declare (ignore key))
1924                                         (not (funcall (truly-the function test) x y))))
1925                                   (if key
1926                                       (lambda (x y key test)
1927                                         (funcall (truly-the function test) x
1928                                                  (funcall (truly-the function key) y)))
1929                                       (lambda (x y key test)
1930                                         (declare (ignore key))
1931                                         (funcall (truly-the function test) x y))))))
1932             (do ((copied (nthcdr start result)))
1933                 ((eq current tail))
1934               (let ((elt (car current)))
1935                 (when (cond (from-end
1936                              (not (funcall member-test elt (cdr copied) key test)))
1937                             (whole
1938                              (not (funcall member-test elt (cdr current) key test)))
1939                             (t
1940                              (do ((it (apply-key key elt))
1941                                   (l (cdr current) (cdr l)))
1942                                  ((eq l tail)
1943                                   t)
1944                                (when (funcall member-test it (car l) key test)
1945                                  (return)))))
1946                   (setf splice (cdr (rplacd splice (list elt))))))
1947               (pop current)))))
1948     (rplacd splice tail)
1949     (cdr result)))
1950
1951 (defun vector-remove-duplicates* (vector test test-not start end key from-end
1952                                          &optional (length (length vector)))
1953   (declare (vector vector) (fixnum start length))
1954   (when (null end) (setf end (length vector)))
1955   (let ((result (%make-sequence-like vector length))
1956         (index 0)
1957         (jndex start))
1958     (declare (fixnum index jndex))
1959     (do ()
1960         ((= index start))
1961       (setf (aref result index) (aref vector index))
1962       (setq index (1+ index)))
1963     (do ((elt))
1964         ((= index end))
1965       (setq elt (aref vector index))
1966       (unless (or (and from-end
1967                        (if test-not
1968                            (position (apply-key key elt) result
1969                                      :start start :end jndex
1970                                      :test-not test-not :key key)
1971                            (position (apply-key key elt) result
1972                                      :start start :end jndex
1973                                      :test test :key key)))
1974                   (and (not from-end)
1975                        (if test-not
1976                            (position (apply-key key elt) vector
1977                                      :start (1+ index) :end end
1978                                      :test-not test-not :key key)
1979                            (position (apply-key key elt) vector
1980                                      :start (1+ index) :end end
1981                                      :test test :key key))))
1982         (setf (aref result jndex) elt)
1983         (setq jndex (1+ jndex)))
1984       (setq index (1+ index)))
1985     (do ()
1986         ((= index length))
1987       (setf (aref result jndex) (aref vector index))
1988       (setq index (1+ index))
1989       (setq jndex (1+ jndex)))
1990     (%shrink-vector result jndex)))
1991
1992 (define-sequence-traverser remove-duplicates
1993     (sequence &rest args &key test test-not start end from-end key)
1994   #!+sb-doc
1995   "The elements of SEQUENCE are compared pairwise, and if any two match,
1996    the one occurring earlier is discarded, unless FROM-END is true, in
1997    which case the one later in the sequence is discarded. The resulting
1998    sequence is returned.
1999
2000    The :TEST-NOT argument is deprecated."
2001   (declare (fixnum start)
2002            (truly-dynamic-extent args))
2003   (declare (explicit-check sequence :result))
2004   (seq-dispatch-checking=>seq sequence
2005     (if sequence
2006         (list-remove-duplicates* sequence test test-not
2007                                  start end key from-end))
2008     (vector-remove-duplicates* sequence test test-not start end key from-end)
2009     (apply #'sb!sequence:remove-duplicates sequence args)))
2010 \f
2011 ;;;; DELETE-DUPLICATES
2012 (defun list-delete-duplicates* (list test test-not key from-end start end)
2013   (declare (index start)
2014            (list list))
2015   (let* ((handle (cons nil list))
2016          (from-end-start (and from-end
2017                               (nthcdr (1+ start) handle)))
2018          (length (length list))
2019          (end (or end length))
2020          (tail (and (/= length (truly-the fixnum end))
2021                     (nthcdr end list))))
2022     (declare (truly-dynamic-extent handle))
2023     (do* ((previous (nthcdr start handle))
2024           (current (cdr previous) (cdr current)))
2025          ((eq current tail)
2026           (cdr handle))
2027       (if (do ((end (if from-end
2028                         current
2029                         tail))
2030                (x (if from-end
2031                       from-end-start
2032                       (cdr current))
2033                   (cdr x)))
2034               ((eq x end))
2035             (if (if test-not
2036                     (not (funcall (truly-the function test-not)
2037                                   (apply-key-function key (car current))
2038                                   (apply-key-function key (car x))))
2039                     (funcall (truly-the function test)
2040                              (apply-key-function key (car current))
2041                              (apply-key-function key (car x))))
2042                 (return t)))
2043           (rplacd previous (cdr current))
2044           (pop previous)))))
2045
2046 (defun vector-delete-duplicates* (vector test test-not key from-end start end
2047                                          &optional (length (length vector)))
2048   (declare (vector vector) (fixnum start length))
2049   (when (null end) (setf end (length vector)))
2050   (do ((index start (1+ index))
2051        (jndex start))
2052       ((= index end)
2053        (do ((index index (1+ index))            ; copy the rest of the vector
2054             (jndex jndex (1+ jndex)))
2055            ((= index length)
2056             (shrink-vector vector jndex))
2057          (setf (aref vector jndex) (aref vector index))))
2058     (declare (fixnum index jndex))
2059     (setf (aref vector jndex) (aref vector index))
2060     (unless (if test-not
2061                 (position (apply-key key (aref vector index)) vector :key key
2062                           :start (if from-end start (1+ index))
2063                           :end (if from-end jndex end)
2064                           :test-not test-not)
2065                 (position (apply-key key (aref vector index)) vector :key key
2066                           :start (if from-end start (1+ index))
2067                           :end (if from-end jndex end)
2068                           :test test))
2069       (setq jndex (1+ jndex)))))
2070
2071 (define-sequence-traverser delete-duplicates
2072     (sequence &rest args &key test test-not start end from-end key)
2073   #!+sb-doc
2074   "The elements of SEQUENCE are examined, and if any two match, one is
2075    discarded. The resulting sequence, which may be formed by destroying the
2076    given sequence, is returned.
2077
2078    The :TEST-NOT argument is deprecated."
2079   (declare (truly-dynamic-extent args))
2080   (declare (explicit-check sequence :result))
2081   (seq-dispatch-checking=>seq sequence
2082     (when sequence
2083       (list-delete-duplicates* sequence test test-not
2084                                key from-end start end))
2085     (vector-delete-duplicates* sequence test test-not key from-end start end)
2086     (apply #'sb!sequence:delete-duplicates sequence args)))
2087 \f
2088 ;;;; SUBSTITUTE
2089
2090 (defun list-substitute* (pred new list start end count key test test-not old)
2091   (declare (fixnum start end count)
2092            (type (or null function) key)
2093            (optimize speed))
2094   (let* ((result (list nil))
2095          (test (or test-not test))
2096          (test-not (or test-not
2097                        (eq pred 'if-not)))
2098          elt
2099          (splice result)
2100          (list list))      ; Get a local list for a stepper.
2101     (declare (function test))
2102     (do ((index 0 (1+ index)))
2103         ((= index start))
2104       (declare (fixnum index))
2105       (setf splice (cdr (rplacd splice (list (car list))))
2106             list (cdr list)))
2107     (do ((index start (1+ index)))
2108         ((or (= index end) (null list) (= count 0)))
2109       (declare (fixnum index))
2110       (setf elt (car list)
2111             splice
2112             (cdr (rplacd splice
2113                          (list
2114                           (cond ((let* ((elt (apply-key key elt))
2115                                         (value (if (eq pred 'normal)
2116                                                    (funcall test old elt)
2117                                                    (funcall test elt))))
2118                                    (if test-not
2119                                        (not value)
2120                                        value))
2121                                  (decf count)
2122                                  new)
2123                                 (t elt)))))
2124             list (cdr list)))
2125     (do ()
2126         ((null list))
2127       (setf splice (cdr (rplacd splice (list (car list))))
2128             list (cdr list)))
2129     (cdr result)))
2130
2131 ;;; Replace old with new in sequence moving from left to right by incrementer
2132 ;;; on each pass through the loop. Called by all three substitute functions.
2133 (defun vector-substitute* (pred new sequence incrementer left right length
2134                            start end count key test test-not old)
2135   (declare (fixnum start count end incrementer right)
2136            (type (or null function) key))
2137   (let* ((result (make-vector-like sequence length))
2138          (getter (the function (svref %%data-vector-reffers%%
2139                                       (%other-pointer-widetag sequence))))
2140          (setter (the function (svref %%data-vector-setters%%
2141                                       (%other-pointer-widetag result))))
2142          (test (or test-not test))
2143          (test-not (or test-not
2144                        (eq pred 'if-not)))
2145          (index left))
2146     (declare (fixnum index)
2147              (function test))
2148     (do ()
2149         ((= index start))
2150       (funcall setter result index
2151                (funcall getter sequence index))
2152       (incf index incrementer))
2153     (do ((elt))
2154         ((or (= index end) (= count 0)))
2155       (setf elt (funcall getter sequence index))
2156       (funcall setter result index
2157                (cond ((let* ((elt (apply-key key elt))
2158                              (value (if (eq pred 'normal)
2159                                         (funcall test old elt)
2160                                         (funcall test elt))))
2161                         (if test-not
2162                             (not value)
2163                             value))
2164                       (decf count)
2165                       new)
2166                      (t elt)))
2167       (incf index incrementer))
2168     (do ()
2169         ((= index right))
2170       (funcall setter result index
2171                (funcall getter sequence index))
2172       (incf index incrementer))
2173     result))
2174
2175 (eval-when (:compile-toplevel :execute)
2176
2177 (sb!xc:defmacro subst-dispatch (pred)
2178   `(seq-dispatch-checking=>seq sequence
2179      (let ((end (or end length)))
2180        (declare (type index end))
2181        (if from-end
2182            (nreverse (list-substitute* ,pred
2183                                        new
2184                                        (reverse sequence)
2185                                        (- (the fixnum length)
2186                                           (the fixnum end))
2187                                        (- (the fixnum length)
2188                                           (the fixnum start))
2189                                        count key test test-not old))
2190            (list-substitute* ,pred
2191                              new sequence start end count key test test-not
2192                              old)))
2193
2194      (let ((end (or end length)))
2195        (declare (type index end))
2196        (if from-end
2197            (vector-substitute* ,pred new sequence -1 (1- (the fixnum length))
2198                                -1 length (1- (the fixnum end))
2199                                (1- (the fixnum start))
2200                                count key test test-not old)
2201            (vector-substitute* ,pred new sequence 1 0 length length
2202                                start end count key test test-not old)))
2203
2204     ;; FIXME: wow, this is an odd way to implement the dispatch.  PRED
2205     ;; here is (QUOTE [NORMAL|IF|IF-NOT]).  Not only is this pretty
2206     ;; pointless, but also LIST-SUBSTITUTE* and VECTOR-SUBSTITUTE*
2207     ;; dispatch once per element on PRED's run-time identity.
2208     ,(ecase (cadr pred)
2209        ((normal) `(apply #'sb!sequence:substitute new old sequence args))
2210        ((if) `(apply #'sb!sequence:substitute-if new predicate sequence args))
2211        ((if-not) `(apply #'sb!sequence:substitute-if-not new predicate sequence args)))))
2212 ) ; EVAL-WHEN
2213
2214 (define-sequence-traverser substitute
2215     (new old sequence &rest args &key from-end test test-not
2216          start count end key)
2217   #!+sb-doc
2218   "Return a sequence of the same kind as SEQUENCE with the same elements,
2219   except that all elements equal to OLD are replaced with NEW."
2220   (declare (type fixnum start)
2221            (explicit-check sequence :result)
2222            (truly-dynamic-extent args))
2223   (subst-dispatch 'normal))
2224 \f
2225 ;;;; SUBSTITUTE-IF, SUBSTITUTE-IF-NOT
2226
2227 (define-sequence-traverser substitute-if
2228     (new predicate sequence &rest args &key from-end start end count key)
2229   #!+sb-doc
2230   "Return a sequence of the same kind as SEQUENCE with the same elements
2231   except that all elements satisfying the PRED are replaced with NEW."
2232   (declare (type fixnum start)
2233            (explicit-check sequence :result)
2234            (truly-dynamic-extent args))
2235   (let ((test predicate)
2236         (test-not nil)
2237         old)
2238     (subst-dispatch 'if)))
2239
2240 (define-sequence-traverser substitute-if-not
2241     (new predicate sequence &rest args &key from-end start end count key)
2242   #!+sb-doc
2243   "Return a sequence of the same kind as SEQUENCE with the same elements
2244   except that all elements not satisfying the PRED are replaced with NEW."
2245   (declare (type fixnum start)
2246            (explicit-check sequence :result)
2247            (truly-dynamic-extent args))
2248   (let ((test predicate)
2249         (test-not nil)
2250         old)
2251     (subst-dispatch 'if-not)))
2252 \f
2253 ;;;; NSUBSTITUTE
2254
2255 (define-sequence-traverser nsubstitute
2256     (new old sequence &rest args &key from-end test test-not
2257          end count key start)
2258   #!+sb-doc
2259   "Return a sequence of the same kind as SEQUENCE with the same elements
2260   except that all elements equal to OLD are replaced with NEW. SEQUENCE
2261   may be destructively modified."
2262   (declare (type fixnum start)
2263            (truly-dynamic-extent args))
2264   (declare (explicit-check sequence :result))
2265   (seq-dispatch-checking=>seq sequence
2266     (let ((end (or end length)))
2267       (declare (type index end))
2268       (if from-end
2269           (nreverse (nlist-substitute*
2270                      new old (nreverse (the list sequence))
2271                      test test-not (- length end) (- length start)
2272                      count key))
2273           (nlist-substitute* new old sequence
2274                              test test-not start end count key)))
2275     (let ((end (or end length)))
2276       (declare (type index end))
2277       (if from-end
2278           (nvector-substitute* new old sequence -1
2279                                test test-not (1- end) (1- start) count key)
2280           (nvector-substitute* new old sequence 1
2281                                test test-not start end count key)))
2282     (apply #'sb!sequence:nsubstitute new old sequence args)))
2283
2284 (defun nlist-substitute* (new old sequence test test-not start end count key)
2285   (declare (fixnum start count end)
2286            (type (or null function) key))
2287   (do ((test (or test-not test))
2288        (list (nthcdr start sequence) (cdr list))
2289        (index start (1+ index)))
2290       ((or (= index end) (null list) (= count 0)) sequence)
2291     (declare (fixnum index)
2292              (function test))
2293     (let ((value (funcall test old (apply-key key (car list)))))
2294      (when (if test-not
2295                (not value)
2296                value)
2297        (rplaca list new)
2298        (decf count)))))
2299
2300 (defun nvector-substitute* (new old sequence incrementer
2301                             test test-not start end count key)
2302   (declare (fixnum start count end)
2303            (type (integer -1 1) incrementer)
2304            (type (or null function) key))
2305   (let* ((test (or test-not test))
2306          (tag (%other-pointer-widetag sequence))
2307          (getter (the function (svref %%data-vector-reffers%% tag)))
2308          (setter (the function (svref %%data-vector-setters%% tag))))
2309     (declare (function test))
2310     (do ((index start (+ index incrementer)))
2311         ((or (= index end) (= count 0)) sequence)
2312       (declare (fixnum index))
2313       (let* ((value (apply-key key (funcall getter sequence index)))
2314              (test (and (funcall test old value) 0)))
2315         (when (if test-not
2316                   (not test)
2317                   test)
2318           (funcall setter sequence index new)
2319           (decf count))))))
2320 \f
2321 ;;;; NSUBSTITUTE-IF, NSUBSTITUTE-IF-NOT
2322
2323 (define-sequence-traverser nsubstitute-if
2324     (new predicate sequence &rest args &key from-end start end count key)
2325   #!+sb-doc
2326   "Return a sequence of the same kind as SEQUENCE with the same elements
2327    except that all elements satisfying PREDICATE are replaced with NEW.
2328    SEQUENCE may be destructively modified."
2329   (declare (type fixnum start)
2330            (truly-dynamic-extent args))
2331   (declare (explicit-check sequence :result))
2332   (seq-dispatch-checking=>seq sequence
2333     (let ((end (or end length)))
2334       (declare (type index end))
2335       (if from-end
2336           (nreverse (nlist-substitute-if*
2337                      new predicate (nreverse (the list sequence))
2338                      (- length end) (- length start) count key))
2339           (nlist-substitute-if* new predicate sequence
2340                                 start end count key)))
2341     (let ((end (or end length)))
2342       (declare (type index end))
2343       (if from-end
2344           (nvector-substitute-if* new predicate sequence -1
2345                                   (1- end) (1- start) count key)
2346           (nvector-substitute-if* new predicate sequence 1
2347                                   start end count key)))
2348     (apply #'sb!sequence:nsubstitute-if new predicate sequence args)))
2349
2350 (defun nlist-substitute-if* (new test sequence start end count key)
2351   (declare (type fixnum start end count)
2352            (type (or null function) key)
2353            (type function test)) ; coercion is done by caller
2354   (do ((list (nthcdr start sequence) (cdr list))
2355        (index start (1+ index)))
2356       ((or (= index end) (null list) (= count 0)) sequence)
2357     (declare (fixnum index))
2358     (when (funcall test (apply-key key (car list)))
2359       (rplaca list new)
2360       (decf count))))
2361
2362 (defun nvector-substitute-if* (new test sequence incrementer
2363                                start end count key)
2364   (declare (type fixnum end count)
2365            (type (integer -1 1) incrementer)
2366            (type (or null function) key)
2367            (type function test)) ; coercion is done by caller
2368   (let* ((tag (%other-pointer-widetag sequence))
2369          (getter (the function (svref %%data-vector-reffers%% tag)))
2370          (setter (the function (svref %%data-vector-setters%% tag))))
2371     (do ((index start (+ index incrementer)))
2372         ((or (= index end) (= count 0)) sequence)
2373       (declare (fixnum index))
2374       (when (funcall test (apply-key key (funcall getter sequence index)))
2375         (funcall setter sequence index new)
2376         (decf count)))))
2377
2378 (define-sequence-traverser nsubstitute-if-not
2379     (new predicate sequence &rest args &key from-end start end count key)
2380   #!+sb-doc
2381   "Return a sequence of the same kind as SEQUENCE with the same elements
2382    except that all elements not satisfying PREDICATE are replaced with NEW.
2383    SEQUENCE may be destructively modified."
2384   (declare (type fixnum start)
2385            (truly-dynamic-extent args))
2386   (declare (explicit-check sequence :result))
2387   (seq-dispatch-checking=>seq sequence
2388     (let ((end (or end length)))
2389       (declare (fixnum end))
2390       (if from-end
2391           (nreverse (nlist-substitute-if-not*
2392                      new predicate (nreverse (the list sequence))
2393                      (- length end) (- length start) count key))
2394           (nlist-substitute-if-not* new predicate sequence
2395                                     start end count key)))
2396     (let ((end (or end length)))
2397       (declare (fixnum end))
2398       (if from-end
2399           (nvector-substitute-if-not* new predicate sequence -1
2400                                       (1- end) (1- start) count key)
2401           (nvector-substitute-if-not* new predicate sequence 1
2402                                       start end count key)))
2403     (apply #'sb!sequence:nsubstitute-if-not new predicate sequence args)))
2404
2405 (defun nlist-substitute-if-not* (new test sequence start end count key)
2406   (declare (type fixnum start end count)
2407            (type (or null function) key)
2408            (type function test))        ; coercion is done by caller
2409   (do ((list (nthcdr start sequence) (cdr list))
2410        (index start (1+ index)))
2411       ((or (= index end) (null list) (= count 0)) sequence)
2412     (declare (fixnum index))
2413     (when (not (funcall test (apply-key key (car list))))
2414       (rplaca list new)
2415       (decf count))))
2416
2417 (defun nvector-substitute-if-not* (new test sequence incrementer
2418                                    start end count key)
2419   (declare (type fixnum end count)
2420            (type (integer -1 1) incrementer)
2421            (type (or null function) key)
2422            (type function test))        ; coercion is done by caller
2423   (let* ((tag (%other-pointer-widetag sequence))
2424          (getter (the function (svref %%data-vector-reffers%% tag)))
2425          (setter (the function (svref %%data-vector-setters%% tag))))
2426     (do ((index start (+ index incrementer)))
2427         ((or (= index end) (= count 0)) sequence)
2428       (declare (fixnum index))
2429       (when (not (funcall test (apply-key key (funcall getter sequence index))))
2430         (funcall setter sequence index new)
2431         (decf count)))))
2432 \f
2433 ;;;; FIND, POSITION, and their -IF and -IF-NOT variants
2434
2435 (defun effective-find-position-test (test test-not)
2436   (effective-find-position-test test test-not))
2437 (defun effective-find-position-key (key)
2438   (effective-find-position-key key))
2439
2440 ;;; shared guts of out-of-line FIND, POSITION, FIND-IF, and POSITION-IF
2441 (macrolet (;; shared logic for defining %FIND-POSITION and
2442            ;; %FIND-POSITION-IF in terms of various inlineable cases
2443            ;; of the expression defined in FROB and VECTOR*-FROB
2444            (frobs (&optional bit-frob)
2445              `(seq-dispatch-checking sequence-arg
2446                (frob sequence-arg from-end)
2447                (with-array-data ((sequence sequence-arg :offset-var offset)
2448                                  (start start)
2449                                  (end end)
2450                                  :check-fill-pointer t)
2451                  (multiple-value-bind (f p)
2452                      (macrolet ((frob2 () `(if from-end
2453                                                (frob sequence t)
2454                                                (frob sequence nil))))
2455                        (typecase sequence
2456                          #!+sb-unicode
2457                          ((simple-array character (*)) (frob2))
2458                          ((simple-array base-char (*)) (frob2))
2459                          ,@(when bit-frob
2460                              `((simple-bit-vector
2461                                 (if (and (typep item 'bit)
2462                                          (eq #'identity key)
2463                                          (or (eq #'eq test)
2464                                              (eq #'eql test)
2465                                              (eq #'equal test)))
2466                                     (let ((p (%bit-position item sequence
2467                                                             from-end start end)))
2468                                       (if p
2469                                           (values item p)
2470                                           (values nil nil)))
2471                                     (vector*-frob sequence)))))
2472                          (t
2473                           (vector*-frob sequence))))
2474                    (declare (type (or index null) p))
2475                    (values f (and p (the index (- p offset))))))
2476                ;; EXTENDED-SEQUENCE is not allowed.
2477                )))
2478   (defun %find-position (item sequence-arg from-end start end key test)
2479     (declare (explicit-check sequence-arg))
2480     (macrolet ((frob (sequence from-end)
2481                  `(%find-position item ,sequence
2482                                   ,from-end start end key test))
2483                (vector*-frob (sequence)
2484                  `(%find-position-vector-macro item ,sequence
2485                                                from-end start end key test)))
2486       (frobs t)))
2487   (defun %find-position-if (predicate sequence-arg from-end start end key)
2488     (declare (explicit-check sequence-arg))
2489     (macrolet ((frob (sequence from-end)
2490                  `(%find-position-if predicate ,sequence
2491                                      ,from-end start end key))
2492                (vector*-frob (sequence)
2493                  `(%find-position-if-vector-macro predicate ,sequence
2494                                                   from-end start end key)))
2495       (frobs)))
2496   (defun %find-position-if-not (predicate sequence-arg from-end start end key)
2497     (declare (explicit-check sequence-arg))
2498     (macrolet ((frob (sequence from-end)
2499                  `(%find-position-if-not predicate ,sequence
2500                                          ,from-end start end key))
2501                (vector*-frob (sequence)
2502                  `(%find-position-if-not-vector-macro predicate ,sequence
2503                                                   from-end start end key)))
2504       (frobs))))
2505
2506 (defun find
2507     (item sequence &rest args &key from-end (start 0) end key test test-not)
2508   (declare (truly-dynamic-extent args))
2509   (declare (explicit-check sequence))
2510   (seq-dispatch-checking sequence
2511     (nth-value 0 (%find-position
2512                   item sequence from-end start end
2513                   (effective-find-position-key key)
2514                   (effective-find-position-test test test-not)))
2515     (nth-value 0 (%find-position
2516                   item sequence from-end start end
2517                   (effective-find-position-key key)
2518                   (effective-find-position-test test test-not)))
2519     (apply #'sb!sequence:find item sequence args)))
2520 (defun position
2521     (item sequence &rest args &key from-end (start 0) end key test test-not)
2522   (declare (truly-dynamic-extent args))
2523   (declare (explicit-check sequence))
2524   (seq-dispatch-checking sequence
2525     (nth-value 1 (%find-position
2526                   item sequence from-end start end
2527                   (effective-find-position-key key)
2528                   (effective-find-position-test test test-not)))
2529     (nth-value 1 (%find-position
2530                   item sequence from-end start end
2531                   (effective-find-position-key key)
2532                   (effective-find-position-test test test-not)))
2533     (apply #'sb!sequence:position item sequence args)))
2534
2535 (defun find-if (predicate sequence &rest args &key from-end (start 0) end key)
2536   (declare (truly-dynamic-extent args))
2537   (declare (explicit-check sequence))
2538   (seq-dispatch-checking sequence
2539     (nth-value 0 (%find-position-if
2540                   (%coerce-callable-to-fun predicate)
2541                   sequence from-end start end
2542                   (effective-find-position-key key)))
2543     (nth-value 0 (%find-position-if
2544                   (%coerce-callable-to-fun predicate)
2545                   sequence from-end start end
2546                   (effective-find-position-key key)))
2547     (apply #'sb!sequence:find-if predicate sequence args)))
2548 (defun position-if
2549     (predicate sequence &rest args &key from-end (start 0) end key)
2550   (declare (truly-dynamic-extent args))
2551   (declare (explicit-check sequence))
2552   (seq-dispatch-checking sequence
2553     (nth-value 1 (%find-position-if
2554                   (%coerce-callable-to-fun predicate)
2555                   sequence from-end start end
2556                   (effective-find-position-key key)))
2557     (nth-value 1 (%find-position-if
2558                   (%coerce-callable-to-fun predicate)
2559                   sequence from-end start end
2560                   (effective-find-position-key key)))
2561     (apply #'sb!sequence:position-if predicate sequence args)))
2562
2563 (defun find-if-not
2564     (predicate sequence &rest args &key from-end (start 0) end key)
2565   (declare (truly-dynamic-extent args))
2566   (declare (explicit-check sequence))
2567   (seq-dispatch-checking sequence
2568     (nth-value 0 (%find-position-if-not
2569                   (%coerce-callable-to-fun predicate)
2570                   sequence from-end start end
2571                   (effective-find-position-key key)))
2572     (nth-value 0 (%find-position-if-not
2573                   (%coerce-callable-to-fun predicate)
2574                   sequence from-end start end
2575                   (effective-find-position-key key)))
2576     (apply #'sb!sequence:find-if-not predicate sequence args)))
2577 (defun position-if-not
2578     (predicate sequence &rest args &key from-end (start 0) end key)
2579   (declare (truly-dynamic-extent args))
2580   (declare (explicit-check sequence))
2581   (seq-dispatch-checking sequence
2582     (nth-value 1 (%find-position-if-not
2583                   (%coerce-callable-to-fun predicate)
2584                   sequence from-end start end
2585                   (effective-find-position-key key)))
2586     (nth-value 1 (%find-position-if-not
2587                   (%coerce-callable-to-fun predicate)
2588                   sequence from-end start end
2589                   (effective-find-position-key key)))
2590     (apply #'sb!sequence:position-if-not predicate sequence args)))
2591 \f
2592 ;;;; COUNT-IF, COUNT-IF-NOT, and COUNT
2593
2594 (eval-when (:compile-toplevel :execute)
2595
2596 (sb!xc:defmacro vector-count-if (notp from-end-p predicate sequence)
2597   (let ((next-index (if from-end-p '(1- index) '(1+ index)))
2598         (pred `(funcall ,predicate (apply-key key (aref ,sequence index)))))
2599     `(let ((%start ,(if from-end-p '(1- end) 'start))
2600            (%end ,(if from-end-p '(1- start) 'end)))
2601       (do ((index %start ,next-index)
2602            (count 0))
2603           ((= index (the fixnum %end)) count)
2604         (declare (fixnum index count))
2605         (,(if notp 'unless 'when) ,pred
2606           (setq count (1+ count)))))))
2607
2608 (sb!xc:defmacro list-count-if (notp from-end-p predicate sequence)
2609   (let ((pred `(funcall ,predicate (apply-key key (pop sequence)))))
2610     `(let ((%start ,(if from-end-p '(- length end) 'start))
2611            (%end ,(if from-end-p '(- length start) 'end))
2612            (sequence ,(if from-end-p '(reverse sequence) 'sequence)))
2613       (do ((sequence (nthcdr %start ,sequence))
2614            (index %start (1+ index))
2615            (count 0))
2616           ((or (= index (the fixnum %end)) (null sequence)) count)
2617         (declare (fixnum index count))
2618         (,(if notp 'unless 'when) ,pred
2619           (setq count (1+ count)))))))
2620
2621
2622 ) ; EVAL-WHEN
2623
2624 (define-sequence-traverser count-if
2625     (pred sequence &rest args &key from-end start end key)
2626   #!+sb-doc
2627   "Return the number of elements in SEQUENCE satisfying PRED(el)."
2628   (declare (type fixnum start)
2629            (truly-dynamic-extent args))
2630   (declare (explicit-check sequence))
2631   (let ((pred (%coerce-callable-to-fun pred)))
2632     (seq-dispatch-checking sequence
2633       (let ((end (or end length)))
2634         (declare (type index end))
2635         (if from-end
2636             (list-count-if nil t pred sequence)
2637             (list-count-if nil nil pred sequence)))
2638       (let ((end (or end length)))
2639         (declare (type index end))
2640         (if from-end
2641             (vector-count-if nil t pred sequence)
2642             (vector-count-if nil nil pred sequence)))
2643       (apply #'sb!sequence:count-if pred sequence args))))
2644
2645 (define-sequence-traverser count-if-not
2646     (pred sequence &rest args &key from-end start end key)
2647   #!+sb-doc
2648   "Return the number of elements in SEQUENCE not satisfying TEST(el)."
2649   (declare (type fixnum start)
2650            (truly-dynamic-extent args))
2651   (declare (explicit-check sequence))
2652   (let ((pred (%coerce-callable-to-fun pred)))
2653     (seq-dispatch-checking sequence
2654       (let ((end (or end length)))
2655         (declare (type index end))
2656         (if from-end
2657             (list-count-if t t pred sequence)
2658             (list-count-if t nil pred sequence)))
2659       (let ((end (or end length)))
2660         (declare (type index end))
2661         (if from-end
2662             (vector-count-if t t pred sequence)
2663             (vector-count-if t nil pred sequence)))
2664       (apply #'sb!sequence:count-if-not pred sequence args))))
2665
2666 (define-sequence-traverser count
2667     (item sequence &rest args &key from-end start end
2668           key (test #'eql test-p) (test-not nil test-not-p))
2669   #!+sb-doc
2670   "Return the number of elements in SEQUENCE satisfying a test with ITEM,
2671    which defaults to EQL."
2672   (declare (type fixnum start)
2673            (truly-dynamic-extent args))
2674   (declare (explicit-check sequence))
2675   (when (and test-p test-not-p)
2676     ;; Use the same wording as EFFECTIVE-FIND-POSITION-TEST
2677     (error "can't specify both :TEST and :TEST-NOT"))
2678   (let ((%test (if test-not-p
2679                    (lambda (x)
2680                      (not (funcall test-not item x)))
2681                    (lambda (x)
2682                      (funcall test item x)))))
2683     (seq-dispatch-checking sequence
2684       (let ((end (or end length)))
2685         (declare (type index end))
2686         (if from-end
2687             (list-count-if nil t %test sequence)
2688             (list-count-if nil nil %test sequence)))
2689       (let ((end (or end length)))
2690         (declare (type index end))
2691         (if from-end
2692             (vector-count-if nil t %test sequence)
2693             (vector-count-if nil nil %test sequence)))
2694       (apply #'sb!sequence:count item sequence args))))
2695 \f
2696 ;;;; MISMATCH
2697
2698 (eval-when (:compile-toplevel :execute)
2699
2700 (sb!xc:defmacro match-vars (&rest body)
2701   `(let ((inc (if from-end -1 1))
2702          (start1 (if from-end (1- (the fixnum end1)) start1))
2703          (start2 (if from-end (1- (the fixnum end2)) start2))
2704          (end1 (if from-end (1- (the fixnum start1)) end1))
2705          (end2 (if from-end (1- (the fixnum start2)) end2)))
2706      (declare (fixnum inc start1 start2 end1 end2))
2707      ,@body))
2708
2709 (sb!xc:defmacro matchify-list ((sequence start length end) &body body)
2710   (declare (ignore end)) ;; ### Should END be used below?
2711   `(let ((,sequence (if from-end
2712                         (nthcdr (- (the fixnum ,length) (the fixnum ,start) 1)
2713                                 (reverse (the list ,sequence)))
2714                         (nthcdr ,start ,sequence))))
2715      (declare (type list ,sequence))
2716      ,@body))
2717
2718 ) ; EVAL-WHEN
2719
2720 (eval-when (:compile-toplevel :execute)
2721
2722 (sb!xc:defmacro if-mismatch (elt1 elt2)
2723   `(cond ((= (the fixnum index1) (the fixnum end1))
2724           (return (if (= (the fixnum index2) (the fixnum end2))
2725                       nil
2726                       (if from-end
2727                           (1+ (the fixnum index1))
2728                           (the fixnum index1)))))
2729          ((= (the fixnum index2) (the fixnum end2))
2730           (return (if from-end (1+ (the fixnum index1)) index1)))
2731          (test-not
2732           (if (funcall test-not (apply-key key ,elt1) (apply-key key ,elt2))
2733               (return (if from-end (1+ (the fixnum index1)) index1))))
2734          (t (if (not (funcall test (apply-key key ,elt1)
2735                               (apply-key key ,elt2)))
2736                 (return (if from-end (1+ (the fixnum index1)) index1))))))
2737
2738 (sb!xc:defmacro mumble-mumble-mismatch ()
2739   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2740         (index2 start2 (+ index2 (the fixnum inc))))
2741        (())
2742      (declare (fixnum index1 index2))
2743      (if-mismatch (aref sequence1 index1) (aref sequence2 index2))))
2744
2745 (sb!xc:defmacro mumble-list-mismatch ()
2746   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2747         (index2 start2 (+ index2 (the fixnum inc))))
2748        (())
2749      (declare (fixnum index1 index2))
2750      (if-mismatch (aref sequence1 index1) (pop sequence2))))
2751 \f
2752 (sb!xc:defmacro list-mumble-mismatch ()
2753   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2754         (index2 start2 (+ index2 (the fixnum inc))))
2755        (())
2756      (declare (fixnum index1 index2))
2757      (if-mismatch (pop sequence1) (aref sequence2 index2))))
2758
2759 (sb!xc:defmacro list-list-mismatch ()
2760   `(do ((sequence1 sequence1)
2761         (sequence2 sequence2)
2762         (index1 start1 (+ index1 (the fixnum inc)))
2763         (index2 start2 (+ index2 (the fixnum inc))))
2764        (())
2765      (declare (fixnum index1 index2))
2766      (if-mismatch (pop sequence1) (pop sequence2))))
2767
2768 ) ; EVAL-WHEN
2769
2770 (define-sequence-traverser mismatch
2771     (sequence1 sequence2 &rest args &key from-end test test-not
2772      start1 end1 start2 end2 key)
2773   #!+sb-doc
2774   "The specified subsequences of SEQUENCE1 and SEQUENCE2 are compared
2775    element-wise. If they are of equal length and match in every element, the
2776    result is NIL. Otherwise, the result is a non-negative integer, the index
2777    within SEQUENCE1 of the leftmost position at which they fail to match; or,
2778    if one is shorter than and a matching prefix of the other, the index within
2779    SEQUENCE1 beyond the last position tested is returned. If a non-NIL
2780    :FROM-END argument is given, then one plus the index of the rightmost
2781    position in which the sequences differ is returned."
2782   (declare (type fixnum start1 start2))
2783   (declare (truly-dynamic-extent args))
2784   (declare (explicit-check sequence1 sequence2 :result))
2785   (seq-dispatch-checking sequence1
2786     (seq-dispatch-checking sequence2
2787      (return-from mismatch
2788       (let ((end1 (or end1 length1))
2789             (end2 (or end2 length2)))
2790         (declare (type index end1 end2))
2791         (match-vars
2792          (matchify-list (sequence1 start1 length1 end1)
2793            (matchify-list (sequence2 start2 length2 end2)
2794              (list-list-mismatch))))))
2795      (return-from mismatch
2796       (let ((end1 (or end1 length1))
2797             (end2 (or end2 length2)))
2798         (declare (type index end1 end2))
2799         (match-vars
2800          (matchify-list (sequence1 start1 length1 end1)
2801            (list-mumble-mismatch)))))
2802      nil)
2803     (seq-dispatch-checking sequence2
2804      (return-from mismatch
2805       (let ((end1 (or end1 length1))
2806             (end2 (or end2 length2)))
2807         (declare (type index end1 end2))
2808         (match-vars
2809          (matchify-list (sequence2 start2 length2 end2)
2810            (mumble-list-mismatch)))))
2811      (return-from mismatch
2812       (let ((end1 (or end1 length1))
2813             (end2 (or end2 length2)))
2814         (declare (type index end1 end2))
2815         (match-vars
2816          (mumble-mumble-mismatch))))
2817      nil)
2818     t)
2819   ;; If sequence1 is an extended-sequence, we know nothing about sequence2.
2820   ;; If sequence1 was a list or vector, then sequence2 is an extended-sequence
2821   ;; or not a sequence. Either way, check it.
2822   (the (or index null)
2823     (values (apply #'sb!sequence:mismatch sequence1
2824                    (the sequence sequence2) args))))
2825 \f
2826 ;;; search comparison functions
2827
2828 (eval-when (:compile-toplevel :execute)
2829
2830 ;;; Compare two elements and return if they don't match.
2831 (sb!xc:defmacro compare-elements (elt1 elt2)
2832   `(if test-not
2833        (if (funcall test-not (apply-key key ,elt1) (apply-key key ,elt2))
2834            (return nil)
2835            t)
2836        (if (not (funcall test (apply-key key ,elt1) (apply-key key ,elt2)))
2837            (return nil)
2838            t)))
2839
2840 (sb!xc:defmacro search-compare-list-list (main sub)
2841   `(do ((main ,main (cdr main))
2842         (jndex start1 (1+ jndex))
2843         (sub (nthcdr start1 ,sub) (cdr sub)))
2844        ((or (endp main) (endp sub) (<= end1 jndex))
2845         t)
2846      (declare (type (integer 0) jndex))
2847      (compare-elements (car sub) (car main))))
2848
2849 (sb!xc:defmacro search-compare-list-vector (main sub)
2850   `(do ((main ,main (cdr main))
2851         (index start1 (1+ index)))
2852        ((or (endp main) (= index end1)) t)
2853      (compare-elements (aref ,sub index) (car main))))
2854
2855 (sb!xc:defmacro search-compare-vector-list (main sub index)
2856   `(do ((sub (nthcdr start1 ,sub) (cdr sub))
2857         (jndex start1 (1+ jndex))
2858         (index ,index (1+ index)))
2859        ((or (<= end1 jndex) (endp sub)) t)
2860      (declare (type (integer 0) jndex))
2861      (compare-elements (car sub) (aref ,main index))))
2862
2863 (sb!xc:defmacro search-compare-vector-vector (main sub index)
2864   `(do ((index ,index (1+ index))
2865         (sub-index start1 (1+ sub-index)))
2866        ((= sub-index end1) t)
2867      (compare-elements (aref ,sub sub-index) (aref ,main index))))
2868
2869 (sb!xc:defmacro search-compare (main-type main sub index)
2870   (if (eq main-type 'list)
2871       `(seq-dispatch ,sub
2872          (search-compare-list-list ,main ,sub)
2873          (search-compare-list-vector ,main ,sub)
2874          ;; KLUDGE: just hack it together so that it works
2875          (return-from search (apply #'sb!sequence:search sequence1 sequence2 args)))
2876       `(seq-dispatch ,sub
2877          (search-compare-vector-list ,main ,sub ,index)
2878          (search-compare-vector-vector ,main ,sub ,index)
2879          (return-from search (apply #'sb!sequence:search sequence1 sequence2 args)))))
2880
2881 ) ; EVAL-WHEN
2882 \f
2883 ;;;; SEARCH
2884
2885 (eval-when (:compile-toplevel :execute)
2886
2887 (sb!xc:defmacro list-search (main sub)
2888   `(do ((main (nthcdr start2 ,main) (cdr main))
2889         (index2 start2 (1+ index2))
2890         (terminus (- end2 (the (integer 0) (- end1 start1))))
2891         (last-match ()))
2892        ((> index2 terminus) last-match)
2893      (declare (type (integer 0) index2))
2894      (if (search-compare list main ,sub index2)
2895          (if from-end
2896              (setq last-match index2)
2897              (return index2)))))
2898
2899 (sb!xc:defmacro vector-search (main sub)
2900   `(do ((index2 start2 (1+ index2))
2901         (terminus (- end2 (the (integer 0) (- end1 start1))))
2902         (last-match ()))
2903        ((> index2 terminus) last-match)
2904      (declare (type (integer 0) index2))
2905      (if (search-compare vector ,main ,sub index2)
2906          (if from-end
2907              (setq last-match index2)
2908              (return index2)))))
2909
2910 ) ; EVAL-WHEN
2911
2912 (define-sequence-traverser search
2913     (sequence1 sequence2 &rest args &key
2914      from-end test test-not start1 end1 start2 end2 key)
2915   (declare (type fixnum start1 start2)
2916            (truly-dynamic-extent args))
2917   (declare (explicit-check sequence2))
2918   (seq-dispatch-checking sequence2
2919     (let ((end1 (or end1 length1))
2920           (end2 (or end2 length2)))
2921       (declare (type index end1 end2))
2922       (list-search sequence2 sequence1))
2923     (let ((end1 (or end1 length1))
2924           (end2 (or end2 length2)))
2925       (declare (type index end1 end2))
2926       (vector-search sequence2 sequence1))
2927     (apply #'sb!sequence:search sequence1 sequence2 args)))
2928
2929 ;;; FIXME: this was originally in array.lisp; it might be better to
2930 ;;; put it back there, and make DOSEQUENCE and SEQ-DISPATCH be in
2931 ;;; a new early-seq.lisp file.
2932 (macrolet ((body (lambda-list endp-test start-recursion next-layer)
2933               `(let ((index 0))
2934                  (labels ((frob ,lambda-list
2935                             (cond (,endp-test
2936                                    (setf (aref vector index) contents)
2937                                    (incf index))
2938                                   (t
2939                                    (unless (typep contents 'sequence)
2940                                      (error "malformed :INITIAL-CONTENTS: ~S is not a ~
2941                                              sequence, but ~W more layer~:P needed."
2942                                             contents
2943                                             (- (length dimensions) axis)))
2944                                    (let ((k this-dimension)
2945                                          (l (length contents)))
2946                                      (unless (= k l)
2947                                        (error "malformed :INITIAL-CONTENTS: Dimension of ~
2948                                                axis ~W is ~W, but ~S is ~W long."
2949                                               axis k contents l)))
2950                                    (sb!sequence:dosequence (content contents)
2951                                      ,next-layer)))))
2952                    ,start-recursion))))
2953
2954   (defun fill-data-vector (vector dimensions initial-contents)
2955     (declare (explicit-check))
2956     (symbol-macrolet ((this-dimension (car dims)))
2957       (body (axis dims contents) (null dims)
2958             (frob 0 dimensions initial-contents)
2959             (frob (1+ axis) (cdr dims) content))))
2960
2961   ;; Identical to FILL-DATA-VECTOR but avoid reference
2962   ;; to DIMENSIONS as a list except in case of error.
2963   (defun fill-array (initial-contents array)
2964     (declare (explicit-check))
2965     (let ((rank (array-rank array))
2966           (vector (%array-data-vector array)))
2967       (symbol-macrolet ((dimensions (array-dimensions array))
2968                         (this-dimension (%array-dimension array axis)))
2969         (body (axis contents) (= axis rank)
2970               (frob 0 initial-contents)
2971               (frob (1+ axis) content))))
2972     array))