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
  31 (defparameter *sequence-keyword-info*
  32   ;; (name default supplied-p adjustment new-type)
  33   `((count nil
  34            nil
  35            (etypecase count
  36              (null (1- most-positive-fixnum))
  37              (fixnum (max 0 count))
  38              (integer (if (minusp count)
  39                           0
  40                           (1- most-positive-fixnum))))
  41            (mod #.sb!xc:most-positive-fixnum))
  42     ;; Entries for {start,end}{,1,2}
  43     ,@(mapcan (lambda (names)
  44                 (destructuring-bind (start end length sequence) names
  45                   (list
  46                    `(,start
  47                      0
  48                      nil
  49                      ;; Only evaluate LENGTH (which may be expensive)
  50                      ;; if START is non-NIL.
  51                      (if (or (zerop ,start) (<= 0 ,start ,length))
  52                          ,start
  53                          (sequence-bounding-indices-bad-error ,sequence ,start ,end))
  54                      index)
  55                    `(,end
  56                      nil
  57                      nil
  58                      ;; Only evaluate LENGTH (which may be expensive)
  59                      ;; if END is non-NIL.
  60                      (if (or (null ,end) (<= ,start ,end ,length))
  61                          ;; Defaulting of NIL is done inside the
  62                          ;; bodies, for ease of sharing with compiler
  63                          ;; transforms.
  64                          ;;
  65                          ;; FIXME: defend against non-number non-NIL
  66                          ;; stuff?
  67                          ,end
  68                          (sequence-bounding-indices-bad-error ,sequence ,start ,end))
  69                      (or null index)))))
  70               '((start end length sequence)
  71                 (start1 end1 length1 sequence1)
  72                 (start2 end2 length2 sequence2)))
  73     (key nil
  74          nil
  75          (and key (%coerce-callable-to-fun key))
  76          (or null function))
  77     (test #'eql
  78           nil
  79           (%coerce-callable-to-fun test)
  80           function)
  81     (test-not nil
  82               nil
  83               (and test-not (%coerce-callable-to-fun test-not))
  84               (or null function))))
  85
  86 (sb!xc:defmacro define-sequence-traverser (name args &body body)
  87   (multiple-value-bind (body declarations docstring)
  88       (parse-body body :doc-string-allowed t)
  89     (collect ((new-args)
  90               (new-declarations)
  91               ;; Things which are definitely used in any code path.
  92               (rebindings/eager)
  93               ;; Things which may be used/are only used in certain
  94               ;; code paths (e.g. length).
  95               (rebindings/lazy))
  96       (dolist (arg args)
  97         (case arg
  98           ;; FIXME: make this robust.  And clean.
  99           ((sequence sequence1 sequence2)
 100            (let* ((length-var (ecase arg
 101                                 (sequence  'length)
 102                                 (sequence1 'length1)
 103                                 (sequence2 'length2)))
 104                   (cache-var (symbolicate length-var '#:-cache)))
 105              (new-args arg)
 106              (rebindings/eager `(,cache-var nil))
 107              (rebindings/lazy
 108               `(,length-var (truly-the
 109                              index
 110                              (or ,cache-var (setf ,cache-var (length ,arg))))))))
 111           ((function predicate)
 112            (new-args arg)
 113            (rebindings/eager `(,arg (%coerce-callable-to-fun ,arg))))
 114           (t
 115            (let ((info (cdr (assoc arg *sequence-keyword-info*))))
 116              (cond (info
 117                     (destructuring-bind (default supplied-p adjuster type) info
 118                       (new-args `(,arg ,default ,@(when supplied-p (list supplied-p))))
 119                       (rebindings/eager `(,arg ,adjuster))
 120                       (new-declarations `(type ,type ,arg))))
 121                    (t (new-args arg)))))))
 122       `(defun ,name ,(new-args)
 123          ,@(when docstring (list docstring))
 124          ,@declarations
 125          (symbol-macrolet (,@(rebindings/lazy))
 126            (let* (,@(rebindings/eager))
 127              (declare ,@(new-declarations))
 128              ,@body
 129              ))))))
 130
 131 ;;; SEQ-DISPATCH does an efficient type-dispatch on the given SEQUENCE.
 132 ;;;
 133 ;;; FIXME: It might be worth making three cases here, LIST,
 134 ;;; SIMPLE-VECTOR, and VECTOR, instead of the current LIST and VECTOR.
 135 ;;; It tends to make code run faster but be bigger; some benchmarking
 136 ;;; is needed to decide.
 137 (sb!xc:defmacro seq-dispatch
 138     (sequence list-form array-form &optional other-form)
 139   `(if (listp ,sequence)
 140        (let ((,sequence (truly-the list ,sequence)))
 141          (declare (ignorable ,sequence))
 142          ,list-form)
 143        ,@(if other-form
 144              `((if (arrayp ,sequence)
 145                    (let ((,sequence (truly-the vector ,sequence)))
 146                      (declare (ignorable ,sequence))
 147                      ,array-form)
 148                    ,other-form))
 149              `((let ((,sequence (truly-the vector ,sequence)))
 150                  (declare (ignorable ,sequence))
 151                  ,array-form)))))
 152
 153 ;; Same as above, but don't assume that ARRAYP implies VECTORP,
 154 ;; and call SEQUENCEP only after checking for not LISTP and not VECTORP.
 155 ;; This is for dispatching within sequence functions that have the
 156 ;; EXPLICIT-CHECK attribute. [Because there is no way to have the compiler
 157 ;; insert checks for a subset of arguments, it is inconvenient to declare
 158 ;; things like DELETE-IF with explicit-check to suppress checking of the
 159 ;; 'sequence' because then you have to manually check all other arguments.]
 160 (sb!xc:defmacro seq-dispatch-checking
 161     (sequence list-form array-form &optional other-form)
 162   `(if (listp ,sequence)
 163        (let ((,sequence (truly-the list ,sequence)))
 164          (declare (ignorable ,sequence))
 165          ,list-form)
 166        ,@(if other-form
 167              `((if (vectorp ,sequence)
 168                    (let ((,sequence (truly-the vector ,sequence)))
 169                      (declare (ignorable ,sequence))
 170                      ,array-form)
 171                    ;; This could assert (THE EXTENDED-SEQUENCE ,sequence)
 172                    ;; for a slight win, however the error string would be wrong.
 173                    ;; It needs to be "<x> is not a SEQUENCE", not "<x> is not
 174                    ;; an EXTENDED-SEQUENCE".
 175                    (let ((,sequence (the sequence ,sequence)))
 176                      ,other-form)))
 177              `((let ((,sequence (the vector ,sequence)))
 178                  (declare (ignorable ,sequence))
 179                  ,array-form)))))
 180
 181 (sb!xc:defmacro %make-sequence-like (sequence length)
 182   #!+sb-doc
 183   "Return a sequence of the same type as SEQUENCE and the given LENGTH."
 184   `(seq-dispatch ,sequence
 185      (make-list ,length)
 186      (make-array ,length :element-type (array-element-type ,sequence))
 187      (sb!sequence:make-sequence-like ,sequence ,length)))
 188
 189 (sb!xc:defmacro bad-sequence-type-error (type-spec)
 190   `(error 'simple-type-error
 191           :datum ,type-spec
 192           :expected-type '(satisfies is-a-valid-sequence-type-specifier-p)
 193           :format-control "~S is a bad type specifier for sequences."
 194           :format-arguments (list ,type-spec)))
 195
 196 (sb!xc:defmacro sequence-type-length-mismatch-error (type length)
 197   `(error 'simple-type-error
 198           :datum ,length
 199           :expected-type (cond ((array-type-p ,type)
 200                                 `(eql ,(car (array-type-dimensions ,type))))
 201                                ((type= ,type (specifier-type 'null))
 202                                 '(eql 0))
 203                                ((cons-type-p ,type)
 204                                 '(integer 1))
 205                                (t (bug "weird type in S-T-L-M-ERROR")))
 206           ;; FIXME: this format control causes ugly printing.  There's
 207           ;; probably some ~<~@:_~> incantation that would make it
 208           ;; nicer. -- CSR, 2002-10-18
 209           :format-control "The length requested (~S) does not match the type restriction in ~S."
 210           :format-arguments (list ,length (type-specifier ,type))))
 211
 212 (sb!xc:defmacro sequence-type-too-hairy (type-spec)
 213   ;; FIXME: Should this be a BUG? I'm inclined to think not; there are
 214   ;; words that give some but not total support to this position in
 215   ;; ANSI.  Essentially, we are justified in throwing this on
 216   ;; e.g. '(OR SIMPLE-VECTOR (VECTOR FIXNUM)), but maybe not (by ANSI)
 217   ;; on '(CONS * (CONS * NULL)) -- CSR, 2002-10-18
 218
 219   ;; On the other hand, I'm not sure it deserves to be a type-error,
 220   ;; either. -- bem, 2005-08-10
 221   `(error 'simple-program-error
 222           :format-control "~S is too hairy for sequence functions."
 223           :format-arguments (list ,type-spec)))
 224 ) ; EVAL-WHEN
 225
 226 (defun is-a-valid-sequence-type-specifier-p (type)
 227   (let ((type (specifier-type type)))
 228     (or (csubtypep type (specifier-type 'list))
 229         (csubtypep type (specifier-type 'vector)))))
 230
 231 ;;; It's possible with some sequence operations to declare the length
 232 ;;; of a result vector, and to be safe, we really ought to verify that
 233 ;;; the actual result has the declared length.
 234 (defun vector-of-checked-length-given-length (vector declared-length)
 235   (declare (type vector vector))
 236   (declare (type index declared-length))
 237   (let ((actual-length (length vector)))
 238     (unless (= actual-length declared-length)
 239       (error 'simple-type-error
 240              :datum vector
 241              :expected-type `(vector ,declared-length)
 242              :format-control
 243              "Vector length (~W) doesn't match declared length (~W)."
 244              :format-arguments (list actual-length declared-length))))
 245   vector)
 246
 247 (defun sequence-of-checked-length-given-type (sequence result-type)
 248   (let ((ctype (specifier-type result-type)))
 249     (if (not (array-type-p ctype))
 250         sequence
 251         (let ((declared-length (first (array-type-dimensions ctype))))
 252           (if (eq declared-length '*)
 253               sequence
 254               (vector-of-checked-length-given-length sequence
 255                                                      declared-length))))))
 256
 257 (declaim (ftype (function (sequence index) nil) signal-index-too-large-error))
 258 (defun signal-index-too-large-error (sequence index)
 259   (let* ((length (length sequence))
 260          (max-index (and (plusp length)
 261                          (1- length))))
 262     (error 'index-too-large-error
 263            :datum index
 264            :expected-type (if max-index
 265                               `(integer 0 ,max-index)
 266                               ;; This seems silly, is there something better?
 267                               '(integer 0 (0))))))
 268
 269 (declaim (ftype (function (t t t) nil) sequence-bounding-indices-bad-error))
 270 (defun sequence-bounding-indices-bad-error (sequence start end)
 271   (let ((size (length sequence)))
 272     (error 'bounding-indices-bad-error
 273            :datum (cons start end)
 274            :expected-type `(cons (integer 0 ,size)
 275                                  (integer ,start ,size))
 276            :object sequence)))
 277
 278 (declaim (ftype (function (t t t) nil) array-bounding-indices-bad-error))
 279 (defun array-bounding-indices-bad-error (array start end)
 280   (let ((size (array-total-size array)))
 281     (error 'bounding-indices-bad-error
 282            :datum (cons start end)
 283            :expected-type `(cons (integer 0 ,size)
 284                                  (integer ,start ,size))
 285            :object array)))
 286
 287 (declaim (ftype (function (t) nil) circular-list-error))
 288 (defun circular-list-error (list)
 289   (let ((*print-circle* t))
 290     (error 'simple-type-error
 291            :format-control "List is circular:~%  ~S"
 292            :format-arguments (list list)
 293            :datum list
 294            :type '(and list (satisfies list-length)))))
 295
 296 \f
 297
 298 (defun emptyp (sequence)
 299   #!+sb-doc
 300   "Returns T if SEQUENCE is an empty sequence and NIL
 301    otherwise. Signals an error if SEQUENCE is not a sequence."
 302   (seq-dispatch sequence
 303                 (null sequence)
 304                 (zerop (length sequence))
 305                 (sb!sequence:emptyp sequence)))
 306
 307 (defun elt (sequence index)
 308   #!+sb-doc "Return the element of SEQUENCE specified by INDEX."
 309   (seq-dispatch sequence
 310                 (do ((count index (1- count))
 311                      (list sequence (cdr list)))
 312                     ((= count 0)
 313                      (if (endp list)
 314                          (signal-index-too-large-error sequence index)
 315                          (car list)))
 316                   (declare (type (integer 0) count)))
 317                 (progn
 318                   (when (>= index (length sequence))
 319                     (signal-index-too-large-error sequence index))
 320                   (aref sequence index))
 321                 (sb!sequence:elt sequence index)))
 322
 323 (defun %setelt (sequence index newval)
 324   #!+sb-doc "Store NEWVAL as the component of SEQUENCE specified by INDEX."
 325   (seq-dispatch sequence
 326                 (do ((count index (1- count))
 327                      (seq sequence))
 328                     ((= count 0) (rplaca seq newval) newval)
 329                   (declare (fixnum count))
 330                   (if (atom (cdr seq))
 331                       (signal-index-too-large-error sequence index)
 332                       (setq seq (cdr seq))))
 333                 (progn
 334                   (when (>= index (length sequence))
 335                     (signal-index-too-large-error sequence index))
 336                   (setf (aref sequence index) newval))
 337                 (setf (sb!sequence:elt sequence index) newval)))
 338
 339 (defun length (sequence)
 340   #!+sb-doc "Return an integer that is the length of SEQUENCE."
 341   (seq-dispatch-checking sequence
 342                 (length sequence)
 343                 (length sequence)
 344                 (sb!sequence:length sequence)))
 345
 346 (defun make-sequence (type length &key (initial-element nil iep))
 347   #!+sb-doc
 348   "Return a sequence of the given TYPE and LENGTH, with elements initialized
 349   to INITIAL-ELEMENT."
 350   (declare (fixnum length))
 351   (let* ((expanded-type (typexpand type))
 352          (adjusted-type
 353           (typecase expanded-type
 354             (atom (cond
 355                     ((eq expanded-type 'string) '(vector character))
 356                     ((eq expanded-type 'simple-string)
 357                      '(simple-array character (*)))
 358                     (t expanded-type)))
 359             (cons (cond
 360                     ((eq (car expanded-type) 'string)
 361                      `(vector character ,@(cdr expanded-type)))
 362                     ((eq (car expanded-type) 'simple-string)
 363                      `(simple-array character ,(if (cdr expanded-type)
 364                                                    (cdr expanded-type)
 365                                                    '(*))))
 366                     (t expanded-type)))))
 367          (type (specifier-type adjusted-type)))
 368     (cond ((csubtypep type (specifier-type 'list))
 369            (cond
 370              ((type= type (specifier-type 'list))
 371               (make-list length :initial-element initial-element))
 372              ((eq type *empty-type*)
 373               (bad-sequence-type-error nil))
 374              ((type= type (specifier-type 'null))
 375               (if (= length 0)
 376                   'nil
 377                   (sequence-type-length-mismatch-error type length)))
 378              ((cons-type-p type)
 379               (multiple-value-bind (min exactp)
 380                   (sb!kernel::cons-type-length-info type)
 381                 (if exactp
 382                     (unless (= length min)
 383                       (sequence-type-length-mismatch-error type length))
 384                     (unless (>= length min)
 385                       (sequence-type-length-mismatch-error type length)))
 386                 (make-list length :initial-element initial-element)))
 387              ;; We'll get here for e.g. (OR NULL (CONS INTEGER *)),
 388              ;; which may seem strange and non-ideal, but then I'd say
 389              ;; it was stranger to feed that type in to MAKE-SEQUENCE.
 390              (t (sequence-type-too-hairy (type-specifier type)))))
 391           ((csubtypep type (specifier-type 'vector))
 392            (cond
 393              (;; is it immediately obvious what the result type is?
 394               (typep type 'array-type)
 395               (progn
 396                 (aver (= (length (array-type-dimensions type)) 1))
 397                 (let* ((etype (type-specifier
 398                                (array-type-specialized-element-type type)))
 399                        (etype (if (eq etype '*) t etype))
 400                        (type-length (car (array-type-dimensions type))))
 401                   (unless (or (eq type-length '*)
 402                               (= type-length length))
 403                     (sequence-type-length-mismatch-error type length))
 404                   ;; FIXME: These calls to MAKE-ARRAY can't be
 405                   ;; open-coded, as the :ELEMENT-TYPE argument isn't
 406                   ;; constant.  Probably we ought to write a
 407                   ;; DEFTRANSFORM for MAKE-SEQUENCE.  -- CSR,
 408                   ;; 2002-07-22
 409                   (if iep
 410                       (make-array length :element-type etype
 411                                   :initial-element initial-element)
 412                       (make-array length :element-type etype)))))
 413              (t (sequence-type-too-hairy (type-specifier type)))))
 414           ((and (csubtypep type (specifier-type 'sequence))
 415                 (awhen (find-class adjusted-type nil)
 416                   (let ((prototype (sb!mop:class-prototype
 417                                     (sb!pcl:ensure-class-finalized it))))
 418                     (if iep
 419                         (sb!sequence:make-sequence-like
 420                          prototype length :initial-element initial-element)
 421                         (sb!sequence:make-sequence-like
 422                          prototype length))))))
 423           (t (bad-sequence-type-error (type-specifier type))))))
 424 \f
 425 ;;;; SUBSEQ
 426 ;;;;
 427
 428 (define-array-dispatch vector-subseq-dispatch (array start end)
 429   (declare (optimize speed (safety 0)))
 430   (declare (type index start end))
 431   (subseq array start end))
 432
 433 ;;;; The support routines for SUBSEQ are used by compiler transforms,
 434 ;;;; so we worry about dealing with END being supplied or defaulting
 435 ;;;; to NIL at this level.
 436
 437 (defun vector-subseq* (sequence start end)
 438   (declare (type vector sequence))
 439   (declare (type index start)
 440            (type (or null index) end)
 441            (optimize speed))
 442   (with-array-data ((data sequence)
 443                     (start start)
 444                     (end end)
 445                     :check-fill-pointer t
 446                     :force-inline t)
 447     (vector-subseq-dispatch data start end)))
 448
 449 (defun list-subseq* (sequence start end)
 450   (declare (type list sequence)
 451            (type unsigned-byte start)
 452            (type (or null unsigned-byte) end))
 453   (flet ((oops ()
 454            (sequence-bounding-indices-bad-error sequence start end)))
 455     (let ((pointer sequence))
 456       (unless (zerop start)
 457         ;; If START > 0 the list cannot be empty. So CDR down to
 458         ;; it START-1 times, check that we still have something, then
 459         ;; CDR the final time.
 460         ;;
 461         ;; If START was zero, the list may be empty if END is NIL or
 462         ;; also zero.
 463         (when (> start 1)
 464           (setf pointer (nthcdr (1- start) pointer)))
 465         (if pointer
 466             (pop pointer)
 467             (oops)))
 468       (if end
 469           (let ((n (- end start)))
 470             (declare (integer n))
 471             (when (minusp n)
 472               (oops))
 473             (when (plusp n)
 474               (let* ((head (list nil))
 475                      (tail head))
 476                 (macrolet ((pop-one ()
 477                              `(let ((tmp (list (pop pointer))))
 478                                 (setf (cdr tail) tmp
 479                                       tail tmp))))
 480                   ;; Bignum case
 481                   (loop until (fixnump n)
 482                         do (pop-one)
 483                            (decf n))
 484                   ;; Fixnum case, but leave last element, so we should
 485                   ;; still have something left in the sequence.
 486                   (let ((m (1- n)))
 487                     (declare (fixnum m))
 488                     (loop repeat m
 489                           do (pop-one)))
 490                   (unless pointer
 491                     (oops))
 492                   ;; OK, pop the last one.
 493                   (pop-one)
 494                   (cdr head)))))
 495             (loop while pointer
 496                   collect (pop pointer))))))
 497
 498 (defun subseq (sequence start &optional end)
 499   #!+sb-doc
 500   "Return a copy of a subsequence of SEQUENCE starting with element number
 501    START and continuing to the end of SEQUENCE or the optional END."
 502   (seq-dispatch sequence
 503     (list-subseq* sequence start end)
 504     (vector-subseq* sequence start end)
 505     (sb!sequence:subseq sequence start end)))
 506 \f
 507 ;;;; COPY-SEQ
 508
 509 (defun copy-seq (sequence)
 510   #!+sb-doc "Return a copy of SEQUENCE which is EQUAL to SEQUENCE but not EQ."
 511   (seq-dispatch sequence
 512     (list-copy-seq* sequence)
 513     (vector-subseq* sequence 0 nil)
 514     (sb!sequence:copy-seq sequence)))
 515
 516 (defun list-copy-seq* (sequence)
 517   (!copy-list-macro sequence :check-proper-list t))
 518 \f
 519 ;;;; FILL
 520
 521 (defun list-fill* (sequence item start end)
 522   (declare (type list sequence)
 523            (type unsigned-byte start)
 524            (type (or null unsigned-byte) end))
 525   (flet ((oops ()
 526            (sequence-bounding-indices-bad-error sequence start end)))
 527     (let ((pointer sequence))
 528       (unless (zerop start)
 529         ;; If START > 0 the list cannot be empty. So CDR down to it
 530         ;; START-1 times, check that we still have something, then CDR
 531         ;; the final time.
 532         ;;
 533         ;; If START was zero, the list may be empty if END is NIL or
 534         ;; also zero.
 535         (unless (= start 1)
 536           (setf pointer (nthcdr (1- start) pointer)))
 537         (if pointer
 538             (pop pointer)
 539             (oops)))
 540       (if end
 541           (let ((n (- end start)))
 542             (declare (integer n))
 543             (when (minusp n)
 544               (oops))
 545             (when (plusp n)
 546               (loop repeat n
 547                     do (setf pointer (cdr (rplaca pointer item))))))
 548           (loop while pointer
 549                 do (setf pointer (cdr (rplaca pointer item)))))))
 550   sequence)
 551
 552 (defun vector-fill* (sequence item start end)
 553   (with-array-data ((data sequence)
 554                     (start start)
 555                     (end end)
 556                     :force-inline t
 557                     :check-fill-pointer t)
 558     (let ((setter (!find-data-vector-setter data)))
 559       (declare (optimize (speed 3) (safety 0)))
 560       (do ((index start (1+ index)))
 561           ((= index end) sequence)
 562         (declare (index index))
 563         (funcall setter data index item)))))
 564
 565 (defun string-fill* (sequence item start end)
 566   (declare (string sequence))
 567   (with-array-data ((data sequence)
 568                     (start start)
 569                     (end end)
 570                     :force-inline t
 571                     :check-fill-pointer t)
 572     ;; DEFTRANSFORM for FILL will turn these into
 573     ;; calls to UB*-BASH-FILL.
 574     (etypecase data
 575       #!+sb-unicode
 576       ((simple-array character (*))
 577        (let ((item (locally (declare (optimize (safety 3)))
 578                      (the character item))))
 579          (fill data item :start start :end end)))
 580       ((simple-array base-char (*))
 581        (let ((item (locally (declare (optimize (safety 3)))
 582                      (the base-char item))))
 583          (fill data item :start start :end end))))))
 584
 585 (defun fill (sequence item &key (start 0) end)
 586   #!+sb-doc
 587   "Replace the specified elements of SEQUENCE with ITEM."
 588   (seq-dispatch sequence
 589    (list-fill* sequence item start end)
 590    (vector-fill* sequence item start end)
 591    (sb!sequence:fill sequence item
 592                      :start start
 593                      :end (%check-generic-sequence-bounds sequence start end))))
 594 \f
 595 ;;;; REPLACE
 596
 597 (eval-when (:compile-toplevel :execute)
 598
 599 ;;; If we are copying around in the same vector, be careful not to copy the
 600 ;;; same elements over repeatedly. We do this by copying backwards.
 601 (sb!xc:defmacro mumble-replace-from-mumble ()
 602   `(if (and (eq target-sequence source-sequence) (> target-start source-start))
 603        (let ((nelts (min (- target-end target-start)
 604                          (- source-end source-start))))
 605          (do ((target-index (+ (the fixnum target-start) (the fixnum nelts) -1)
 606                             (1- target-index))
 607               (source-index (+ (the fixnum source-start) (the fixnum nelts) -1)
 608                             (1- source-index)))
 609              ((= target-index (the fixnum (1- target-start))) target-sequence)
 610            (declare (fixnum target-index source-index))
 611            ;; disable bounds checking
 612            (declare (optimize (safety 0)))
 613            (setf (aref target-sequence target-index)
 614                  (aref source-sequence source-index))))
 615        (do ((target-index target-start (1+ target-index))
 616             (source-index source-start (1+ source-index)))
 617            ((or (= target-index (the fixnum target-end))
 618                 (= source-index (the fixnum source-end)))
 619             target-sequence)
 620          (declare (fixnum target-index source-index))
 621          ;; disable bounds checking
 622          (declare (optimize (safety 0)))
 623          (setf (aref target-sequence target-index)
 624                (aref source-sequence source-index)))))
 625
 626 (sb!xc:defmacro list-replace-from-list ()
 627   `(if (and (eq target-sequence source-sequence) (> target-start source-start))
 628        (let ((new-elts (subseq source-sequence source-start
 629                                (+ (the fixnum source-start)
 630                                   (the fixnum
 631                                        (min (- (the fixnum target-end)
 632                                                (the fixnum target-start))
 633                                             (- (the fixnum source-end)
 634                                                (the fixnum source-start))))))))
 635          (do ((n new-elts (cdr n))
 636               (o (nthcdr target-start target-sequence) (cdr o)))
 637              ((null n) target-sequence)
 638            (rplaca o (car n))))
 639        (do ((target-index target-start (1+ target-index))
 640             (source-index source-start (1+ source-index))
 641             (target-sequence-ref (nthcdr target-start target-sequence)
 642                                  (cdr target-sequence-ref))
 643             (source-sequence-ref (nthcdr source-start source-sequence)
 644                                  (cdr source-sequence-ref)))
 645            ((or (= target-index (the fixnum target-end))
 646                 (= source-index (the fixnum source-end))
 647                 (null target-sequence-ref) (null source-sequence-ref))
 648             target-sequence)
 649          (declare (fixnum target-index source-index))
 650          (rplaca target-sequence-ref (car source-sequence-ref)))))
 651
 652 (sb!xc:defmacro list-replace-from-mumble ()
 653   `(do ((target-index target-start (1+ target-index))
 654         (source-index source-start (1+ source-index))
 655         (target-sequence-ref (nthcdr target-start target-sequence)
 656                              (cdr target-sequence-ref)))
 657        ((or (= target-index (the fixnum target-end))
 658             (= source-index (the fixnum source-end))
 659             (null target-sequence-ref))
 660         target-sequence)
 661      (declare (fixnum source-index target-index))
 662      (rplaca target-sequence-ref (aref source-sequence source-index))))
 663
 664 (sb!xc:defmacro mumble-replace-from-list ()
 665   `(do ((target-index target-start (1+ target-index))
 666         (source-index source-start (1+ source-index))
 667         (source-sequence (nthcdr source-start source-sequence)
 668                          (cdr source-sequence)))
 669        ((or (= target-index (the fixnum target-end))
 670             (= source-index (the fixnum source-end))
 671             (null source-sequence))
 672         target-sequence)
 673      (declare (fixnum target-index source-index))
 674      (setf (aref target-sequence target-index) (car source-sequence))))
 675
 676 ) ; EVAL-WHEN
 677
 678 ;;;; The support routines for REPLACE are used by compiler transforms, so we
 679 ;;;; worry about dealing with END being supplied or defaulting to NIL
 680 ;;;; at this level.
 681
 682 (defun list-replace-from-list* (target-sequence source-sequence target-start
 683                                 target-end source-start source-end)
 684   (when (null target-end) (setq target-end (length target-sequence)))
 685   (when (null source-end) (setq source-end (length source-sequence)))
 686   (list-replace-from-list))
 687
 688 (defun list-replace-from-vector* (target-sequence source-sequence target-start
 689                                   target-end source-start source-end)
 690   (when (null target-end) (setq target-end (length target-sequence)))
 691   (when (null source-end) (setq source-end (length source-sequence)))
 692   (list-replace-from-mumble))
 693
 694 (defun vector-replace-from-list* (target-sequence source-sequence target-start
 695                                   target-end source-start source-end)
 696   (when (null target-end) (setq target-end (length target-sequence)))
 697   (when (null source-end) (setq source-end (length source-sequence)))
 698   (mumble-replace-from-list))
 699
 700 (defun vector-replace-from-vector* (target-sequence source-sequence
 701                                     target-start target-end source-start
 702                                     source-end)
 703   (when (null target-end) (setq target-end (length target-sequence)))
 704   (when (null source-end) (setq source-end (length source-sequence)))
 705   (mumble-replace-from-mumble))
 706
 707 #!+sb-unicode
 708 (defun simple-character-string-replace-from-simple-character-string*
 709     (target-sequence source-sequence
 710      target-start target-end source-start source-end)
 711   (declare (type (simple-array character (*)) target-sequence source-sequence))
 712   (when (null target-end) (setq target-end (length target-sequence)))
 713   (when (null source-end) (setq source-end (length source-sequence)))
 714   (mumble-replace-from-mumble))
 715
 716 (define-sequence-traverser replace
 717     (sequence1 sequence2 &rest args &key start1 end1 start2 end2)
 718   #!+sb-doc
 719   "Destructively modifies SEQUENCE1 by copying successive elements
 720 into it from the SEQUENCE2.
 721
 722 Elements are copied to the subseqeuence bounded by START1 and END1,
 723 from the subsequence bounded by START2 and END2. If these subsequences
 724 are not of the same length, then the shorter length determines how
 725 many elements are copied."
 726   (declare (truly-dynamic-extent args))
 727   (let* (;; KLUDGE: absent either rewriting FOO-REPLACE-FROM-BAR, or
 728          ;; excessively polluting DEFINE-SEQUENCE-TRAVERSER, we rebind
 729          ;; these things here so that legacy code gets the names it's
 730          ;; expecting.  We could use &AUX instead :-/.
 731          (target-sequence sequence1)
 732          (source-sequence sequence2)
 733          (target-start start1)
 734          (source-start start2)
 735          (target-end (or end1 length1))
 736          (source-end (or end2 length2)))
 737     (seq-dispatch target-sequence
 738       (seq-dispatch source-sequence
 739         (list-replace-from-list)
 740         (list-replace-from-mumble)
 741         (apply #'sb!sequence:replace sequence1 sequence2 args))
 742       (seq-dispatch source-sequence
 743         (mumble-replace-from-list)
 744         (mumble-replace-from-mumble)
 745         (apply #'sb!sequence:replace sequence1 sequence2 args))
 746       (apply #'sb!sequence:replace sequence1 sequence2 args))))
 747 \f
 748 ;;;; REVERSE
 749
 750 (eval-when (:compile-toplevel :execute)
 751
 752 (sb!xc:defmacro vector-reverse (sequence)
 753   `(let ((length (length ,sequence)))
 754      (declare (fixnum length))
 755      (do ((forward-index 0 (1+ forward-index))
 756           (backward-index (1- length) (1- backward-index))
 757           (new-sequence (%make-sequence-like sequence length)))
 758          ((= forward-index length) new-sequence)
 759        (declare (fixnum forward-index backward-index))
 760        (setf (aref new-sequence forward-index)
 761              (aref ,sequence backward-index)))))
 762
 763 (sb!xc:defmacro list-reverse-macro (sequence)
 764   `(do ((new-list ()))
 765        ((endp ,sequence) new-list)
 766      (push (pop ,sequence) new-list)))
 767
 768 ) ; EVAL-WHEN
 769
 770 (defun reverse (sequence)
 771   #!+sb-doc
 772   "Return a new sequence containing the same elements but in reverse order."
 773   (seq-dispatch-checking sequence
 774     (list-reverse* sequence)
 775     (vector-reverse* sequence)
 776     ;; The type deriver says that LIST => LIST and VECTOR => VECTOR
 777     ;; but does not claim to know anything about extended-sequences.
 778     ;; So this could theoretically return any subtype of SEQUENCE
 779     ;; given an EXTENDED-SEQUENCE as input. But fndb says this returns
 780     ;; a CONSED-SEQUENCE, which precludes non-simple vectors.
 781     ;; But a CLOS sequence can apparently decide to return a LIST when
 782     ;; reversed. [Is that too weird? Make this EXTENDED-SEQUENCE maybe?]
 783     (the consed-sequence (values (sb!sequence:reverse sequence)))))
 784
 785 ;;; internal frobs
 786
 787 (defun list-reverse* (sequence)
 788   (list-reverse-macro sequence))
 789
 790 (defun vector-reverse* (sequence)
 791   (vector-reverse sequence))
 792 \f
 793 ;;;; NREVERSE
 794
 795 (eval-when (:compile-toplevel :execute)
 796
 797 (sb!xc:defmacro vector-nreverse (sequence)
 798   `(let ((length (length (the vector ,sequence))))
 799      (when (>= length 2)
 800        (do ((left-index 0 (1+ left-index))
 801             (right-index (1- length) (1- right-index)))
 802            ((<= right-index left-index))
 803          (declare (type index left-index right-index))
 804          (rotatef (aref ,sequence left-index)
 805                   (aref ,sequence right-index))))
 806      ,sequence))
 807
 808 (sb!xc:defmacro list-nreverse-macro (list)
 809   `(do ((1st (cdr ,list) (if (endp 1st) 1st (cdr 1st)))
 810         (2nd ,list 1st)
 811         (3rd '() 2nd))
 812        ((atom 2nd) 3rd)
 813      (rplacd 2nd 3rd)))
 814
 815 ) ; EVAL-WHEN
 816
 817 (defun list-nreverse* (sequence)
 818   (list-nreverse-macro sequence))
 819
 820 (defun vector-nreverse* (sequence)
 821   (vector-nreverse sequence))
 822
 823 (defun nreverse (sequence)
 824   #!+sb-doc
 825   "Return a sequence of the same elements in reverse order; the argument
 826    is destroyed."
 827   (seq-dispatch-checking sequence
 828     (list-nreverse* sequence)
 829     (vector-nreverse* sequence)
 830     ;; The type deriver for this is 'result-type-first-arg',
 831     ;; meaning it should return definitely an EXTENDED-SEQUENCE
 832     ;; and not a list or vector.
 833     (the extended-sequence (values (sb!sequence:nreverse sequence)))))
 834 \f
 835 ;;;; CONCATENATE
 836
 837 (defmacro sb!sequence:dosequence ((element sequence &optional return) &body body)
 838   #!+sb-doc
 839   "Executes BODY with ELEMENT subsequently bound to each element of
 840   SEQUENCE, then returns RETURN."
 841   (multiple-value-bind (forms decls) (parse-body body :doc-string-allowed nil)
 842     (once-only ((sequence sequence))
 843       (with-unique-names (state limit from-end step endp elt)
 844         `(block nil
 845            (seq-dispatch ,sequence
 846              (dolist (,element ,sequence ,return) ,@body)
 847              (do-vector-data (,element ,sequence ,return) ,@body)
 848              (multiple-value-bind (,state ,limit ,from-end ,step ,endp ,elt)
 849                  (sb!sequence:make-sequence-iterator ,sequence)
 850                (do ((,state ,state (funcall ,step ,sequence ,state ,from-end)))
 851                    ((funcall ,endp ,sequence ,state ,limit ,from-end)
 852                     (let ((,element nil))
 853                       ,@(filter-dolist-declarations decls)
 854                       (declare (ignorable ,element))
 855                       ,return))
 856                  (let ((,element (funcall ,elt ,sequence ,state)))
 857                    ,@decls
 858                    (tagbody
 859                       ,@forms))))))))))
 860
 861 \f
 862 (defun concatenate (output-type-spec &rest sequences)
 863   #!+sb-doc
 864   "Return a new sequence of all the argument sequences concatenated together
 865   which shares no structure with the original argument sequences of the
 866   specified OUTPUT-TYPE-SPEC."
 867   (flet ((concat-to-list* (sequences)
 868            (let ((result (list nil)))
 869              (do ((sequences sequences (cdr sequences))
 870                   (splice result))
 871                  ((null sequences) (cdr result))
 872                (let ((sequence (car sequences)))
 873                  (sb!sequence:dosequence (e sequence)
 874                    (setq splice (cdr (rplacd splice (list e)))))))))
 875          (concat-to-simple* (type-spec sequences)
 876            (do ((seqs sequences (cdr seqs))
 877                 (total-length 0)
 878                 (lengths ()))
 879                ((null seqs)
 880                 (do ((sequences sequences (cdr sequences))
 881                      (lengths lengths (cdr lengths))
 882                      (index 0)
 883                      (result (make-sequence type-spec total-length)))
 884                     ((= index total-length) result)
 885                   (declare (fixnum index))
 886                   (let ((sequence (car sequences)))
 887                     (sb!sequence:dosequence (e sequence)
 888                       (setf (aref result index) e)
 889                       (incf index)))))
 890              (let ((length (length (car seqs))))
 891                (declare (fixnum length))
 892                (setq lengths (nconc lengths (list length)))
 893                (setq total-length (+ total-length length))))))
 894     (let ((type (specifier-type output-type-spec)))
 895       (cond
 896         ((csubtypep type (specifier-type 'list))
 897          (cond
 898            ((type= type (specifier-type 'list))
 899             (concat-to-list* sequences))
 900            ((eq type *empty-type*)
 901             (bad-sequence-type-error nil))
 902            ((type= type (specifier-type 'null))
 903             (unless (every #'emptyp sequences)
 904               (sequence-type-length-mismatch-error
 905                type (reduce #'+ sequences :key #'length))) ; FIXME: circular list issues.
 906             '())
 907            ((cons-type-p type)
 908             (multiple-value-bind (min exactp)
 909                 (sb!kernel::cons-type-length-info type)
 910               (let ((length (reduce #'+ sequences :key #'length)))
 911                 (if exactp
 912                     (unless (= length min)
 913                       (sequence-type-length-mismatch-error type length))
 914                     (unless (>= length min)
 915                       (sequence-type-length-mismatch-error type length)))
 916                 (concat-to-list* sequences))))
 917            (t (sequence-type-too-hairy (type-specifier type)))))
 918         ((csubtypep type (specifier-type 'vector))
 919          (concat-to-simple* output-type-spec sequences))
 920         ((and (csubtypep type (specifier-type 'sequence))
 921               (find-class output-type-spec nil))
 922          (coerce (concat-to-simple* 'vector sequences) output-type-spec))
 923         (t
 924          (bad-sequence-type-error output-type-spec))))))
 925
 926 ;;; Efficient out-of-line concatenate for strings. Compiler transforms
 927 ;;; CONCATENATE 'STRING &co into these.
 928 (macrolet ((def (name element-type)
 929              `(defun ,name (&rest sequences)
 930                 (declare (dynamic-extent sequences)
 931                          (optimize speed)
 932                          (optimize (sb!c::insert-array-bounds-checks 0)))
 933                 (let* ((lengths (mapcar #'length sequences))
 934                        (result (make-array (the integer (apply #'+ lengths))
 935                                            :element-type ',element-type))
 936                        (start 0))
 937                   (declare (index start))
 938                   (dolist (seq sequences)
 939                     (string-dispatch
 940                         ((simple-array character (*))
 941                          (simple-array base-char (*))
 942                          t)
 943                         seq
 944                       (replace result seq :start1 start))
 945                     (incf start (the index (pop lengths))))
 946                   result))))
 947   (def %concatenate-to-string character)
 948   (def %concatenate-to-base-string base-char))
 949 \f
 950 ;;;; MAP
 951
 952 ;;; helper functions to handle arity-1 subcases of MAP
 953 (defun %map-to-list-arity-1 (fun sequence)
 954   (let ((reversed-result nil)
 955         (really-fun (%coerce-callable-to-fun fun)))
 956     (sb!sequence:dosequence (element sequence)
 957       (push (funcall really-fun element)
 958             reversed-result))
 959     (nreverse reversed-result)))
 960 (defun %map-to-simple-vector-arity-1 (fun sequence)
 961   (let ((result (make-array (length sequence)))
 962         (index 0)
 963         (really-fun (%coerce-callable-to-fun fun)))
 964     (declare (type index index))
 965     (sb!sequence:dosequence (element sequence)
 966       (setf (aref result index)
 967             (funcall really-fun element))
 968       (incf index))
 969     result))
 970 (defun %map-for-effect-arity-1 (fun sequence)
 971   (let ((really-fun (%coerce-callable-to-fun fun)))
 972     (sb!sequence:dosequence (element sequence)
 973       (funcall really-fun element)))
 974   nil)
 975
 976 (declaim (maybe-inline %map-for-effect))
 977 (defun %map-for-effect (fun sequences)
 978   (declare (type function fun) (type list sequences))
 979   (let ((%sequences sequences)
 980         (%iters (mapcar (lambda (s)
 981                           (seq-dispatch s
 982                             s
 983                             0
 984                             (multiple-value-list
 985                              (sb!sequence:make-sequence-iterator s))))
 986                         sequences))
 987         (%apply-args (make-list (length sequences))))
 988     ;; this is almost efficient (except in the general case where we
 989     ;; trampoline to MAKE-SEQUENCE-ITERATOR; if we had DX allocation
 990     ;; of MAKE-LIST, the whole of %MAP would be cons-free.
 991     (declare (type list %sequences %iters %apply-args))
 992     (loop
 993      (do ((in-sequences  %sequences  (cdr in-sequences))
 994           (in-iters      %iters      (cdr in-iters))
 995           (in-apply-args %apply-args (cdr in-apply-args)))
 996          ((null in-sequences) (apply fun %apply-args))
 997        (let ((i (car in-iters)))
 998          (declare (type (or list index) i))
 999          (cond
1000            ((listp (car in-sequences))
1001             (if (null i)
1002                 (return-from %map-for-effect nil)
1003                 (setf (car in-apply-args) (car i)
1004                       (car in-iters) (cdr i))))
1005            ((typep i 'index)
1006             (let ((v (the vector (car in-sequences))))
1007               (if (>= i (length v))
1008                   (return-from %map-for-effect nil)
1009                   (setf (car in-apply-args) (aref v i)
1010                         (car in-iters) (1+ i)))))
1011            (t
1012             (destructuring-bind (state limit from-end step endp elt &rest ignore)
1013                 i
1014               (declare (type function step endp elt)
1015                        (ignore ignore))
1016               (let ((s (car in-sequences)))
1017                 (if (funcall endp s state limit from-end)
1018                     (return-from %map-for-effect nil)
1019                     (progn
1020                       (setf (car in-apply-args) (funcall elt s state))
1021                       (setf (caar in-iters) (funcall step s state from-end)))))))))))))
1022 (defun %map-to-list (fun sequences)
1023   (declare (type function fun)
1024            (type list sequences))
1025   (let ((result nil))
1026     (flet ((f (&rest args)
1027              (declare (truly-dynamic-extent args))
1028              (push (apply fun args) result)))
1029       (declare (truly-dynamic-extent #'f))
1030       (%map-for-effect #'f sequences))
1031     (nreverse result)))
1032 (defun %map-to-vector (output-type-spec fun sequences)
1033   (declare (type function fun)
1034            (type list sequences))
1035   (let ((min-len 0))
1036     (flet ((f (&rest args)
1037              (declare (truly-dynamic-extent args))
1038              (declare (ignore args))
1039              (incf min-len)))
1040       (declare (truly-dynamic-extent #'f))
1041       (%map-for-effect #'f sequences))
1042     (let ((result (make-sequence output-type-spec min-len))
1043           (i 0))
1044       (declare (type (simple-array * (*)) result))
1045       (flet ((f (&rest args)
1046                (declare (truly-dynamic-extent args))
1047                (setf (aref result i) (apply fun args))
1048                (incf i)))
1049         (declare (truly-dynamic-extent #'f))
1050         (%map-for-effect #'f sequences))
1051       result)))
1052 (defun %map-to-sequence (result-type fun sequences)
1053   (declare (type function fun)
1054            (type list sequences))
1055   (let ((min-len 0))
1056     (flet ((f (&rest args)
1057              (declare (truly-dynamic-extent args))
1058              (declare (ignore args))
1059              (incf min-len)))
1060       (declare (truly-dynamic-extent #'f))
1061       (%map-for-effect #'f sequences))
1062     (let ((result (make-sequence result-type min-len)))
1063       (multiple-value-bind (state limit from-end step endp elt setelt)
1064           (sb!sequence:make-sequence-iterator result)
1065         (declare (ignore limit endp elt))
1066         (flet ((f (&rest args)
1067                  (declare (truly-dynamic-extent args))
1068                  (funcall setelt (apply fun args) result state)
1069                  (setq state (funcall step result state from-end))))
1070           (declare (truly-dynamic-extent #'f))
1071           (%map-for-effect #'f sequences)))
1072       result)))
1073
1074 ;;; %MAP is just MAP without the final just-to-be-sure check that
1075 ;;; length of the output sequence matches any length specified
1076 ;;; in RESULT-TYPE.
1077 (defun %map (result-type function first-sequence &rest more-sequences)
1078   (labels ((slower-map (type)
1079              (let ((really-fun (%coerce-callable-to-fun function))
1080                    (sequences (cons first-sequence more-sequences)))
1081                (cond
1082                  ((eq type *empty-type*)
1083                   (%map-for-effect really-fun sequences))
1084                  ((csubtypep type (specifier-type 'list))
1085                   (%map-to-list really-fun sequences))
1086                  ((csubtypep type (specifier-type 'vector))
1087                   (%map-to-vector result-type really-fun sequences))
1088                  ((and (csubtypep type (specifier-type 'sequence))
1089                        (find-class result-type nil))
1090                   (%map-to-sequence result-type really-fun sequences))
1091                  (t
1092                   (bad-sequence-type-error result-type)))))
1093            (slow-map ()
1094              (let ((type (specifier-type result-type)))
1095                (cond
1096                  (more-sequences
1097                   (slower-map type))
1098                  ((eq type *empty-type*)
1099                   (%map-for-effect-arity-1 function first-sequence))
1100                  ((csubtypep type (specifier-type 'list))
1101                   (%map-to-list-arity-1 function first-sequence))
1102                  ((or (csubtypep type (specifier-type 'simple-vector))
1103                       (csubtypep type (specifier-type '(vector t))))
1104                   (%map-to-simple-vector-arity-1 function first-sequence))
1105                  (t
1106                   (slower-map type))))))
1107     ;; Handle some easy cases faster
1108     (cond (more-sequences
1109            (slow-map))
1110           ((null result-type)
1111            (%map-for-effect-arity-1 function first-sequence))
1112           ((or (eq result-type 'list)
1113                (eq result-type 'cons))
1114            (%map-to-list-arity-1 function first-sequence))
1115           ((or (eq result-type 'vector)
1116                (eq result-type 'simple-vector))
1117            (%map-to-simple-vector-arity-1 function first-sequence))
1118           (t
1119            (slow-map)))))
1120
1121 (defun map (result-type function first-sequence &rest more-sequences)
1122   (apply #'%map
1123          result-type
1124          function
1125          first-sequence
1126          more-sequences))
1127
1128 ;;;; MAP-INTO
1129
1130 (defmacro map-into-lambda (sequences params &body body)
1131   (check-type sequences symbol)
1132   `(flet ((f ,params ,@body))
1133      (declare (truly-dynamic-extent #'f))
1134      ;; Note (MAP-INTO SEQ (LAMBDA () ...)) is a different animal,
1135      ;; hence the awkward flip between MAP and LOOP.
1136      (if ,sequences
1137          (apply #'map nil #'f ,sequences)
1138          (loop (f)))))
1139
1140 (define-array-dispatch vector-map-into (data start end fun sequences)
1141   (declare (optimize speed (safety 0))
1142            (type index start end)
1143            (type function fun)
1144            (type list sequences))
1145   (let ((index start))
1146     (declare (type index index))
1147     (block mapping
1148       (map-into-lambda sequences (&rest args)
1149         (declare (truly-dynamic-extent args))
1150         (when (eql index end)
1151           (return-from mapping))
1152         (setf (aref data index) (apply fun args))
1153         (incf index)))
1154     index))
1155
1156 ;;; Uses the machinery of (MAP NIL ...). For non-vectors we avoid
1157 ;;; computing the length of the result sequence since we can detect
1158 ;;; the end during mapping (if MAP even gets that far).
1159 ;;;
1160 ;;; For each result type, define a mapping function which is
1161 ;;; responsible for replacing RESULT-SEQUENCE elements and for
1162 ;;; terminating itself if the end of RESULT-SEQUENCE is reached.
1163 ;;; The mapping function is defined with MAP-INTO-LAMBDA.
1164 ;;;
1165 ;;; MAP-INTO-LAMBDAs are optimized since they are the inner loops.
1166 ;;; Because we are manually doing bounds checking with known types,
1167 ;;; safety is turned off for vectors and lists but kept for generic
1168 ;;; sequences.
1169 (defun map-into (result-sequence function &rest sequences)
1170   (let ((really-fun (%coerce-callable-to-fun function)))
1171     (etypecase result-sequence
1172       (vector
1173        (with-array-data ((data result-sequence) (start) (end)
1174                          ;; MAP-INTO ignores fill pointer when mapping
1175                          :check-fill-pointer nil)
1176          (let ((new-end (vector-map-into data start end really-fun sequences)))
1177            (when (array-has-fill-pointer-p result-sequence)
1178              (setf (fill-pointer result-sequence) (- new-end start))))))
1179       (list
1180        (let ((node result-sequence))
1181          (declare (type list node))
1182          (map-into-lambda sequences (&rest args)
1183            (declare (truly-dynamic-extent args)
1184                     (optimize speed (safety 0)))
1185            (when (null node)
1186              (return-from map-into result-sequence))
1187            (setf (car node) (apply really-fun args))
1188            (setf node (cdr node)))))
1189       (sequence
1190        (multiple-value-bind (iter limit from-end)
1191            (sb!sequence:make-sequence-iterator result-sequence)
1192          (map-into-lambda sequences (&rest args)
1193            (declare (truly-dynamic-extent args) (optimize speed))
1194            (when (sb!sequence:iterator-endp result-sequence
1195                                             iter limit from-end)
1196              (return-from map-into result-sequence))
1197            (setf (sb!sequence:iterator-element result-sequence iter)
1198                  (apply really-fun args))
1199            (setf iter (sb!sequence:iterator-step result-sequence
1200                                                            iter from-end)))))))
1201   result-sequence)
1202 \f
1203 ;;;; quantifiers
1204
1205 ;;; We borrow the logic from (MAP NIL ..) to handle iteration over
1206 ;;; arbitrary sequence arguments, both in the full call case and in
1207 ;;; the open code case.
1208 (macrolet ((defquantifier (name found-test found-result
1209                                 &key doc (unfound-result (not found-result)))
1210              `(progn
1211                 ;; KLUDGE: It would be really nice if we could simply
1212                 ;; do something like this
1213                 ;;  (declaim (inline ,name))
1214                 ;;  (defun ,name (pred first-seq &rest more-seqs)
1215                 ;;    ,doc
1216                 ;;    (flet ((map-me (&rest rest)
1217                 ;;             (let ((pred-value (apply pred rest)))
1218                 ;;               (,found-test pred-value
1219                 ;;                 (return-from ,name
1220                 ;;                   ,found-result)))))
1221                 ;;      (declare (inline map-me))
1222                 ;;      (apply #'map nil #'map-me first-seq more-seqs)
1223                 ;;      ,unfound-result))
1224                 ;; but Python doesn't seem to be smart enough about
1225                 ;; inlining and APPLY to recognize that it can use
1226                 ;; the DEFTRANSFORM for MAP in the resulting inline
1227                 ;; expansion. I don't have any appetite for deep
1228                 ;; compiler hacking right now, so I'll just work
1229                 ;; around the apparent problem by using a compiler
1230                 ;; macro instead. -- WHN 20000410
1231                 (defun ,name (pred first-seq &rest more-seqs)
1232                   #!+sb-doc ,doc
1233                   (flet ((map-me (&rest rest)
1234                            (let ((pred-value (apply pred rest)))
1235                              (,found-test pred-value
1236                                           (return-from ,name
1237                                             ,found-result)))))
1238                     (declare (inline map-me))
1239                     (apply #'map nil #'map-me first-seq more-seqs)
1240                     ,unfound-result))
1241                 ;; KLUDGE: It would be more obviously correct -- but
1242                 ;; also significantly messier -- for PRED-VALUE to be
1243                 ;; a gensym. However, a private symbol really does
1244                 ;; seem to be good enough; and anyway the really
1245                 ;; obviously correct solution is to make Python smart
1246                 ;; enough that we can use an inline function instead
1247                 ;; of a compiler macro (as above). -- WHN 20000410
1248                 ;;
1249                 ;; FIXME: The DEFINE-COMPILER-MACRO here can be
1250                 ;; important for performance, and it'd be good to have
1251                 ;; it be visible throughout the compilation of all the
1252                 ;; target SBCL code. That could be done by defining
1253                 ;; SB-XC:DEFINE-COMPILER-MACRO and using it here,
1254                 ;; moving this DEFQUANTIFIER stuff (and perhaps other
1255                 ;; inline definitions in seq.lisp as well) into a new
1256                 ;; seq.lisp, and moving remaining target-only stuff
1257                 ;; from the old seq.lisp into target-seq.lisp.
1258                 (define-compiler-macro ,name (pred first-seq &rest more-seqs)
1259                   (let ((elements (make-gensym-list (1+ (length more-seqs))))
1260                         (blockname (sb!xc:gensym "BLOCK"))
1261                         (wrapper (sb!xc:gensym "WRAPPER")))
1262                     (once-only ((pred pred))
1263                       `(block ,blockname
1264                          (flet ((,wrapper (,@elements)
1265                                   (declare (optimize (sb!c::check-tag-existence 0)))
1266                                   (let ((pred-value (funcall ,pred ,@elements)))
1267                                     (,',found-test pred-value
1268                                                    (return-from ,blockname
1269                                                      ,',found-result)))))
1270                            (declare (inline ,wrapper)
1271                                     (dynamic-extent #',wrapper))
1272                            (map nil #',wrapper ,first-seq
1273                                 ,@more-seqs))
1274                          ,',unfound-result)))))))
1275   (defquantifier some when pred-value :unfound-result nil :doc
1276   "Apply PREDICATE to the 0-indexed elements of the sequences, then
1277    possibly to those with index 1, and so on. Return the first
1278    non-NIL value encountered, or NIL if the end of any sequence is reached.")
1279   (defquantifier every unless nil :doc
1280   "Apply PREDICATE to the 0-indexed elements of the sequences, then
1281    possibly to those with index 1, and so on. Return NIL as soon
1282    as any invocation of PREDICATE returns NIL, or T if every invocation
1283    is non-NIL.")
1284   (defquantifier notany when nil :doc
1285   "Apply PREDICATE to the 0-indexed elements of the sequences, then
1286    possibly to those with index 1, and so on. Return NIL as soon
1287    as any invocation of PREDICATE returns a non-NIL value, or T if the end
1288    of any sequence is reached.")
1289   (defquantifier notevery unless t :doc
1290   "Apply PREDICATE to 0-indexed elements of the sequences, then
1291    possibly to those with index 1, and so on. Return T as soon
1292    as any invocation of PREDICATE returns NIL, or NIL if every invocation
1293    is non-NIL."))
1294 \f
1295 ;;;; REDUCE
1296
1297 (eval-when (:compile-toplevel :execute)
1298
1299 (sb!xc:defmacro mumble-reduce (function
1300                                sequence
1301                                key
1302                                start
1303                                end
1304                                initial-value
1305                                ref)
1306   `(do ((index ,start (1+ index))
1307         (value ,initial-value))
1308        ((>= index ,end) value)
1309      (setq value (funcall ,function value
1310                           (apply-key ,key (,ref ,sequence index))))))
1311
1312 (sb!xc:defmacro mumble-reduce-from-end (function
1313                                         sequence
1314                                         key
1315                                         start
1316                                         end
1317                                         initial-value
1318                                         ref)
1319   `(do ((index (1- ,end) (1- index))
1320         (value ,initial-value)
1321         (terminus (1- ,start)))
1322        ((<= index terminus) value)
1323      (setq value (funcall ,function
1324                           (apply-key ,key (,ref ,sequence index))
1325                           value))))
1326
1327 (sb!xc:defmacro list-reduce (function
1328                              sequence
1329                              key
1330                              start
1331                              end
1332                              initial-value
1333                              ivp)
1334   `(let ((sequence (nthcdr ,start ,sequence)))
1335      (do ((count (if ,ivp ,start (1+ ,start))
1336                  (1+ count))
1337           (sequence (if ,ivp sequence (cdr sequence))
1338                     (cdr sequence))
1339           (value (if ,ivp ,initial-value (apply-key ,key (car sequence)))
1340                  (funcall ,function value (apply-key ,key (car sequence)))))
1341          ((>= count ,end) value))))
1342
1343 (sb!xc:defmacro list-reduce-from-end (function
1344                                       sequence
1345                                       key
1346                                       start
1347                                       end
1348                                       initial-value
1349                                       ivp)
1350   `(let ((sequence (nthcdr (- (length ,sequence) ,end)
1351                            (reverse ,sequence))))
1352      (do ((count (if ,ivp ,start (1+ ,start))
1353                  (1+ count))
1354           (sequence (if ,ivp sequence (cdr sequence))
1355                     (cdr sequence))
1356           (value (if ,ivp ,initial-value (apply-key ,key (car sequence)))
1357                  (funcall ,function (apply-key ,key (car sequence)) value)))
1358          ((>= count ,end) value))))
1359
1360 ) ; EVAL-WHEN
1361
1362 (define-sequence-traverser reduce (function sequence &rest args &key key
1363                                    from-end start end (initial-value nil ivp))
1364   (declare (type index start)
1365            (truly-dynamic-extent args))
1366   (seq-dispatch sequence
1367     (let ((end (or end length)))
1368       (declare (type index end))
1369       (if (= end start)
1370           (if ivp initial-value (funcall function))
1371           (if from-end
1372               (list-reduce-from-end function sequence key start end
1373                                     initial-value ivp)
1374               (list-reduce function sequence key start end
1375                            initial-value ivp))))
1376     (let ((end (or end length)))
1377       (declare (type index end))
1378       (if (= end start)
1379           (if ivp initial-value (funcall function))
1380           (if from-end
1381               (progn
1382                 (when (not ivp)
1383                   (setq end (1- (the fixnum end)))
1384                   (setq initial-value (apply-key key (aref sequence end))))
1385                 (mumble-reduce-from-end function sequence key start end
1386                                         initial-value aref))
1387               (progn
1388                 (when (not ivp)
1389                   (setq initial-value (apply-key key (aref sequence start)))
1390                   (setq start (1+ start)))
1391                 (mumble-reduce function sequence key start end
1392                                initial-value aref)))))
1393     (apply #'sb!sequence:reduce function sequence args)))
1394 \f
1395 ;;;; DELETE
1396
1397 (eval-when (:compile-toplevel :execute)
1398
1399 (sb!xc:defmacro mumble-delete (pred)
1400   `(do ((index start (1+ index))
1401         (jndex start)
1402         (number-zapped 0))
1403        ((or (= index (the fixnum end)) (= number-zapped count))
1404         (do ((index index (1+ index))           ; Copy the rest of the vector.
1405              (jndex jndex (1+ jndex)))
1406             ((= index (the fixnum length))
1407              (shrink-vector sequence jndex))
1408           (declare (fixnum index jndex))
1409           (setf (aref sequence jndex) (aref sequence index))))
1410      (declare (fixnum index jndex number-zapped))
1411      (setf (aref sequence jndex) (aref sequence index))
1412      (if ,pred
1413          (incf number-zapped)
1414          (incf jndex))))
1415
1416 (sb!xc:defmacro mumble-delete-from-end (pred)
1417   `(do ((index (1- (the fixnum end)) (1- index)) ; Find the losers.
1418         (number-zapped 0)
1419         (losers ())
1420         this-element
1421         (terminus (1- start)))
1422        ((or (= index terminus) (= number-zapped count))
1423         (do ((losers losers)                     ; Delete the losers.
1424              (index start (1+ index))
1425              (jndex start))
1426             ((or (null losers) (= index (the fixnum end)))
1427              (do ((index index (1+ index))       ; Copy the rest of the vector.
1428                   (jndex jndex (1+ jndex)))
1429                  ((= index (the fixnum length))
1430                   (shrink-vector sequence jndex))
1431                (declare (fixnum index jndex))
1432                (setf (aref sequence jndex) (aref sequence index))))
1433           (declare (fixnum index jndex))
1434           (setf (aref sequence jndex) (aref sequence index))
1435           (if (= index (the fixnum (car losers)))
1436               (pop losers)
1437               (incf jndex))))
1438      (declare (fixnum index number-zapped terminus))
1439      (setq this-element (aref sequence index))
1440      (when ,pred
1441        (incf number-zapped)
1442        (push index losers))))
1443
1444 (sb!xc:defmacro normal-mumble-delete ()
1445   `(mumble-delete
1446     (if test-not
1447         (not (funcall test-not item (apply-key key (aref sequence index))))
1448         (funcall test item (apply-key key (aref sequence index))))))
1449
1450 (sb!xc:defmacro normal-mumble-delete-from-end ()
1451   `(mumble-delete-from-end
1452     (if test-not
1453         (not (funcall test-not item (apply-key key this-element)))
1454         (funcall test item (apply-key key this-element)))))
1455
1456 (sb!xc:defmacro list-delete (pred)
1457   `(let ((handle (cons nil sequence)))
1458      (do ((current (nthcdr start sequence) (cdr current))
1459           (previous (nthcdr start handle))
1460           (index start (1+ index))
1461           (number-zapped 0))
1462          ((or (= index (the fixnum end)) (= number-zapped count))
1463           (cdr handle))
1464        (declare (fixnum index number-zapped))
1465        (cond (,pred
1466               (rplacd previous (cdr current))
1467               (incf number-zapped))
1468              (t
1469               (setq previous (cdr previous)))))))
1470
1471 (sb!xc:defmacro list-delete-from-end (pred)
1472   `(let* ((reverse (nreverse (the list sequence)))
1473           (handle (cons nil reverse)))
1474      (do ((current (nthcdr (- (the fixnum length) (the fixnum end)) reverse)
1475                    (cdr current))
1476           (previous (nthcdr (- (the fixnum length) (the fixnum end)) handle))
1477           (index start (1+ index))
1478           (number-zapped 0))
1479          ((or (= index (the fixnum end)) (= number-zapped count))
1480           (nreverse (cdr handle)))
1481        (declare (fixnum index number-zapped))
1482        (cond (,pred
1483               (rplacd previous (cdr current))
1484               (incf number-zapped))
1485              (t
1486               (setq previous (cdr previous)))))))
1487
1488 (sb!xc:defmacro normal-list-delete ()
1489   '(list-delete
1490     (if test-not
1491         (not (funcall test-not item (apply-key key (car current))))
1492         (funcall test item (apply-key key (car current))))))
1493
1494 (sb!xc:defmacro normal-list-delete-from-end ()
1495   '(list-delete-from-end
1496     (if test-not
1497         (not (funcall test-not item (apply-key key (car current))))
1498         (funcall test item (apply-key key (car current))))))
1499
1500 ) ; EVAL-WHEN
1501
1502 (define-sequence-traverser delete
1503     (item sequence &rest args &key from-end test test-not start
1504      end count key)
1505   #!+sb-doc
1506   "Return a sequence formed by destructively removing the specified ITEM from
1507   the given SEQUENCE."
1508   (declare (type fixnum start)
1509            (truly-dynamic-extent args))
1510   (seq-dispatch sequence
1511     (let ((end (or end length)))
1512       (declare (type index end))
1513       (if from-end
1514           (normal-list-delete-from-end)
1515           (normal-list-delete)))
1516     (let ((end (or end length)))
1517       (declare (type index end))
1518       (if from-end
1519           (normal-mumble-delete-from-end)
1520           (normal-mumble-delete)))
1521     (apply #'sb!sequence:delete item sequence args)))
1522
1523 (eval-when (:compile-toplevel :execute)
1524
1525 (sb!xc:defmacro if-mumble-delete ()
1526   `(mumble-delete
1527     (funcall predicate (apply-key key (aref sequence index)))))
1528
1529 (sb!xc:defmacro if-mumble-delete-from-end ()
1530   `(mumble-delete-from-end
1531     (funcall predicate (apply-key key this-element))))
1532
1533 (sb!xc:defmacro if-list-delete ()
1534   '(list-delete
1535     (funcall predicate (apply-key key (car current)))))
1536
1537 (sb!xc:defmacro if-list-delete-from-end ()
1538   '(list-delete-from-end
1539     (funcall predicate (apply-key key (car current)))))
1540
1541 ) ; EVAL-WHEN
1542
1543 (define-sequence-traverser delete-if
1544     (predicate sequence &rest args &key from-end start key end count)
1545   #!+sb-doc
1546   "Return a sequence formed by destructively removing the elements satisfying
1547   the specified PREDICATE from the given SEQUENCE."
1548   (declare (type fixnum start)
1549            (truly-dynamic-extent args))
1550   (seq-dispatch sequence
1551     (let ((end (or end length)))
1552       (declare (type index end))
1553       (if from-end
1554           (if-list-delete-from-end)
1555           (if-list-delete)))
1556     (let ((end (or end length)))
1557       (declare (type index end))
1558       (if from-end
1559           (if-mumble-delete-from-end)
1560           (if-mumble-delete)))
1561     (apply #'sb!sequence:delete-if predicate sequence args)))
1562
1563 (eval-when (:compile-toplevel :execute)
1564
1565 (sb!xc:defmacro if-not-mumble-delete ()
1566   `(mumble-delete
1567     (not (funcall predicate (apply-key key (aref sequence index))))))
1568
1569 (sb!xc:defmacro if-not-mumble-delete-from-end ()
1570   `(mumble-delete-from-end
1571     (not (funcall predicate (apply-key key this-element)))))
1572
1573 (sb!xc:defmacro if-not-list-delete ()
1574   '(list-delete
1575     (not (funcall predicate (apply-key key (car current))))))
1576
1577 (sb!xc:defmacro if-not-list-delete-from-end ()
1578   '(list-delete-from-end
1579     (not (funcall predicate (apply-key key (car current))))))
1580
1581 ) ; EVAL-WHEN
1582
1583 (define-sequence-traverser delete-if-not
1584     (predicate sequence &rest args &key from-end start end key count)
1585   #!+sb-doc
1586   "Return a sequence formed by destructively removing the elements not
1587   satisfying the specified PREDICATE from the given SEQUENCE."
1588   (declare (type fixnum start)
1589            (truly-dynamic-extent args))
1590   (seq-dispatch sequence
1591     (let ((end (or end length)))
1592       (declare (type index end))
1593       (if from-end
1594           (if-not-list-delete-from-end)
1595           (if-not-list-delete)))
1596     (let ((end (or end length)))
1597       (declare (type index end))
1598       (if from-end
1599           (if-not-mumble-delete-from-end)
1600           (if-not-mumble-delete)))
1601     (apply #'sb!sequence:delete-if-not predicate sequence args)))
1602 \f
1603 ;;;; REMOVE
1604
1605 (eval-when (:compile-toplevel :execute)
1606
1607 ;;; MUMBLE-REMOVE-MACRO does not include (removes) each element that
1608 ;;; satisfies the predicate.
1609 (sb!xc:defmacro mumble-remove-macro (bump left begin finish right pred)
1610   `(do ((index ,begin (,bump index))
1611         (result
1612          (do ((index ,left (,bump index))
1613               (result (%make-sequence-like sequence length)))
1614              ((= index (the fixnum ,begin)) result)
1615            (declare (fixnum index))
1616            (setf (aref result index) (aref sequence index))))
1617         (new-index ,begin)
1618         (number-zapped 0)
1619         (this-element))
1620        ((or (= index (the fixnum ,finish))
1621             (= number-zapped count))
1622         (do ((index index (,bump index))
1623              (new-index new-index (,bump new-index)))
1624             ((= index (the fixnum ,right)) (%shrink-vector result new-index))
1625           (declare (fixnum index new-index))
1626           (setf (aref result new-index) (aref sequence index))))
1627      (declare (fixnum index new-index number-zapped))
1628      (setq this-element (aref sequence index))
1629      (cond (,pred (incf number-zapped))
1630            (t (setf (aref result new-index) this-element)
1631               (setq new-index (,bump new-index))))))
1632
1633 (sb!xc:defmacro mumble-remove (pred)
1634   `(mumble-remove-macro 1+ 0 start end length ,pred))
1635
1636 (sb!xc:defmacro mumble-remove-from-end (pred)
1637   `(let ((sequence (copy-seq sequence)))
1638      (mumble-delete-from-end ,pred)))
1639
1640 (sb!xc:defmacro normal-mumble-remove ()
1641   `(mumble-remove
1642     (if test-not
1643         (not (funcall test-not item (apply-key key this-element)))
1644         (funcall test item (apply-key key this-element)))))
1645
1646 (sb!xc:defmacro normal-mumble-remove-from-end ()
1647   `(mumble-remove-from-end
1648     (if test-not
1649         (not (funcall test-not item (apply-key key this-element)))
1650         (funcall test item (apply-key key this-element)))))
1651
1652 (sb!xc:defmacro if-mumble-remove ()
1653   `(mumble-remove (funcall predicate (apply-key key this-element))))
1654
1655 (sb!xc:defmacro if-mumble-remove-from-end ()
1656   `(mumble-remove-from-end (funcall predicate (apply-key key this-element))))
1657
1658 (sb!xc:defmacro if-not-mumble-remove ()
1659   `(mumble-remove (not (funcall predicate (apply-key key this-element)))))
1660
1661 (sb!xc:defmacro if-not-mumble-remove-from-end ()
1662   `(mumble-remove-from-end
1663     (not (funcall predicate (apply-key key this-element)))))
1664
1665 ;;; LIST-REMOVE-MACRO does not include (removes) each element that satisfies
1666 ;;; the predicate.
1667 (sb!xc:defmacro list-remove-macro (pred reverse?)
1668   `(let* ((sequence ,(if reverse?
1669                          '(reverse (the list sequence))
1670                          'sequence))
1671           (%start ,(if reverse? '(- length end) 'start))
1672           (%end ,(if reverse? '(- length start) 'end))
1673           (splice (list nil))
1674           (results (do ((index 0 (1+ index))
1675                         (before-start splice))
1676                        ((= index (the fixnum %start)) before-start)
1677                      (declare (fixnum index))
1678                      (setq splice
1679                            (cdr (rplacd splice (list (pop sequence))))))))
1680      (do ((index %start (1+ index))
1681           (this-element)
1682           (number-zapped 0))
1683          ((or (= index (the fixnum %end)) (= number-zapped count))
1684           (do ((index index (1+ index)))
1685               ((null sequence)
1686                ,(if reverse?
1687                     '(nreverse (the list (cdr results)))
1688                     '(cdr results)))
1689             (declare (fixnum index))
1690             (setq splice (cdr (rplacd splice (list (pop sequence)))))))
1691        (declare (fixnum index number-zapped))
1692        (setq this-element (pop sequence))
1693        (if ,pred
1694            (setq number-zapped (1+ number-zapped))
1695            (setq splice (cdr (rplacd splice (list this-element))))))))
1696
1697 (sb!xc:defmacro list-remove (pred)
1698   `(list-remove-macro ,pred nil))
1699
1700 (sb!xc:defmacro list-remove-from-end (pred)
1701   `(list-remove-macro ,pred t))
1702
1703 (sb!xc:defmacro normal-list-remove ()
1704   `(list-remove
1705     (if test-not
1706         (not (funcall test-not item (apply-key key this-element)))
1707         (funcall test item (apply-key key this-element)))))
1708
1709 (sb!xc:defmacro normal-list-remove-from-end ()
1710   `(list-remove-from-end
1711     (if test-not
1712         (not (funcall test-not item (apply-key key this-element)))
1713         (funcall test item (apply-key key this-element)))))
1714
1715 (sb!xc:defmacro if-list-remove ()
1716   `(list-remove
1717     (funcall predicate (apply-key key this-element))))
1718
1719 (sb!xc:defmacro if-list-remove-from-end ()
1720   `(list-remove-from-end
1721     (funcall predicate (apply-key key this-element))))
1722
1723 (sb!xc:defmacro if-not-list-remove ()
1724   `(list-remove
1725     (not (funcall predicate (apply-key key this-element)))))
1726
1727 (sb!xc:defmacro if-not-list-remove-from-end ()
1728   `(list-remove-from-end
1729     (not (funcall predicate (apply-key key this-element)))))
1730
1731 ) ; EVAL-WHEN
1732
1733 (define-sequence-traverser remove
1734     (item sequence &rest args &key from-end test test-not start
1735      end count key)
1736   #!+sb-doc
1737   "Return a copy of SEQUENCE with elements satisfying the test (default is
1738    EQL) with ITEM removed."
1739   (declare (type fixnum start)
1740            (truly-dynamic-extent args))
1741   (seq-dispatch sequence
1742     (let ((end (or end length)))
1743       (declare (type index end))
1744       (if from-end
1745           (normal-list-remove-from-end)
1746           (normal-list-remove)))
1747     (let ((end (or end length)))
1748       (declare (type index end))
1749       (if from-end
1750           (normal-mumble-remove-from-end)
1751           (normal-mumble-remove)))
1752     (apply #'sb!sequence:remove item sequence args)))
1753
1754 (define-sequence-traverser remove-if
1755     (predicate sequence &rest args &key from-end start end count key)
1756   #!+sb-doc
1757   "Return a copy of sequence with elements satisfying PREDICATE removed."
1758   (declare (type fixnum start)
1759            (truly-dynamic-extent args))
1760   (seq-dispatch sequence
1761     (let ((end (or end length)))
1762       (declare (type index end))
1763       (if from-end
1764           (if-list-remove-from-end)
1765           (if-list-remove)))
1766     (let ((end (or end length)))
1767       (declare (type index end))
1768       (if from-end
1769           (if-mumble-remove-from-end)
1770           (if-mumble-remove)))
1771     (apply #'sb!sequence:remove-if predicate sequence args)))
1772
1773 (define-sequence-traverser remove-if-not
1774     (predicate sequence &rest args &key from-end start end count key)
1775   #!+sb-doc
1776   "Return a copy of sequence with elements not satisfying PREDICATE removed."
1777   (declare (type fixnum start)
1778            (truly-dynamic-extent args))
1779   (seq-dispatch sequence
1780     (let ((end (or end length)))
1781       (declare (type index end))
1782       (if from-end
1783           (if-not-list-remove-from-end)
1784           (if-not-list-remove)))
1785     (let ((end (or end length)))
1786       (declare (type index end))
1787       (if from-end
1788           (if-not-mumble-remove-from-end)
1789           (if-not-mumble-remove)))
1790     (apply #'sb!sequence:remove-if-not predicate sequence args)))
1791 \f
1792 ;;;; REMOVE-DUPLICATES
1793
1794 ;;; Remove duplicates from a list. If from-end, remove the later duplicates,
1795 ;;; not the earlier ones. Thus if we check from-end we don't copy an item
1796 ;;; if we look into the already copied structure (from after :start) and see
1797 ;;; the item. If we check from beginning we check into the rest of the
1798 ;;; original list up to the :end marker (this we have to do by running a
1799 ;;; do loop down the list that far and using our test.
1800 (defun list-remove-duplicates* (list test test-not start end key from-end)
1801   (declare (fixnum start))
1802   (let* ((result (list ())) ; Put a marker on the beginning to splice with.
1803          (splice result)
1804          (current list)
1805          (end (or end (length list)))
1806          (hash (and (> (- end start) 20)
1807                     test
1808                     (not key)
1809                     (not test-not)
1810                     (or (eql test #'eql)
1811                         (eql test #'eq)
1812                         (eql test #'equal)
1813                         (eql test #'equalp))
1814                     (make-hash-table :test test :size (- end start)))))
1815     (do ((index 0 (1+ index)))
1816         ((= index start))
1817       (declare (fixnum index))
1818       (setq splice (cdr (rplacd splice (list (car current)))))
1819       (setq current (cdr current)))
1820     (if hash
1821         (do ((index start (1+ index)))
1822             ((or (and end (= index (the fixnum end)))
1823                  (atom current)))
1824           (declare (fixnum index))
1825           ;; The hash table contains links from values that are
1826           ;; already in result to the cons cell *preceding* theirs
1827           ;; in the list.  That is, for each value v in the list,
1828           ;; v and (cadr (gethash v hash)) are equal under TEST.
1829           (let ((prev (gethash (car current) hash)))
1830             (cond
1831              ((not prev)
1832               (setf (gethash (car current) hash) splice)
1833               (setq splice (cdr (rplacd splice (list (car current))))))
1834              ((not from-end)
1835               (let* ((old (cdr prev))
1836                      (next (cdr old)))
1837                 (if next
1838                   (let ((next-val (car next)))
1839                     ;; (assert (eq (gethash next-val hash) old))
1840                     (setf (cdr prev) next
1841                           (gethash next-val hash) prev
1842                           (gethash (car current) hash) splice
1843                           splice (cdr (rplacd splice (list (car current))))))
1844                   (setf (car old) (car current)))))))
1845           (setq current (cdr current)))
1846       (do ((index start (1+ index)))
1847           ((or (and end (= index (the fixnum end)))
1848                (atom current)))
1849         (declare (fixnum index))
1850         (if (or (and from-end
1851                      (not (if test-not
1852                               (member (apply-key key (car current))
1853                                       (nthcdr (1+ start) result)
1854                                       :test-not test-not
1855                                       :key key)
1856                             (member (apply-key key (car current))
1857                                     (nthcdr (1+ start) result)
1858                                     :test test
1859                                     :key key))))
1860                 (and (not from-end)
1861                      (not (do ((it (apply-key key (car current)))
1862                                (l (cdr current) (cdr l))
1863                                (i (1+ index) (1+ i)))
1864                               ((or (atom l) (and end (= i (the fixnum end))))
1865                                ())
1866                             (declare (fixnum i))
1867                             (if (if test-not
1868                                     (not (funcall test-not
1869                                                   it
1870                                                   (apply-key key (car l))))
1871                                   (funcall test it (apply-key key (car l))))
1872                                 (return t))))))
1873             (setq splice (cdr (rplacd splice (list (car current))))))
1874         (setq current (cdr current))))
1875     (do ()
1876         ((atom current))
1877       (setq splice (cdr (rplacd splice (list (car current)))))
1878       (setq current (cdr current)))
1879     (cdr result)))
1880
1881 (defun vector-remove-duplicates* (vector test test-not start end key from-end
1882                                          &optional (length (length vector)))
1883   (declare (vector vector) (fixnum start length))
1884   (when (null end) (setf end (length vector)))
1885   (let ((result (%make-sequence-like vector length))
1886         (index 0)
1887         (jndex start))
1888     (declare (fixnum index jndex))
1889     (do ()
1890         ((= index start))
1891       (setf (aref result index) (aref vector index))
1892       (setq index (1+ index)))
1893     (do ((elt))
1894         ((= index end))
1895       (setq elt (aref vector index))
1896       (unless (or (and from-end
1897                        (if test-not
1898                            (position (apply-key key elt) result
1899                                      :start start :end jndex
1900                                      :test-not test-not :key key)
1901                            (position (apply-key key elt) result
1902                                      :start start :end jndex
1903                                      :test test :key key)))
1904                   (and (not from-end)
1905                        (if test-not
1906                            (position (apply-key key elt) vector
1907                                      :start (1+ index) :end end
1908                                      :test-not test-not :key key)
1909                            (position (apply-key key elt) vector
1910                                      :start (1+ index) :end end
1911                                      :test test :key key))))
1912         (setf (aref result jndex) elt)
1913         (setq jndex (1+ jndex)))
1914       (setq index (1+ index)))
1915     (do ()
1916         ((= index length))
1917       (setf (aref result jndex) (aref vector index))
1918       (setq index (1+ index))
1919       (setq jndex (1+ jndex)))
1920     (%shrink-vector result jndex)))
1921
1922 (define-sequence-traverser remove-duplicates
1923     (sequence &rest args &key test test-not start end from-end key)
1924   #!+sb-doc
1925   "The elements of SEQUENCE are compared pairwise, and if any two match,
1926    the one occurring earlier is discarded, unless FROM-END is true, in
1927    which case the one later in the sequence is discarded. The resulting
1928    sequence is returned.
1929
1930    The :TEST-NOT argument is deprecated."
1931   (declare (fixnum start)
1932            (truly-dynamic-extent args))
1933   (seq-dispatch sequence
1934     (if sequence
1935         (list-remove-duplicates* sequence test test-not
1936                                  start end key from-end))
1937     (vector-remove-duplicates* sequence test test-not start end key from-end)
1938     (apply #'sb!sequence:remove-duplicates sequence args)))
1939 \f
1940 ;;;; DELETE-DUPLICATES
1941
1942 (defun list-delete-duplicates* (list test test-not key from-end start end)
1943   (declare (fixnum start))
1944   (let ((handle (cons nil list)))
1945     (do ((current (nthcdr start list) (cdr current))
1946          (previous (nthcdr start handle))
1947          (index start (1+ index)))
1948         ((or (and end (= index (the fixnum end))) (null current))
1949          (cdr handle))
1950       (declare (fixnum index))
1951       (if (do ((x (if from-end
1952                       (nthcdr (1+ start) handle)
1953                       (cdr current))
1954                   (cdr x))
1955                (i (1+ index) (1+ i)))
1956               ((or (null x)
1957                    (and (not from-end) end (= i (the fixnum end)))
1958                    (eq x current))
1959                nil)
1960             (declare (fixnum i))
1961             (if (if test-not
1962                     (not (funcall test-not
1963                                   (apply-key key (car current))
1964                                   (apply-key key (car x))))
1965                     (funcall test
1966                              (apply-key key (car current))
1967                              (apply-key key (car x))))
1968                 (return t)))
1969           (rplacd previous (cdr current))
1970           (setq previous (cdr previous))))))
1971
1972 (defun vector-delete-duplicates* (vector test test-not key from-end start end
1973                                          &optional (length (length vector)))
1974   (declare (vector vector) (fixnum start length))
1975   (when (null end) (setf end (length vector)))
1976   (do ((index start (1+ index))
1977        (jndex start))
1978       ((= index end)
1979        (do ((index index (1+ index))            ; copy the rest of the vector
1980             (jndex jndex (1+ jndex)))
1981            ((= index length)
1982             (shrink-vector vector jndex))
1983          (setf (aref vector jndex) (aref vector index))))
1984     (declare (fixnum index jndex))
1985     (setf (aref vector jndex) (aref vector index))
1986     (unless (if test-not
1987                 (position (apply-key key (aref vector index)) vector :key key
1988                           :start (if from-end start (1+ index))
1989                           :end (if from-end jndex end)
1990                           :test-not test-not)
1991                 (position (apply-key key (aref vector index)) vector :key key
1992                           :start (if from-end start (1+ index))
1993                           :end (if from-end jndex end)
1994                           :test test))
1995       (setq jndex (1+ jndex)))))
1996
1997 (define-sequence-traverser delete-duplicates
1998     (sequence &rest args &key test test-not start end from-end key)
1999   #!+sb-doc
2000   "The elements of SEQUENCE are examined, and if any two match, one is
2001    discarded. The resulting sequence, which may be formed by destroying the
2002    given sequence, is returned.
2003
2004    The :TEST-NOT argument is deprecated."
2005   (declare (truly-dynamic-extent args))
2006   (seq-dispatch sequence
2007     (when sequence
2008       (list-delete-duplicates* sequence test test-not
2009                                key from-end start end))
2010     (vector-delete-duplicates* sequence test test-not key from-end start end)
2011     (apply #'sb!sequence:delete-duplicates sequence args)))
2012 \f
2013 ;;;; SUBSTITUTE
2014
2015 (defun list-substitute* (pred new list start end count key test test-not old)
2016   (declare (fixnum start end count))
2017   (let* ((result (list nil))
2018          elt
2019          (splice result)
2020          (list list))      ; Get a local list for a stepper.
2021     (do ((index 0 (1+ index)))
2022         ((= index start))
2023       (declare (fixnum index))
2024       (setq splice (cdr (rplacd splice (list (car list)))))
2025       (setq list (cdr list)))
2026     (do ((index start (1+ index)))
2027         ((or (= index end) (null list) (= count 0)))
2028       (declare (fixnum index))
2029       (setq elt (car list))
2030       (setq splice
2031             (cdr (rplacd splice
2032                          (list
2033                           (cond
2034                            ((case pred
2035                                    (normal
2036                                     (if test-not
2037                                         (not
2038                                          (funcall test-not old (apply-key key elt)))
2039                                         (funcall test old (apply-key key elt))))
2040                                    (if (funcall test (apply-key key elt)))
2041                                    (if-not (not (funcall test (apply-key key elt)))))
2042                             (decf count)
2043                             new)
2044                                 (t elt))))))
2045       (setq list (cdr list)))
2046     (do ()
2047         ((null list))
2048       (setq splice (cdr (rplacd splice (list (car list)))))
2049       (setq list (cdr list)))
2050     (cdr result)))
2051
2052 ;;; Replace old with new in sequence moving from left to right by incrementer
2053 ;;; on each pass through the loop. Called by all three substitute functions.
2054 (defun vector-substitute* (pred new sequence incrementer left right length
2055                            start end count key test test-not old)
2056   (declare (fixnum start count end incrementer right))
2057   (let ((result (%make-sequence-like sequence length))
2058         (index left))
2059     (declare (fixnum index))
2060     (do ()
2061         ((= index start))
2062       (setf (aref result index) (aref sequence index))
2063       (setq index (+ index incrementer)))
2064     (do ((elt))
2065         ((or (= index end) (= count 0)))
2066       (setq elt (aref sequence index))
2067       (setf (aref result index)
2068             (cond ((case pred
2069                           (normal
2070                             (if test-not
2071                                 (not (funcall test-not old (apply-key key elt)))
2072                                 (funcall test old (apply-key key elt))))
2073                           (if (funcall test (apply-key key elt)))
2074                           (if-not (not (funcall test (apply-key key elt)))))
2075                    (setq count (1- count))
2076                    new)
2077                   (t elt)))
2078       (setq index (+ index incrementer)))
2079     (do ()
2080         ((= index right))
2081       (setf (aref result index) (aref sequence index))
2082       (setq index (+ index incrementer)))
2083     result))
2084
2085 (eval-when (:compile-toplevel :execute)
2086
2087 (sb!xc:defmacro subst-dispatch (pred)
2088   `(seq-dispatch sequence
2089      (let ((end (or end length)))
2090        (declare (type index end))
2091        (if from-end
2092            (nreverse (list-substitute* ,pred
2093                                        new
2094                                        (reverse sequence)
2095                                        (- (the fixnum length)
2096                                           (the fixnum end))
2097                                        (- (the fixnum length)
2098                                           (the fixnum start))
2099                                        count key test test-not old))
2100            (list-substitute* ,pred
2101                              new sequence start end count key test test-not
2102                              old)))
2103
2104      (let ((end (or end length)))
2105        (declare (type index end))
2106        (if from-end
2107            (vector-substitute* ,pred new sequence -1 (1- (the fixnum length))
2108                                -1 length (1- (the fixnum end))
2109                                (1- (the fixnum start))
2110                                count key test test-not old)
2111            (vector-substitute* ,pred new sequence 1 0 length length
2112                                start end count key test test-not old)))
2113
2114     ;; FIXME: wow, this is an odd way to implement the dispatch.  PRED
2115     ;; here is (QUOTE [NORMAL|IF|IF-NOT]).  Not only is this pretty
2116     ;; pointless, but also LIST-SUBSTITUTE* and VECTOR-SUBSTITUTE*
2117     ;; dispatch once per element on PRED's run-time identity.
2118     ,(ecase (cadr pred)
2119        ((normal) `(apply #'sb!sequence:substitute new old sequence args))
2120        ((if) `(apply #'sb!sequence:substitute-if new predicate sequence args))
2121        ((if-not) `(apply #'sb!sequence:substitute-if-not new predicate sequence args)))))
2122 ) ; EVAL-WHEN
2123
2124 (define-sequence-traverser substitute
2125     (new old sequence &rest args &key from-end test test-not
2126          start count end key)
2127   #!+sb-doc
2128   "Return a sequence of the same kind as SEQUENCE with the same elements,
2129   except that all elements equal to OLD are replaced with NEW."
2130   (declare (type fixnum start)
2131            (truly-dynamic-extent args))
2132   (subst-dispatch 'normal))
2133 \f
2134 ;;;; SUBSTITUTE-IF, SUBSTITUTE-IF-NOT
2135
2136 (define-sequence-traverser substitute-if
2137     (new predicate sequence &rest args &key from-end start end count key)
2138   #!+sb-doc
2139   "Return a sequence of the same kind as SEQUENCE with the same elements
2140   except that all elements satisfying the PRED are replaced with NEW."
2141   (declare (type fixnum start)
2142            (truly-dynamic-extent args))
2143   (let ((test predicate)
2144         (test-not nil)
2145         old)
2146     (subst-dispatch 'if)))
2147
2148 (define-sequence-traverser substitute-if-not
2149     (new predicate sequence &rest args &key from-end start end count key)
2150   #!+sb-doc
2151   "Return a sequence of the same kind as SEQUENCE with the same elements
2152   except that all elements not satisfying the PRED are replaced with NEW."
2153   (declare (type fixnum start)
2154            (truly-dynamic-extent args))
2155   (let ((test predicate)
2156         (test-not nil)
2157         old)
2158     (subst-dispatch 'if-not)))
2159 \f
2160 ;;;; NSUBSTITUTE
2161
2162 (define-sequence-traverser nsubstitute
2163     (new old sequence &rest args &key from-end test test-not
2164          end count key start)
2165   #!+sb-doc
2166   "Return a sequence of the same kind as SEQUENCE with the same elements
2167   except that all elements equal to OLD are replaced with NEW. SEQUENCE
2168   may be destructively modified."
2169   (declare (type fixnum start)
2170            (truly-dynamic-extent args))
2171   (seq-dispatch sequence
2172     (let ((end (or end length)))
2173       (declare (type index end))
2174       (if from-end
2175           (nreverse (nlist-substitute*
2176                      new old (nreverse (the list sequence))
2177                      test test-not (- length end) (- length start)
2178                      count key))
2179           (nlist-substitute* new old sequence
2180                              test test-not start end count key)))
2181     (let ((end (or end length)))
2182       (declare (type index end))
2183       (if from-end
2184           (nvector-substitute* new old sequence -1
2185                                test test-not (1- end) (1- start) count key)
2186           (nvector-substitute* new old sequence 1
2187                                test test-not start end count key)))
2188     (apply #'sb!sequence:nsubstitute new old sequence args)))
2189
2190 (defun nlist-substitute* (new old sequence test test-not start end count key)
2191   (declare (fixnum start count end))
2192   (do ((list (nthcdr start sequence) (cdr list))
2193        (index start (1+ index)))
2194       ((or (= index end) (null list) (= count 0)) sequence)
2195     (declare (fixnum index))
2196     (when (if test-not
2197               (not (funcall test-not old (apply-key key (car list))))
2198               (funcall test old (apply-key key (car list))))
2199       (rplaca list new)
2200       (setq count (1- count)))))
2201
2202 (defun nvector-substitute* (new old sequence incrementer
2203                             test test-not start end count key)
2204   (declare (fixnum start incrementer count end))
2205   (do ((index start (+ index incrementer)))
2206       ((or (= index end) (= count 0)) sequence)
2207     (declare (fixnum index))
2208     (when (if test-not
2209               (not (funcall test-not
2210                             old
2211                             (apply-key key (aref sequence index))))
2212               (funcall test old (apply-key key (aref sequence index))))
2213       (setf (aref sequence index) new)
2214       (setq count (1- count)))))
2215 \f
2216 ;;;; NSUBSTITUTE-IF, NSUBSTITUTE-IF-NOT
2217
2218 (define-sequence-traverser nsubstitute-if
2219     (new predicate sequence &rest args &key from-end start end count key)
2220   #!+sb-doc
2221   "Return a sequence of the same kind as SEQUENCE with the same elements
2222    except that all elements satisfying PREDICATE are replaced with NEW.
2223    SEQUENCE may be destructively modified."
2224   (declare (type fixnum start)
2225            (truly-dynamic-extent args))
2226   (seq-dispatch sequence
2227     (let ((end (or end length)))
2228       (declare (type index end))
2229       (if from-end
2230           (nreverse (nlist-substitute-if*
2231                      new predicate (nreverse (the list sequence))
2232                      (- length end) (- length start) count key))
2233           (nlist-substitute-if* new predicate sequence
2234                                 start end count key)))
2235     (let ((end (or end length)))
2236       (declare (type index end))
2237       (if from-end
2238           (nvector-substitute-if* new predicate sequence -1
2239                                   (1- end) (1- start) count key)
2240           (nvector-substitute-if* new predicate sequence 1
2241                                   start end count key)))
2242     (apply #'sb!sequence:nsubstitute-if new predicate sequence args)))
2243
2244 (defun nlist-substitute-if* (new test sequence start end count key)
2245   (declare (type fixnum end)
2246            (type function test)) ; coercion is done by caller
2247   (do ((list (nthcdr start sequence) (cdr list))
2248        (index start (1+ index)))
2249       ((or (= index end) (null list) (= count 0)) sequence)
2250     (when (funcall test (apply-key key (car list)))
2251       (rplaca list new)
2252       (setq count (1- count)))))
2253
2254 (defun nvector-substitute-if* (new test sequence incrementer
2255                                start end count key)
2256   (declare (type fixnum end)
2257            (type function test)) ; coercion is done by caller
2258   (do ((index start (+ index incrementer)))
2259       ((or (= index end) (= count 0)) sequence)
2260     (when (funcall test (apply-key key (aref sequence index)))
2261       (setf (aref sequence index) new)
2262       (setq count (1- count)))))
2263
2264 (define-sequence-traverser nsubstitute-if-not
2265     (new predicate sequence &rest args &key from-end start end count key)
2266   #!+sb-doc
2267   "Return a sequence of the same kind as SEQUENCE with the same elements
2268    except that all elements not satisfying PREDICATE are replaced with NEW.
2269    SEQUENCE may be destructively modified."
2270   (declare (type fixnum start)
2271            (truly-dynamic-extent args))
2272   (seq-dispatch sequence
2273     (let ((end (or end length)))
2274       (declare (fixnum end))
2275       (if from-end
2276           (nreverse (nlist-substitute-if-not*
2277                      new predicate (nreverse (the list sequence))
2278                      (- length end) (- length start) count key))
2279           (nlist-substitute-if-not* new predicate sequence
2280                                     start end count key)))
2281     (let ((end (or end length)))
2282       (declare (fixnum end))
2283       (if from-end
2284           (nvector-substitute-if-not* new predicate sequence -1
2285                                       (1- end) (1- start) count key)
2286           (nvector-substitute-if-not* new predicate sequence 1
2287                                       start end count key)))
2288     (apply #'sb!sequence:nsubstitute-if-not new predicate sequence args)))
2289
2290 (defun nlist-substitute-if-not* (new test sequence start end count key)
2291   (declare (type fixnum end)
2292            (type function test)) ; coercion is done by caller
2293   (do ((list (nthcdr start sequence) (cdr list))
2294        (index start (1+ index)))
2295       ((or (= index end) (null list) (= count 0)) sequence)
2296     (when (not (funcall test (apply-key key (car list))))
2297       (rplaca list new)
2298       (decf count))))
2299
2300 (defun nvector-substitute-if-not* (new test sequence incrementer
2301                                    start end count key)
2302   (declare (type fixnum end)
2303            (type function test)) ; coercion is done by caller
2304   (do ((index start (+ index incrementer)))
2305       ((or (= index end) (= count 0)) sequence)
2306     (when (not (funcall test (apply-key key (aref sequence index))))
2307       (setf (aref sequence index) new)
2308       (decf count))))
2309 \f
2310 ;;;; FIND, POSITION, and their -IF and -IF-NOT variants
2311
2312 (defun effective-find-position-test (test test-not)
2313   (effective-find-position-test test test-not))
2314 (defun effective-find-position-key (key)
2315   (effective-find-position-key key))
2316
2317 ;;; shared guts of out-of-line FIND, POSITION, FIND-IF, and POSITION-IF
2318 (macrolet (;; shared logic for defining %FIND-POSITION and
2319            ;; %FIND-POSITION-IF in terms of various inlineable cases
2320            ;; of the expression defined in FROB and VECTOR*-FROB
2321            (frobs (&optional bit-frob)
2322              `(seq-dispatch sequence-arg
2323                (frob sequence-arg from-end)
2324                (with-array-data ((sequence sequence-arg :offset-var offset)
2325                                  (start start)
2326                                  (end end)
2327                                  :check-fill-pointer t)
2328                  (multiple-value-bind (f p)
2329                      (macrolet ((frob2 () `(if from-end
2330                                                (frob sequence t)
2331                                                (frob sequence nil))))
2332                        (typecase sequence
2333                          #!+sb-unicode
2334                          ((simple-array character (*)) (frob2))
2335                          ((simple-array base-char (*)) (frob2))
2336                          ,@(when bit-frob
2337                              `((simple-bit-vector
2338                                 (if (and (typep item 'bit)
2339                                          (eq #'identity key)
2340                                          (or (eq #'eq test)
2341                                              (eq #'eql test)
2342                                              (eq #'equal test)))
2343                                     (let ((p (%bit-position item sequence
2344                                                             from-end start end)))
2345                                       (if p
2346                                           (values item p)
2347                                           (values nil nil)))
2348                                     (vector*-frob sequence)))))
2349                          (t
2350                           (vector*-frob sequence))))
2351                    (declare (type (or index null) p))
2352                    (values f (and p (the index (- p offset)))))))))
2353   (defun %find-position (item sequence-arg from-end start end key test)
2354     (macrolet ((frob (sequence from-end)
2355                  `(%find-position item ,sequence
2356                                   ,from-end start end key test))
2357                (vector*-frob (sequence)
2358                  `(%find-position-vector-macro item ,sequence
2359                                                from-end start end key test)))
2360       (frobs t)))
2361   (defun %find-position-if (predicate sequence-arg from-end start end key)
2362     (macrolet ((frob (sequence from-end)
2363                  `(%find-position-if predicate ,sequence
2364                                      ,from-end start end key))
2365                (vector*-frob (sequence)
2366                  `(%find-position-if-vector-macro predicate ,sequence
2367                                                   from-end start end key)))
2368       (frobs)))
2369   (defun %find-position-if-not (predicate sequence-arg from-end start end key)
2370     (macrolet ((frob (sequence from-end)
2371                  `(%find-position-if-not predicate ,sequence
2372                                          ,from-end start end key))
2373                (vector*-frob (sequence)
2374                  `(%find-position-if-not-vector-macro predicate ,sequence
2375                                                   from-end start end key)))
2376       (frobs))))
2377
2378 (defun find
2379     (item sequence &rest args &key from-end (start 0) end key test test-not)
2380   (declare (truly-dynamic-extent args))
2381   (seq-dispatch sequence
2382     (nth-value 0 (%find-position
2383                   item sequence from-end start end
2384                   (effective-find-position-key key)
2385                   (effective-find-position-test test test-not)))
2386     (nth-value 0 (%find-position
2387                   item sequence from-end start end
2388                   (effective-find-position-key key)
2389                   (effective-find-position-test test test-not)))
2390     (apply #'sb!sequence:find item sequence args)))
2391 (defun position
2392     (item sequence &rest args &key from-end (start 0) end key test test-not)
2393   (declare (truly-dynamic-extent args))
2394   (seq-dispatch sequence
2395     (nth-value 1 (%find-position
2396                   item sequence from-end start end
2397                   (effective-find-position-key key)
2398                   (effective-find-position-test test test-not)))
2399     (nth-value 1 (%find-position
2400                   item sequence from-end start end
2401                   (effective-find-position-key key)
2402                   (effective-find-position-test test test-not)))
2403     (apply #'sb!sequence:position item sequence args)))
2404
2405 (defun find-if (predicate sequence &rest args &key from-end (start 0) end key)
2406   (declare (truly-dynamic-extent args))
2407   (seq-dispatch sequence
2408     (nth-value 0 (%find-position-if
2409                   (%coerce-callable-to-fun predicate)
2410                   sequence from-end start end
2411                   (effective-find-position-key key)))
2412     (nth-value 0 (%find-position-if
2413                   (%coerce-callable-to-fun predicate)
2414                   sequence from-end start end
2415                   (effective-find-position-key key)))
2416     (apply #'sb!sequence:find-if predicate sequence args)))
2417 (defun position-if
2418     (predicate sequence &rest args &key from-end (start 0) end key)
2419   (declare (truly-dynamic-extent args))
2420   (seq-dispatch sequence
2421     (nth-value 1 (%find-position-if
2422                   (%coerce-callable-to-fun predicate)
2423                   sequence from-end start end
2424                   (effective-find-position-key key)))
2425     (nth-value 1 (%find-position-if
2426                   (%coerce-callable-to-fun predicate)
2427                   sequence from-end start end
2428                   (effective-find-position-key key)))
2429     (apply #'sb!sequence:position-if predicate sequence args)))
2430
2431 (defun find-if-not
2432     (predicate sequence &rest args &key from-end (start 0) end key)
2433   (declare (truly-dynamic-extent args))
2434   (seq-dispatch sequence
2435     (nth-value 0 (%find-position-if-not
2436                   (%coerce-callable-to-fun predicate)
2437                   sequence from-end start end
2438                   (effective-find-position-key key)))
2439     (nth-value 0 (%find-position-if-not
2440                   (%coerce-callable-to-fun predicate)
2441                   sequence from-end start end
2442                   (effective-find-position-key key)))
2443     (apply #'sb!sequence:find-if-not predicate sequence args)))
2444 (defun position-if-not
2445     (predicate sequence &rest args &key from-end (start 0) end key)
2446   (declare (truly-dynamic-extent args))
2447   (seq-dispatch sequence
2448     (nth-value 1 (%find-position-if-not
2449                   (%coerce-callable-to-fun predicate)
2450                   sequence from-end start end
2451                   (effective-find-position-key key)))
2452     (nth-value 1 (%find-position-if-not
2453                   (%coerce-callable-to-fun predicate)
2454                   sequence from-end start end
2455                   (effective-find-position-key key)))
2456     (apply #'sb!sequence:position-if-not predicate sequence args)))
2457 \f
2458 ;;;; COUNT-IF, COUNT-IF-NOT, and COUNT
2459
2460 (eval-when (:compile-toplevel :execute)
2461
2462 (sb!xc:defmacro vector-count-if (notp from-end-p predicate sequence)
2463   (let ((next-index (if from-end-p '(1- index) '(1+ index)))
2464         (pred `(funcall ,predicate (apply-key key (aref ,sequence index)))))
2465     `(let ((%start ,(if from-end-p '(1- end) 'start))
2466            (%end ,(if from-end-p '(1- start) 'end)))
2467       (do ((index %start ,next-index)
2468            (count 0))
2469           ((= index (the fixnum %end)) count)
2470         (declare (fixnum index count))
2471         (,(if notp 'unless 'when) ,pred
2472           (setq count (1+ count)))))))
2473
2474 (sb!xc:defmacro list-count-if (notp from-end-p predicate sequence)
2475   (let ((pred `(funcall ,predicate (apply-key key (pop sequence)))))
2476     `(let ((%start ,(if from-end-p '(- length end) 'start))
2477            (%end ,(if from-end-p '(- length start) 'end))
2478            (sequence ,(if from-end-p '(reverse sequence) 'sequence)))
2479       (do ((sequence (nthcdr %start ,sequence))
2480            (index %start (1+ index))
2481            (count 0))
2482           ((or (= index (the fixnum %end)) (null sequence)) count)
2483         (declare (fixnum index count))
2484         (,(if notp 'unless 'when) ,pred
2485           (setq count (1+ count)))))))
2486
2487
2488 ) ; EVAL-WHEN
2489
2490 (define-sequence-traverser count-if
2491     (pred sequence &rest args &key from-end start end key)
2492   #!+sb-doc
2493   "Return the number of elements in SEQUENCE satisfying PRED(el)."
2494   (declare (type fixnum start)
2495            (truly-dynamic-extent args))
2496   (let ((pred (%coerce-callable-to-fun pred)))
2497     (seq-dispatch sequence
2498       (let ((end (or end length)))
2499         (declare (type index end))
2500         (if from-end
2501             (list-count-if nil t pred sequence)
2502             (list-count-if nil nil pred sequence)))
2503       (let ((end (or end length)))
2504         (declare (type index end))
2505         (if from-end
2506             (vector-count-if nil t pred sequence)
2507             (vector-count-if nil nil pred sequence)))
2508       (apply #'sb!sequence:count-if pred sequence args))))
2509
2510 (define-sequence-traverser count-if-not
2511     (pred sequence &rest args &key from-end start end key)
2512   #!+sb-doc
2513   "Return the number of elements in SEQUENCE not satisfying TEST(el)."
2514   (declare (type fixnum start)
2515            (truly-dynamic-extent args))
2516   (let ((pred (%coerce-callable-to-fun pred)))
2517     (seq-dispatch sequence
2518       (let ((end (or end length)))
2519         (declare (type index end))
2520         (if from-end
2521             (list-count-if t t pred sequence)
2522             (list-count-if t nil pred sequence)))
2523       (let ((end (or end length)))
2524         (declare (type index end))
2525         (if from-end
2526             (vector-count-if t t pred sequence)
2527             (vector-count-if t nil pred sequence)))
2528       (apply #'sb!sequence:count-if-not pred sequence args))))
2529
2530 (define-sequence-traverser count
2531     (item sequence &rest args &key from-end start end
2532           key (test #'eql test-p) (test-not nil test-not-p))
2533   #!+sb-doc
2534   "Return the number of elements in SEQUENCE satisfying a test with ITEM,
2535    which defaults to EQL."
2536   (declare (type fixnum start)
2537            (truly-dynamic-extent args))
2538   (when (and test-p test-not-p)
2539     ;; ANSI Common Lisp has left the behavior in this situation unspecified.
2540     ;; (CLHS 17.2.1)
2541     (error ":TEST and :TEST-NOT are both present."))
2542   (let ((%test (if test-not-p
2543                    (lambda (x)
2544                      (not (funcall test-not item x)))
2545                    (lambda (x)
2546                      (funcall test item x)))))
2547     (seq-dispatch sequence
2548       (let ((end (or end length)))
2549         (declare (type index end))
2550         (if from-end
2551             (list-count-if nil t %test sequence)
2552             (list-count-if nil nil %test sequence)))
2553       (let ((end (or end length)))
2554         (declare (type index end))
2555         (if from-end
2556             (vector-count-if nil t %test sequence)
2557             (vector-count-if nil nil %test sequence)))
2558       (apply #'sb!sequence:count item sequence args))))
2559 \f
2560 ;;;; MISMATCH
2561
2562 (eval-when (:compile-toplevel :execute)
2563
2564 (sb!xc:defmacro match-vars (&rest body)
2565   `(let ((inc (if from-end -1 1))
2566          (start1 (if from-end (1- (the fixnum end1)) start1))
2567          (start2 (if from-end (1- (the fixnum end2)) start2))
2568          (end1 (if from-end (1- (the fixnum start1)) end1))
2569          (end2 (if from-end (1- (the fixnum start2)) end2)))
2570      (declare (fixnum inc start1 start2 end1 end2))
2571      ,@body))
2572
2573 (sb!xc:defmacro matchify-list ((sequence start length end) &body body)
2574   (declare (ignore end)) ;; ### Should END be used below?
2575   `(let ((,sequence (if from-end
2576                         (nthcdr (- (the fixnum ,length) (the fixnum ,start) 1)
2577                                 (reverse (the list ,sequence)))
2578                         (nthcdr ,start ,sequence))))
2579      (declare (type list ,sequence))
2580      ,@body))
2581
2582 ) ; EVAL-WHEN
2583
2584 (eval-when (:compile-toplevel :execute)
2585
2586 (sb!xc:defmacro if-mismatch (elt1 elt2)
2587   `(cond ((= (the fixnum index1) (the fixnum end1))
2588           (return (if (= (the fixnum index2) (the fixnum end2))
2589                       nil
2590                       (if from-end
2591                           (1+ (the fixnum index1))
2592                           (the fixnum index1)))))
2593          ((= (the fixnum index2) (the fixnum end2))
2594           (return (if from-end (1+ (the fixnum index1)) index1)))
2595          (test-not
2596           (if (funcall test-not (apply-key key ,elt1) (apply-key key ,elt2))
2597               (return (if from-end (1+ (the fixnum index1)) index1))))
2598          (t (if (not (funcall test (apply-key key ,elt1)
2599                               (apply-key key ,elt2)))
2600                 (return (if from-end (1+ (the fixnum index1)) index1))))))
2601
2602 (sb!xc:defmacro mumble-mumble-mismatch ()
2603   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2604         (index2 start2 (+ index2 (the fixnum inc))))
2605        (())
2606      (declare (fixnum index1 index2))
2607      (if-mismatch (aref sequence1 index1) (aref sequence2 index2))))
2608
2609 (sb!xc:defmacro mumble-list-mismatch ()
2610   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2611         (index2 start2 (+ index2 (the fixnum inc))))
2612        (())
2613      (declare (fixnum index1 index2))
2614      (if-mismatch (aref sequence1 index1) (pop sequence2))))
2615 \f
2616 (sb!xc:defmacro list-mumble-mismatch ()
2617   `(do ((index1 start1 (+ index1 (the fixnum inc)))
2618         (index2 start2 (+ index2 (the fixnum inc))))
2619        (())
2620      (declare (fixnum index1 index2))
2621      (if-mismatch (pop sequence1) (aref sequence2 index2))))
2622
2623 (sb!xc:defmacro list-list-mismatch ()
2624   `(do ((sequence1 sequence1)
2625         (sequence2 sequence2)
2626         (index1 start1 (+ index1 (the fixnum inc)))
2627         (index2 start2 (+ index2 (the fixnum inc))))
2628        (())
2629      (declare (fixnum index1 index2))
2630      (if-mismatch (pop sequence1) (pop sequence2))))
2631
2632 ) ; EVAL-WHEN
2633
2634 (define-sequence-traverser mismatch
2635     (sequence1 sequence2 &rest args &key from-end test test-not
2636      start1 end1 start2 end2 key)
2637   #!+sb-doc
2638   "The specified subsequences of SEQUENCE1 and SEQUENCE2 are compared
2639    element-wise. If they are of equal length and match in every element, the
2640    result is NIL. Otherwise, the result is a non-negative integer, the index
2641    within SEQUENCE1 of the leftmost position at which they fail to match; or,
2642    if one is shorter than and a matching prefix of the other, the index within
2643    SEQUENCE1 beyond the last position tested is returned. If a non-NIL
2644    :FROM-END argument is given, then one plus the index of the rightmost
2645    position in which the sequences differ is returned."
2646   (declare (type fixnum start1 start2))
2647   (declare (truly-dynamic-extent args))
2648   (seq-dispatch sequence1
2649     (seq-dispatch sequence2
2650       (let ((end1 (or end1 length1))
2651             (end2 (or end2 length2)))
2652         (declare (type index end1 end2))
2653         (match-vars
2654          (matchify-list (sequence1 start1 length1 end1)
2655            (matchify-list (sequence2 start2 length2 end2)
2656              (list-list-mismatch)))))
2657       (let ((end1 (or end1 length1))
2658             (end2 (or end2 length2)))
2659         (declare (type index end1 end2))
2660         (match-vars
2661          (matchify-list (sequence1 start1 length1 end1)
2662            (list-mumble-mismatch))))
2663       (apply #'sb!sequence:mismatch sequence1 sequence2 args))
2664     (seq-dispatch sequence2
2665       (let ((end1 (or end1 length1))
2666             (end2 (or end2 length2)))
2667         (declare (type index end1 end2))
2668         (match-vars
2669          (matchify-list (sequence2 start2 length2 end2)
2670            (mumble-list-mismatch))))
2671       (let ((end1 (or end1 length1))
2672             (end2 (or end2 length2)))
2673         (declare (type index end1 end2))
2674         (match-vars
2675          (mumble-mumble-mismatch)))
2676       (apply #'sb!sequence:mismatch sequence1 sequence2 args))
2677     (apply #'sb!sequence:mismatch sequence1 sequence2 args)))
2678
2679 \f
2680 ;;; search comparison functions
2681
2682 (eval-when (:compile-toplevel :execute)
2683
2684 ;;; Compare two elements and return if they don't match.
2685 (sb!xc:defmacro compare-elements (elt1 elt2)
2686   `(if test-not
2687        (if (funcall test-not (apply-key key ,elt1) (apply-key key ,elt2))
2688            (return nil)
2689            t)
2690        (if (not (funcall test (apply-key key ,elt1) (apply-key key ,elt2)))
2691            (return nil)
2692            t)))
2693
2694 (sb!xc:defmacro search-compare-list-list (main sub)
2695   `(do ((main ,main (cdr main))
2696         (jndex start1 (1+ jndex))
2697         (sub (nthcdr start1 ,sub) (cdr sub)))
2698        ((or (endp main) (endp sub) (<= end1 jndex))
2699         t)
2700      (declare (type (integer 0) jndex))
2701      (compare-elements (car sub) (car main))))
2702
2703 (sb!xc:defmacro search-compare-list-vector (main sub)
2704   `(do ((main ,main (cdr main))
2705         (index start1 (1+ index)))
2706        ((or (endp main) (= index end1)) t)
2707      (compare-elements (aref ,sub index) (car main))))
2708
2709 (sb!xc:defmacro search-compare-vector-list (main sub index)
2710   `(do ((sub (nthcdr start1 ,sub) (cdr sub))
2711         (jndex start1 (1+ jndex))
2712         (index ,index (1+ index)))
2713        ((or (<= end1 jndex) (endp sub)) t)
2714      (declare (type (integer 0) jndex))
2715      (compare-elements (car sub) (aref ,main index))))
2716
2717 (sb!xc:defmacro search-compare-vector-vector (main sub index)
2718   `(do ((index ,index (1+ index))
2719         (sub-index start1 (1+ sub-index)))
2720        ((= sub-index end1) t)
2721      (compare-elements (aref ,sub sub-index) (aref ,main index))))
2722
2723 (sb!xc:defmacro search-compare (main-type main sub index)
2724   (if (eq main-type 'list)
2725       `(seq-dispatch ,sub
2726          (search-compare-list-list ,main ,sub)
2727          (search-compare-list-vector ,main ,sub)
2728          ;; KLUDGE: just hack it together so that it works
2729          (return-from search (apply #'sb!sequence:search sequence1 sequence2 args)))
2730       `(seq-dispatch ,sub
2731          (search-compare-vector-list ,main ,sub ,index)
2732          (search-compare-vector-vector ,main ,sub ,index)
2733          (return-from search (apply #'sb!sequence:search sequence1 sequence2 args)))))
2734
2735 ) ; EVAL-WHEN
2736 \f
2737 ;;;; SEARCH
2738
2739 (eval-when (:compile-toplevel :execute)
2740
2741 (sb!xc:defmacro list-search (main sub)
2742   `(do ((main (nthcdr start2 ,main) (cdr main))
2743         (index2 start2 (1+ index2))
2744         (terminus (- end2 (the (integer 0) (- end1 start1))))
2745         (last-match ()))
2746        ((> index2 terminus) last-match)
2747      (declare (type (integer 0) index2))
2748      (if (search-compare list main ,sub index2)
2749          (if from-end
2750              (setq last-match index2)
2751              (return index2)))))
2752
2753 (sb!xc:defmacro vector-search (main sub)
2754   `(do ((index2 start2 (1+ index2))
2755         (terminus (- end2 (the (integer 0) (- end1 start1))))
2756         (last-match ()))
2757        ((> index2 terminus) last-match)
2758      (declare (type (integer 0) index2))
2759      (if (search-compare vector ,main ,sub index2)
2760          (if from-end
2761              (setq last-match index2)
2762              (return index2)))))
2763
2764 ) ; EVAL-WHEN
2765
2766 (define-sequence-traverser search
2767     (sequence1 sequence2 &rest args &key
2768      from-end test test-not start1 end1 start2 end2 key)
2769   (declare (type fixnum start1 start2)
2770            (truly-dynamic-extent args))
2771   (seq-dispatch sequence2
2772     (let ((end1 (or end1 length1))
2773           (end2 (or end2 length2)))
2774       (declare (type index end1 end2))
2775       (list-search sequence2 sequence1))
2776     (let ((end1 (or end1 length1))
2777           (end2 (or end2 length2)))
2778       (declare (type index end1 end2))
2779       (vector-search sequence2 sequence1))
2780     (apply #'sb!sequence:search sequence1 sequence2 args)))
2781
2782 ;;; FIXME: this was originally in array.lisp; it might be better to
2783 ;;; put it back there, and make DOSEQUENCE and SEQ-DISPATCH be in
2784 ;;; a new early-seq.lisp file.
2785 (defun fill-data-vector (vector dimensions initial-contents)
2786   (let ((index 0))
2787     (labels ((frob (axis dims contents)
2788                (cond ((null dims)
2789                       (setf (aref vector index) contents)
2790                       (incf index))
2791                      (t
2792                       (unless (typep contents 'sequence)
2793                         (error "malformed :INITIAL-CONTENTS: ~S is not a ~
2794                                 sequence, but ~W more layer~:P needed."
2795                                contents
2796                                (- (length dimensions) axis)))
2797                       (unless (= (length contents) (car dims))
2798                         (error "malformed :INITIAL-CONTENTS: Dimension of ~
2799                                 axis ~W is ~W, but ~S is ~W long."
2800                                axis (car dims) contents (length contents)))
2801                       (sb!sequence:dosequence (content contents)
2802                         (frob (1+ axis) (cdr dims) content))))))
2803       (frob 0 dimensions initial-contents))))