lisp/emacs-lisp/cl-extra.el

   1 ;;; cl-extra.el --- Common Lisp features, part 2 -*-byte-compile-dynamic: t;-*-
   2
   3 ;; Copyright (C) 1993, 2000, 2002, 2003, 2004,
   4 ;;   2005, 2006 Free Software Foundation, Inc.
   5
   6 ;; Author: Dave Gillespie <daveg@synaptics.com>
   7 ;; Keywords: extensions
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 2, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; These are extensions to Emacs Lisp that provide a degree of
  29 ;; Common Lisp compatibility, beyond what is already built-in
  30 ;; in Emacs Lisp.
  31 ;;
  32 ;; This package was written by Dave Gillespie; it is a complete
  33 ;; rewrite of Cesar Quiroz's original cl.el package of December 1986.
  34 ;;
  35 ;; Bug reports, comments, and suggestions are welcome!
  36
  37 ;; This file contains portions of the Common Lisp extensions
  38 ;; package which are autoloaded since they are relatively obscure.
  39
  40 ;;; Code:
  41
  42 (require 'cl)
  43
  44 ;;; Type coercion.
  45
  46 (defun coerce (x type)
  47   "Coerce OBJECT to type TYPE.
  48 TYPE is a Common Lisp type specifier.
  49 \n(fn OBJECT TYPE)"
  50   (cond ((eq type 'list) (if (listp x) x (append x nil)))
  51         ((eq type 'vector) (if (vectorp x) x (vconcat x)))
  52         ((eq type 'string) (if (stringp x) x (concat x)))
  53         ((eq type 'array) (if (arrayp x) x (vconcat x)))
  54         ((and (eq type 'character) (stringp x) (= (length x) 1)) (aref x 0))
  55         ((and (eq type 'character) (symbolp x)) (coerce (symbol-name x) type))
  56         ((eq type 'float) (float x))
  57         ((typep x type) x)
  58         (t (error "Can't coerce %s to type %s" x type))))
  59
  60
  61 ;;; Predicates.
  62
  63 (defun equalp (x y)
  64   "Return t if two Lisp objects have similar structures and contents.
  65 This is like `equal', except that it accepts numerically equal
  66 numbers of different types (float vs. integer), and also compares
  67 strings case-insensitively."
  68   (cond ((eq x y) t)
  69         ((stringp x)
  70          (and (stringp y) (= (length x) (length y))
  71               (or (string-equal x y)
  72                   (string-equal (downcase x) (downcase y)))))   ; lazy but simple!
  73         ((numberp x)
  74          (and (numberp y) (= x y)))
  75         ((consp x)
  76          (while (and (consp x) (consp y) (equalp (car x) (car y)))
  77            (setq x (cdr x) y (cdr y)))
  78          (and (not (consp x)) (equalp x y)))
  79         ((vectorp x)
  80          (and (vectorp y) (= (length x) (length y))
  81               (let ((i (length x)))
  82                 (while (and (>= (setq i (1- i)) 0)
  83                             (equalp (aref x i) (aref y i))))
  84                 (< i 0))))
  85         (t (equal x y))))
  86
  87
  88 ;;; Control structures.
  89
  90 (defun cl-mapcar-many (cl-func cl-seqs)
  91   (if (cdr (cdr cl-seqs))
  92       (let* ((cl-res nil)
  93              (cl-n (apply 'min (mapcar 'length cl-seqs)))
  94              (cl-i 0)
  95              (cl-args (copy-sequence cl-seqs))
  96              cl-p1 cl-p2)
  97         (setq cl-seqs (copy-sequence cl-seqs))
  98         (while (< cl-i cl-n)
  99           (setq cl-p1 cl-seqs cl-p2 cl-args)
 100           (while cl-p1
 101             (setcar cl-p2
 102                     (if (consp (car cl-p1))
 103                         (prog1 (car (car cl-p1))
 104                           (setcar cl-p1 (cdr (car cl-p1))))
 105                       (aref (car cl-p1) cl-i)))
 106             (setq cl-p1 (cdr cl-p1) cl-p2 (cdr cl-p2)))
 107           (push (apply cl-func cl-args) cl-res)
 108           (setq cl-i (1+ cl-i)))
 109         (nreverse cl-res))
 110     (let ((cl-res nil)
 111           (cl-x (car cl-seqs))
 112           (cl-y (nth 1 cl-seqs)))
 113       (let ((cl-n (min (length cl-x) (length cl-y)))
 114             (cl-i -1))
 115         (while (< (setq cl-i (1+ cl-i)) cl-n)
 116           (push (funcall cl-func
 117                             (if (consp cl-x) (pop cl-x) (aref cl-x cl-i))
 118                             (if (consp cl-y) (pop cl-y) (aref cl-y cl-i)))
 119                    cl-res)))
 120       (nreverse cl-res))))
 121
 122 (defun map (cl-type cl-func cl-seq &rest cl-rest)
 123   "Map a FUNCTION across one or more SEQUENCEs, returning a sequence.
 124 TYPE is the sequence type to return.
 125 \n(fn TYPE FUNCTION SEQUENCE...)"
 126   (let ((cl-res (apply 'mapcar* cl-func cl-seq cl-rest)))
 127     (and cl-type (coerce cl-res cl-type))))
 128
 129 (defun maplist (cl-func cl-list &rest cl-rest)
 130   "Map FUNCTION to each sublist of LIST or LISTs.
 131 Like `mapcar', except applies to lists and their cdr's rather than to
 132 the elements themselves.
 133 \n(fn FUNCTION LIST...)"
 134   (if cl-rest
 135       (let ((cl-res nil)
 136             (cl-args (cons cl-list (copy-sequence cl-rest)))
 137             cl-p)
 138         (while (not (memq nil cl-args))
 139           (push (apply cl-func cl-args) cl-res)
 140           (setq cl-p cl-args)
 141           (while cl-p (setcar cl-p (cdr (pop cl-p)) )))
 142         (nreverse cl-res))
 143     (let ((cl-res nil))
 144       (while cl-list
 145         (push (funcall cl-func cl-list) cl-res)
 146         (setq cl-list (cdr cl-list)))
 147       (nreverse cl-res))))
 148
 149 (defun cl-mapc (cl-func cl-seq &rest cl-rest)
 150   "Like `mapcar', but does not accumulate values returned by the function.
 151 \n(fn FUNCTION SEQUENCE...)"
 152   (if cl-rest
 153       (progn (apply 'map nil cl-func cl-seq cl-rest)
 154              cl-seq)
 155     (mapc cl-func cl-seq)))
 156
 157 (defun mapl (cl-func cl-list &rest cl-rest)
 158   "Like `maplist', but does not accumulate values returned by the function.
 159 \n(fn FUNCTION LIST...)"
 160   (if cl-rest
 161       (apply 'maplist cl-func cl-list cl-rest)
 162     (let ((cl-p cl-list))
 163       (while cl-p (funcall cl-func cl-p) (setq cl-p (cdr cl-p)))))
 164   cl-list)
 165
 166 (defun mapcan (cl-func cl-seq &rest cl-rest)
 167   "Like `mapcar', but nconc's together the values returned by the function.
 168 \n(fn FUNCTION SEQUENCE...)"
 169   (apply 'nconc (apply 'mapcar* cl-func cl-seq cl-rest)))
 170
 171 (defun mapcon (cl-func cl-list &rest cl-rest)
 172   "Like `maplist', but nconc's together the values returned by the function.
 173 \n(fn FUNCTION LIST...)"
 174   (apply 'nconc (apply 'maplist cl-func cl-list cl-rest)))
 175
 176 (defun some (cl-pred cl-seq &rest cl-rest)
 177   "Return true if PREDICATE is true of any element of SEQ or SEQs.
 178 If so, return the true (non-nil) value returned by PREDICATE.
 179 \n(fn PREDICATE SEQ...)"
 180   (if (or cl-rest (nlistp cl-seq))
 181       (catch 'cl-some
 182         (apply 'map nil
 183                (function (lambda (&rest cl-x)
 184                            (let ((cl-res (apply cl-pred cl-x)))
 185                              (if cl-res (throw 'cl-some cl-res)))))
 186                cl-seq cl-rest) nil)
 187     (let ((cl-x nil))
 188       (while (and cl-seq (not (setq cl-x (funcall cl-pred (pop cl-seq))))))
 189       cl-x)))
 190
 191 (defun every (cl-pred cl-seq &rest cl-rest)
 192   "Return true if PREDICATE is true of every element of SEQ or SEQs.
 193 \n(fn PREDICATE SEQ...)"
 194   (if (or cl-rest (nlistp cl-seq))
 195       (catch 'cl-every
 196         (apply 'map nil
 197                (function (lambda (&rest cl-x)
 198                            (or (apply cl-pred cl-x) (throw 'cl-every nil))))
 199                cl-seq cl-rest) t)
 200     (while (and cl-seq (funcall cl-pred (car cl-seq)))
 201       (setq cl-seq (cdr cl-seq)))
 202     (null cl-seq)))
 203
 204 (defun notany (cl-pred cl-seq &rest cl-rest)
 205   "Return true if PREDICATE is false of every element of SEQ or SEQs.
 206 \n(fn PREDICATE SEQ...)"
 207   (not (apply 'some cl-pred cl-seq cl-rest)))
 208
 209 (defun notevery (cl-pred cl-seq &rest cl-rest)
 210   "Return true if PREDICATE is false of some element of SEQ or SEQs.
 211 \n(fn PREDICATE SEQ...)"
 212   (not (apply 'every cl-pred cl-seq cl-rest)))
 213
 214 ;;; Support for `loop'.
 215 (defalias 'cl-map-keymap 'map-keymap)
 216
 217 (defun cl-map-keymap-recursively (cl-func-rec cl-map &optional cl-base)
 218   (or cl-base
 219       (setq cl-base (copy-sequence [0])))
 220   (map-keymap
 221    (function
 222     (lambda (cl-key cl-bind)
 223       (aset cl-base (1- (length cl-base)) cl-key)
 224       (if (keymapp cl-bind)
 225           (cl-map-keymap-recursively
 226            cl-func-rec cl-bind
 227            (vconcat cl-base (list 0)))
 228         (funcall cl-func-rec cl-base cl-bind))))
 229    cl-map))
 230
 231 (defun cl-map-intervals (cl-func &optional cl-what cl-prop cl-start cl-end)
 232   (or cl-what (setq cl-what (current-buffer)))
 233   (if (bufferp cl-what)
 234       (let (cl-mark cl-mark2 (cl-next t) cl-next2)
 235         (with-current-buffer cl-what
 236           (setq cl-mark (copy-marker (or cl-start (point-min))))
 237           (setq cl-mark2 (and cl-end (copy-marker cl-end))))
 238         (while (and cl-next (or (not cl-mark2) (< cl-mark cl-mark2)))
 239           (setq cl-next (if cl-prop (next-single-property-change
 240                                      cl-mark cl-prop cl-what)
 241                           (next-property-change cl-mark cl-what))
 242                 cl-next2 (or cl-next (with-current-buffer cl-what
 243                                        (point-max))))
 244           (funcall cl-func (prog1 (marker-position cl-mark)
 245                              (set-marker cl-mark cl-next2))
 246                    (if cl-mark2 (min cl-next2 cl-mark2) cl-next2)))
 247         (set-marker cl-mark nil) (if cl-mark2 (set-marker cl-mark2 nil)))
 248     (or cl-start (setq cl-start 0))
 249     (or cl-end (setq cl-end (length cl-what)))
 250     (while (< cl-start cl-end)
 251       (let ((cl-next (or (if cl-prop (next-single-property-change
 252                                       cl-start cl-prop cl-what)
 253                            (next-property-change cl-start cl-what))
 254                          cl-end)))
 255         (funcall cl-func cl-start (min cl-next cl-end))
 256         (setq cl-start cl-next)))))
 257
 258 (defun cl-map-overlays (cl-func &optional cl-buffer cl-start cl-end cl-arg)
 259   (or cl-buffer (setq cl-buffer (current-buffer)))
 260   (if (fboundp 'overlay-lists)
 261
 262       ;; This is the preferred algorithm, though overlay-lists is undocumented.
 263       (let (cl-ovl)
 264         (with-current-buffer cl-buffer
 265           (setq cl-ovl (overlay-lists))
 266           (if cl-start (setq cl-start (copy-marker cl-start)))
 267           (if cl-end (setq cl-end (copy-marker cl-end))))
 268         (setq cl-ovl (nconc (car cl-ovl) (cdr cl-ovl)))
 269         (while (and cl-ovl
 270                     (or (not (overlay-start (car cl-ovl)))
 271                         (and cl-end (>= (overlay-start (car cl-ovl)) cl-end))
 272                         (and cl-start (<= (overlay-end (car cl-ovl)) cl-start))
 273                         (not (funcall cl-func (car cl-ovl) cl-arg))))
 274           (setq cl-ovl (cdr cl-ovl)))
 275         (if cl-start (set-marker cl-start nil))
 276         (if cl-end (set-marker cl-end nil)))
 277
 278     ;; This alternate algorithm fails to find zero-length overlays.
 279     (let ((cl-mark (with-current-buffer cl-buffer
 280                      (copy-marker (or cl-start (point-min)))))
 281           (cl-mark2 (and cl-end (with-current-buffer cl-buffer
 282                                   (copy-marker cl-end))))
 283           cl-pos cl-ovl)
 284       (while (save-excursion
 285                (and (setq cl-pos (marker-position cl-mark))
 286                     (< cl-pos (or cl-mark2 (point-max)))
 287                     (progn
 288                       (set-buffer cl-buffer)
 289                       (setq cl-ovl (overlays-at cl-pos))
 290                       (set-marker cl-mark (next-overlay-change cl-pos)))))
 291         (while (and cl-ovl
 292                     (or (/= (overlay-start (car cl-ovl)) cl-pos)
 293                         (not (and (funcall cl-func (car cl-ovl) cl-arg)
 294                                   (set-marker cl-mark nil)))))
 295           (setq cl-ovl (cdr cl-ovl))))
 296       (set-marker cl-mark nil) (if cl-mark2 (set-marker cl-mark2 nil)))))
 297
 298 ;;; Support for `setf'.
 299 (defun cl-set-frame-visible-p (frame val)
 300   (cond ((null val) (make-frame-invisible frame))
 301         ((eq val 'icon) (iconify-frame frame))
 302         (t (make-frame-visible frame)))
 303   val)
 304
 305 ;;; Support for `progv'.
 306 (defvar cl-progv-save)
 307 (defun cl-progv-before (syms values)
 308   (while syms
 309     (push (if (boundp (car syms))
 310                  (cons (car syms) (symbol-value (car syms)))
 311                (car syms)) cl-progv-save)
 312     (if values
 313         (set (pop syms) (pop values))
 314       (makunbound (pop syms)))))
 315
 316 (defun cl-progv-after ()
 317   (while cl-progv-save
 318     (if (consp (car cl-progv-save))
 319         (set (car (car cl-progv-save)) (cdr (car cl-progv-save)))
 320       (makunbound (car cl-progv-save)))
 321     (pop cl-progv-save)))
 322
 323
 324 ;;; Numbers.
 325
 326 (defun gcd (&rest args)
 327   "Return the greatest common divisor of the arguments."
 328   (let ((a (abs (or (pop args) 0))))
 329     (while args
 330       (let ((b (abs (pop args))))
 331         (while (> b 0) (setq b (% a (setq a b))))))
 332     a))
 333
 334 (defun lcm (&rest args)
 335   "Return the least common multiple of the arguments."
 336   (if (memq 0 args)
 337       0
 338     (let ((a (abs (or (pop args) 1))))
 339       (while args
 340         (let ((b (abs (pop args))))
 341           (setq a (* (/ a (gcd a b)) b))))
 342       a)))
 343
 344 (defun isqrt (x)
 345   "Return the integer square root of the argument."
 346   (if (and (integerp x) (> x 0))
 347       (let ((g (cond ((<= x 100) 10) ((<= x 10000) 100)
 348                      ((<= x 1000000) 1000) (t x)))
 349             g2)
 350         (while (< (setq g2 (/ (+ g (/ x g)) 2)) g)
 351           (setq g g2))
 352         g)
 353     (if (eq x 0) 0 (signal 'arith-error nil))))
 354
 355 (defun floor* (x &optional y)
 356   "Return a list of the floor of X and the fractional part of X.
 357 With two arguments, return floor and remainder of their quotient."
 358   (let ((q (floor x y)))
 359     (list q (- x (if y (* y q) q)))))
 360
 361 (defun ceiling* (x &optional y)
 362   "Return a list of the ceiling of X and the fractional part of X.
 363 With two arguments, return ceiling and remainder of their quotient."
 364   (let ((res (floor* x y)))
 365     (if (= (car (cdr res)) 0) res
 366       (list (1+ (car res)) (- (car (cdr res)) (or y 1))))))
 367
 368 (defun truncate* (x &optional y)
 369   "Return a list of the integer part of X and the fractional part of X.
 370 With two arguments, return truncation and remainder of their quotient."
 371   (if (eq (>= x 0) (or (null y) (>= y 0)))
 372       (floor* x y) (ceiling* x y)))
 373
 374 (defun round* (x &optional y)
 375   "Return a list of X rounded to the nearest integer and the remainder.
 376 With two arguments, return rounding and remainder of their quotient."
 377   (if y
 378       (if (and (integerp x) (integerp y))
 379           (let* ((hy (/ y 2))
 380                  (res (floor* (+ x hy) y)))
 381             (if (and (= (car (cdr res)) 0)
 382                      (= (+ hy hy) y)
 383                      (/= (% (car res) 2) 0))
 384                 (list (1- (car res)) hy)
 385               (list (car res) (- (car (cdr res)) hy))))
 386         (let ((q (round (/ x y))))
 387           (list q (- x (* q y)))))
 388     (if (integerp x) (list x 0)
 389       (let ((q (round x)))
 390         (list q (- x q))))))
 391
 392 (defun mod* (x y)
 393   "The remainder of X divided by Y, with the same sign as Y."
 394   (nth 1 (floor* x y)))
 395
 396 (defun rem* (x y)
 397   "The remainder of X divided by Y, with the same sign as X."
 398   (nth 1 (truncate* x y)))
 399
 400 (defun signum (x)
 401   "Return 1 if X is positive, -1 if negative, 0 if zero."
 402   (cond ((> x 0) 1) ((< x 0) -1) (t 0)))
 403
 404
 405 ;; Random numbers.
 406
 407 (defvar *random-state*)
 408 (defun random* (lim &optional state)
 409   "Return a random nonnegative number less than LIM, an integer or float.
 410 Optional second arg STATE is a random-state object."
 411   (or state (setq state *random-state*))
 412   ;; Inspired by "ran3" from Numerical Recipes.  Additive congruential method.
 413   (let ((vec (aref state 3)))
 414     (if (integerp vec)
 415         (let ((i 0) (j (- 1357335 (% (abs vec) 1357333))) (k 1) ii)
 416           (aset state 3 (setq vec (make-vector 55 nil)))
 417           (aset vec 0 j)
 418           (while (> (setq i (% (+ i 21) 55)) 0)
 419             (aset vec i (setq j (prog1 k (setq k (- j k))))))
 420           (while (< (setq i (1+ i)) 200) (random* 2 state))))
 421     (let* ((i (aset state 1 (% (1+ (aref state 1)) 55)))
 422            (j (aset state 2 (% (1+ (aref state 2)) 55)))
 423            (n (logand 8388607 (aset vec i (- (aref vec i) (aref vec j))))))
 424       (if (integerp lim)
 425           (if (<= lim 512) (% n lim)
 426             (if (> lim 8388607) (setq n (+ (lsh n 9) (random* 512 state))))
 427             (let ((mask 1023))
 428               (while (< mask (1- lim)) (setq mask (1+ (+ mask mask))))
 429               (if (< (setq n (logand n mask)) lim) n (random* lim state))))
 430         (* (/ n '8388608e0) lim)))))
 431
 432 (defun make-random-state (&optional state)
 433   "Return a copy of random-state STATE, or of `*random-state*' if omitted.
 434 If STATE is t, return a new state object seeded from the time of day."
 435   (cond ((null state) (make-random-state *random-state*))
 436         ((vectorp state) (cl-copy-tree state t))
 437         ((integerp state) (vector 'cl-random-state-tag -1 30 state))
 438         (t (make-random-state (cl-random-time)))))
 439
 440 (defun random-state-p (object)
 441   "Return t if OBJECT is a random-state object."
 442   (and (vectorp object) (= (length object) 4)
 443        (eq (aref object 0) 'cl-random-state-tag)))
 444
 445
 446 ;; Implementation limits.
 447
 448 (defun cl-finite-do (func a b)
 449   (condition-case err
 450       (let ((res (funcall func a b)))   ; check for IEEE infinity
 451         (and (numberp res) (/= res (/ res 2)) res))
 452     (arith-error nil)))
 453
 454 (defvar most-positive-float)
 455 (defvar most-negative-float)
 456 (defvar least-positive-float)
 457 (defvar least-negative-float)
 458 (defvar least-positive-normalized-float)
 459 (defvar least-negative-normalized-float)
 460 (defvar float-epsilon)
 461 (defvar float-negative-epsilon)
 462
 463 (defun cl-float-limits ()
 464   (or most-positive-float (not (numberp '2e1))
 465       (let ((x '2e0) y z)
 466         ;; Find maximum exponent (first two loops are optimizations)
 467         (while (cl-finite-do '* x x) (setq x (* x x)))
 468         (while (cl-finite-do '* x (/ x 2)) (setq x (* x (/ x 2))))
 469         (while (cl-finite-do '+ x x) (setq x (+ x x)))
 470         (setq z x y (/ x 2))
 471         ;; Now fill in 1's in the mantissa.
 472         (while (and (cl-finite-do '+ x y) (/= (+ x y) x))
 473           (setq x (+ x y) y (/ y 2)))
 474         (setq most-positive-float x
 475               most-negative-float (- x))
 476         ;; Divide down until mantissa starts rounding.
 477         (setq x (/ x z) y (/ 16 z) x (* x y))
 478         (while (condition-case err (and (= x (* (/ x 2) 2)) (> (/ y 2) 0))
 479                  (arith-error nil))
 480           (setq x (/ x 2) y (/ y 2)))
 481         (setq least-positive-normalized-float y
 482               least-negative-normalized-float (- y))
 483         ;; Divide down until value underflows to zero.
 484         (setq x (/ 1 z) y x)
 485         (while (condition-case err (> (/ x 2) 0) (arith-error nil))
 486           (setq x (/ x 2)))
 487         (setq least-positive-float x
 488               least-negative-float (- x))
 489         (setq x '1e0)
 490         (while (/= (+ '1e0 x) '1e0) (setq x (/ x 2)))
 491         (setq float-epsilon (* x 2))
 492         (setq x '1e0)
 493         (while (/= (- '1e0 x) '1e0) (setq x (/ x 2)))
 494         (setq float-negative-epsilon (* x 2))))
 495   nil)
 496
 497
 498 ;;; Sequence functions.
 499
 500 (defun subseq (seq start &optional end)
 501   "Return the subsequence of SEQ from START to END.
 502 If END is omitted, it defaults to the length of the sequence.
 503 If START or END is negative, it counts from the end."
 504   (if (stringp seq) (substring seq start end)
 505     (let (len)
 506       (and end (< end 0) (setq end (+ end (setq len (length seq)))))
 507       (if (< start 0) (setq start (+ start (or len (setq len (length seq))))))
 508       (cond ((listp seq)
 509              (if (> start 0) (setq seq (nthcdr start seq)))
 510              (if end
 511                  (let ((res nil))
 512                    (while (>= (setq end (1- end)) start)
 513                      (push (pop seq) res))
 514                    (nreverse res))
 515                (copy-sequence seq)))
 516             (t
 517              (or end (setq end (or len (length seq))))
 518              (let ((res (make-vector (max (- end start) 0) nil))
 519                    (i 0))
 520                (while (< start end)
 521                  (aset res i (aref seq start))
 522                  (setq i (1+ i) start (1+ start)))
 523                res))))))
 524
 525 (defun concatenate (type &rest seqs)
 526   "Concatenate, into a sequence of type TYPE, the argument SEQUENCEs.
 527 \n(fn TYPE SEQUENCE...)"
 528   (cond ((eq type 'vector) (apply 'vconcat seqs))
 529         ((eq type 'string) (apply 'concat seqs))
 530         ((eq type 'list) (apply 'append (append seqs '(nil))))
 531         (t (error "Not a sequence type name: %s" type))))
 532
 533
 534 ;;; List functions.
 535
 536 (defun revappend (x y)
 537   "Equivalent to (append (reverse X) Y)."
 538   (nconc (reverse x) y))
 539
 540 (defun nreconc (x y)
 541   "Equivalent to (nconc (nreverse X) Y)."
 542   (nconc (nreverse x) y))
 543
 544 (defun list-length (x)
 545   "Return the length of list X.  Return nil if list is circular."
 546   (let ((n 0) (fast x) (slow x))
 547     (while (and (cdr fast) (not (and (eq fast slow) (> n 0))))
 548       (setq n (+ n 2) fast (cdr (cdr fast)) slow (cdr slow)))
 549     (if fast (if (cdr fast) nil (1+ n)) n)))
 550
 551 (defun tailp (sublist list)
 552   "Return true if SUBLIST is a tail of LIST."
 553   (while (and (consp list) (not (eq sublist list)))
 554     (setq list (cdr list)))
 555   (if (numberp sublist) (equal sublist list) (eq sublist list)))
 556
 557 (defalias 'cl-copy-tree 'copy-tree)
 558
 559
 560 ;;; Property lists.
 561
 562 (defun get* (sym tag &optional def)    ; See compiler macro in cl-macs.el
 563   "Return the value of SYMBOL's PROPNAME property, or DEFAULT if none.
 564 \n(fn SYMBOL PROPNAME &optional DEFAULT)"
 565   (or (get sym tag)
 566       (and def
 567            (let ((plist (symbol-plist sym)))
 568              (while (and plist (not (eq (car plist) tag)))
 569                (setq plist (cdr (cdr plist))))
 570              (if plist (car (cdr plist)) def)))))
 571
 572 (defun getf (plist tag &optional def)
 573   "Search PROPLIST for property PROPNAME; return its value or DEFAULT.
 574 PROPLIST is a list of the sort returned by `symbol-plist'.
 575 \n(fn PROPLIST PROPNAME &optional DEFAULT)"
 576   (setplist '--cl-getf-symbol-- plist)
 577   (or (get '--cl-getf-symbol-- tag)
 578       ;; Originally we called get* here,
 579       ;; but that fails, because get* has a compiler macro
 580       ;; definition that uses getf!
 581       (when def
 582         (while (and plist (not (eq (car plist) tag)))
 583           (setq plist (cdr (cdr plist))))
 584         (if plist (car (cdr plist)) def))))
 585
 586 (defun cl-set-getf (plist tag val)
 587   (let ((p plist))
 588     (while (and p (not (eq (car p) tag))) (setq p (cdr (cdr p))))
 589     (if p (progn (setcar (cdr p) val) plist) (list* tag val plist))))
 590
 591 (defun cl-do-remf (plist tag)
 592   (let ((p (cdr plist)))
 593     (while (and (cdr p) (not (eq (car (cdr p)) tag))) (setq p (cdr (cdr p))))
 594     (and (cdr p) (progn (setcdr p (cdr (cdr (cdr p)))) t))))
 595
 596 (defun cl-remprop (sym tag)
 597   "Remove from SYMBOL's plist the property PROPNAME and its value.
 598 \n(fn SYMBOL PROPNAME)"
 599   (let ((plist (symbol-plist sym)))
 600     (if (and plist (eq tag (car plist)))
 601         (progn (setplist sym (cdr (cdr plist))) t)
 602       (cl-do-remf plist tag))))
 603 (defalias 'remprop 'cl-remprop)
 604
 605
 606
 607 ;;; Hash tables.
 608 ;; This is just kept for compatibility with code byte-compiled by Emacs-20.
 609
 610 ;; No idea if this might still be needed.
 611 (defun cl-not-hash-table (x &optional y &rest z)
 612   (signal 'wrong-type-argument (list 'cl-hash-table-p (or y x))))
 613
 614 (defvar cl-builtin-gethash (symbol-function 'gethash))
 615 (defvar cl-builtin-remhash (symbol-function 'remhash))
 616 (defvar cl-builtin-clrhash (symbol-function 'clrhash))
 617 (defvar cl-builtin-maphash (symbol-function 'maphash))
 618
 619 (defalias 'cl-gethash 'gethash)
 620 (defalias 'cl-puthash 'puthash)
 621 (defalias 'cl-remhash 'remhash)
 622 (defalias 'cl-clrhash 'clrhash)
 623 (defalias 'cl-maphash 'maphash)
 624 ;; These three actually didn't exist in Emacs-20.
 625 (defalias 'cl-make-hash-table 'make-hash-table)
 626 (defalias 'cl-hash-table-p 'hash-table-p)
 627 (defalias 'cl-hash-table-count 'hash-table-count)
 628
 629 ;;; Some debugging aids.
 630
 631 (defun cl-prettyprint (form)
 632   "Insert a pretty-printed rendition of a Lisp FORM in current buffer."
 633   (let ((pt (point)) last)
 634     (insert "\n" (prin1-to-string form) "\n")
 635     (setq last (point))
 636     (goto-char (1+ pt))
 637     (while (search-forward "(quote " last t)
 638       (delete-backward-char 7)
 639       (insert "'")
 640       (forward-sexp)
 641       (delete-char 1))
 642     (goto-char (1+ pt))
 643     (cl-do-prettyprint)))
 644
 645 (defun cl-do-prettyprint ()
 646   (skip-chars-forward " ")
 647   (if (looking-at "(")
 648       (let ((skip (or (looking-at "((") (looking-at "(prog")
 649                       (looking-at "(unwind-protect ")
 650                       (looking-at "(function (")
 651                       (looking-at "(cl-block-wrapper ")))
 652             (two (or (looking-at "(defun ") (looking-at "(defmacro ")))
 653             (let (or (looking-at "(let\\*? ") (looking-at "(while ")))
 654             (set (looking-at "(p?set[qf] ")))
 655         (if (or skip let
 656                 (progn
 657                   (forward-sexp)
 658                   (and (>= (current-column) 78) (progn (backward-sexp) t))))
 659             (let ((nl t))
 660               (forward-char 1)
 661               (cl-do-prettyprint)
 662               (or skip (looking-at ")") (cl-do-prettyprint))
 663               (or (not two) (looking-at ")") (cl-do-prettyprint))
 664               (while (not (looking-at ")"))
 665                 (if set (setq nl (not nl)))
 666                 (if nl (insert "\n"))
 667                 (lisp-indent-line)
 668                 (cl-do-prettyprint))
 669               (forward-char 1))))
 670     (forward-sexp)))
 671
 672 (defvar cl-macroexpand-cmacs nil)
 673 (defvar cl-closure-vars nil)
 674
 675 (defun cl-macroexpand-all (form &optional env)
 676   "Expand all macro calls through a Lisp FORM.
 677 This also does some trivial optimizations to make the form prettier."
 678   (while (or (not (eq form (setq form (macroexpand form env))))
 679              (and cl-macroexpand-cmacs
 680                   (not (eq form (setq form (compiler-macroexpand form)))))))
 681   (cond ((not (consp form)) form)
 682         ((memq (car form) '(let let*))
 683          (if (null (nth 1 form))
 684              (cl-macroexpand-all (cons 'progn (cddr form)) env)
 685            (let ((letf nil) (res nil) (lets (cadr form)))
 686              (while lets
 687                (push (if (consp (car lets))
 688                             (let ((exp (cl-macroexpand-all (caar lets) env)))
 689                               (or (symbolp exp) (setq letf t))
 690                               (cons exp (cl-macroexpand-body (cdar lets) env)))
 691                           (let ((exp (cl-macroexpand-all (car lets) env)))
 692                             (if (symbolp exp) exp
 693                               (setq letf t) (list exp nil)))) res)
 694                (setq lets (cdr lets)))
 695              (list* (if letf (if (eq (car form) 'let) 'letf 'letf*) (car form))
 696                     (nreverse res) (cl-macroexpand-body (cddr form) env)))))
 697         ((eq (car form) 'cond)
 698          (cons (car form)
 699                (mapcar (function (lambda (x) (cl-macroexpand-body x env)))
 700                        (cdr form))))
 701         ((eq (car form) 'condition-case)
 702          (list* (car form) (nth 1 form) (cl-macroexpand-all (nth 2 form) env)
 703                 (mapcar (function
 704                          (lambda (x)
 705                            (cons (car x) (cl-macroexpand-body (cdr x) env))))
 706                         (cdddr form))))
 707         ((memq (car form) '(quote function))
 708          (if (eq (car-safe (nth 1 form)) 'lambda)
 709              (let ((body (cl-macroexpand-body (cddadr form) env)))
 710                (if (and cl-closure-vars (eq (car form) 'function)
 711                         (cl-expr-contains-any body cl-closure-vars))
 712                    (let* ((new (mapcar 'gensym cl-closure-vars))
 713                           (sub (pairlis cl-closure-vars new)) (decls nil))
 714                      (while (or (stringp (car body))
 715                                 (eq (car-safe (car body)) 'interactive))
 716                        (push (list 'quote (pop body)) decls))
 717                      (put (car (last cl-closure-vars)) 'used t)
 718                      (append
 719                       (list 'list '(quote lambda) '(quote (&rest --cl-rest--)))
 720                       (sublis sub (nreverse decls))
 721                       (list
 722                        (list* 'list '(quote apply)
 723                               (list 'function
 724                                     (list* 'lambda
 725                                            (append new (cadadr form))
 726                                            (sublis sub body)))
 727                               (nconc (mapcar (function
 728                                               (lambda (x)
 729                                                 (list 'list '(quote quote) x)))
 730                                              cl-closure-vars)
 731                                      '((quote --cl-rest--)))))))
 732                  (list (car form) (list* 'lambda (cadadr form) body))))
 733            (let ((found (assq (cadr form) env)))
 734              (if (and found (ignore-errors
 735                               (eq (cadr (caddr found)) 'cl-labels-args)))
 736                  (cl-macroexpand-all (cadr (caddr (cadddr found))) env)
 737                form))))
 738         ((memq (car form) '(defun defmacro))
 739          (list* (car form) (nth 1 form) (cl-macroexpand-body (cddr form) env)))
 740         ((and (eq (car form) 'progn) (not (cddr form)))
 741          (cl-macroexpand-all (nth 1 form) env))
 742         ((eq (car form) 'setq)
 743          (let* ((args (cl-macroexpand-body (cdr form) env)) (p args))
 744            (while (and p (symbolp (car p))) (setq p (cddr p)))
 745            (if p (cl-macroexpand-all (cons 'setf args)) (cons 'setq args))))
 746         ((consp (car form))
 747          (cl-macroexpand-all (list* 'funcall
 748                                     (list 'function (car form))
 749                                     (cdr form))
 750                              env))
 751         (t (cons (car form) (cl-macroexpand-body (cdr form) env)))))
 752
 753 (defun cl-macroexpand-body (body &optional env)
 754   (mapcar (function (lambda (x) (cl-macroexpand-all x env))) body))
 755
 756 (defun cl-prettyexpand (form &optional full)
 757   (message "Expanding...")
 758   (let ((cl-macroexpand-cmacs full) (cl-compiling-file full)
 759         (byte-compile-macro-environment nil))
 760     (setq form (cl-macroexpand-all form
 761                                    (and (not full) '((block) (eval-when)))))
 762     (message "Formatting...")
 763     (prog1 (cl-prettyprint form)
 764       (message ""))))
 765
 766
 767
 768 (run-hooks 'cl-extra-load-hook)
 769
 770 ;; arch-tag: bcd03437-0871-43fb-a8f1-ad0e0b5427ed
 771 ;;; cl-extra.el ends here