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 (defglobal %%fill-bashers%% (make-array (1+ sb!vm:widetag-mask)))
 591 #.`(progn
 592    ,@(loop for saetp across sb!vm:*specialized-array-element-type-properties*
 593            for et = (sb!vm:saetp-specifier saetp)
 594            if (or (null et)
 595                   (sb!vm:valid-bit-bash-saetp-p saetp))
 596            collect
 597            (multiple-value-bind (basher value-transform)
 598                (if et
 599                    (sb!c::find-basher saetp)
 600                    '(lambda (item vector start length)
 601                      (declare (ignore item start length))
 602                      (data-nil-vector-ref (truly-the (simple-array nil (*)) vector) 0)))
 603              `(setf
 604                (aref %%fill-bashers%% ,(sb!vm:saetp-typecode saetp))
 605                (cons #',basher
 606                      ,(if et
 607                           `(lambda (sb!c::item)
 608                              (declare (type ,et sb!c::item))
 609                              ,value-transform)
 610                           '#'identity))))
 611            else do
 612            ;; vector-fill* depends on this assertion
 613            (assert (member et '(t (complex double-float)
 614                                 #!-64-bit (complex single-float))
 615                            :test #'equal))))
 616
 617 (defun vector-fill* (vector item start end)
 618   (declare (type index start) (type (or index null) end)
 619            (optimize speed))
 620   (with-array-data ((vector vector)
 621                     (start start)
 622                     (end end)
 623                     :force-inline t
 624                     :check-fill-pointer t)
 625     (if (simple-vector-p vector)
 626         (locally
 627             (declare (optimize (speed 3) (safety 0))) ; transform will kick in
 628           (fill (truly-the simple-vector vector) item
 629                 :start start :end end))
 630         (let* ((widetag (%other-pointer-widetag vector))
 631                (bashers (svref %%fill-bashers%% widetag)))
 632           (macrolet ((fill-complex (type)
 633                        `(locally
 634                             (declare (optimize (speed 3) (safety 0))
 635                                      (type (complex ,type) item)
 636                                      (type (simple-array (complex ,type) (*))
 637                                            vector))
 638                           (do ((index start (1+ index)))
 639                               ((= index end))
 640                             (declare (index index))
 641                             (setf (aref vector index) item)))))
 642             (cond ((neq bashers 0)
 643                    (funcall (truly-the function (car (truly-the cons bashers)))
 644                             (funcall (truly-the function (cdr bashers)) item)
 645                             vector start (- end start)))
 646                   #!-64-bit
 647                   ((eq widetag sb!vm:simple-array-single-float-widetag)
 648                    (fill-complex single-float))
 649                   (t
 650                    (fill-complex double-float)))))))
 651   vector)
 652
 653 (defun string-fill* (sequence item start end)
 654   (declare (string sequence))
 655   (with-array-data ((data sequence)
 656                     (start start)
 657                     (end end)
 658                     :force-inline t
 659                     :check-fill-pointer t)
 660     ;; DEFTRANSFORM for FILL will turn these into
 661     ;; calls to UB*-BASH-FILL.
 662     (etypecase data
 663       #!+sb-unicode
 664       ((simple-array character (*))
 665        (let ((item (locally (declare (optimize (safety 3)))
 666                      (the character item))))
 667          (fill data item :start start :end end)))
 668       ((simple-array base-char (*))
 669        (let ((item (locally (declare (optimize (safety 3)))
 670                      (the base-char item))))
 671          (fill data item :start start :end end))))))
 672
 673 (defun fill (sequence item &key (start 0) end)
 674   #!+sb-doc
 675   "Replace the specified elements of SEQUENCE with ITEM."
 676   (declare (explicit-check sequence :result))
 677   (seq-dispatch-checking=>seq sequence
 678    (list-fill* sequence item start end)
 679    (vector-fill* sequence item start end)
 680    (sb!sequence:fill sequence item
 681                      :start start
 682                      :end (%check-generic-sequence-bounds sequence start end))))
 683 \f
 684 ;;;; REPLACE
 685
 686 (eval-when (:compile-toplevel :execute)
 687
 688 ;;; If we are copying around in the same vector, be careful not to copy the
 689 ;;; same elements over repeatedly. We do this by copying backwards.
 690 (sb!xc:defmacro mumble-replace-from-mumble ()
 691   `(if (and (eq target-sequence source-sequence) (> target-start source-start))
 692        (let ((nelts (min (- target-end target-start)
 693                          (- source-end source-start))))
 694          (do ((target-index (+ (the fixnum target-start) (the fixnum nelts) -1)
 695                             (1- target-index))
 696               (source-index (+ (the fixnum source-start) (the fixnum nelts) -1)
 697                             (1- source-index)))
 698              ((= target-index (the fixnum (1- target-start))) target-sequence)
 699            (declare (fixnum target-index source-index))
 700            ;; disable bounds checking
 701            (declare (optimize (safety 0)))
 702            (setf (aref target-sequence target-index)
 703                  (aref source-sequence source-index))))
 704        (do ((target-index target-start (1+ target-index))
 705             (source-index source-start (1+ source-index)))
 706            ((or (= target-index (the fixnum target-end))
 707                 (= source-index (the fixnum source-end)))
 708             target-sequence)
 709          (declare (fixnum target-index source-index))
 710          ;; disable bounds checking
 711          (declare (optimize (safety 0)))
 712          (setf (aref target-sequence target-index)
 713                (aref source-sequence source-index)))))
 714
 715 (sb!xc:defmacro list-replace-from-list ()
 716   `(if (and (eq target-sequence source-sequence) (> target-start source-start))
 717        (let ((new-elts (subseq source-sequence source-start
 718                                (+ (the fixnum source-start)
 719                                   (the fixnum
 720                                        (min (- (the fixnum target-end)
 721                                                (the fixnum target-start))
 722                                             (- (the fixnum source-end)
 723                                                (the fixnum source-start))))))))
 724          (do ((n new-elts (cdr n))
 725               (o (nthcdr target-start target-sequence) (cdr o)))
 726              ((null n) target-sequence)
 727            (rplaca o (car n))))
 728        (do ((target-index target-start (1+ target-index))
 729             (source-index source-start (1+ source-index))
 730             (target-sequence-ref (nthcdr target-start target-sequence)
 731                                  (cdr target-sequence-ref))
 732             (source-sequence-ref (nthcdr source-start source-sequence)
 733                                  (cdr source-sequence-ref)))
 734            ((or (= target-index (the fixnum target-end))
 735                 (= source-index (the fixnum source-end))
 736                 (null target-sequence-ref) (null source-sequence-ref))
 737             target-sequence)
 738          (declare (fixnum target-index source-index))
 739          (rplaca target-sequence-ref (car source-sequence-ref)))))
 740
 741 (sb!xc:defmacro list-replace-from-mumble ()
 742   `(do ((target-index target-start (1+ target-index))
 743         (source-index source-start (1+ source-index))
 744         (target-sequence-ref (nthcdr target-start target-sequence)
 745                              (cdr target-sequence-ref)))
 746        ((or (= target-index (the fixnum target-end))
 747             (= source-index (the fixnum source-end))
 748             (null target-sequence-ref))
 749         target-sequence)
 750      (declare (fixnum source-index target-index))
 751      (rplaca target-sequence-ref (aref source-sequence source-index))))
 752
 753 (sb!xc:defmacro mumble-replace-from-list ()
 754   `(do ((target-index target-start (1+ target-index))
 755         (source-index source-start (1+ source-index))
 756         (source-sequence (nthcdr source-start source-sequence)
 757                          (cdr source-sequence)))
 758        ((or (= target-index (the fixnum target-end))
 759             (= source-index (the fixnum source-end))
 760             (null source-sequence))
 761         target-sequence)
 762      (declare (fixnum target-index source-index))
 763      (setf (aref target-sequence target-index) (car source-sequence))))
 764
 765 ) ; EVAL-WHEN
 766
 767 ;;;; The support routines for REPLACE are used by compiler transforms, so we
 768 ;;;; worry about dealing with END being supplied or defaulting to NIL
 769 ;;;; at this level.
 770
 771 (defun list-replace-from-list* (target-sequence source-sequence target-start
 772                                 target-end source-start source-end)
 773   (when (null target-end) (setq target-end (length target-sequence)))
 774   (when (null source-end) (setq source-end (length source-sequence)))
 775   (list-replace-from-list))
 776
 777 (defun list-replace-from-vector* (target-sequence source-sequence target-start
 778                                   target-end source-start source-end)
 779   (when (null target-end) (setq target-end (length target-sequence)))
 780   (when (null source-end) (setq source-end (length source-sequence)))
 781   (list-replace-from-mumble))
 782
 783 (defun vector-replace-from-list* (target-sequence source-sequence target-start
 784                                   target-end source-start source-end)
 785   (when (null target-end) (setq target-end (length target-sequence)))
 786   (when (null source-end) (setq source-end (length source-sequence)))
 787   (mumble-replace-from-list))
 788
 789 (defun vector-replace-from-vector* (target-sequence source-sequence
 790                                     target-start target-end source-start
 791                                     source-end)
 792   (when (null target-end) (setq target-end (length target-sequence)))
 793   (when (null source-end) (setq source-end (length source-sequence)))
 794   (mumble-replace-from-mumble))
 795
 796 #!+sb-unicode
 797 (defun simple-character-string-replace-from-simple-character-string*
 798     (target-sequence source-sequence
 799      target-start target-end source-start source-end)
 800   (declare (type (simple-array character (*)) target-sequence source-sequence))
 801   (when (null target-end) (setq target-end (length target-sequence)))
 802   (when (null source-end) (setq source-end (length source-sequence)))
 803   (mumble-replace-from-mumble))
 804
 805 (define-sequence-traverser replace
 806     (sequence1 sequence2 &rest args &key start1 end1 start2 end2)
 807   #!+sb-doc
 808   "Destructively modifies SEQUENCE1 by copying successive elements
 809 into it from the SEQUENCE2.
 810
 811 Elements are copied to the subseqeuence bounded by START1 and END1,
 812 from the subsequence bounded by START2 and END2. If these subsequences
 813 are not of the same length, then the shorter length determines how
 814 many elements are copied."
 815   (declare (truly-dynamic-extent args))
 816   (declare (explicit-check sequence1 sequence2 :result))
 817   (let* (;; KLUDGE: absent either rewriting FOO-REPLACE-FROM-BAR, or
 818          ;; excessively polluting DEFINE-SEQUENCE-TRAVERSER, we rebind
 819          ;; these things here so that legacy code gets the names it's
 820          ;; expecting.  We could use &AUX instead :-/.
 821          (target-sequence sequence1)
 822          (source-sequence sequence2)
 823          (target-start start1)
 824          (source-start start2)
 825          (target-end (or end1 length1))
 826          (source-end (or end2 length2)))
 827     (seq-dispatch-checking target-sequence
 828       (seq-dispatch-checking source-sequence
 829         (return-from replace (list-replace-from-list))
 830         (return-from replace (list-replace-from-mumble))
 831         nil)
 832       (seq-dispatch-checking source-sequence
 833         (return-from replace (mumble-replace-from-list))
 834         (return-from replace (mumble-replace-from-mumble))
 835         nil)
 836       t)
 837     ;; If sequence1 is an extended-sequence, we know nothing about sequence2.
 838     ;; If sequence1 was a list or vector, then sequence2 is an extended-sequence
 839     ;; or not a sequence. Either way, check it.
 840     (the sequence
 841       (values (apply #'sb!sequence:replace sequence1
 842                      (the sequence sequence2) args)))))
 843 \f
 844 ;;;; REVERSE
 845 (defun reverse (sequence)
 846   #!+sb-doc
 847   "Return a new sequence containing the same elements but in reverse order."
 848   (declare (explicit-check))
 849   (seq-dispatch-checking sequence
 850     (list-reverse sequence)
 851     (vector-reverse sequence)
 852     ;; The type deriver says that LIST => LIST and VECTOR => VECTOR
 853     ;; but does not claim to know anything about extended-sequences.
 854     ;; So this could theoretically return any subtype of SEQUENCE
 855     ;; given an EXTENDED-SEQUENCE as input. But fndb says this returns
 856     ;; a CONSED-SEQUENCE, which precludes non-simple vectors.
 857     ;; But a CLOS sequence can apparently decide to return a LIST when
 858     ;; reversed. [Is that too weird? Make this EXTENDED-SEQUENCE maybe?]
 859     (the consed-sequence (values (sb!sequence:reverse sequence)))))
 860
 861 (defun list-reverse (list)
 862   (do ((new-list ()))
 863       ((endp list) new-list)
 864     (push (pop list) new-list)))
 865
 866 (defmacro word-specialized-vector-tag-p (tag)
 867   `(or
 868     ,@(loop for saetp across sb!vm:*specialized-array-element-type-properties*
 869            when (and (eq (sb!vm:saetp-n-bits saetp) sb!vm:n-word-bits)
 870                      (not (eq (sb!vm:saetp-specifier saetp) t)))
 871            collect `(eq ,tag ,(sb!vm:saetp-typecode saetp)))))
 872
 873 (defun reverse-word-specialized-vector (from to end)
 874   (declare (vector from))
 875   (do ((length (length to))
 876        (left-index 0 (1+ left-index))
 877        (right-index end))
 878       ((= left-index length))
 879     (declare (type index left-index right-index))
 880     (decf right-index)
 881     (setf (%vector-raw-bits to left-index)
 882           (%vector-raw-bits from right-index)))
 883   to)
 884
 885 (defun vector-reverse (vector)
 886   (declare (vector vector))
 887   (let ((length (length vector)))
 888     (with-array-data ((vector vector) (start) (end)
 889                       :check-fill-pointer t)
 890       (declare (ignore start))
 891       (let* ((tag (%other-pointer-widetag vector))
 892              (new-vector (allocate-vector-with-widetag tag length)))
 893         (cond ((= tag sb!vm:simple-vector-widetag)
 894                (do ((left-index 0 (1+ left-index))
 895                     (right-index end))
 896                    ((= left-index length))
 897                  (declare (type index left-index right-index))
 898                  (decf right-index)
 899                  (setf (svref new-vector left-index)
 900                        (svref vector right-index))))
 901               ((word-specialized-vector-tag-p tag)
 902                (reverse-word-specialized-vector vector new-vector end))
 903               (t
 904                (let ((getter (the function (svref %%data-vector-reffers%% tag)))
 905                      (setter (the function (svref %%data-vector-setters%% tag))))
 906                  (declare (fixnum length))
 907                  (do ((forward-index 0 (1+ forward-index))
 908                       (backward-index (1- end) (1- backward-index)))
 909                      ((= forward-index length))
 910                    (declare (fixnum forward-index backward-index))
 911                    (funcall setter new-vector forward-index
 912                             (funcall getter vector backward-index))))))
 913         new-vector))))
 914 \f
 915 ;;;; NREVERSE
 916
 917 (defun list-nreverse (list)
 918   (do ((1st (cdr list) (if (endp 1st) 1st (cdr 1st)))
 919        (2nd list 1st)
 920        (3rd '() 2nd))
 921       ((atom 2nd) 3rd)
 922     (rplacd 2nd 3rd)))
 923
 924 (defun nreverse-word-specialized-vector (vector start end)
 925   (do ((left-index start (1+ left-index))
 926        (right-index (1- end) (1- right-index)))
 927       ((<= right-index left-index))
 928     (declare (type index left-index right-index))
 929     (let ((left (%vector-raw-bits vector left-index))
 930           (right (%vector-raw-bits vector right-index)))
 931       (setf (%vector-raw-bits vector left-index) right
 932             (%vector-raw-bits vector right-index) left)))
 933   vector)
 934
 935 (defun vector-nreverse (vector)
 936   (declare (vector vector))
 937   (when (> (length vector) 1)
 938     (with-array-data ((vector vector) (start) (end)
 939                       :check-fill-pointer t)
 940       (let ((tag (%other-pointer-widetag vector)))
 941         (cond ((= tag sb!vm:simple-vector-widetag)
 942                (do ((left-index start (1+ left-index))
 943                     (right-index (1- end) (1- right-index)))
 944                    ((<= right-index left-index))
 945                  (declare (type index left-index right-index))
 946                  (let ((left (svref vector left-index))
 947                        (right (svref vector right-index)))
 948                    (setf (svref vector left-index) right
 949                          (svref vector right-index) left))))
 950               ((word-specialized-vector-tag-p tag)
 951                (nreverse-word-specialized-vector vector start end))
 952               (t
 953                (let* ((getter (the function (svref %%data-vector-reffers%% tag)))
 954                       (setter (the function (svref %%data-vector-setters%% tag))))
 955                  (do ((left-index start (1+ left-index))
 956                       (right-index (1- end) (1- right-index)))
 957                      ((<= right-index left-index))
 958                    (declare (type index left-index right-index))
 959                    (let ((left (funcall getter vector left-index))
 960                          (right (funcall getter vector right-index)))
 961                      (funcall setter vector left-index right)
 962                      (funcall setter vector right-index left)))))))))
 963   vector)
 964
 965 (defun nreverse (sequence)
 966   #!+sb-doc
 967   "Return a sequence of the same elements in reverse order; the argument
 968    is destroyed."
 969   (declare (explicit-check))
 970   (seq-dispatch-checking sequence
 971     (list-nreverse sequence)
 972     (vector-nreverse sequence)
 973     ;; The type deriver for this is 'result-type-first-arg',
 974     ;; meaning it should return definitely an EXTENDED-SEQUENCE
 975     ;; and not a list or vector.
 976     (the extended-sequence (values (sb!sequence:nreverse sequence)))))
 977 \f
 978
 979 (defmacro sb!sequence:dosequence ((element sequence &optional return) &body body)
 980   #!+sb-doc
 981   "Executes BODY with ELEMENT subsequently bound to each element of
 982   SEQUENCE, then returns RETURN."
 983   (multiple-value-bind (forms decls) (parse-body body nil)
 984     (once-only ((sequence sequence))
 985       (with-unique-names (state limit from-end step endp elt)
 986         `(block nil
 987            (seq-dispatch ,sequence
 988              (dolist (,element ,sequence ,return) ,@body)
 989              (do-vector-data (,element ,sequence ,return) ,@body)
 990              (multiple-value-bind (,state ,limit ,from-end ,step ,endp ,elt)
 991                  (sb!sequence:make-sequence-iterator ,sequence)
 992                (declare (function ,step ,endp ,elt))
 993                (do ((,state ,state (funcall ,step ,sequence ,state ,from-end)))
 994                    ((funcall ,endp ,sequence ,state ,limit ,from-end)
 995                     (let ((,element nil))
 996                       ,@(filter-dolist-declarations decls)
 997                       (declare (ignorable ,element))
 998                       ,return))
 999                  (let ((,element (funcall ,elt ,sequence ,state)))
1000                    ,@decls
1001                    (tagbody
1002                       ,@forms))))))))))
1003
1004 \f
1005 ;;;; CONCATENATE
1006
1007 (defun concatenate (result-type &rest sequences)
1008   #!+sb-doc
1009   "Return a new sequence of all the argument sequences concatenated together
1010   which shares no structure with the original argument sequences of the
1011   specified RESULT-TYPE."
1012   (declare (explicit-check)
1013            (dynamic-extent sequences))
1014   (flet ((concat-to-simple* (type-spec sequences)
1015            (do ((seqs sequences (cdr seqs))
1016                 (total-length 0)
1017                 (lengths ()))
1018                ((null seqs)
1019                 (do ((sequences sequences (cdr sequences))
1020                      (lengths lengths (cdr lengths))
1021                      (index 0)
1022                      (result (make-sequence type-spec total-length)))
1023                     ((= index total-length) result)
1024                   (declare (fixnum index))
1025                   (let ((sequence (car sequences)))
1026                     (sb!sequence:dosequence (e sequence)
1027                       (setf (aref result index) e)
1028                       (incf index)))))
1029              (let ((length (length (car seqs))))
1030                (declare (fixnum length))
1031                (setq lengths (nconc lengths (list length)))
1032                (setq total-length (+ total-length length))))))
1033     (case result-type
1034       ;; Pick up some common cases first
1035       (list
1036        (apply #'%concatenate-to-list sequences))
1037       ((vector simple-vector)
1038        (apply #'%concatenate-to-simple-vector sequences))
1039       #!+sb-unicode
1040       ((string simple-string)
1041        (apply #'%concatenate-to-string sequences))
1042       ((simple-base-string #!-sb-unicode string #!-sb-unicode simple-string)
1043        (apply #'%concatenate-to-base-string sequences))
1044       (t
1045        (let ((type (specifier-type result-type)))
1046          (cond
1047            ((csubtypep type (specifier-type 'list))
1048             (cond
1049               ((type= type (specifier-type 'list))
1050                (apply #'%concatenate-to-list sequences))
1051               ((eq type *empty-type*)
1052                (bad-sequence-type-error nil))
1053               ((type= type (specifier-type 'null))
1054                (unless (every #'emptyp sequences)
1055                  (sequence-type-length-mismatch-error
1056                   type (reduce #'+ sequences :key #'length))) ; FIXME: circular list issues.
1057                '())
1058               ((cons-type-p type)
1059                (multiple-value-bind (min exactp)
1060                    (sb!kernel::cons-type-length-info type)
1061                  (let ((length (reduce #'+ sequences :key #'length)))
1062                    (if exactp
1063                        (unless (= length min)
1064                          (sequence-type-length-mismatch-error type length))
1065                        (unless (>= length min)
1066                          (sequence-type-length-mismatch-error type length)))
1067                    (apply #'%concatenate-to-list sequences))))
1068               (t (sequence-type-too-hairy (type-specifier type)))))
1069            ((csubtypep type (specifier-type 'vector))
1070             (concat-to-simple* result-type sequences))
1071            ((when-extended-sequence-type
1072                 (result-type type :expandedp nil :prototype prototype)
1073               ;; This function has the EXPLICIT-CHECK declaration,
1074               ;; so we manually assert that it returns a SEQUENCE.
1075               (the extended-sequence
1076                    (apply #'sb!sequence:concatenate prototype sequences))))
1077            (t
1078             (bad-sequence-type-error result-type))))))))
1079
1080 ;;; Efficient out-of-line concatenate for strings. Compiler transforms
1081 ;;; CONCATENATE 'STRING &co into these.
1082 (macrolet ((def (name element-type &rest dispatch)
1083              `(defun ,name (&rest sequences)
1084                 (declare (explicit-check)
1085                          (optimize (sb!c::insert-array-bounds-checks 0)))
1086                 (let ((length 0))
1087                   (declare (index length))
1088                   (do-rest-arg ((seq) sequences)
1089                     (incf length (length seq)))
1090                   (let ((result (make-array length :element-type ',element-type))
1091                         (start 0))
1092                     (declare (index start))
1093                     (do-rest-arg ((seq) sequences)
1094                       (string-dispatch (,@dispatch t)
1095                                        seq
1096                         (let ((length (length seq)))
1097                           (replace result seq :start1 start)
1098                           (incf start length))))
1099                     result)))))
1100   #!+sb-unicode
1101   (def %concatenate-to-string character
1102     (simple-array character (*)) (simple-array base-char (*)))
1103   (def %concatenate-to-base-string base-char
1104     (simple-array base-char (*)) #!+sb-unicode (simple-array character (*)))
1105   (def %concatenate-to-simple-vector t simple-vector))
1106
1107 (defun %concatenate-to-list (&rest sequences)
1108   (declare (explicit-check))
1109   (let* ((result (list nil))
1110          (splice result))
1111     (do-rest-arg ((sequence) sequences)
1112       (sb!sequence:dosequence (e sequence)
1113         (setf splice (cdr (rplacd splice (list e))))))
1114     (cdr result)))
1115
1116 (defun %concatenate-to-vector (widetag &rest sequences)
1117   (declare (explicit-check))
1118   (let ((length 0))
1119     (declare (index length))
1120     (do-rest-arg ((seq) sequences)
1121       (incf length (length seq)))
1122     (let ((result (allocate-vector-with-widetag widetag length))
1123           (setter (the function (svref %%data-vector-setters%% widetag)))
1124           (index 0))
1125       (declare (index index))
1126       (do-rest-arg ((seq) sequences)
1127         (sb!sequence:dosequence (e seq)
1128           (funcall setter result index e)
1129           (incf index)))
1130       result)))
1131 \f
1132 ;;;; MAP
1133
1134 ;;; helper functions to handle arity-1 subcases of MAP
1135 (defun %map-to-list-arity-1 (fun sequence)
1136   (declare (explicit-check))
1137   (let ((reversed-result nil)
1138         (really-fun (%coerce-callable-to-fun fun)))
1139     (sb!sequence:dosequence (element sequence)
1140       (push (funcall really-fun element)
1141             reversed-result))
1142     (nreverse reversed-result)))
1143 (defun %map-to-simple-vector-arity-1 (fun sequence)
1144   (declare (explicit-check))
1145   (let ((result (make-array (length sequence)))
1146         (index 0)
1147         (really-fun (%coerce-callable-to-fun fun)))
1148     (declare (type index index))
1149     (sb!sequence:dosequence (element sequence)
1150       (setf (aref result index)
1151             (funcall really-fun element))
1152       (incf index))
1153     result))
1154 (defun %map-for-effect-arity-1 (fun sequence)
1155   (declare (explicit-check))
1156   (let ((really-fun (%coerce-callable-to-fun fun)))
1157     (sb!sequence:dosequence (element sequence)
1158       (funcall really-fun element)))
1159   nil)
1160
1161 (declaim (maybe-inline %map-for-effect))
1162 (defun %map-for-effect (fun sequences)
1163   (declare (type function fun) (type list sequences))
1164   (let ((%sequences sequences)
1165         (%iters (mapcar (lambda (s)
1166                           (seq-dispatch s
1167                             s
1168                             0
1169                             (multiple-value-list
1170                              (sb!sequence:make-sequence-iterator s))))
1171                         sequences))
1172         (%apply-args (make-list (length sequences))))
1173     ;; this is almost efficient (except in the general case where we
1174     ;; trampoline to MAKE-SEQUENCE-ITERATOR; if we had DX allocation
1175     ;; of MAKE-LIST, the whole of %MAP would be cons-free.
1176     ;; TODO: on x86-64, we do have. Now see if the above remark is true.
1177     (declare (type list %sequences %iters %apply-args))
1178     (loop
1179      (do ((in-sequences  %sequences  (cdr in-sequences))
1180           (in-iters      %iters      (cdr in-iters))
1181           (in-apply-args %apply-args (cdr in-apply-args)))
1182          ((null in-sequences) (apply fun %apply-args))
1183        (let ((i (car in-iters)))
1184          (declare (type (or list index) i))
1185          (cond
1186            ((listp (car in-sequences))
1187             (if (null i)
1188                 (return-from %map-for-effect nil)
1189                 (setf (car in-apply-args) (car i)
1190                       (car in-iters) (cdr i))))
1191            ((typep i 'index)
1192             (let ((v (the vector (car in-sequences))))
1193               (if (>= i (length v))
1194                   (return-from %map-for-effect nil)
1195                   (setf (car in-apply-args) (aref v i)
1196                         (car in-iters) (1+ i)))))
1197            (t
1198             ;; While on one hand this could benefit from a zero-safety ds-bind,
1199             ;; on the other, why not coerce these tuples to vectors or structs?
1200             (destructuring-bind (state limit from-end step endp elt &rest ignore)
1201                 i
1202               (declare (type function step endp elt)
1203                        (ignore ignore))
1204               (let ((s (car in-sequences)))
1205                 (if (funcall endp s state limit from-end)
1206                     (return-from %map-for-effect nil)
1207                     (progn
1208                       (setf (car in-apply-args) (funcall elt s state))
1209                       (setf (caar in-iters) (funcall step s state from-end)))))))))))))
1210 (defun %map-to-list (fun sequences)
1211   (declare (type function fun)
1212            (type list sequences))
1213   (let ((result nil))
1214     (flet ((f (&rest args)
1215              (declare (truly-dynamic-extent args))
1216              (push (apply fun args) result)))
1217       (declare (truly-dynamic-extent #'f))
1218       (%map-for-effect #'f sequences))
1219     (nreverse result)))
1220 (defun %map-to-vector (output-type-spec fun sequences)
1221   (declare (type function fun)
1222            (type list sequences))
1223   (let ((min-len 0))
1224     (flet ((f (&rest args)
1225              (declare (truly-dynamic-extent args))
1226              (declare (ignore args))
1227              (incf min-len)))
1228       (declare (truly-dynamic-extent #'f))
1229       (%map-for-effect #'f sequences))
1230     (let ((result (make-sequence output-type-spec min-len))
1231           (i 0))
1232       (declare (type (simple-array * (*)) result))
1233       (flet ((f (&rest args)
1234                (declare (truly-dynamic-extent args))
1235                (setf (aref result i) (apply fun args))
1236                (incf i)))
1237         (declare (truly-dynamic-extent #'f))
1238         (%map-for-effect #'f sequences))
1239       result)))
1240
1241 ;;; %MAP is just MAP without the final just-to-be-sure check that
1242 ;;; length of the output sequence matches any length specified
1243 ;;; in RESULT-TYPE.
1244 (defun %map (result-type function &rest sequences)
1245   (declare (explicit-check))
1246   (declare (dynamic-extent sequences))
1247   ;; Everything that we end up calling uses %COERCE-TO-CALLABLE
1248   ;; on FUNCTION so we don't need to declare it of type CALLABLE here.
1249   ;; Additionally all the arity-1 mappers use SEQ-DISPATCH which asserts
1250   ;; that the input is a SEQUENCE. Despite SEQ-DISPATCH being "less safe"
1251   ;; than SEQ-DISPATCH-CHECKING, both are in fact equally safe, because
1252   ;; the ARRAY case (which assumes that all arrays are vectors) utilizes
1253   ;; %WITH-ARRAY-DATA/FP which asserts that its input is a vector.
1254   (labels ((slower-map (type)
1255              (let ((really-fun (%coerce-callable-to-fun function)))
1256                (cond
1257                  ((eq type *empty-type*)
1258                   (%map-for-effect really-fun sequences))
1259                  ((csubtypep type (specifier-type 'list))
1260                   (%map-to-list really-fun sequences))
1261                  ((csubtypep type (specifier-type 'vector))
1262                   (%map-to-vector result-type really-fun sequences))
1263                  ((when-extended-sequence-type
1264                       (result-type type :expandedp nil :prototype prototype)
1265                     ;; This function has the EXPLICIT-CHECK
1266                     ;; declaration, so we manually assert that it
1267                     ;; returns a SEQUENCE.
1268                     (the extended-sequence
1269                          (apply #'sb!sequence:map
1270                                 prototype really-fun sequences))))
1271                  (t
1272                   (bad-sequence-type-error result-type))))))
1273     ;; Handle some easy cases faster
1274     (if (/= (length sequences) 1)
1275         (slower-map (specifier-type result-type))
1276         (let ((first-sequence (fast-&rest-nth 0 sequences)))
1277           (case result-type
1278            ((nil)
1279             (%map-for-effect-arity-1 function first-sequence))
1280            ((list cons)
1281             (%map-to-list-arity-1 function first-sequence))
1282            ((vector simple-vector)
1283             (%map-to-simple-vector-arity-1 function first-sequence))
1284            (t
1285             (let ((type (specifier-type result-type)))
1286               (cond ((eq type *empty-type*)
1287                      (%map-for-effect-arity-1 function first-sequence))
1288                     ((csubtypep type (specifier-type 'list))
1289                      (%map-to-list-arity-1 function first-sequence))
1290                     ((csubtypep type (specifier-type '(vector t)))
1291                      (%map-to-simple-vector-arity-1 function first-sequence))
1292                     (t
1293                      (slower-map type))))))))))
1294
1295 (defun map (result-type function first-sequence &rest more-sequences)
1296   (declare (explicit-check))
1297   (let ((result
1298          (apply #'%map result-type function first-sequence more-sequences)))
1299     (if (or (eq result-type 'nil) (typep result result-type))
1300         result
1301         (error 'simple-type-error
1302                :format-control "MAP result ~S is not a sequence of type ~S"
1303                :datum result
1304                :expected-type result-type
1305                :format-arguments (list result result-type)))))
1306
1307 ;;;; MAP-INTO
1308
1309 (defmacro map-into-lambda (sequences params &body body)
1310   (check-type sequences symbol)
1311   `(flet ((f ,params ,@body))
1312      (declare (truly-dynamic-extent #'f))
1313      ;; Note (MAP-INTO SEQ (LAMBDA () ...)) is a different animal,
1314      ;; hence the awkward flip between MAP and LOOP.
1315      (if ,sequences
1316          (apply #'%map nil #'f ,sequences)
1317          (loop (f)))))
1318
1319 (!define-array-dispatch vector-map-into (data start end fun sequences)
1320   (declare (type index start end)
1321            (type function fun)
1322            (type list sequences))
1323   (declare (explicit-check))
1324   (let ((index start))
1325     (declare (type index index))
1326     (block mapping
1327       (map-into-lambda sequences (&rest args)
1328         (declare (truly-dynamic-extent args))
1329         (when (eql index end)
1330           (return-from mapping))
1331         (setf (aref data index) (apply fun args))
1332         (incf index)))
1333     index))
1334
1335 ;;; Uses the machinery of (MAP NIL ...). For non-vectors we avoid
1336 ;;; computing the length of the result sequence since we can detect
1337 ;;; the end during mapping (if MAP even gets that far).
1338 ;;;
1339 ;;; For each result type, define a mapping function which is
1340 ;;; responsible for replacing RESULT-SEQUENCE elements and for
1341 ;;; terminating itself if the end of RESULT-SEQUENCE is reached.
1342 ;;; The mapping function is defined with MAP-INTO-LAMBDA.
1343 ;;;
1344 ;;; MAP-INTO-LAMBDAs are optimized since they are the inner loops.
1345 ;;; Because we are manually doing bounds checking with known types,
1346 ;;; safety is turned off for vectors and lists but kept for generic
1347 ;;; sequences.
1348 (defun map-into (result-sequence function &rest sequences)
1349   (declare (optimize (sb!c::check-tag-existence 0)))
1350   (let ((really-fun (%coerce-callable-to-fun function)))
1351     (etypecase result-sequence
1352       (vector
1353        (with-array-data ((data result-sequence) (start) (end)
1354                          ;; MAP-INTO ignores fill pointer when mapping
1355                          :check-fill-pointer nil)
1356          (let ((new-end (vector-map-into data start end really-fun sequences)))
1357            (when (array-has-fill-pointer-p result-sequence)
1358              (setf (fill-pointer result-sequence) (- new-end start))))))
1359       (list
1360        (let ((node result-sequence))
1361          (declare (type list node))
1362          (map-into-lambda sequences (&rest args)
1363            (declare (truly-dynamic-extent args))
1364            (cond ((null node)
1365                   (return-from map-into result-sequence))
1366                  ((not (listp (cdr node)))
1367                   (error 'simple-type-error
1368                          :format-control "~a is not a proper list"
1369                          :format-arguments (list result-sequence)
1370                          :expected-type 'list
1371                          :datum result-sequence)))
1372            (setf (car node) (apply really-fun args))
1373            (setf node (cdr node)))))
1374       (sequence
1375        (multiple-value-bind (iter limit from-end)
1376            (sb!sequence:make-sequence-iterator result-sequence)
1377          (map-into-lambda sequences (&rest args)
1378            (declare (truly-dynamic-extent args) (optimize speed))
1379            (when (sb!sequence:iterator-endp result-sequence
1380                                             iter limit from-end)
1381              (return-from map-into result-sequence))
1382            (setf (sb!sequence:iterator-element result-sequence iter)
1383                  (apply really-fun args))
1384            (setf iter (sb!sequence:iterator-step result-sequence
1385                                                            iter from-end)))))))
1386   result-sequence)
1387 \f
1388 ;;;; REDUCE
1389
1390 (eval-when (:compile-toplevel :execute)
1391
1392 (sb!xc:defmacro mumble-reduce (function
1393                                sequence
1394                                key
1395                                start
1396                                end
1397                                initial-value
1398                                ref)
1399   `(do ((index ,start (1+ index))
1400         (value ,initial-value))
1401        ((>= index ,end) value)
1402      (setq value (funcall ,function value
1403                           (apply-key ,key (,ref ,sequence index))))))
1404
1405 (sb!xc:defmacro mumble-reduce-from-end (function
1406                                         sequence
1407                                         key
1408                                         start
1409                                         end
1410                                         initial-value
1411                                         ref)
1412   `(do ((index (1- ,end) (1- index))
1413         (value ,initial-value)
1414         (terminus (1- ,start)))
1415        ((<= index terminus) value)
1416      (setq value (funcall ,function
1417                           (apply-key ,key (,ref ,sequence index))
1418                           value))))
1419
1420 (sb!xc:defmacro list-reduce (function
1421                              sequence
1422                              key
1423                              start
1424                              end
1425                              initial-value
1426                              ivp)
1427   `(let ((sequence (nthcdr ,start ,sequence)))
1428      (do ((count (if ,ivp ,start (1+ ,start))
1429                  (1+ count))
1430           (sequence (if ,ivp sequence (cdr sequence))
1431                     (cdr sequence))
1432           (value (if ,ivp ,initial-value (apply-key ,key (car sequence)))
1433                  (funcall ,function value (apply-key ,key (car sequence)))))
1434          ((>= count ,end) value))))
1435
1436 (sb!xc:defmacro list-reduce-from-end (function
1437                                       sequence
1438                                       key
1439                                       start
1440                                       end
1441                                       initial-value
1442                                       ivp)
1443   `(let ((sequence (nthcdr (- (length ,sequence) ,end)
1444                            (reverse ,sequence))))
1445      (do ((count (if ,ivp ,start (1+ ,start))
1446                  (1+ count))
1447           (sequence (if ,ivp sequence (cdr sequence))
1448                     (cdr sequence))
1449           (value (if ,ivp ,initial-value (apply-key ,key (car sequence)))
1450                  (funcall ,function (apply-key ,key (car sequence)) value)))
1451          ((>= count ,end) value))))
1452
1453 ) ; EVAL-WHEN
1454
1455 (define-sequence-traverser reduce (function sequence &rest args &key key
1456                                    from-end start end (initial-value nil ivp))
1457   (declare (type index start)
1458            (truly-dynamic-extent args))
1459   (declare (explicit-check sequence))
1460   (seq-dispatch-checking sequence
1461     (let ((end (or end length)))
1462       (declare (type index end))
1463       (if (= end start)
1464           (if ivp initial-value (funcall function))
1465           (if from-end
1466               (list-reduce-from-end function sequence key start end
1467                                     initial-value ivp)
1468               (list-reduce function sequence key start end
1469                            initial-value ivp))))
1470     (let ((end (or end length)))
1471       (declare (type index end))
1472       (if (= end start)
1473           (if ivp initial-value (funcall function))
1474           (if from-end
1475               (progn
1476                 (when (not ivp)
1477                   (setq end (1- (the fixnum end)))
1478                   (setq initial-value (apply-key key (aref sequence end))))
1479                 (mumble-reduce-from-end function sequence key start end
1480                                         initial-value aref))
1481               (progn
1482                 (when (not ivp)
1483                   (setq initial-value (apply-key key (aref sequence start)))
1484                   (setq start (1+ start)))
1485                 (mumble-reduce function sequence key start end
1486                                initial-value aref)))))
1487     (apply #'sb!sequence:reduce function sequence args)))
1488 \f
1489 ;;;; DELETE
1490
1491 (eval-when (:compile-toplevel :execute)
1492
1493 (sb!xc:defmacro mumble-delete (pred)
1494   `(do ((index start (1+ index))
1495         (jndex start)
1496         (number-zapped 0))
1497        ((or (= index (the fixnum end)) (= number-zapped count))
1498         (do ((index index (1+ index))           ; Copy the rest of the vector.
1499              (jndex jndex (1+ jndex)))
1500             ((= index (the fixnum length))
1501              (shrink-vector sequence jndex))
1502           (declare (fixnum index jndex))
1503           (setf (aref sequence jndex) (aref sequence index))))
1504      (declare (fixnum index jndex number-zapped))
1505      (setf (aref sequence jndex) (aref sequence index))
1506      (if ,pred
1507          (incf number-zapped)
1508          (incf jndex))))
1509
1510 (sb!xc:defmacro mumble-delete-from-end (pred)
1511   `(do ((index (1- (the fixnum end)) (1- index)) ; Find the losers.
1512         (number-zapped 0)
1513         (losers ())
1514         this-element
1515         (terminus (1- start)))
1516        ((or (= index terminus) (= number-zapped count))
1517         (do ((losers losers)                     ; Delete the losers.
1518              (index start (1+ index))
1519              (jndex start))
1520             ((or (null losers) (= index (the fixnum end)))
1521              (do ((index index (1+ index))       ; Copy the rest of the vector.
1522                   (jndex jndex (1+ jndex)))
1523                  ((= index (the fixnum length))
1524                   (shrink-vector sequence jndex))
1525                (declare (fixnum index jndex))
1526                (setf (aref sequence jndex) (aref sequence index))))
1527           (declare (fixnum index jndex))
1528           (setf (aref sequence jndex) (aref sequence index))
1529           (if (= index (the fixnum (car losers)))
1530               (pop losers)
1531               (incf jndex))))
1532      (declare (fixnum index number-zapped terminus))
1533      (setq this-element (aref sequence index))
1534      (when ,pred
1535        (incf number-zapped)
1536        (push index losers))))
1537
1538 (sb!xc:defmacro normal-mumble-delete ()
1539   `(mumble-delete
1540     (if test-not
1541         (not (funcall test-not item (apply-key key (aref sequence index))))
1542         (funcall test item (apply-key key (aref sequence index))))))
1543
1544 (sb!xc:defmacro normal-mumble-delete-from-end ()
1545   `(mumble-delete-from-end
1546     (if test-not
1547         (not (funcall test-not item (apply-key key this-element)))
1548         (funcall test item (apply-key key this-element)))))
1549
1550 (sb!xc:defmacro list-delete (pred)
1551   `(let ((handle (cons nil sequence)))
1552      (declare (truly-dynamic-extent handle))
1553      (do* ((previous (nthcdr start handle))
1554            (current (cdr previous) (cdr current))
1555            (index start (1+ index))
1556            (number-zapped 0))
1557           ((or (= index end) (= number-zapped count))
1558            (cdr handle))
1559        (declare (index index number-zapped))
1560        (cond (,pred
1561               (rplacd previous (cdr current))
1562               (incf number-zapped))
1563              (t
1564               (pop previous))))))
1565
1566 (sb!xc:defmacro list-delete-from-end (pred)
1567   `(let* ((reverse (nreverse sequence))
1568           (handle (cons nil reverse)))
1569      (declare (truly-dynamic-extent handle))
1570      (do* ((previous (nthcdr (- length end) handle))
1571            (current (cdr previous) (cdr current))
1572            (index start (1+ index))
1573            (number-zapped 0))
1574           ((or (= index end) (= number-zapped count))
1575            (nreverse (cdr handle)))
1576        (declare (index index number-zapped))
1577        (cond (,pred
1578               (rplacd previous (cdr current))
1579               (incf number-zapped))
1580              (t
1581               (pop previous))))))
1582
1583 (sb!xc:defmacro normal-list-delete ()
1584   '(list-delete
1585     (if test-not
1586         (not (funcall test-not item (apply-key key (car current))))
1587         (funcall test item (apply-key key (car current))))))
1588
1589 (sb!xc:defmacro normal-list-delete-from-end ()
1590   '(list-delete-from-end
1591     (if test-not
1592         (not (funcall test-not item (apply-key key (car current))))
1593         (funcall test item (apply-key key (car current))))))
1594
1595 ) ; EVAL-WHEN
1596
1597 (define-sequence-traverser delete
1598     (item sequence &rest args &key from-end test test-not start
1599      end count key)
1600   #!+sb-doc
1601   "Return a sequence formed by destructively removing the specified ITEM from
1602   the given SEQUENCE."
1603   (declare (type fixnum start)
1604            (truly-dynamic-extent args))
1605   (declare (explicit-check sequence :result))
1606   (seq-dispatch-checking=>seq sequence
1607     (let ((end (or end length)))
1608       (declare (type index end))
1609       (if from-end
1610           (normal-list-delete-from-end)
1611           (normal-list-delete)))
1612     (let ((end (or end length)))
1613       (declare (type index end))
1614       (if from-end
1615           (normal-mumble-delete-from-end)
1616           (normal-mumble-delete)))
1617     (apply #'sb!sequence:delete item sequence args)))
1618
1619 (eval-when (:compile-toplevel :execute)
1620
1621 (sb!xc:defmacro if-mumble-delete ()
1622   `(mumble-delete
1623     (funcall predicate (apply-key key (aref sequence index)))))
1624
1625 (sb!xc:defmacro if-mumble-delete-from-end ()
1626   `(mumble-delete-from-end
1627     (funcall predicate (apply-key key this-element))))
1628
1629 (sb!xc:defmacro if-list-delete ()
1630   '(list-delete
1631     (funcall predicate (apply-key key (car current)))))
1632
1633 (sb!xc:defmacro if-list-delete-from-end ()
1634   '(list-delete-from-end
1635     (funcall predicate (apply-key key (car current)))))
1636
1637 ) ; EVAL-WHEN
1638
1639 (define-sequence-traverser delete-if
1640     (predicate sequence &rest args &key from-end start key end count)
1641   #!+sb-doc
1642   "Return a sequence formed by destructively removing the elements satisfying
1643   the specified PREDICATE from the given SEQUENCE."
1644   (declare (type fixnum start)
1645            (truly-dynamic-extent args))
1646   (declare (explicit-check sequence :result))
1647   (seq-dispatch-checking=>seq sequence
1648     (let ((end (or end length)))
1649       (declare (type index end))
1650       (if from-end
1651           (if-list-delete-from-end)
1652           (if-list-delete)))
1653     (let ((end (or end length)))
1654       (declare (type index end))
1655       (if from-end
1656           (if-mumble-delete-from-end)
1657           (if-mumble-delete)))
1658     (apply #'sb!sequence:delete-if predicate sequence args)))
1659
1660 (eval-when (:compile-toplevel :execute)
1661
1662 (sb!xc:defmacro if-not-mumble-delete ()
1663   `(mumble-delete
1664     (not (funcall predicate (apply-key key (aref sequence index))))))
1665
1666 (sb!xc:defmacro if-not-mumble-delete-from-end ()
1667   `(mumble-delete-from-end
1668     (not (funcall predicate (apply-key key this-element)))))
1669
1670 (sb!xc:defmacro if-not-list-delete ()
1671   '(list-delete
1672     (not (funcall predicate (apply-key key (car current))))))
1673
1674 (sb!xc:defmacro if-not-list-delete-from-end ()
1675   '(list-delete-from-end
1676     (not (funcall predicate (apply-key key (car current))))))
1677
1678 ) ; EVAL-WHEN
1679
1680 (define-sequence-traverser delete-if-not
1681     (predicate sequence &rest args &key from-end start end key count)
1682   #!+sb-doc
1683   "Return a sequence formed by destructively removing the elements not
1684   satisfying the specified PREDICATE from the given SEQUENCE."
1685   (declare (type fixnum start)
1686            (truly-dynamic-extent args))
1687   (declare (explicit-check sequence :result))
1688   (seq-dispatch-checking=>seq sequence
1689     (let ((end (or end length)))
1690       (declare (type index end))
1691       (if from-end
1692           (if-not-list-delete-from-end)
1693           (if-not-list-delete)))
1694     (let ((end (or end length)))
1695       (declare (type index end))
1696       (if from-end
1697           (if-not-mumble-delete-from-end)
1698           (if-not-mumble-delete)))
1699     (apply #'sb!sequence:delete-if-not predicate sequence args)))
1700 \f
1701 ;;;; REMOVE
1702
1703 (eval-when (:compile-toplevel :execute)
1704
1705 ;;; MUMBLE-REMOVE-MACRO does not include (removes) each element that
1706 ;;; satisfies the predicate.
1707 (sb!xc:defmacro mumble-remove-macro (bump left begin finish right pred)
1708   `(do ((index ,begin (,bump index))
1709         (result
1710          (do ((index ,left (,bump index))
1711               (result (%make-sequence-like sequence length)))
1712              ((= index (the fixnum ,begin)) result)
1713            (declare (fixnum index))
1714            (setf (aref result index) (aref sequence index))))
1715         (new-index ,begin)
1716         (number-zapped 0)
1717         (this-element))
1718        ((or (= index (the fixnum ,finish))
1719             (= number-zapped count))
1720         (do ((index index (,bump index))
1721              (new-index new-index (,bump new-index)))
1722             ((= index (the fixnum ,right)) (%shrink-vector result new-index))
1723           (declare (fixnum index new-index))
1724           (setf (aref result new-index) (aref sequence index))))
1725      (declare (fixnum index new-index number-zapped))
1726      (setq this-element (aref sequence index))
1727      (cond (,pred (incf number-zapped))
1728            (t (setf (aref result new-index) this-element)
1729               (setq new-index (,bump new-index))))))
1730
1731 (sb!xc:defmacro mumble-remove (pred)
1732   `(mumble-remove-macro 1+ 0 start end length ,pred))
1733
1734 (sb!xc:defmacro mumble-remove-from-end (pred)
1735   `(let ((sequence (copy-seq sequence)))
1736      (mumble-delete-from-end ,pred)))
1737
1738 (sb!xc:defmacro normal-mumble-remove ()
1739   `(mumble-remove
1740     (if test-not
1741         (not (funcall test-not item (apply-key key this-element)))
1742         (funcall test item (apply-key key this-element)))))
1743
1744 (sb!xc:defmacro normal-mumble-remove-from-end ()
1745   `(mumble-remove-from-end
1746     (if test-not
1747         (not (funcall test-not item (apply-key key this-element)))
1748         (funcall test item (apply-key key this-element)))))
1749
1750 (sb!xc:defmacro if-mumble-remove ()
1751   `(mumble-remove (funcall predicate (apply-key key this-element))))
1752
1753 (sb!xc:defmacro if-mumble-remove-from-end ()
1754   `(mumble-remove-from-end (funcall predicate (apply-key key this-element))))
1755
1756 (sb!xc:defmacro if-not-mumble-remove ()
1757   `(mumble-remove (not (funcall predicate (apply-key key this-element)))))
1758
1759 (sb!xc:defmacro if-not-mumble-remove-from-end ()
1760   `(mumble-remove-from-end
1761     (not (funcall predicate (apply-key key this-element)))))
1762
1763 ;;; LIST-REMOVE-MACRO does not include (removes) each element that satisfies
1764 ;;; the predicate.
1765 (sb!xc:defmacro list-remove-macro (pred reverse?)
1766   `(let* ((sequence ,(if reverse?
1767                          '(reverse (the list sequence))
1768                          'sequence))
1769           (%start ,(if reverse? '(- length end) 'start))
1770           (%end ,(if reverse? '(- length start) 'end))
1771           (splice (list nil))
1772           (tail (and (/= %end length)
1773                      (nthcdr %end sequence)))
1774           (results ,(if reverse?
1775                           ;; It's already copied by REVERSE, so it can
1776                           ;; be modified here
1777                           `(if (plusp %start)
1778                                (let* ((tail (nthcdr (1- %start) sequence))
1779                                       (remaining (cdr tail)))
1780                                  (setf (cdr tail) nil)
1781                                  (prog1 splice
1782                                    (rplacd splice sequence)
1783                                    (setf splice tail
1784                                          sequence remaining)))
1785                                splice)
1786                           `(do ((index 0 (1+ index))
1787                                 (before-start splice))
1788                                ((= index (the fixnum %start)) before-start)
1789                              (declare (fixnum index))
1790                              (setf splice
1791                                    (cdr (rplacd splice (list (pop sequence)))))))))
1792      (declare (truly-dynamic-extent splice))
1793      (do ((this-element)
1794           (number-zapped 0))
1795          ((cond ((eq tail sequence)
1796                  (rplacd splice tail)
1797                  t)
1798                 ((= number-zapped count)
1799                  (rplacd splice sequence)
1800                  t))
1801           ,(if reverse?
1802                '(nreverse (the list (cdr results)))
1803                '(cdr results)))
1804        (declare (index number-zapped))
1805        (setf this-element (pop sequence))
1806        (if ,pred
1807            (incf number-zapped)
1808            (setf splice (cdr (rplacd splice (list this-element))))))))
1809
1810 (sb!xc:defmacro list-remove (pred)
1811   `(list-remove-macro ,pred nil))
1812
1813 (sb!xc:defmacro list-remove-from-end (pred)
1814   `(list-remove-macro ,pred t))
1815
1816 (sb!xc:defmacro normal-list-remove ()
1817   `(list-remove
1818     (if test-not
1819         (not (funcall test-not item (apply-key key this-element)))
1820         (funcall test item (apply-key key this-element)))))
1821
1822 (sb!xc:defmacro normal-list-remove-from-end ()
1823   `(list-remove-from-end
1824     (if test-not
1825         (not (funcall test-not item (apply-key key this-element)))
1826         (funcall test item (apply-key key this-element)))))
1827
1828 (sb!xc:defmacro if-list-remove ()
1829   `(list-remove
1830     (funcall predicate (apply-key key this-element))))
1831
1832 (sb!xc:defmacro if-list-remove-from-end ()
1833   `(list-remove-from-end
1834     (funcall predicate (apply-key key this-element))))
1835
1836 (sb!xc:defmacro if-not-list-remove ()
1837   `(list-remove
1838     (not (funcall predicate (apply-key key this-element)))))
1839
1840 (sb!xc:defmacro if-not-list-remove-from-end ()
1841   `(list-remove-from-end
1842     (not (funcall predicate (apply-key key this-element)))))
1843
1844 ) ; EVAL-WHEN
1845
1846 (define-sequence-traverser remove
1847     (item sequence &rest args &key from-end test test-not start
1848      end count key)
1849   #!+sb-doc
1850   "Return a copy of SEQUENCE with elements satisfying the test (default is
1851    EQL) with ITEM removed."
1852   (declare (type fixnum start)
1853            (truly-dynamic-extent args))
1854   (declare (explicit-check sequence :result))
1855   (seq-dispatch-checking=>seq sequence
1856     (let ((end (or end length)))
1857       (declare (type index end))
1858       (if from-end
1859           (normal-list-remove-from-end)
1860           (normal-list-remove)))
1861     (let ((end (or end length)))
1862       (declare (type index end))
1863       (if from-end
1864           (normal-mumble-remove-from-end)
1865           (normal-mumble-remove)))
1866     (apply #'sb!sequence:remove item sequence args)))
1867
1868 (define-sequence-traverser remove-if
1869     (predicate sequence &rest args &key from-end start end count key)
1870   #!+sb-doc
1871   "Return a copy of sequence with elements satisfying PREDICATE removed."
1872   (declare (type fixnum start)
1873            (truly-dynamic-extent args))
1874   (declare (explicit-check sequence :result))
1875   (seq-dispatch-checking=>seq sequence
1876     (let ((end (or end length)))
1877       (declare (type index end))
1878       (if from-end
1879           (if-list-remove-from-end)
1880           (if-list-remove)))
1881     (let ((end (or end length)))
1882       (declare (type index end))
1883       (if from-end
1884           (if-mumble-remove-from-end)
1885           (if-mumble-remove)))
1886     (apply #'sb!sequence:remove-if predicate sequence args)))
1887
1888 (define-sequence-traverser remove-if-not
1889     (predicate sequence &rest args &key from-end start end count key)
1890   #!+sb-doc
1891   "Return a copy of sequence with elements not satisfying PREDICATE removed."
1892   (declare (type fixnum start)
1893            (truly-dynamic-extent args))
1894   (declare (explicit-check sequence :result))
1895   (seq-dispatch-checking=>seq sequence
1896     (let ((end (or end length)))
1897       (declare (type index end))
1898       (if from-end
1899           (if-not-list-remove-from-end)
1900           (if-not-list-remove)))
1901     (let ((end (or end length)))
1902       (declare (type index end))
1903       (if from-end
1904           (if-not-mumble-remove-from-end)
1905           (if-not-mumble-remove)))
1906     (apply #'sb!sequence:remove-if-not predicate sequence args)))
1907 \f
1908 ;;;; REMOVE-DUPLICATES
1909
1910 ;;; Remove duplicates from a list. If from-end, remove the later duplicates,
1911 ;;; not the earlier ones. Thus if we check from-end we don't copy an item
1912 ;;; if we look into the already copied structure (from after :start) and see
1913 ;;; the item. If we check from beginning we check into the rest of the
1914 ;;; original list up to the :end marker (this we have to do by running a
1915 ;;; do loop down the list that far and using our test.
1916 (defun list-remove-duplicates* (list test test-not start end key from-end)
1917   (declare (fixnum start)
1918            (list list))
1919   (let* ((result (list ())) ; Put a marker on the beginning to splice with.
1920          (splice result)
1921          (current list)
1922          (length (length list))
1923          (end (or end length))
1924          (whole (= end length))
1925          (hash (and (> (- end start) 20)
1926                     (not key)
1927                     (not test-not)
1928                     (hash-table-test-p test)
1929                     (make-hash-table :test test :size (- end start))))
1930          (tail (and (not whole)
1931                     (nthcdr end list))))
1932     (declare (truly-dynamic-extent result))
1933     (do ((index 0 (1+ index)))
1934         ((= index start))
1935       (declare (fixnum index))
1936       (setq splice (cdr (rplacd splice (list (car current)))))
1937       (setq current (cdr current)))
1938     (if hash
1939         (do ()
1940             ((eq current tail))
1941           ;; The hash table contains links from values that are
1942           ;; already in result to the cons cell *preceding* theirs
1943           ;; in the list.  That is, for each value v in the list,
1944           ;; v and (cadr (gethash v hash)) are equal under TEST.
1945           (let ((prev (gethash (car current) hash)))
1946             (cond
1947               ((not prev)
1948                (setf (gethash (car current) hash) splice)
1949                (setq splice (cdr (rplacd splice (list (car current))))))
1950               ((not from-end)
1951                (let* ((old (cdr prev))
1952                       (next (cdr old)))
1953                  (if next
1954                      (let ((next-val (car next)))
1955                        ;; (assert (eq (gethash next-val hash) old))
1956                        (setf (cdr prev) next
1957                              (gethash next-val hash) prev
1958                              (gethash (car current) hash) splice
1959                              splice (cdr (rplacd splice (list (car current))))))
1960                      (setf (car old) (car current)))))))
1961           (setq current (cdr current)))
1962         (let ((testp test) ;; for with-member-test
1963               (notp test-not))
1964           (with-member-test (member-test
1965                              ((and (not from-end)
1966                                    (not whole))
1967                               (if notp
1968                                   (if key
1969                                       (lambda (x y key test)
1970                                         (not (funcall (truly-the function test) x
1971                                                       (funcall (truly-the function key) y))))
1972                                       (lambda (x y key test)
1973                                         (declare (ignore key))
1974                                         (not (funcall (truly-the function test) x y))))
1975                                   (if key
1976                                       (lambda (x y key test)
1977                                         (funcall (truly-the function test) x
1978                                                  (funcall (truly-the function key) y)))
1979                                       (lambda (x y key test)
1980                                         (declare (ignore key))
1981                                         (funcall (truly-the function test) x y))))))
1982             (do ((copied (nthcdr start result)))
1983                 ((eq current tail))
1984               (let ((elt (car current)))
1985                 (when (cond (from-end
1986                              (not (funcall member-test elt (cdr copied) key test)))
1987                             (whole
1988                              (not (funcall member-test elt (cdr current) key test)))
1989                             (t
1990                              (do ((it (apply-key key elt))
1991                                   (l (cdr current) (cdr l)))
1992                                  ((eq l tail)
1993                                   t)
1994                                (when (funcall member-test it (car l) key test)
1995                                  (return)))))
1996                   (setf splice (cdr (rplacd splice (list elt))))))
1997               (pop current)))))
1998     (rplacd splice tail)
1999     (cdr result)))
2000
2001 (defun vector-remove-duplicates* (vector test test-not start end key from-end
2002                                          &optional (length (length vector)))
2003   (declare (vector vector) (fixnum start length))
2004   (when (null end) (setf end (length vector)))
2005   (let ((result (%make-sequence-like vector length))
2006         (index 0)
2007         (jndex start))
2008     (declare (fixnum index jndex))
2009     (do ()
2010         ((= index start))
2011       (setf (aref result index) (aref vector index))
2012       (setq index (1+ index)))
2013     (do ((elt))
2014         ((= index end))
2015       (setq elt (aref vector index))
2016       (unless (or (and from-end
2017                        (if test-not
2018                            (position (apply-key key elt) result
2019                                      :start start :end jndex
2020                                      :test-not test-not :key key)
2021                            (position (apply-key key elt) result
2022                                      :start start :end jndex
2023                                      :test test :key key)))
2024                   (and (not from-end)
2025                        (if test-not
2026                            (position (apply-key key elt) vector
2027                                      :start (1+ index) :end end
2028                                      :test-not test-not :key key)
2029                            (position (apply-key key elt) vector
2030                                      :start (1+ index) :end end
2031                                      :test test :key key))))
2032         (setf (aref result jndex) elt)
2033         (setq jndex (1+ jndex)))
2034       (setq index (1+ index)))
2035     (do ()
2036         ((= index length))
2037       (setf (aref result jndex) (aref vector index))
2038       (setq index (1+ index))
2039       (setq jndex (1+ jndex)))
2040     (%shrink-vector result jndex)))
2041
2042 (define-sequence-traverser remove-duplicates
2043     (sequence &rest args &key test test-not start end from-end key)
2044   #!+sb-doc
2045   "The elements of SEQUENCE are compared pairwise, and if any two match,
2046    the one occurring earlier is discarded, unless FROM-END is true, in
2047    which case the one later in the sequence is discarded. The resulting
2048    sequence is returned.
2049
2050    The :TEST-NOT argument is deprecated."
2051   (declare (fixnum start)
2052            (truly-dynamic-extent args))
2053   (declare (explicit-check sequence :result))
2054   (seq-dispatch-checking=>seq sequence
2055     (if sequence
2056         (list-remove-duplicates* sequence test test-not
2057                                  start end key from-end))
2058     (vector-remove-duplicates* sequence test test-not start end key from-end)
2059     (apply #'sb!sequence:remove-duplicates sequence args)))
2060 \f
2061 ;;;; DELETE-DUPLICATES
2062 (defun list-delete-duplicates* (list test test-not key from-end start end)
2063   (declare (index start)
2064            (list list))
2065   (let* ((handle (cons nil list))
2066          (from-end-start (and from-end
2067                               (nthcdr (1+ start) handle)))
2068          (length (length list))
2069          (end (or end length))
2070          (tail (and (/= length (truly-the fixnum end))
2071                     (nthcdr end list))))
2072     (declare (truly-dynamic-extent handle))
2073     (do* ((previous (nthcdr start handle))
2074           (current (cdr previous) (cdr current)))
2075          ((eq current tail)
2076           (cdr handle))
2077       (if (do ((end (if from-end
2078                         current
2079                         tail))
2080                (x (if from-end
2081                       from-end-start
2082                       (cdr current))
2083                   (cdr x)))
2084               ((eq x end))
2085             (if (if test-not
2086                     (not (funcall (truly-the function test-not)
2087                                   (apply-key-function key (car current))
2088                                   (apply-key-function key (car x))))
2089                     (funcall (truly-the function test)
2090                              (apply-key-function key (car current))
2091                              (apply-key-function key (car x))))
2092                 (return t)))
2093           (rplacd previous (cdr current))
2094           (pop previous)))))
2095
2096 (defun vector-delete-duplicates* (vector test test-not key from-end start end
2097                                          &optional (length (length vector)))
2098   (declare (vector vector) (fixnum start length))
2099   (when (null end) (setf end (length vector)))
2100   (do ((index start (1+ index))
2101        (jndex start))
2102       ((= index end)
2103        (do ((index index (1+ index))            ; copy the rest of the vector
2104             (jndex jndex (1+ jndex)))
2105            ((= index length)
2106             (shrink-vector vector jndex))
2107          (setf (aref vector jndex) (aref vector index))))
2108     (declare (fixnum index jndex))
2109     (setf (aref vector jndex) (aref vector index))
2110     (unless (if test-not
2111                 (position (apply-key key (aref vector index)) vector :key key
2112                           :start (if from-end start (1+ index))
2113                           :end (if from-end jndex end)
2114                           :test-not test-not)
2115                 (position (apply-key key (aref vector index)) vector :key key
2116                           :start (if from-end start (1+ index))
2117                           :end (if from-end jndex end)
2118                           :test test))
2119       (setq jndex (1+ jndex)))))
2120
2121 (define-sequence-traverser delete-duplicates
2122     (sequence &rest args &key test test-not start end from-end key)
2123   #!+sb-doc
2124   "The elements of SEQUENCE are examined, and if any two match, one is
2125    discarded. The resulting sequence, which may be formed by destroying the
2126    given sequence, is returned.
2127
2128    The :TEST-NOT argument is deprecated."
2129   (declare (truly-dynamic-extent args))
2130   (declare (explicit-check sequence :result))
2131   (seq-dispatch-checking=>seq sequence
2132     (when sequence
2133       (list-delete-duplicates* sequence test test-not
2134                                key from-end start end))
2135     (vector-delete-duplicates* sequence test test-not key from-end start end)
2136     (apply #'sb!sequence:delete-duplicates sequence args)))
2137 \f
2138 ;;;; SUBSTITUTE
2139
2140 (defun list-substitute* (pred new list start end count key test test-not old)
2141   (declare (fixnum start end count)
2142            (type (or null function) key)
2143            (optimize speed))
2144   (let* ((result (list nil))
2145          (test (or test-not test))
2146          (test-not (or test-not
2147                        (eq pred 'if-not)))
2148          elt
2149          (splice result)
2150          (list list))      ; Get a local list for a stepper.
2151     (declare (function test))
2152     (do ((index 0 (1+ index)))
2153         ((= index start))
2154       (declare (fixnum index))
2155       (setf splice (cdr (rplacd splice (list (car list))))
2156             list (cdr list)))
2157     (do ((index start (1+ index)))
2158         ((or (= index end) (null list) (= count 0)))
2159       (declare (fixnum index))
2160       (setf elt (car list)
2161             splice
2162             (cdr (rplacd splice
2163                          (list
2164                           (cond ((let* ((elt (apply-key key elt))
2165                                         (value (if (eq pred 'normal)
2166                                                    (funcall test old elt)
2167                                                    (funcall test elt))))
2168                                    (if test-not
2169                                        (not value)
2170                                        value))
2171                                  (decf count)
2172                                  new)
2173                                 (t elt)))))
2174             list (cdr list)))
2175     (do ()
2176         ((null list))
2177       (setf splice (cdr (rplacd splice (list (car list))))
2178             list (cdr list)))
2179     (cdr result)))
2180
2181 ;;; Replace old with new in sequence moving from left to right by incrementer
2182 ;;; on each pass through the loop. Called by all three substitute functions.
2183 (defun vector-substitute* (pred new sequence incrementer left right length
2184                            start end count key test test-not old)
2185   (declare (fixnum start count end incrementer right)
2186            (type (or null function) key))
2187   (let* ((result (make-vector-like sequence length))
2188          (getter (the function (svref %%data-vector-reffers%%
2189                                       (%other-pointer-widetag sequence))))
2190          (setter (the function (svref %%data-vector-setters%%
2191                                       (%other-pointer-widetag result))))
2192          (test (or test-not test))
2193          (test-not (or test-not
2194                        (eq pred 'if-not)))
2195          (index left))
2196     (declare (fixnum index)
2197              (function test))
2198     (do ()
2199         ((= index start))
2200       (funcall setter result index
2201                (funcall getter sequence index))
2202       (incf index incrementer))
2203     (do ((elt))
2204         ((or (= index end) (= count 0)))
2205       (setf elt (funcall getter sequence index))
2206       (funcall setter result index
2207                (cond ((let* ((elt (apply-key key elt))
2208                              (value (if (eq pred 'normal)
2209                                         (funcall test old elt)
2210                                         (funcall test elt))))
2211                         (if test-not
2212                             (not value)
2213                             value))
2214                       (decf count)
2215                       new)
2216                      (t elt)))
2217       (incf index incrementer))
2218     (do ()
2219         ((= index right))
2220       (funcall setter result index
2221                (funcall getter sequence index))
2222       (incf index incrementer))
2223     result))
2224
2225 (eval-when (:compile-toplevel :execute)
2226
2227 (sb!xc:defmacro subst-dispatch (pred)
2228   `(seq-dispatch-checking=>seq sequence
2229      (let ((end (or end length)))
2230        (declare (type index end))
2231        (if from-end
2232            (nreverse (list-substitute* ,pred
2233                                        new
2234                                        (reverse sequence)
2235                                        (- (the fixnum length)
2236                                           (the fixnum end))
2237                                        (- (the fixnum length)
2238                                           (the fixnum start))
2239                                        count key test test-not old))
2240            (list-substitute* ,pred
2241                              new sequence start end count key test test-not
2242                              old)))
2243
2244      (let ((end (or end length)))
2245        (declare (type index end))
2246        (if from-end
2247            (vector-substitute* ,pred new sequence -1 (1- (the fixnum length))
2248                                -1 length (1- (the fixnum end))
2249                                (1- (the fixnum start))
2250                                count key test test-not old)
2251            (vector-substitute* ,pred new sequence 1 0 length length
2252                                start end count key test test-not old)))
2253
2254     ;; FIXME: wow, this is an odd way to implement the dispatch.  PRED
2255     ;; here is (QUOTE [NORMAL|IF|IF-NOT]).  Not only is this pretty
2256     ;; pointless, but also LIST-SUBSTITUTE* and VECTOR-SUBSTITUTE*
2257     ;; dispatch once per element on PRED's run-time identity.
2258     ,(ecase (cadr pred)
2259        ((normal) `(apply #'sb!sequence:substitute new old sequence args))
2260        ((if) `(apply #'sb!sequence:substitute-if new predicate sequence args))
2261        ((if-not) `(apply #'sb!sequence:substitute-if-not new predicate sequence args)))))
2262 ) ; EVAL-WHEN
2263
2264 (define-sequence-traverser substitute
2265     (new old sequence &rest args &key from-end test test-not
2266          start count end key)
2267   #!+sb-doc
2268   "Return a sequence of the same kind as SEQUENCE with the same elements,
2269   except that all elements equal to OLD are replaced with NEW."
2270   (declare (type fixnum start)
2271            (explicit-check sequence :result)
2272            (truly-dynamic-extent args))
2273   (subst-dispatch 'normal))
2274 \f
2275 ;;;; SUBSTITUTE-IF, SUBSTITUTE-IF-NOT
2276
2277 (define-sequence-traverser substitute-if
2278     (new predicate sequence &rest args &key from-end start end count key)
2279   #!+sb-doc
2280   "Return a sequence of the same kind as SEQUENCE with the same elements
2281   except that all elements satisfying the PRED are replaced with NEW."
2282   (declare (type fixnum start)
2283            (explicit-check sequence :result)
2284            (truly-dynamic-extent args))
2285   (let ((test predicate)
2286         (test-not nil)
2287         old)
2288     (subst-dispatch 'if)))
2289
2290 (define-sequence-traverser substitute-if-not
2291     (new predicate sequence &rest args &key from-end start end count key)
2292   #!+sb-doc
2293   "Return a sequence of the same kind as SEQUENCE with the same elements
2294   except that all elements not satisfying the PRED are replaced with NEW."
2295   (declare (type fixnum start)
2296            (explicit-check sequence :result)
2297            (truly-dynamic-extent args))
2298   (let ((test predicate)
2299         (test-not nil)
2300         old)
2301     (subst-dispatch 'if-not)))
2302 \f
2303 ;;;; NSUBSTITUTE
2304
2305 (define-sequence-traverser nsubstitute
2306     (new old sequence &rest args &key from-end test test-not
2307          end count key start)
2308   #!+sb-doc
2309   "Return a sequence of the same kind as SEQUENCE with the same elements
2310   except that all elements equal to OLD are replaced with NEW. SEQUENCE
2311   may be destructively modified."
2312   (declare (type fixnum start)
2313            (truly-dynamic-extent args))
2314   (declare (explicit-check sequence :result))
2315   (seq-dispatch-checking=>seq sequence
2316     (let ((end (or end length)))
2317       (declare (type index end))
2318       (if from-end
2319           (nreverse (nlist-substitute*
2320                      new old (nreverse (the list sequence))
2321                      test test-not (- length end) (- length start)
2322                      count key))
2323           (nlist-substitute* new old sequence
2324                              test test-not start end count key)))
2325     (let ((end (or end length)))
2326       (declare (type index end))
2327       (if from-end
2328           (nvector-substitute* new old sequence -1
2329                                test test-not (1- end) (1- start) count key)
2330           (nvector-substitute* new old sequence 1
2331                                test test-not start end count key)))
2332     (apply #'sb!sequence:nsubstitute new old sequence args)))
2333
2334 (defun nlist-substitute* (new old sequence test test-not start end count key)
2335   (declare (fixnum start count end)
2336            (type (or null function) key))
2337   (do ((test (or test-not test))
2338        (list (nthcdr start sequence) (cdr list))
2339        (index start (1+ index)))
2340       ((or (= index end) (null list) (= count 0)) sequence)
2341     (declare (fixnum index)
2342              (function test))
2343     (let ((value (funcall test old (apply-key key (car list)))))
2344      (when (if test-not
2345                (not value)
2346                value)
2347        (rplaca list new)
2348        (decf count)))))
2349
2350 (defun nvector-substitute* (new old sequence incrementer
2351                             test test-not start end count key)
2352   (declare (fixnum start count end)
2353            (type (integer -1 1) incrementer)
2354            (type (or null function) key))
2355   (let* ((test (or test-not test))
2356          (tag (%other-pointer-widetag sequence))
2357          (getter (the function (svref %%data-vector-reffers%% tag)))
2358          (setter (the function (svref %%data-vector-setters%% tag))))
2359     (declare (function test))
2360     (do ((index start (+ index incrementer)))
2361         ((or (= index end) (= count 0)) sequence)
2362       (declare (fixnum index))
2363       (let* ((value (apply-key key (funcall getter sequence index)))
2364              (test (and (funcall test old value) 0)))
2365         (when (if test-not
2366                   (not test)
2367                   test)
2368           (funcall setter sequence index new)
2369           (decf count))))))
2370 \f
2371 ;;;; NSUBSTITUTE-IF, NSUBSTITUTE-IF-NOT
2372
2373 (define-sequence-traverser nsubstitute-if
2374     (new predicate sequence &rest args &key from-end start end count key)
2375   #!+sb-doc
2376   "Return a sequence of the same kind as SEQUENCE with the same elements
2377    except that all elements satisfying PREDICATE are replaced with NEW.
2378    SEQUENCE may be destructively modified."
2379   (declare (type fixnum start)
2380            (truly-dynamic-extent args))
2381   (declare (explicit-check sequence :result))
2382   (seq-dispatch-checking=>seq sequence
2383     (let ((end (or end length)))
2384       (declare (type index end))
2385       (if from-end
2386           (nreverse (nlist-substitute-if*
2387                      new predicate (nreverse (the list sequence))
2388                      (- length end) (- length start) count key))
2389           (nlist-substitute-if* new predicate sequence
2390                                 start end count key)))
2391     (let ((end (or end length)))
2392       (declare (type index end))
2393       (if from-end
2394           (nvector-substitute-if* new predicate sequence -1
2395                                   (1- end) (1- start) count key)
2396           (nvector-substitute-if* new predicate sequence 1
2397                                   start end count key)))
2398     (apply #'sb!sequence:nsubstitute-if new predicate sequence args)))
2399
2400 (defun nlist-substitute-if* (new test sequence start end count key)
2401   (declare (type fixnum start end count)
2402            (type (or null function) key)
2403            (type function test)) ; coercion is done by caller
2404   (do ((list (nthcdr start sequence) (cdr list))
2405        (index start (1+ index)))
2406       ((or (= index end) (null list) (= count 0)) sequence)
2407     (declare (fixnum index))
2408     (when (funcall test (apply-key key (car list)))
2409       (rplaca list new)
2410       (decf count))))
2411
2412 (defun nvector-substitute-if* (new test sequence incrementer
2413                                start end count key)
2414   (declare (type fixnum end count)
2415            (type (integer -1 1) incrementer)
2416            (type (or null function) key)
2417            (type function test)) ; coercion is done by caller
2418   (let* ((tag (%other-pointer-widetag sequence))
2419          (getter (the function (svref %%data-vector-reffers%% tag)))
2420          (setter (the function (svref %%data-vector-setters%% tag))))
2421     (do ((index start (+ index incrementer)))
2422         ((or (= index end) (= count 0)) sequence)
2423       (declare (fixnum index))
2424       (when (funcall test (apply-key key (funcall getter sequence index)))
2425         (funcall setter sequence index new)
2426         (decf count)))))
2427
2428 (define-sequence-traverser nsubstitute-if-not
2429     (new predicate sequence &rest args &key from-end start end count key)
2430   #!+sb-doc
2431   "Return a sequence of the same kind as SEQUENCE with the same elements
2432    except that all elements not satisfying PREDICATE are replaced with NEW.
2433    SEQUENCE may be destructively modified."
2434   (declare (type fixnum start)
2435            (truly-dynamic-extent args))
2436   (declare (explicit-check sequence :result))
2437   (seq-dispatch-checking=>seq sequence
2438     (let ((end (or end length)))
2439       (declare (fixnum end))
2440       (if from-end
2441           (nreverse (nlist-substitute-if-not*
2442                      new predicate (nreverse (the list sequence))
2443                      (- length end) (- length start) count key))
2444           (nlist-substitute-if-not* new predicate sequence
2445                                     start end count key)))
2446     (let ((end (or end length)))
2447       (declare (fixnum end))
2448       (if from-end
2449           (nvector-substitute-if-not* new predicate sequence -1
2450                                       (1- end) (1- start) count key)
2451           (nvector-substitute-if-not* new predicate sequence 1
2452                                       start end count key)))
2453     (apply #'sb!sequence:nsubstitute-if-not new predicate sequence args)))
2454
2455 (defun nlist-substitute-if-not* (new test sequence start end count key)
2456   (declare (type fixnum start end count)
2457            (type (or null function) key)
2458            (type function test))        ; coercion is done by caller
2459   (do ((list (nthcdr start sequence) (cdr list))
2460        (index start (1+ index)))
2461       ((or (= index end) (null list) (= count 0)) sequence)
2462     (declare (fixnum index))
2463     (when (not (funcall test (apply-key key (car list))))
2464       (rplaca list new)
2465       (decf count))))
2466
2467 (defun nvector-substitute-if-not* (new test sequence incrementer
2468                                    start end count key)
2469   (declare (type fixnum end count)
2470            (type (integer -1 1) incrementer)
2471            (type (or null function) key)
2472            (type function test))        ; coercion is done by caller
2473   (let* ((tag (%other-pointer-widetag sequence))
2474          (getter (the function (svref %%data-vector-reffers%% tag)))
2475          (setter (the function (svref %%data-vector-setters%% tag))))
2476     (do ((index start (+ index incrementer)))
2477         ((or (= index end) (= count 0)) sequence)
2478       (declare (fixnum index))
2479       (when (not (funcall test (apply-key key (funcall getter sequence index))))
2480         (funcall setter sequence index new)
2481         (decf count)))))
2482 \f
2483 ;;;; FIND, POSITION, and their -IF and -IF-NOT variants
2484
2485 (defun effective-find-position-test (test test-not)
2486   (effective-find-position-test test test-not))
2487 (defun effective-find-position-key (key)
2488   (effective-find-position-key key))
2489
2490 ;;; shared guts of out-of-line FIND, POSITION, FIND-IF, and POSITION-IF
2491 (macrolet (;; shared logic for defining %FIND-POSITION and
2492            ;; %FIND-POSITION-IF in terms of various inlineable cases
2493            ;; of the expression defined in FROB and VECTOR*-FROB
2494            (frobs (&optional bit-frob)
2495              `(seq-dispatch-checking sequence-arg
2496                (frob sequence-arg from-end)
2497                (with-array-data ((sequence sequence-arg :offset-var offset)
2498                                  (start start)
2499                                  (end end)
2500                                  :check-fill-pointer t)
2501                  (multiple-value-bind (f p)
2502                      (macrolet ((frob2 () `(if from-end
2503                                                (frob sequence t)
2504                                                (frob sequence nil))))
2505                        (typecase sequence
2506                          #!+sb-unicode
2507                          ((simple-array character (*)) (frob2))
2508                          ((simple-array base-char (*)) (frob2))
2509                          ,@(when bit-frob
2510                              `((simple-bit-vector
2511                                 (if (and (typep item 'bit)
2512                                          (eq #'identity key)
2513                                          (or (eq #'eq test)
2514                                              (eq #'eql test)
2515                                              (eq #'equal test)))
2516                                     (let ((p (%bit-position item sequence
2517                                                             from-end start end)))
2518                                       (if p
2519                                           (values item p)
2520                                           (values nil nil)))
2521                                     (vector*-frob sequence)))))
2522                          (t
2523                           (vector*-frob sequence))))
2524                    (declare (type (or index null) p))
2525                    (values f (and p (the index (- p offset))))))
2526                ;; EXTENDED-SEQUENCE is not allowed.
2527                )))
2528   (defun %find-position (item sequence-arg from-end start end key test)
2529     (declare (explicit-check sequence-arg))
2530     (macrolet ((frob (sequence from-end)
2531                  `(%find-position item ,sequence
2532                                   ,from-end start end key test))
2533                (vector*-frob (sequence)
2534                  `(%find-position-vector-macro item ,sequence
2535                                                from-end start end key test)))
2536       (frobs t)))
2537   (defun %find-position-if (predicate sequence-arg from-end start end key)
2538     (declare (explicit-check sequence-arg))
2539     (macrolet ((frob (sequence from-end)
2540                  `(%find-position-if predicate ,sequence
2541                                      ,from-end start end key))
2542                (vector*-frob (sequence)
2543                  `(%find-position-if-vector-macro predicate ,sequence
2544                                                   from-end start end key)))
2545       (frobs)))
2546   (defun %find-position-if-not (predicate sequence-arg from-end start end key)
2547     (declare (explicit-check sequence-arg))
2548     (macrolet ((frob (sequence from-end)
2549                  `(%find-position-if-not predicate ,sequence
2550                                          ,from-end start end key))
2551                (vector*-frob (sequence)
2552                  `(%find-position-if-not-vector-macro predicate ,sequence
2553                                                   from-end start end key)))
2554       (frobs))))
2555
2556 (defun find
2557     (item sequence &rest args &key from-end (start 0) end key test test-not)
2558   (declare (truly-dynamic-extent args))
2559   (declare (explicit-check sequence))
2560   (seq-dispatch-checking sequence
2561     (nth-value 0 (%find-position
2562                   item sequence from-end start end
2563                   (effective-find-position-key key)
2564                   (effective-find-position-test test test-not)))
2565     (nth-value 0 (%find-position
2566                   item sequence from-end start end
2567                   (effective-find-position-key key)
2568                   (effective-find-position-test test test-not)))
2569     (apply #'sb!sequence:find item sequence args)))
2570 (defun position
2571     (item sequence &rest args &key from-end (start 0) end key test test-not)
2572   (declare (truly-dynamic-extent args))
2573   (declare (explicit-check sequence))
2574   (seq-dispatch-checking sequence
2575     (nth-value 1 (%find-position
2576                   item sequence from-end start end
2577                   (effective-find-position-key key)
2578                   (effective-find-position-test test test-not)))
2579     (nth-value 1 (%find-position
2580                   item sequence from-end start end
2581                   (effective-find-position-key key)
2582                   (effective-find-position-test test test-not)))
2583     (apply #'sb!sequence:position item sequence args)))
2584
2585 (defun find-if (predicate sequence &rest args &key from-end (start 0) end key)
2586   (declare (truly-dynamic-extent args))
2587   (declare (explicit-check sequence))
2588   (seq-dispatch-checking sequence
2589     (nth-value 0 (%find-position-if
2590                   (%coerce-callable-to-fun predicate)
2591                   sequence from-end start end
2592                   (effective-find-position-key key)))
2593     (nth-value 0 (%find-position-if
2594                   (%coerce-callable-to-fun predicate)
2595                   sequence from-end start end
2596                   (effective-find-position-key key)))
2597     (apply #'sb!sequence:find-if predicate sequence args)))
2598 (defun position-if
2599     (predicate sequence &rest args &key from-end (start 0) end key)
2600   (declare (truly-dynamic-extent args))
2601   (declare (explicit-check sequence))
2602   (seq-dispatch-checking sequence
2603     (nth-value 1 (%find-position-if
2604                   (%coerce-callable-to-fun predicate)
2605                   sequence from-end start end
2606                   (effective-find-position-key key)))
2607     (nth-value 1 (%find-position-if
2608                   (%coerce-callable-to-fun predicate)
2609                   sequence from-end start end
2610                   (effective-find-position-key key)))
2611     (apply #'sb!sequence:position-if predicate sequence args)))
2612
2613 (defun find-if-not
2614     (predicate sequence &rest args &key from-end (start 0) end key)
2615   (declare (truly-dynamic-extent args))
2616   (declare (explicit-check sequence))
2617   (seq-dispatch-checking sequence
2618     (nth-value 0 (%find-position-if-not
2619                   (%coerce-callable-to-fun predicate)
2620                   sequence from-end start end
2621                   (effective-find-position-key key)))
2622     (nth-value 0 (%find-position-if-not
2623                   (%coerce-callable-to-fun predicate)
2624                   sequence from-end start end
2625                   (effective-find-position-key key)))
2626     (apply #'sb!sequence:find-if-not predicate sequence args)))
2627 (defun position-if-not
2628     (predicate sequence &rest args &key from-end (start 0) end key)
2629   (declare (truly-dynamic-extent args))
2630   (declare (explicit-check sequence))
2631   (seq-dispatch-checking sequence
2632     (nth-value 1 (%find-position-if-not
2633                   (%coerce-callable-to-fun predicate)
2634                   sequence from-end start end
2635                   (effective-find-position-key key)))
2636     (nth-value 1 (%find-position-if-not
2637                   (%coerce-callable-to-fun predicate)
2638                   sequence from-end start end
2639                   (effective-find-position-key key)))
2640     (apply #'sb!sequence:position-if-not predicate sequence args)))
2641 \f
2642 ;;;; COUNT-IF, COUNT-IF-NOT, and COUNT
2643
2644 (eval-when (:compile-toplevel :execute)
2645
2646 (sb!xc:defmacro vector-count-if (notp from-end-p predicate sequence)
2647   (let ((next-index (if from-end-p '(1- index) '(1+ index)))
2648         (pred `(funcall ,predicate (apply-key key (aref ,sequence index)))))
2649     `(let ((%start ,(if from-end-p '(1- end) 'start))
2650            (%end ,(if from-end-p '(1- start) 'end)))
2651       (do ((index %start ,next-index)
2652            (count 0))
2653           ((= index (the fixnum %end)) count)
2654         (declare (fixnum index count))
2655         (,(if notp 'unless 'when) ,pred
2656           (setq count (1+ count)))))))
2657
2658 (sb!xc:defmacro list-count-if (notp from-end-p predicate sequence)
2659   (let ((pred `(funcall ,predicate (apply-key key (pop sequence)))))
2660     `(let ((%start ,(if from-end-p '(- length end) 'start))
2661            (%end ,(if from-end-p '(- length start) 'end))
2662            (sequence ,(if from-end-p '(reverse sequence) 'sequence)))
2663       (do ((sequence (nthcdr %start ,sequence))
2664            (index %start (1+ index))
2665            (count 0))
2666           ((or (= index (the fixnum %end)) (null sequence)) count)
2667         (declare (fixnum index count))
2668         (,(if notp 'unless 'when) ,pred
2669           (setq count (1+ count)))))))
2670
2671
2672 ) ; EVAL-WHEN
2673
2674 (define-sequence-traverser count-if
2675     (pred sequence &rest args &key from-end start end key)
2676   #!+sb-doc
2677   "Return the number of elements in SEQUENCE satisfying PRED(el)."
2678   (declare (type fixnum start)
2679            (truly-dynamic-extent args))
2680   (declare (explicit-check sequence))
2681   (let ((pred (%coerce-callable-to-fun pred)))
2682     (seq-dispatch-checking sequence
2683       (let ((end (or end length)))
2684         (declare (type index end))
2685         (if from-end
2686             (list-count-if nil t pred sequence)
2687             (list-count-if nil nil pred sequence)))
2688       (let ((end (or end length)))
2689         (declare (type index end))
2690         (if from-end
2691             (vector-count-if nil t pred sequence)
2692             (vector-count-if nil nil pred sequence)))
2693       (apply #'sb!sequence:count-if pred sequence args))))
2694
2695 (define-sequence-traverser count-if-not
2696     (pred sequence &rest args &key from-end start end key)
2697   #!+sb-doc
2698   "Return the number of elements in SEQUENCE not satisfying TEST(el)."
2699   (declare (type fixnum start)
2700            (truly-dynamic-extent args))
2701   (declare (explicit-check sequence))
2702   (let ((pred (%coerce-callable-to-fun pred)))
2703     (seq-dispatch-checking sequence
2704       (let ((end (or end length)))
2705         (declare (type index end))
2706         (if from-end
2707             (list-count-if t t pred sequence)
2708             (list-count-if t nil pred sequence)))
2709       (let ((end (or end length)))
2710         (declare (type index end))
2711         (if from-end
2712             (vector-count-if t t pred sequence)
2713             (vector-count-if t nil pred sequence)))
2714       (apply #'sb!sequence:count-if-not pred sequence args))))
2715
2716 (define-sequence-traverser count
2717     (item sequence &rest args &key from-end start end
2718           key (test #'eql test-p) (test-not nil test-not-p))
2719   #!+sb-doc
2720   "Return the number of elements in SEQUENCE satisfying a test with ITEM,
2721    which defaults to EQL."
2722   (declare (type fixnum start)
2723            (truly-dynamic-extent args))
2724   (declare (explicit-check sequence))
2725   (when (and test-p test-not-p)
2726     ;; Use the same wording as EFFECTIVE-FIND-POSITION-TEST
2727     (error "can't specify both :TEST and :TEST-NOT"))
2728   (let ((%test (if test-not-p
2729                    (lambda (x)
2730                      (not (funcall test-not item x)))
2731                    (lambda (x)
2732                      (funcall test item x)))))
2733     (seq-dispatch-checking sequence
2734       (let ((end (or end length)))
2735         (declare (type index end))
2736         (if from-end
2737             (list-count-if nil t %test sequence)
2738             (list-count-if nil nil %test sequence)))
2739       (let ((end (or end length)))
2740         (declare (type index end))
2741         (if from-end
2742             (vector-count-if nil t %test sequence)
2743             (vector-count-if nil nil %test sequence)))
2744       (apply #'sb!sequence:count item sequence args))))
2745 \f
2746 ;;;; MISMATCH
2747
2748 (eval-when (:compile-toplevel :execute)
2749
2750 (sb!xc:defmacro match-vars (&rest body)
2751   `(let ((inc (if from-end -1 1))
2752          (start1 (if from-end (1- (the fixnum end1)) start1))
2753          (start2 (if from-end (1- (the fixnum end2)) start2))
2754          (end1 (if from-end (1- (the fixnum start1)) end1))
2755          (end2 (if from-end (1- (the fixnum start2)) end2)))
2756      (declare (fixnum inc start1 start2 end1 end2))
2757      ,@body))
2758
2759 (sb!xc:defmacro matchify-list ((sequence start length end) &body body)
2760   (declare (ignore end)) ;; ### Should END be used below?
2761   `(let ((,sequence (if from-end
2762                         (nthcdr (- (the fixnum ,length) (the fixnum ,start) 1)
2763                                 (reverse (the list ,sequence)))
2764                         (nthcdr ,start ,sequence))))
2765      (declare (type list ,sequence))
2766      ,@body))
2767
2768 ) ; EVAL-WHEN
2769
2770 (eval-when (:compile-toplevel :execute)
2771
2772 (sb!xc:defmacro if-mismatch (elt1 elt2)
2773   `(cond ((= (the fixnum index1) (the fixnum end1))
2774           (return (if (= (the fixnum index2) (the fixnum end2))
2775                       nil
2776                       (if from-end
2777                           (1+ (the fixnum index1))
2778                           (the fixnum index1)))))
2779          ((= (the fixnum index2) (the fixnum end2))
2780           (return (if from-end (1+ (the fixnum index1)) index1)))
2781          (test-not
2782           (if (funcall test-not (apply-key key ,elt1) (apply-key key ,elt2))
2783               (return (if from-end (1+ (the fixnum index1)) index1))))
2784          (t (if (not (funcall test (apply-key key ,elt1)
2785                               (apply-key key ,elt2)))
2786                 (return (if from-end (1+ (the fixnum index1)) index1))))))
2787
2788 (sb!xc:defmacro mumble-mumble-mismatch ()
2789   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2790         (index2 start2 (+ index2 (the fixnum inc))))
2791        (())
2792      (declare (fixnum index1 index2))
2793      (if-mismatch (aref sequence1 index1) (aref sequence2 index2))))
2794
2795 (sb!xc:defmacro mumble-list-mismatch ()
2796   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2797         (index2 start2 (+ index2 (the fixnum inc))))
2798        (())
2799      (declare (fixnum index1 index2))
2800      (if-mismatch (aref sequence1 index1) (pop sequence2))))
2801 \f
2802 (sb!xc:defmacro list-mumble-mismatch ()
2803   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2804         (index2 start2 (+ index2 (the fixnum inc))))
2805        (())
2806      (declare (fixnum index1 index2))
2807      (if-mismatch (pop sequence1) (aref sequence2 index2))))
2808
2809 (sb!xc:defmacro list-list-mismatch ()
2810   `(do ((sequence1 sequence1)
2811         (sequence2 sequence2)
2812         (index1 start1 (+ index1 (the fixnum inc)))
2813         (index2 start2 (+ index2 (the fixnum inc))))
2814        (())
2815      (declare (fixnum index1 index2))
2816      (if-mismatch (pop sequence1) (pop sequence2))))
2817
2818 ) ; EVAL-WHEN
2819
2820 (define-sequence-traverser mismatch
2821     (sequence1 sequence2 &rest args &key from-end test test-not
2822      start1 end1 start2 end2 key)
2823   #!+sb-doc
2824   "The specified subsequences of SEQUENCE1 and SEQUENCE2 are compared
2825    element-wise. If they are of equal length and match in every element, the
2826    result is NIL. Otherwise, the result is a non-negative integer, the index
2827    within SEQUENCE1 of the leftmost position at which they fail to match; or,
2828    if one is shorter than and a matching prefix of the other, the index within
2829    SEQUENCE1 beyond the last position tested is returned. If a non-NIL
2830    :FROM-END argument is given, then one plus the index of the rightmost
2831    position in which the sequences differ is returned."
2832   (declare (type fixnum start1 start2))
2833   (declare (truly-dynamic-extent args))
2834   (declare (explicit-check sequence1 sequence2 :result))
2835   (seq-dispatch-checking sequence1
2836     (seq-dispatch-checking sequence2
2837      (return-from mismatch
2838       (let ((end1 (or end1 length1))
2839             (end2 (or end2 length2)))
2840         (declare (type index end1 end2))
2841         (match-vars
2842          (matchify-list (sequence1 start1 length1 end1)
2843            (matchify-list (sequence2 start2 length2 end2)
2844              (list-list-mismatch))))))
2845      (return-from mismatch
2846       (let ((end1 (or end1 length1))
2847             (end2 (or end2 length2)))
2848         (declare (type index end1 end2))
2849         (match-vars
2850          (matchify-list (sequence1 start1 length1 end1)
2851            (list-mumble-mismatch)))))
2852      nil)
2853     (seq-dispatch-checking sequence2
2854      (return-from mismatch
2855       (let ((end1 (or end1 length1))
2856             (end2 (or end2 length2)))
2857         (declare (type index end1 end2))
2858         (match-vars
2859          (matchify-list (sequence2 start2 length2 end2)
2860            (mumble-list-mismatch)))))
2861      (return-from mismatch
2862       (let ((end1 (or end1 length1))
2863             (end2 (or end2 length2)))
2864         (declare (type index end1 end2))
2865         (match-vars
2866          (mumble-mumble-mismatch))))
2867      nil)
2868     t)
2869   ;; If sequence1 is an extended-sequence, we know nothing about sequence2.
2870   ;; If sequence1 was a list or vector, then sequence2 is an extended-sequence
2871   ;; or not a sequence. Either way, check it.
2872   (the (or index null)
2873     (values (apply #'sb!sequence:mismatch sequence1
2874                    (the sequence sequence2) args))))
2875 \f
2876 ;;; search comparison functions
2877
2878 (eval-when (:compile-toplevel :execute)
2879
2880 ;;; Compare two elements and return if they don't match.
2881 (sb!xc:defmacro compare-elements (elt1 elt2)
2882   `(if test-not
2883        (if (funcall test-not (apply-key key ,elt1) (apply-key key ,elt2))
2884            (return nil)
2885            t)
2886        (if (not (funcall test (apply-key key ,elt1) (apply-key key ,elt2)))
2887            (return nil)
2888            t)))
2889
2890 (sb!xc:defmacro search-compare-list-list (main sub)
2891   `(do ((main ,main (cdr main))
2892         (jndex start1 (1+ jndex))
2893         (sub (nthcdr start1 ,sub) (cdr sub)))
2894        ((or (endp main) (endp sub) (<= end1 jndex))
2895         t)
2896      (declare (type (integer 0) jndex))
2897      (compare-elements (car sub) (car main))))
2898
2899 (sb!xc:defmacro search-compare-list-vector (main sub)
2900   `(do ((main ,main (cdr main))
2901         (index start1 (1+ index)))
2902        ((or (endp main) (= index end1)) t)
2903      (compare-elements (aref ,sub index) (car main))))
2904
2905 (sb!xc:defmacro search-compare-vector-list (main sub index)
2906   `(do ((sub (nthcdr start1 ,sub) (cdr sub))
2907         (jndex start1 (1+ jndex))
2908         (index ,index (1+ index)))
2909        ((or (<= end1 jndex) (endp sub)) t)
2910      (declare (type (integer 0) jndex))
2911      (compare-elements (car sub) (aref ,main index))))
2912
2913 (sb!xc:defmacro search-compare-vector-vector (main sub index)
2914   `(do ((index ,index (1+ index))
2915         (sub-index start1 (1+ sub-index)))
2916        ((= sub-index end1) t)
2917      (compare-elements (aref ,sub sub-index) (aref ,main index))))
2918
2919 (sb!xc:defmacro search-compare (main-type main sub index)
2920   (if (eq main-type 'list)
2921       `(seq-dispatch ,sub
2922          (search-compare-list-list ,main ,sub)
2923          (search-compare-list-vector ,main ,sub)
2924          ;; KLUDGE: just hack it together so that it works
2925          (return-from search (apply #'sb!sequence:search sequence1 sequence2 args)))
2926       `(seq-dispatch ,sub
2927          (search-compare-vector-list ,main ,sub ,index)
2928          (search-compare-vector-vector ,main ,sub ,index)
2929          (return-from search (apply #'sb!sequence:search sequence1 sequence2 args)))))
2930
2931 ) ; EVAL-WHEN
2932 \f
2933 ;;;; SEARCH
2934
2935 (eval-when (:compile-toplevel :execute)
2936
2937 (sb!xc:defmacro list-search (main sub)
2938   `(do ((main (nthcdr start2 ,main) (cdr main))
2939         (index2 start2 (1+ index2))
2940         (terminus (- end2 (the (integer 0) (- end1 start1))))
2941         (last-match ()))
2942        ((> index2 terminus) last-match)
2943      (declare (type (integer 0) index2))
2944      (if (search-compare list main ,sub index2)
2945          (if from-end
2946              (setq last-match index2)
2947              (return index2)))))
2948
2949 (sb!xc:defmacro vector-search (main sub)
2950   `(do ((index2 start2 (1+ index2))
2951         (terminus (- end2 (the (integer 0) (- end1 start1))))
2952         (last-match ()))
2953        ((> index2 terminus) last-match)
2954      (declare (type (integer 0) index2))
2955      (if (search-compare vector ,main ,sub index2)
2956          (if from-end
2957              (setq last-match index2)
2958              (return index2)))))
2959
2960 ) ; EVAL-WHEN
2961
2962 (define-sequence-traverser search
2963     (sequence1 sequence2 &rest args &key
2964      from-end test test-not start1 end1 start2 end2 key)
2965   (declare (type fixnum start1 start2)
2966            (truly-dynamic-extent args))
2967   (declare (explicit-check sequence2))
2968   (seq-dispatch-checking sequence2
2969     (let ((end1 (or end1 length1))
2970           (end2 (or end2 length2)))
2971       (declare (type index end1 end2))
2972       (list-search sequence2 sequence1))
2973     (let ((end1 (or end1 length1))
2974           (end2 (or end2 length2)))
2975       (declare (type index end1 end2))
2976       (vector-search sequence2 sequence1))
2977     (apply #'sb!sequence:search sequence1 sequence2 args)))
2978
2979 ;;; FIXME: this was originally in array.lisp; it might be better to
2980 ;;; put it back there, and make DOSEQUENCE and SEQ-DISPATCH be in
2981 ;;; a new early-seq.lisp file.
2982 (macrolet ((body (lambda-list endp-test start-recursion next-layer)
2983               `(let ((index 0))
2984                  (labels ((frob ,lambda-list
2985                             (cond (,endp-test
2986                                    (setf (aref vector index) contents)
2987                                    (incf index))
2988                                   (t
2989                                    (unless (typep contents 'sequence)
2990                                      (error "malformed :INITIAL-CONTENTS: ~S is not a ~
2991                                              sequence, but ~W more layer~:P needed."
2992                                             contents
2993                                             (- (length dimensions) axis)))
2994                                    (let ((k this-dimension)
2995                                          (l (length contents)))
2996                                      (unless (= k l)
2997                                        (error "malformed :INITIAL-CONTENTS: Dimension of ~
2998                                                axis ~W is ~W, but ~S is ~W long."
2999                                               axis k contents l)))
3000                                    (sb!sequence:dosequence (content contents)
3001                                      ,next-layer)))))
3002                    ,start-recursion))))
3003
3004   (defun fill-data-vector (vector dimensions initial-contents)
3005     (declare (explicit-check))
3006     (symbol-macrolet ((this-dimension (car dims)))
3007       (body (axis dims contents) (null dims)
3008             (frob 0 dimensions initial-contents)
3009             (frob (1+ axis) (cdr dims) content))))
3010
3011   ;; Identical to FILL-DATA-VECTOR but avoid reference
3012   ;; to DIMENSIONS as a list except in case of error.
3013   (defun fill-array (initial-contents array)
3014     (declare (explicit-check))
3015     (let ((rank (array-rank array))
3016           (vector (%array-data-vector array)))
3017       (symbol-macrolet ((dimensions (array-dimensions array))
3018                         (this-dimension (%array-dimension array axis)))
3019         (body (axis contents) (= axis rank)
3020               (frob 0 initial-contents)
3021               (frob (1+ axis) content))))
3022     array))