--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/lisp/cl-extra.el	Mon Aug 13 11:28:15 2007 +0200
@@ -0,0 +1,849 @@
+;;; cl-extra.el --- Common Lisp extensions for GNU Emacs Lisp (part two)
+
+;; Copyright (C) 1993 Free Software Foundation, Inc.
+
+;; Author: Dave Gillespie <daveg@synaptics.com>
+;; Maintainer: XEmacs Development Team
+;; Version: 2.02
+;; Keywords: extensions, dumped
+
+;; This file is part of XEmacs.
+
+;; XEmacs is free software; you can redistribute it and/or modify it
+;; under the terms of the GNU General Public License as published by
+;; the Free Software Foundation; either version 2, or (at your option)
+;; any later version.
+
+;; XEmacs is distributed in the hope that it will be useful, but
+;; WITHOUT ANY WARRANTY; without even the implied warranty of
+;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
+;; General Public License for more details.
+
+;; You should have received a copy of the GNU General Public License
+;; along with XEmacs; see the file COPYING.  If not, write to the Free
+;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
+;; 02111-1307, USA.
+
+;;; Synched up with: FSF 19.34.
+
+;;; Commentary:
+
+;; This file is dumped with XEmacs.
+
+;; These are extensions to Emacs Lisp that provide a degree of
+;; Common Lisp compatibility, beyond what is already built-in
+;; in Emacs Lisp.
+;;
+;; This package was written by Dave Gillespie; it is a complete
+;; rewrite of Cesar Quiroz's original cl.el package of December 1986.
+;;
+;; This package works with Emacs 18, Emacs 19, and XEmacs/Lucid Emacs 19.
+;;
+;; Bug reports, comments, and suggestions are welcome!
+
+;; This file contains portions of the Common Lisp extensions
+;; package which are autoloaded since they are relatively obscure.
+
+;; See cl.el for Change Log.
+
+
+;;; Code:
+(eval-when-compile
+  (require 'obsolete))
+
+(or (memq 'cl-19 features)
+    (error "Tried to load `cl-extra' before `cl'!"))
+
+
+;;; We define these here so that this file can compile without having
+;;; loaded the cl.el file already.
+
+(defmacro cl-push (x place) (list 'setq place (list 'cons x place)))
+(defmacro cl-pop (place)
+  (list 'car (list 'prog1 place (list 'setq place (list 'cdr place)))))
+
+(defvar cl-emacs-type)
+
+
+;;; Type coercion.
+
+(defun coerce (x type)
+  "Coerce OBJECT to type TYPE.
+TYPE is a Common Lisp type specifier."
+  (cond ((eq type 'list) (if (listp x) x (append x nil)))
+	((eq type 'vector) (if (vectorp x) x (vconcat x)))
+	((eq type 'string) (if (stringp x) x (concat x)))
+	((eq type 'array) (if (arrayp x) x (vconcat x)))
+	((and (eq type 'character) (stringp x) (= (length x) 1)) (aref x 0))
+	((and (eq type 'character) (symbolp x)) (coerce (symbol-name x) type))
+	((and (eq type 'character) (numberp x) (char-or-char-int-p x)
+	      (int-char x)))
+	((eq type 'float) (float x))
+	((eq type 'bit-vector) (if (bit-vector-p x) x
+				 (apply 'bit-vector (append x nil))))
+	((eq type 'weak-list)
+	 (if (weak-list-p x) x
+	   (let ((wl (make-weak-list)))
+	     (set-weak-list-list wl (if (listp x) x (append x nil)))
+	     wl)))
+	((typep x type) x)
+	(t (error "Can't coerce %s to type %s" x type))))
+
+
+;;; Predicates.
+
+(defun equalp (x y)
+  "Return t if two Lisp objects have similar structures and contents.
+This is like `equal', except that it accepts numerically equal
+numbers of different types (float vs. integer), and also compares
+strings case-insensitively."
+  (cond ((eq x y) t)
+	((stringp x)
+	 (and (stringp y) (= (length x) (length y))
+	      (or (string-equal x y)
+		  (string-equal (downcase x) (downcase y)))))   ; lazy but simple!
+	((characterp x)
+	 (and (characterp y)
+	      (or (char-equal x y)
+		  (char-equal (downcase x) (downcase y)))))
+	((numberp x)
+	 (and (numberp y) (= x y)))
+	((consp x)
+	 ;; XEmacs change
+	 (while (and (consp x) (consp y) (equalp (car x) (car y)))
+	   (cl-pop x) (cl-pop y))
+	 (and (not (consp x)) (equalp x y)))
+	((vectorp x)
+	 (and (vectorp y) (= (length x) (length y))
+	      (let ((i (length x)))
+		(while (and (>= (setq i (1- i)) 0)
+			    (equalp (aref x i) (aref y i))))
+		(< i 0))))
+	(t (equal x y))))
+
+
+;;; Control structures.
+
+(defun cl-mapcar-many (cl-func cl-seqs)
+  (if (cdr (cdr cl-seqs))
+      (let* ((cl-res nil)
+	     (cl-n (apply 'min (mapcar 'length cl-seqs)))
+	     (cl-i 0)
+	     (cl-args (copy-sequence cl-seqs))
+	     cl-p1 cl-p2)
+	(setq cl-seqs (copy-sequence cl-seqs))
+	(while (< cl-i cl-n)
+	  (setq cl-p1 cl-seqs cl-p2 cl-args)
+	  (while cl-p1
+	    (setcar cl-p2
+		    (if (consp (car cl-p1))
+			(prog1 (car (car cl-p1))
+			  (setcar cl-p1 (cdr (car cl-p1))))
+		      (aref (car cl-p1) cl-i)))
+	    (setq cl-p1 (cdr cl-p1) cl-p2 (cdr cl-p2)))
+	  (cl-push (apply cl-func cl-args) cl-res)
+	  (setq cl-i (1+ cl-i)))
+	(nreverse cl-res))
+    (let ((cl-res nil)
+	  (cl-x (car cl-seqs))
+	  (cl-y (nth 1 cl-seqs)))
+      (let ((cl-n (min (length cl-x) (length cl-y)))
+	    (cl-i -1))
+	(while (< (setq cl-i (1+ cl-i)) cl-n)
+	  (cl-push (funcall cl-func
+			    (if (consp cl-x) (cl-pop cl-x) (aref cl-x cl-i))
+			    (if (consp cl-y) (cl-pop cl-y) (aref cl-y cl-i)))
+		   cl-res)))
+      (nreverse cl-res))))
+
+(defun map (cl-type cl-func cl-seq &rest cl-rest)
+  "Map a function across one or more sequences, returning a sequence.
+TYPE is the sequence type to return, FUNC is the function, and SEQS
+are the argument sequences."
+  (let ((cl-res (apply 'mapcar* cl-func cl-seq cl-rest)))
+    (and cl-type (coerce cl-res cl-type))))
+
+(defun maplist (cl-func cl-list &rest cl-rest)
+  "Map FUNC to each sublist of LIST or LISTS.
+Like `mapcar', except applies to lists and their cdr's rather than to
+the elements themselves."
+  (if cl-rest
+      (let ((cl-res nil)
+	    (cl-args (cons cl-list (copy-sequence cl-rest)))
+	    cl-p)
+	(while (not (memq nil cl-args))
+	  (cl-push (apply cl-func cl-args) cl-res)
+	  (setq cl-p cl-args)
+	  (while cl-p (setcar cl-p (cdr (cl-pop cl-p)) )))
+	(nreverse cl-res))
+    (let ((cl-res nil))
+      (while cl-list
+	(cl-push (funcall cl-func cl-list) cl-res)
+	(setq cl-list (cdr cl-list)))
+      (nreverse cl-res))))
+
+
+(defun mapc (cl-func cl-seq &rest cl-rest)
+  "Like `mapcar', but does not accumulate values returned by the function."
+  (if cl-rest
+      (apply 'map nil cl-func cl-seq cl-rest)
+    ;; XEmacs change: in the simplest case we call mapc-internal,
+    ;; which really doesn't accumulate any results.
+    (mapc-internal cl-func cl-seq))
+  cl-seq)
+
+(defun mapl (cl-func cl-list &rest cl-rest)
+  "Like `maplist', but does not accumulate values returned by the function."
+  (if cl-rest
+      (apply 'maplist cl-func cl-list cl-rest)
+    (let ((cl-p cl-list))
+      (while cl-p (funcall cl-func cl-p) (setq cl-p (cdr cl-p)))))
+  cl-list)
+
+(defun mapcan (cl-func cl-seq &rest cl-rest)
+  "Like `mapcar', but nconc's together the values returned by the function."
+  (apply 'nconc (apply 'mapcar* cl-func cl-seq cl-rest)))
+
+(defun mapcon (cl-func cl-list &rest cl-rest)
+  "Like `maplist', but nconc's together the values returned by the function."
+  (apply 'nconc (apply 'maplist cl-func cl-list cl-rest)))
+
+(defun some (cl-pred cl-seq &rest cl-rest)
+  "Return true if PREDICATE is true of any element of SEQ or SEQs.
+If so, return the true (non-nil) value returned by PREDICATE."
+  (if (or cl-rest (nlistp cl-seq))
+      (catch 'cl-some
+	(apply 'map nil
+	       (function (lambda (&rest cl-x)
+			   (let ((cl-res (apply cl-pred cl-x)))
+			     (if cl-res (throw 'cl-some cl-res)))))
+	       cl-seq cl-rest) nil)
+    (let ((cl-x nil))
+      (while (and cl-seq (not (setq cl-x (funcall cl-pred (cl-pop cl-seq))))))
+      cl-x)))
+
+(defun every (cl-pred cl-seq &rest cl-rest)
+  "Return true if PREDICATE is true of every element of SEQ or SEQs."
+  (if (or cl-rest (nlistp cl-seq))
+      (catch 'cl-every
+	(apply 'map nil
+	       (function (lambda (&rest cl-x)
+			   (or (apply cl-pred cl-x) (throw 'cl-every nil))))
+	       cl-seq cl-rest) t)
+    (while (and cl-seq (funcall cl-pred (car cl-seq)))
+      (setq cl-seq (cdr cl-seq)))
+    (null cl-seq)))
+
+(defun notany (cl-pred cl-seq &rest cl-rest)
+  "Return true if PREDICATE is false of every element of SEQ or SEQs."
+  (not (apply 'some cl-pred cl-seq cl-rest)))
+
+(defun notevery (cl-pred cl-seq &rest cl-rest)
+  "Return true if PREDICATE is false of some element of SEQ or SEQs."
+  (not (apply 'every cl-pred cl-seq cl-rest)))
+
+;;; Support for `loop'.
+(defun cl-map-keymap (cl-func cl-map)
+  (while (symbolp cl-map) (setq cl-map (symbol-function cl-map)))
+  (if (eq cl-emacs-type 'lucid) (funcall 'map-keymap cl-func cl-map)
+    (if (listp cl-map)
+	(let ((cl-p cl-map))
+	  (while (consp (setq cl-p (cdr cl-p)))
+	    (cond ((consp (car cl-p))
+		   (funcall cl-func (car (car cl-p)) (cdr (car cl-p))))
+		  ((vectorp (car cl-p))
+		   (cl-map-keymap cl-func (car cl-p)))
+		  ((eq (car cl-p) 'keymap)
+		   (setq cl-p nil)))))
+      (let ((cl-i -1))
+	(while (< (setq cl-i (1+ cl-i)) (length cl-map))
+	  (if (aref cl-map cl-i)
+	      (funcall cl-func cl-i (aref cl-map cl-i))))))))
+
+(defun cl-map-keymap-recursively (cl-func-rec cl-map &optional cl-base)
+  (or cl-base
+      (setq cl-base (copy-sequence (if (eq cl-emacs-type 18) "0" [0]))))
+  (cl-map-keymap
+   (function
+    (lambda (cl-key cl-bind)
+      (aset cl-base (1- (length cl-base)) cl-key)
+      (if (keymapp cl-bind)
+	  (cl-map-keymap-recursively
+	   cl-func-rec cl-bind
+	   (funcall (if (eq cl-emacs-type 18) 'concat 'vconcat)
+		    cl-base (list 0)))
+	(funcall cl-func-rec cl-base cl-bind))))
+   cl-map))
+
+(defun cl-map-intervals (cl-func &optional cl-what cl-prop cl-start cl-end)
+  (or cl-what (setq cl-what (current-buffer)))
+  (if (bufferp cl-what)
+      (let (cl-mark cl-mark2 (cl-next t) cl-next2)
+	(save-excursion
+	  (set-buffer cl-what)
+	  (setq cl-mark (copy-marker (or cl-start (point-min))))
+	  (setq cl-mark2 (and cl-end (copy-marker cl-end))))
+	(while (and cl-next (or (not cl-mark2) (< cl-mark cl-mark2)))
+	  (setq cl-next (and (fboundp 'next-property-change)
+			     (if cl-prop (next-single-property-change
+					  cl-mark cl-prop cl-what)
+			       (next-property-change cl-mark cl-what)))
+		cl-next2 (or cl-next (save-excursion
+				       (set-buffer cl-what) (point-max))))
+	  (funcall cl-func (prog1 (marker-position cl-mark)
+			     (set-marker cl-mark cl-next2))
+		   (if cl-mark2 (min cl-next2 cl-mark2) cl-next2)))
+	(set-marker cl-mark nil) (if cl-mark2 (set-marker cl-mark2 nil)))
+    (or cl-start (setq cl-start 0))
+    (or cl-end (setq cl-end (length cl-what)))
+    (while (< cl-start cl-end)
+      (let ((cl-next (or (and (fboundp 'next-property-change)
+			      (if cl-prop (next-single-property-change
+					   cl-start cl-prop cl-what)
+				(next-property-change cl-start cl-what)))
+			 cl-end)))
+	(funcall cl-func cl-start (min cl-next cl-end))
+	(setq cl-start cl-next)))))
+
+(defun cl-map-overlays (cl-func &optional cl-buffer cl-start cl-end cl-arg)
+  (or cl-buffer (setq cl-buffer (current-buffer)))
+  (if (fboundp 'overlay-lists)
+
+      ;; This is the preferred algorithm, though overlay-lists is undocumented.
+      (let (cl-ovl)
+	(save-excursion
+	  (set-buffer cl-buffer)
+	  (setq cl-ovl (overlay-lists))
+	  (if cl-start (setq cl-start (copy-marker cl-start)))
+	  (if cl-end (setq cl-end (copy-marker cl-end))))
+	(setq cl-ovl (nconc (car cl-ovl) (cdr cl-ovl)))
+	(while (and cl-ovl
+		    (or (not (overlay-start (car cl-ovl)))
+			(and cl-end (>= (overlay-start (car cl-ovl)) cl-end))
+			(and cl-start (<= (overlay-end (car cl-ovl)) cl-start))
+			(not (funcall cl-func (car cl-ovl) cl-arg))))
+	  (setq cl-ovl (cdr cl-ovl)))
+	(if cl-start (set-marker cl-start nil))
+	(if cl-end (set-marker cl-end nil)))
+
+    ;; This alternate algorithm fails to find zero-length overlays.
+    (let ((cl-mark (save-excursion (set-buffer cl-buffer)
+				   (copy-marker (or cl-start (point-min)))))
+	  (cl-mark2 (and cl-end (save-excursion (set-buffer cl-buffer)
+						(copy-marker cl-end))))
+	  cl-pos cl-ovl)
+      (while (save-excursion
+	       (and (setq cl-pos (marker-position cl-mark))
+		    (< cl-pos (or cl-mark2 (point-max)))
+		    (progn
+		      (set-buffer cl-buffer)
+		      (setq cl-ovl (overlays-at cl-pos))
+		      (set-marker cl-mark (next-overlay-change cl-pos)))))
+	(while (and cl-ovl
+		    (or (/= (overlay-start (car cl-ovl)) cl-pos)
+			(not (and (funcall cl-func (car cl-ovl) cl-arg)
+				  (set-marker cl-mark nil)))))
+	  (setq cl-ovl (cdr cl-ovl))))
+      (set-marker cl-mark nil) (if cl-mark2 (set-marker cl-mark2 nil)))))
+
+;;; Support for `setf'.
+(defun cl-set-frame-visible-p (frame val)
+  (cond ((null val) (make-frame-invisible frame))
+	((eq val 'icon) (iconify-frame frame))
+	(t (make-frame-visible frame)))
+  val)
+
+;;; Support for `progv'.
+(defvar cl-progv-save)
+(defun cl-progv-before (syms values)
+  (while syms
+    (cl-push (if (boundp (car syms))
+		 (cons (car syms) (symbol-value (car syms)))
+	       (car syms)) cl-progv-save)
+    (if values
+	(set (cl-pop syms) (cl-pop values))
+      (makunbound (cl-pop syms)))))
+
+(defun cl-progv-after ()
+  (while cl-progv-save
+    (if (consp (car cl-progv-save))
+	(set (car (car cl-progv-save)) (cdr (car cl-progv-save)))
+      (makunbound (car cl-progv-save)))
+    (cl-pop cl-progv-save)))
+
+
+;;; Numbers.
+
+(defun gcd (&rest args)
+  "Return the greatest common divisor of the arguments."
+  (let ((a (abs (or (cl-pop args) 0))))
+    (while args
+      (let ((b (abs (cl-pop args))))
+	(while (> b 0) (setq b (% a (setq a b))))))
+    a))
+
+(defun lcm (&rest args)
+  "Return the least common multiple of the arguments."
+  (if (memq 0 args)
+      0
+    (let ((a (abs (or (cl-pop args) 1))))
+      (while args
+	(let ((b (abs (cl-pop args))))
+	  (setq a (* (/ a (gcd a b)) b))))
+      a)))
+
+(defun isqrt (a)
+  "Return the integer square root of the argument."
+  (if (and (integerp a) (> a 0))
+      ;; XEmacs change
+      (let ((g (cond ((>= a 1000000) 10000) ((>= a 10000) 1000)
+		     ((>= a 100) 100) (t 10)))
+	    g2)
+	(while (< (setq g2 (/ (+ g (/ a g)) 2)) g)
+	  (setq g g2))
+	g)
+    (if (eq a 0) 0 (signal 'arith-error nil))))
+
+(defun cl-expt (x y)
+  "Return X raised to the power of Y.  Works only for integer arguments."
+  (if (<= y 0) (if (= y 0) 1 (if (memq x '(-1 1)) (cl-expt x (- y)) 0))
+    (* (if (= (% y 2) 0) 1 x) (cl-expt (* x x) (/ y 2)))))
+(or (and (fboundp 'expt) (subrp (symbol-function 'expt)))
+    (defalias 'expt 'cl-expt))
+
+(defun floor* (x &optional y)
+  "Return a list of the floor of X and the fractional part of X.
+With two arguments, return floor and remainder of their quotient."
+  (let ((q (floor x y)))
+    (list q (- x (if y (* y q) q)))))
+
+(defun ceiling* (x &optional y)
+  "Return a list of the ceiling of X and the fractional part of X.
+With two arguments, return ceiling and remainder of their quotient."
+  (let ((res (floor* x y)))
+    (if (= (car (cdr res)) 0) res
+      (list (1+ (car res)) (- (car (cdr res)) (or y 1))))))
+
+(defun truncate* (x &optional y)
+  "Return a list of the integer part of X and the fractional part of X.
+With two arguments, return truncation and remainder of their quotient."
+  (if (eq (>= x 0) (or (null y) (>= y 0)))
+      (floor* x y) (ceiling* x y)))
+
+(defun round* (x &optional y)
+  "Return a list of X rounded to the nearest integer and the remainder.
+With two arguments, return rounding and remainder of their quotient."
+  (if y
+      (if (and (integerp x) (integerp y))
+	  (let* ((hy (/ y 2))
+		 (res (floor* (+ x hy) y)))
+	    (if (and (= (car (cdr res)) 0)
+		     (= (+ hy hy) y)
+		     (/= (% (car res) 2) 0))
+		(list (1- (car res)) hy)
+	      (list (car res) (- (car (cdr res)) hy))))
+	(let ((q (round (/ x y))))
+	  (list q (- x (* q y)))))
+    (if (integerp x) (list x 0)
+      (let ((q (round x)))
+	(list q (- x q))))))
+
+(defun mod* (x y)
+  "The remainder of X divided by Y, with the same sign as Y."
+  (nth 1 (floor* x y)))
+
+(defun rem* (x y)
+  "The remainder of X divided by Y, with the same sign as X."
+  (nth 1 (truncate* x y)))
+
+(defun signum (a)
+  "Return 1 if A is positive, -1 if negative, 0 if zero."
+  (cond ((> a 0) 1) ((< a 0) -1) (t 0)))
+
+
+;; Random numbers.
+
+(defvar *random-state*)
+(defun random* (lim &optional state)
+  "Return a random nonnegative number less than LIM, an integer or float.
+Optional second arg STATE is a random-state object."
+  (or state (setq state *random-state*))
+  ;; Inspired by "ran3" from Numerical Recipes.  Additive congruential method.
+  (let ((vec (aref state 3)))
+    (if (integerp vec)
+	(let ((i 0) (j (- 1357335 (% (abs vec) 1357333))) (k 1))
+	  (aset state 3 (setq vec (make-vector 55 nil)))
+	  (aset vec 0 j)
+	  (while (> (setq i (% (+ i 21) 55)) 0)
+	    (aset vec i (setq j (prog1 k (setq k (- j k))))))
+	  (while (< (setq i (1+ i)) 200) (random* 2 state))))
+    (let* ((i (aset state 1 (% (1+ (aref state 1)) 55)))
+	   (j (aset state 2 (% (1+ (aref state 2)) 55)))
+	   (n (logand 8388607 (aset vec i (- (aref vec i) (aref vec j))))))
+      (if (integerp lim)
+	  (if (<= lim 512) (% n lim)
+	    (if (> lim 8388607) (setq n (+ (lsh n 9) (random* 512 state))))
+	    (let ((mask 1023))
+	      (while (< mask (1- lim)) (setq mask (1+ (+ mask mask))))
+	      (if (< (setq n (logand n mask)) lim) n (random* lim state))))
+	(* (/ n '8388608e0) lim)))))
+
+(defun make-random-state (&optional state)
+  "Return a copy of random-state STATE, or of `*random-state*' if omitted.
+If STATE is t, return a new state object seeded from the time of day."
+  (cond ((null state) (make-random-state *random-state*))
+	((vectorp state) (cl-copy-tree state t))
+	((integerp state) (vector 'cl-random-state-tag -1 30 state))
+	(t (make-random-state (cl-random-time)))))
+
+(defun random-state-p (object)
+  "Return t if OBJECT is a random-state object."
+  (and (vectorp object) (= (length object) 4)
+       (eq (aref object 0) 'cl-random-state-tag)))
+
+
+;; Implementation limits.
+
+(defun cl-finite-do (func a b)
+  (condition-case nil
+      (let ((res (funcall func a b)))   ; check for IEEE infinity
+	(and (numberp res) (/= res (/ res 2)) res))
+    (arith-error nil)))
+
+(defvar most-positive-float)
+(defvar most-negative-float)
+(defvar least-positive-float)
+(defvar least-negative-float)
+(defvar least-positive-normalized-float)
+(defvar least-negative-normalized-float)
+(defvar float-epsilon)
+(defvar float-negative-epsilon)
+
+(defun cl-float-limits ()
+  (or most-positive-float (not (numberp '2e1))
+      (let ((x '2e0) y z)
+	;; Find maximum exponent (first two loops are optimizations)
+	(while (cl-finite-do '* x x) (setq x (* x x)))
+	(while (cl-finite-do '* x (/ x 2)) (setq x (* x (/ x 2))))
+	(while (cl-finite-do '+ x x) (setq x (+ x x)))
+	(setq z x y (/ x 2))
+	;; Now fill in 1's in the mantissa.
+	(while (and (cl-finite-do '+ x y) (/= (+ x y) x))
+	  (setq x (+ x y) y (/ y 2)))
+	(setq most-positive-float x
+	      most-negative-float (- x))
+	;; Divide down until mantissa starts rounding.
+	(setq x (/ x z) y (/ 16 z) x (* x y))
+	(while (condition-case nil (and (= x (* (/ x 2) 2)) (> (/ y 2) 0))
+		 (arith-error nil))
+	  (setq x (/ x 2) y (/ y 2)))
+	(setq least-positive-normalized-float y
+	      least-negative-normalized-float (- y))
+	;; Divide down until value underflows to zero.
+	(setq x (/ 1 z) y x)
+	(while (condition-case nil (> (/ x 2) 0) (arith-error nil))
+	  (setq x (/ x 2)))
+	(setq least-positive-float x
+	      least-negative-float (- x))
+	(setq x '1e0)
+	(while (/= (+ '1e0 x) '1e0) (setq x (/ x 2)))
+	(setq float-epsilon (* x 2))
+	(setq x '1e0)
+	(while (/= (- '1e0 x) '1e0) (setq x (/ x 2)))
+	(setq float-negative-epsilon (* x 2))))
+  nil)
+
+
+;;; Sequence functions.
+
+;XEmacs -- our built-in is more powerful.
+;(defun subseq (seq start &optional end)
+;  "Return the subsequence of SEQ from START to END.
+;If END is omitted, it defaults to the length of the sequence.
+;If START or END is negative, it counts from the end."
+;  (if (stringp seq) (substring seq start end)
+;    (let (len)
+;      (and end (< end 0) (setq end (+ end (setq len (length seq)))))
+;      (if (< start 0) (setq start (+ start (or len (setq len (length seq))))))
+;      (cond ((listp seq)
+;	     (if (> start 0) (setq seq (nthcdr start seq)))
+;	     (if end
+;		 (let ((res nil))
+;		   (while (>= (setq end (1- end)) start)
+;		     (cl-push (cl-pop seq) res))
+;		   (nreverse res))
+;	       (copy-sequence seq)))
+;	    (t
+;	     (or end (setq end (or len (length seq))))
+;	     (let ((res (make-vector (max (- end start) 0) nil))
+;		   (i 0))
+;	       (while (< start end)
+;		 (aset res i (aref seq start))
+;		 (setq i (1+ i) start (1+ start)))
+;	       res))))))
+
+(defun concatenate (type &rest seqs)
+  "Concatenate, into a sequence of type TYPE, the argument SEQUENCES."
+  (case type
+    (vector (apply 'vconcat seqs))
+    (string (apply 'concat seqs))
+    (list   (apply 'append (append seqs '(nil))))
+    (t (error "Not a sequence type name: %s" type))))
+
+;;; List functions.
+
+(defun revappend (x y)
+  "Equivalent to (append (reverse X) Y)."
+  (nconc (reverse x) y))
+
+(defun nreconc (x y)
+  "Equivalent to (nconc (nreverse X) Y)."
+  (nconc (nreverse x) y))
+
+(defun list-length (x)
+  "Return the length of a list.  Return nil if list is circular."
+  (let ((n 0) (fast x) (slow x))
+    (while (and (cdr fast) (not (and (eq fast slow) (> n 0))))
+      (setq n (+ n 2) fast (cdr (cdr fast)) slow (cdr slow)))
+    (if fast (if (cdr fast) nil (1+ n)) n)))
+
+(defun tailp (sublist list)
+  "Return true if SUBLIST is a tail of LIST."
+  (while (and (consp list) (not (eq sublist list)))
+    (setq list (cdr list)))
+  (if (numberp sublist) (equal sublist list) (eq sublist list)))
+
+(defun cl-copy-tree (tree &optional vecp)
+  "Make a copy of TREE.
+If TREE is a cons cell, this recursively copies both its car and its cdr.
+Contrast to copy-sequence, which copies only along the cdrs.  With second
+argument VECP, this copies vectors as well as conses."
+  (if (consp tree)
+      (let ((p (setq tree (copy-list tree))))
+	(while (consp p)
+	  (if (or (consp (car p)) (and vecp (vectorp (car p))))
+	      (setcar p (cl-copy-tree (car p) vecp)))
+	  (or (listp (cdr p)) (setcdr p (cl-copy-tree (cdr p) vecp)))
+	  (cl-pop p)))
+    (if (and vecp (vectorp tree))
+	(let ((i (length (setq tree (copy-sequence tree)))))
+	  (while (>= (setq i (1- i)) 0)
+	    (aset tree i (cl-copy-tree (aref tree i) vecp))))))
+  tree)
+(or (and (fboundp 'copy-tree) (subrp (symbol-function 'copy-tree)))
+    (defalias 'copy-tree 'cl-copy-tree))
+
+
+;;; Property lists.
+
+;; XEmacs: our `get' groks DEFAULT.
+(defalias 'get* 'get)
+
+(defun getf (plist tag &optional def)
+  "Search PROPLIST for property PROPNAME; return its value or DEFAULT.
+PROPLIST is a list of the sort returned by `symbol-plist'."
+  (setplist '--cl-getf-symbol-- plist)
+  (or (get '--cl-getf-symbol-- tag)
+      (and def (get* '--cl-getf-symbol-- tag def))))
+
+(defun cl-set-getf (plist tag val)
+  (let ((p plist))
+    (while (and p (not (eq (car p) tag))) (setq p (cdr (cdr p))))
+    (if p (progn (setcar (cdr p) val) plist) (list* tag val plist))))
+
+(defun cl-do-remf (plist tag)
+  (let ((p (cdr plist)))
+    (while (and (cdr p) (not (eq (car (cdr p)) tag))) (setq p (cdr (cdr p))))
+    (and (cdr p) (progn (setcdr p (cdr (cdr (cdr p)))) t))))
+
+(defun cl-remprop (sym tag)
+  "Remove from SYMBOL's plist the property PROP and its value."
+  (let ((plist (symbol-plist sym)))
+    (if (and plist (eq tag (car plist)))
+	(progn (setplist sym (cdr (cdr plist))) t)
+      (cl-do-remf plist tag))))
+(or (and (fboundp 'remprop) (subrp (symbol-function 'remprop)))
+    (defalias 'remprop 'cl-remprop))
+
+
+
+;;; Hash tables.
+
+;; The `regular' Common Lisp hash-table stuff has been moved into C.
+;; Only backward compatibility stuff remains here.
+(defun make-hashtable (size &optional test)
+  (make-hash-table :test test :size size))
+(defun make-weak-hashtable (size &optional test)
+  (make-hash-table :test test :size size :weakness t))
+(defun make-key-weak-hashtable (size &optional test)
+  (make-hash-table :test test :size size :weakness 'key))
+(defun make-value-weak-hashtable (size &optional test)
+  (make-hash-table :test test :size size :weakness 'value))
+
+(define-obsolete-function-alias 'hashtablep 'hash-table-p)
+(define-obsolete-function-alias 'hashtable-fullness 'hash-table-count)
+(define-obsolete-function-alias 'hashtable-test-function 'hash-table-test)
+(define-obsolete-function-alias 'hashtable-type 'hash-table-type)
+(define-obsolete-function-alias 'hashtable-size 'hash-table-size)
+(define-obsolete-function-alias 'copy-hashtable 'copy-hash-table)
+
+(make-obsolete 'make-hashtable            'make-hash-table)
+(make-obsolete 'make-weak-hashtable       'make-hash-table)
+(make-obsolete 'make-key-weak-hashtable   'make-hash-table)
+(make-obsolete 'make-value-weak-hashtable 'make-hash-table)
+(make-obsolete 'hash-table-type           'hash-table-weakness)
+
+(when (fboundp 'x-keysym-hash-table)
+  (make-obsolete 'x-keysym-hashtable 'x-keysym-hash-table))
+
+;; Compatibility stuff for old kludgy cl.el hash table implementation
+(defvar cl-builtin-gethash (symbol-function 'gethash))
+(defvar cl-builtin-remhash (symbol-function 'remhash))
+(defvar cl-builtin-clrhash (symbol-function 'clrhash))
+(defvar cl-builtin-maphash (symbol-function 'maphash))
+
+(defalias 'cl-gethash 'gethash)
+(defalias 'cl-puthash 'puthash)
+(defalias 'cl-remhash 'remhash)
+(defalias 'cl-clrhash 'clrhash)
+(defalias 'cl-maphash 'maphash)
+
+;;; Some debugging aids.
+
+(defun cl-prettyprint (form)
+  "Insert a pretty-printed rendition of a Lisp FORM in current buffer."
+  (let ((pt (point)) last)
+    (insert "\n" (prin1-to-string form) "\n")
+    (setq last (point))
+    (goto-char (1+ pt))
+    (while (search-forward "(quote " last t)
+      (delete-backward-char 7)
+      (insert "'")
+      (forward-sexp)
+      (delete-char 1))
+    (goto-char (1+ pt))
+    (cl-do-prettyprint)))
+
+(defun cl-do-prettyprint ()
+  (skip-chars-forward " ")
+  (if (looking-at "(")
+      (let ((skip (or (looking-at "((") (looking-at "(prog")
+		      (looking-at "(unwind-protect ")
+		      (looking-at "(function (")
+		      (looking-at "(cl-block-wrapper ")))
+	    (two (or (looking-at "(defun ") (looking-at "(defmacro ")))
+	    (let (or (looking-at "(let\\*? ") (looking-at "(while ")))
+	    (set (looking-at "(p?set[qf] ")))
+	(if (or skip let
+		(progn
+		  (forward-sexp)
+		  (and (>= (current-column) 78) (progn (backward-sexp) t))))
+	    (let ((nl t))
+	      (forward-char 1)
+	      (cl-do-prettyprint)
+	      (or skip (looking-at ")") (cl-do-prettyprint))
+	      (or (not two) (looking-at ")") (cl-do-prettyprint))
+	      (while (not (looking-at ")"))
+		(if set (setq nl (not nl)))
+		(if nl (insert "\n"))
+		(lisp-indent-line)
+		(cl-do-prettyprint))
+	      (forward-char 1))))
+    (forward-sexp)))
+
+(defvar cl-macroexpand-cmacs nil)
+(defvar cl-closure-vars nil)
+
+(defun cl-macroexpand-all (form &optional env)
+  "Expand all macro calls through a Lisp FORM.
+This also does some trivial optimizations to make the form prettier."
+  (while (or (not (eq form (setq form (macroexpand form env))))
+	     (and cl-macroexpand-cmacs
+		  (not (eq form (setq form (compiler-macroexpand form)))))))
+  (cond ((not (consp form)) form)
+	((memq (car form) '(let let*))
+	 (if (null (nth 1 form))
+	     (cl-macroexpand-all (cons 'progn (cddr form)) env)
+	   (let ((letf nil) (res nil) (lets (cadr form)))
+	     (while lets
+	       (cl-push (if (consp (car lets))
+			    (let ((exp (cl-macroexpand-all (caar lets) env)))
+			      (or (symbolp exp) (setq letf t))
+			      (cons exp (cl-macroexpand-body (cdar lets) env)))
+			  (let ((exp (cl-macroexpand-all (car lets) env)))
+			    (if (symbolp exp) exp
+			      (setq letf t) (list exp nil)))) res)
+	       (setq lets (cdr lets)))
+	     (list* (if letf (if (eq (car form) 'let) 'letf 'letf*) (car form))
+		    (nreverse res) (cl-macroexpand-body (cddr form) env)))))
+	((eq (car form) 'cond)
+	 (cons (car form)
+	       (mapcar (function (lambda (x) (cl-macroexpand-body x env)))
+		       (cdr form))))
+	((eq (car form) 'condition-case)
+	 (list* (car form) (nth 1 form) (cl-macroexpand-all (nth 2 form) env)
+		(mapcar (function
+			 (lambda (x)
+			   (cons (car x) (cl-macroexpand-body (cdr x) env))))
+			(cdddr form))))
+	((memq (car form) '(quote function))
+	 (if (eq (car-safe (nth 1 form)) 'lambda)
+	     (let ((body (cl-macroexpand-body (cddadr form) env)))
+	       (if (and cl-closure-vars (eq (car form) 'function)
+			(cl-expr-contains-any body cl-closure-vars))
+		   (let* ((new (mapcar 'gensym cl-closure-vars))
+			  (sub (pairlis cl-closure-vars new)) (decls nil))
+		     (while (or (stringp (car body))
+				(eq (car-safe (car body)) 'interactive))
+		       (cl-push (list 'quote (cl-pop body)) decls))
+		     (put (car (last cl-closure-vars)) 'used t)
+		     (append
+		      (list 'list '(quote lambda) '(quote (&rest --cl-rest--)))
+		      (sublis sub (nreverse decls))
+		      (list
+		       (list* 'list '(quote apply)
+			      (list 'list '(quote quote)
+				    (list 'function
+					  (list* 'lambda
+						 (append new (cadadr form))
+						 (sublis sub body))))
+			      (nconc (mapcar (function
+					      (lambda (x)
+						(list 'list '(quote quote) x)))
+					     cl-closure-vars)
+				     '((quote --cl-rest--)))))))
+		 (list (car form) (list* 'lambda (cadadr form) body))))
+	   (let ((found (assq (cadr form) env)))
+	     (if (eq (cadr (caddr found)) 'cl-labels-args)
+		 (cl-macroexpand-all (cadr (caddr (cadddr found))) env)
+	       form))))
+	((memq (car form) '(defun defmacro))
+	 (list* (car form) (nth 1 form) (cl-macroexpand-body (cddr form) env)))
+	((and (eq (car form) 'progn) (not (cddr form)))
+	 (cl-macroexpand-all (nth 1 form) env))
+	((eq (car form) 'setq)
+	 (let* ((args (cl-macroexpand-body (cdr form) env)) (p args))
+	   (while (and p (symbolp (car p))) (setq p (cddr p)))
+	   (if p (cl-macroexpand-all (cons 'setf args)) (cons 'setq args))))
+	(t (cons (car form) (cl-macroexpand-body (cdr form) env)))))
+
+(defun cl-macroexpand-body (body &optional env)
+  (mapcar (function (lambda (x) (cl-macroexpand-all x env))) body))
+
+(defun cl-prettyexpand (form &optional full)
+  (message "Expanding...")
+  (let ((cl-macroexpand-cmacs full) (cl-compiling-file full)
+	(byte-compile-macro-environment nil))
+    (setq form (cl-macroexpand-all form
+				   (and (not full) '((block) (eval-when)))))
+    (message "Formatting...")
+    (prog1 (cl-prettyprint form)
+      (message ""))))
+
+
+
+(run-hooks 'cl-extra-load-hook)
+
+(provide 'cl-extra)
+
+;;; cl-extra.el ends here