root/trunk/lisp/calc/calc-misc.el

;;; calc-misc.el --- miscellaneous functions for Calc

;; Copyright (C) 1990, 1991, 1992, 1993, 2001, 2002, 2003, 2004
;;   2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Author: David Gillespie <daveg@synaptics.com>
;; Maintainer: Jay Belanger <jay.p.belanger@gmail.com>

;; This file is part of GNU Emacs.

;; GNU Emacs 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 3, or (at your option)
;; any later version.

;; GNU Emacs 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 GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;;; Code:

;; This file is autoloaded from calc.el.

(require 'calc)
(require 'calc-macs)

(defun calc-dispatch-help (arg)
  "C-x* is a prefix key sequence; follow it with one of these letters:

For turning Calc on and off:
  C  calc.  Start the Calculator in a window at the bottom of the screen.
  O  calc-other-window.  Start the Calculator but don't select its window.
  B  calc-big-or-small.  Control whether to use the full Emacs screen for Calc.
  Q  quick-calc.  Use the Calculator in the minibuffer.
  K  calc-keypad.  Start the Calculator in keypad mode (X window system only).
  E  calc-embedded.  Use the Calculator on a formula in this editing buffer.
  J  calc-embedded-select.  Like E, but select appropriate half of => or :=.
  W  calc-embedded-word.  Like E, but activate a single word, i.e., a number.
  Z  calc-user-invocation.  Invoke Calc in the way you defined with `Z I' cmd.
  X  calc-quit.  Turn Calc off.

For moving data into and out of Calc:
  G  calc-grab-region.  Grab the region defined by mark and point into Calc.
  R  calc-grab-rectangle.  Grab the rectangle defined by mark, point into Calc.
  :  calc-grab-sum-down.  Grab a rectangle and sum the columns.
  _  calc-grab-sum-across.  Grab a rectangle and sum the rows.
  Y  calc-copy-to-buffer.  Copy a value from the stack into the editing buffer.

For use with Embedded mode:
  A  calc-embedded-activate.  Find and activate all :='s and =>'s in buffer.
  D  calc-embedded-duplicate.  Make a copy of this formula and select it.
  F  calc-embedded-new-formula.  Insert a new formula at current point.
  N  calc-embedded-next.  Advance cursor to next known formula in buffer.
  P  calc-embedded-previous.  Advance cursor to previous known formula.
  U  calc-embedded-update-formula.  Re-evaluate formula at point.
  `  calc-embedded-edit.  Use calc-edit to edit formula at point.

Documentation:
  I  calc-info.  Read the Calculator manual in the Emacs Info system.
  T  calc-tutorial.  Run the Calculator Tutorial using the Emacs Info system.
  S  calc-summary.  Read the Summary from the Calculator manual in Info.

Miscellaneous:
  L  calc-load-everything.  Load all parts of the Calculator into memory.
  M  read-kbd-macro.  Read a region of keystroke names as a keyboard macro.
  0  (zero) calc-reset.  Reset Calc stack and modes to default state.

Press `*' twice (`C-x * *') to turn Calc on or off using the same
Calc user interface as before (either C-x * C or C-x * K; initially C-x * C).
"
  (interactive "P")
  (calc-check-defines)
  (if calc-dispatch-help
      (progn
        (save-window-excursion
          (describe-function 'calc-dispatch-help)
          (let ((win (get-buffer-window "*Help*")))
            (if win
                (let (key)
                  (select-window win)
                  (while (progn
                           (message "Calc options: Calc, Keypad, ...  %s"
                                    "press SPC, DEL to scroll, C-g to cancel")
                           (memq (car (setq key (calc-read-key t)))
                                 '(?  ?\C-h ?\C-? ?\C-v ?\M-v)))
                    (condition-case err
                        (if (memq (car key) '(?  ?\C-v))
                            (scroll-up)
                          (scroll-down))
                      (error (beep))))
                      (calc-unread-command (cdr key))))))
        (calc-do-dispatch nil))
    (let ((calc-dispatch-help t))
      (calc-do-dispatch arg))))


(defun calc-big-or-small (arg)
  "Toggle Calc between full-screen and regular mode."
  (interactive "P")
  (let ((cwin (get-buffer-window "*Calculator*"))
        (twin (get-buffer-window "*Calc Trail*"))
        (kwin (get-buffer-window "*Calc Keypad*")))
    (if cwin
        (setq calc-full-mode
              (if kwin
                  (and twin (eq (window-width twin) (frame-width)))
                (eq (window-height cwin) (1- (frame-height))))))
    (setq calc-full-mode (if arg
                             (> (prefix-numeric-value arg) 0)
                           (not calc-full-mode)))
    (if kwin
        (progn
          (calc-quit)
          (calc-do-keypad calc-full-mode nil))
      (if cwin
          (progn
            (calc-quit)
            (calc nil calc-full-mode nil))))
    (message (if calc-full-mode
                 "Now using full screen for Calc"
               "Now using partial screen for Calc"))))

(defun calc-other-window (&optional interactive)
  "Invoke the Calculator in another window."
  (interactive "p")
  (if (memq major-mode '(calc-mode calc-trail-mode))
      (progn
        (other-window 1)
        (if (memq major-mode '(calc-mode calc-trail-mode))
            (other-window 1)))
    (if (get-buffer-window "*Calculator*")
        (calc-quit)
      (let ((win (selected-window)))
        (calc nil win interactive)))))

(defun another-calc ()
  "Create another, independent Calculator buffer."
  (interactive)
  (if (eq major-mode 'calc-mode)
      (mapcar (function
               (lambda (v)
                 (set-default v (symbol-value v)))) calc-local-var-list))
  (set-buffer (generate-new-buffer "*Calculator*"))
  (pop-to-buffer (current-buffer))
  (calc-mode))

(defun calc-info ()
  "Run the Emacs Info system on the Calculator documentation."
  (interactive)
  (select-window (get-largest-window))
  (info "Calc"))

(defun calc-info-goto-node (node)
  "Go to a node in the Calculator info documentation."
  (interactive)
  (select-window (get-largest-window))
  (info (concat "(Calc)" node)))

(defun calc-tutorial ()
  "Run the Emacs Info system on the Calculator Tutorial."
  (interactive)
  (if (get-buffer-window "*Calculator*")
      (calc-quit))
  (calc-info-goto-node "Interactive Tutorial")
  (calc-other-window)
  (message "Welcome to the Calc Tutorial!"))

(defun calc-info-summary ()
  "Run the Emacs Info system on the Calculator Summary."
  (interactive)
  (calc-info-goto-node "Summary"))

(defun calc-help ()
  (interactive)
  (let ((msgs (append
         '("Press `h' for complete help; press `?' repeatedly for a summary"
           "Letter keys: Negate; Precision; Yank; Why; Xtended cmd; Quit"
           "Letter keys: SHIFT + Undo, reDo; Keep-args; Inverse, Hyperbolic"
           "Letter keys: SHIFT + sQrt; Sin, Cos, Tan; Exp, Ln, logB"
           "Letter keys: SHIFT + Floor, Round; Abs, conJ, arG; Pi"
           "Letter keys: SHIFT + Num-eval; More-recn; eXec-kbd-macro"
           "Other keys: +, -, *, /, ^, \\ (int div), : (frac div)"
           "Other keys: & (1/x), | (concat), % (modulo), ! (factorial)"
           "Other keys: ' (alg-entry), = (eval), ` (edit); M-RET (last-args)"
           "Other keys: SPC/RET (enter/dup), LFD (over); < > (scroll horiz)"
           "Other keys: DEL (drop), M-DEL (drop-above); { } (scroll vert)"
           "Other keys: TAB (swap/roll-dn), M-TAB (roll-up)"
           "Other keys: [ , ; ] (vector), ( , ) (complex), ( ; ) (polar)"
           "Prefix keys: Algebra, Binary/business, Convert, Display"
           "Prefix keys: Functions, Graphics, Help, J (select)"
           "Prefix keys: Kombinatorics/statistics, Modes, Store/recall"
           "Prefix keys: Trail/time, Units/statistics, Vector/matrix"
           "Prefix keys: Z (user), SHIFT + Z (define)"
           "Prefix keys: prefix + ? gives further help for that prefix")
         (list (format
                "  Calc %s by Dave Gillespie, daveg@synaptics.com"
                calc-version)))))
    (if calc-full-help-flag
        msgs
      (if (or calc-inverse-flag calc-hyperbolic-flag)
          (if calc-inverse-flag
              (if calc-hyperbolic-flag
                  (calc-inv-hyp-prefix-help)
                (calc-inverse-prefix-help))
            (calc-hyperbolic-prefix-help))
        (setq calc-help-phase
              (if (eq this-command last-command)
                  (% (1+ calc-help-phase) (1+ (length msgs)))
                0))
        (let ((msg (nth calc-help-phase msgs)))
          (message "%s" (if msg
                            (concat msg ":"
                                    (make-string (- (apply 'max
                                                           (mapcar 'length
                                                                   msgs))
                                                    (length msg)) 32)
                                    "  [?=MORE]")
                          "")))))))




;;;; Stack and buffer management.

;; The variable calc-last-why-command is set in calc-do-handly-whys
;; and used in calc-why (in calc-stuff.el).
(defvar calc-last-why-command)

(defun calc-do-handle-whys ()
  (setq calc-why (sort calc-next-why
                       (function
                        (lambda (x y)
                          (and (eq (car x) '*) (not (eq (car y) '*))))))
        calc-next-why nil)
  (if (and calc-why (or (eq calc-auto-why t)
                        (and (eq (car (car calc-why)) '*)
                             calc-auto-why)))
      (progn
        (require 'calc-ext)
        (calc-explain-why (car calc-why)
                          (if (eq calc-auto-why t)
                              (cdr calc-why)
                            (if calc-auto-why
                                (eq (car (nth 1 calc-why)) '*))))
        (setq calc-last-why-command this-command)
        (calc-clear-command-flag 'clear-message))))

(defun calc-record-why (&rest stuff)
  (if (eq (car stuff) 'quiet)
      (setq stuff (cdr stuff))
    (if (and (symbolp (car stuff))
             (cdr stuff)
             (or (Math-objectp (nth 1 stuff))
                 (and (Math-vectorp (nth 1 stuff))
                      (math-constp (nth 1 stuff)))
                 (math-infinitep (nth 1 stuff))))
        (setq stuff (cons '* stuff))
      (if (and (stringp (car stuff))
               (string-match "\\`\\*" (car stuff)))
          (setq stuff (cons '* (cons (substring (car stuff) 1)
                                     (cdr stuff)))))))
  (setq calc-next-why (cons stuff calc-next-why))
  nil)

;;; True if A is a constant or vector of constants.  [P x] [Public]
(defun math-constp (a)
  (or (Math-scalarp a)
      (and (memq (car a) '(sdev intv mod vec))
           (progn
             (while (and (setq a (cdr a))
                         (or (Math-scalarp (car a))  ; optimization
                             (math-constp (car a)))))
             (null a)))))


(defun calc-roll-down-stack (n &optional m)
  (if (< n 0)
      (calc-roll-up-stack (- n) m)
    (if (or (= n 0) (> n (calc-stack-size))) (setq n (calc-stack-size)))
    (or m (setq m 1))
    (and (> n 1)
         (< m n)
         (if (and calc-any-selections
                  (not calc-use-selections))
             (calc-roll-down-with-selections n m)
           (calc-pop-push-list n
                               (append (calc-top-list m 1)
                                       (calc-top-list (- n m) (1+ m))))))))

(defun calc-roll-up-stack (n &optional m)
  (if (< n 0)
      (calc-roll-down-stack (- n) m)
    (if (or (= n 0) (> n (calc-stack-size))) (setq n (calc-stack-size)))
    (or m (setq m 1))
    (and (> n 1)
         (< m n)
         (if (and calc-any-selections
                  (not calc-use-selections))
             (calc-roll-up-with-selections n m)
           (calc-pop-push-list n
                               (append (calc-top-list (- n m) 1)
                                       (calc-top-list m (- n m -1))))))))


(defun calc-do-refresh ()
  (if calc-hyperbolic-flag
      (progn
        (setq calc-display-dirty t)
        nil)
    (calc-refresh)
    t))


(defun calc-record-list (vals &optional prefix)
  (while vals
    (or (eq (car vals) 'top-of-stack)
        (progn
          (calc-record (car vals) prefix)
          (setq prefix "...")))
    (setq vals (cdr vals))))


(defun calc-last-args-stub (arg)
  (interactive "p")
  (require 'calc-ext)
  (calc-last-args arg))


(defun calc-power (arg)
  (interactive "P")
  (calc-slow-wrapper
   (if (and (featurep 'calc-ext)
            (calc-is-inverse))
       (calc-binary-op "root" 'calcFunc-nroot arg nil nil)
     (calc-binary-op "^" 'calcFunc-pow arg nil nil '^))))

(defun calc-mod (arg)
  (interactive "P")
  (calc-slow-wrapper
   (calc-binary-op "%" 'calcFunc-mod arg nil nil '%)))

(defun calc-inv (arg)
  (interactive "P")
  (calc-slow-wrapper
   (calc-unary-op "inv" 'calcFunc-inv arg)))

(defun calc-percent ()
  (interactive)
  (calc-slow-wrapper
   (calc-pop-push-record-list
    1 "%" (list (list 'calcFunc-percent (calc-top-n 1))))))


(defun calc-over (n)
  (interactive "P")
  (if n
      (calc-enter (- (prefix-numeric-value n)))
    (calc-enter -2)))


(defun calc-pop-above (n)
  (interactive "P")
  (if n
      (calc-pop (- (prefix-numeric-value n)))
    (calc-pop -2)))

(defun calc-roll-down (n)
  (interactive "P")
  (calc-wrapper
   (let ((nn (prefix-numeric-value n)))
     (cond ((null n)
            (calc-roll-down-stack 2))
           ((> nn 0)
            (calc-roll-down-stack nn))
           ((= nn 0)
            (calc-pop-push-list (calc-stack-size)
                                (reverse
                                 (calc-top-list (calc-stack-size)))))
           (t
            (calc-roll-down-stack (calc-stack-size) (- nn)))))))

(defun calc-roll-up (n)
  (interactive "P")
  (calc-wrapper
   (let ((nn (prefix-numeric-value n)))
     (cond ((null n)
            (calc-roll-up-stack 3))
           ((> nn 0)
            (calc-roll-up-stack nn))
           ((= nn 0)
            (calc-pop-push-list (calc-stack-size)
                                (reverse
                                 (calc-top-list (calc-stack-size)))))
           (t
            (calc-roll-up-stack (calc-stack-size) (- nn)))))))




;;; Other commands.

(defun calc-num-prefix-name (n)
  (cond ((eq n '-) "- ")
        ((equal n '(4)) "C-u ")
        ((consp n) (format "%d " (car n)))
        ((integerp n) (format "%d " n))
        (t "")))

(defun calc-missing-key (n)
  "This is a placeholder for a command which needs to be loaded from calc-ext.
When this key is used, calc-ext (the Calculator extensions module) will be
loaded and the keystroke automatically re-typed."
  (interactive "P")
  (require 'calc-ext)
  (if (keymapp (key-binding (char-to-string last-command-char)))
      (message "%s%c-" (calc-num-prefix-name n) last-command-char))
  (calc-unread-command)
  (setq prefix-arg n))

(defun calc-shift-Y-prefix-help ()
  (interactive)
  (require 'calc-ext)
  (calc-do-prefix-help calc-Y-help-msgs "other" ?Y))




(defun calcDigit-letter ()
  (interactive)
  (if (calc-minibuffer-contains "[-+]?\\(1[1-9]\\|[2-9][0-9]\\)#.*")
      (progn
        (setq last-command-char (upcase last-command-char))
        (calcDigit-key))
    (calcDigit-nondigit)))


;; A Lisp version of temp_minibuffer_message from minibuf.c.
(defun calc-temp-minibuffer-message (m)
  (let ((savemax (point-max)))
    (save-excursion
      (goto-char (point-max))
      (insert m))
    (let ((okay nil))
      (unwind-protect
          (progn
            (sit-for 2)
            (identity 1)   ; this forces a call to QUIT; in bytecode.c.
            (setq okay t))
        (progn
          (delete-region savemax (point-max))
          (or okay (abort-recursive-edit)))))))


(put 'math-with-extra-prec 'lisp-indent-hook 1)


;;; Concatenate two vectors, or a vector and an object.  [V O O] [Public]
(defun math-concat (v1 v2)
  (if (stringp v1)
      (concat v1 v2)
    (require 'calc-ext)
    (if (and (or (math-objvecp v1) (math-known-scalarp v1))
             (or (math-objvecp v2) (math-known-scalarp v2)))
        (append (if (and (math-vectorp v1)
                         (or (math-matrixp v1)
                             (not (math-matrixp v2))))
                    v1
                  (list 'vec v1))
                (if (and (math-vectorp v2)
                         (or (math-matrixp v2)
                             (not (math-matrixp v1))))
                    (cdr v2)
                  (list v2)))
      (list '| v1 v2))))


;;; True if A is zero.  Works for un-normalized values.  [P n] [Public]
(defun math-zerop (a)
  (if (consp a)
      (cond ((memq (car a) '(bigpos bigneg))
             (while (eq (car (setq a (cdr a))) 0))
             (null a))
            ((memq (car a) '(frac float polar mod))
             (math-zerop (nth 1 a)))
            ((eq (car a) 'cplx)
             (and (math-zerop (nth 1 a)) (math-zerop (nth 2 a))))
            ((eq (car a) 'hms)
             (and (math-zerop (nth 1 a))
                  (math-zerop (nth 2 a))
                  (math-zerop (nth 3 a)))))
    (eq a 0)))


;;; True if A is real and negative.  [P n] [Public]

(defun math-negp (a)
  (if (consp a)
      (cond ((eq (car a) 'bigpos) nil)
            ((eq (car a) 'bigneg) (cdr a))
            ((memq (car a) '(float frac))
             (Math-integer-negp (nth 1 a)))
            ((eq (car a) 'hms)
             (if (math-zerop (nth 1 a))
                 (if (math-zerop (nth 2 a))
                     (math-negp (nth 3 a))
                   (math-negp (nth 2 a)))
               (math-negp (nth 1 a))))
            ((eq (car a) 'date)
             (math-negp (nth 1 a)))
            ((eq (car a) 'intv)
             (or (math-negp (nth 3 a))
                 (and (math-zerop (nth 3 a))
                      (memq (nth 1 a) '(0 2)))))
            ((equal a '(neg (var inf var-inf))) t))
    (< a 0)))

;;; True if A is a negative number or an expression the starts with '-'.
(defun math-looks-negp (a)   ; [P x] [Public]
  (or (Math-negp a)
      (eq (car-safe a) 'neg)
      (and (memq (car-safe a) '(* /))
           (or (math-looks-negp (nth 1 a))
               (math-looks-negp (nth 2 a))))
      (and (eq (car-safe a) '-)
           (math-looks-negp (nth 1 a)))))


;;; True if A is real and positive.  [P n] [Public]
(defun math-posp (a)
  (if (consp a)
      (cond ((eq (car a) 'bigpos) (cdr a))
            ((eq (car a) 'bigneg) nil)
            ((memq (car a) '(float frac))
             (Math-integer-posp (nth 1 a)))
            ((eq (car a) 'hms)
             (if (math-zerop (nth 1 a))
                 (if (math-zerop (nth 2 a))
                     (math-posp (nth 3 a))
                   (math-posp (nth 2 a)))
               (math-posp (nth 1 a))))
            ((eq (car a) 'date)
             (math-posp (nth 1 a)))
            ((eq (car a) 'mod)
             (not (math-zerop (nth 1 a))))
            ((eq (car a) 'intv)
             (or (math-posp (nth 2 a))
                 (and (math-zerop (nth 2 a))
                      (memq (nth 1 a) '(0 1)))))
            ((equal a '(var inf var-inf)) t))
    (> a 0)))

(defalias 'math-fixnump 'integerp)
(defalias 'math-fixnatnump 'natnump)


;;; True if A is an even integer.  [P R R] [Public]
(defun math-evenp (a)
  (if (consp a)
      (and (memq (car a) '(bigpos bigneg))
           (= (% (nth 1 a) 2) 0))
    (= (% a 2) 0)))

;;; Compute A / 2, for small or big integer A.  [I i]
;;; If A is negative, type of truncation is undefined.
(defun math-div2 (a)
  (if (consp a)
      (if (cdr a)
          (math-normalize (cons (car a) (math-div2-bignum (cdr a))))
        0)
    (/ a 2)))

(defun math-div2-bignum (a)   ; [l l]
  (if (cdr a)
      (cons (+ (/ (car a) 2) (* (% (nth 1 a) 2) 500))
            (math-div2-bignum (cdr a)))
    (list (/ (car a) 2))))


;;; Reject an argument to a calculator function.  [Public]
(defun math-reject-arg (&optional a p option)
  (if option
      (calc-record-why option p a)
    (if p
        (calc-record-why p a)))
  (signal 'wrong-type-argument (and a (if p (list p a) (list a)))))


;;; Coerce A to be an integer (by truncation toward zero).  [I N] [Public]

;; The variable math-trunc-prec is local to math-trunc, but used by
;; math-trunc-fancy in calc-arith.el, which is called by math-trunc.

(defun math-trunc (a &optional math-trunc-prec)
  (cond (math-trunc-prec
         (require 'calc-ext)
         (math-trunc-special a math-trunc-prec))
        ((Math-integerp a) a)
        ((Math-looks-negp a)
         (math-neg (math-trunc (math-neg a))))
        ((eq (car a) 'float)
         (math-scale-int (nth 1 a) (nth 2 a)))
        (t (require 'calc-ext)
           (math-trunc-fancy a))))
(defalias 'calcFunc-trunc 'math-trunc)

;;; Coerce A to be an integer (by truncation toward minus infinity).  [I N]

;; The variable math-floor-prec is local to math-floor, but used by
;; math-floor-fancy in calc-arith.el, which is called by math-floor.

(defun math-floor (a &optional math-floor-prec)    ;  [Public]
  (cond (math-floor-prec
         (require 'calc-ext)
         (math-floor-special a math-floor-prec))
        ((Math-integerp a) a)
        ((Math-messy-integerp a) (math-trunc a))
        ((Math-realp a)
         (if (Math-negp a)
             (math-add (math-trunc a) -1)
           (math-trunc a)))
        (t (require 'calc-ext)
           (math-floor-fancy a))))
(defalias 'calcFunc-floor 'math-floor)


(defun math-imod (a b)   ; [I I I] [Public]
  (if (and (not (consp a)) (not (consp b)))
      (if (= b 0)
          (math-reject-arg a "*Division by zero")
        (% a b))
    (cdr (math-idivmod a b))))


(defun calcFunc-inv (m)
  (if (Math-vectorp m)
      (progn
        (require 'calc-ext)
        (if (math-square-matrixp m)
            (or (math-with-extra-prec 2 (math-matrix-inv-raw m))
                (math-reject-arg m "*Singular matrix"))
          (math-reject-arg m 'square-matrixp)))
    (if (and
         (require 'calc-arith)
         (math-known-matrixp m))
        (math-pow m -1)
      (math-div 1 m))))

(defun math-do-working (msg arg)
  (or executing-kbd-macro
      (progn
        (calc-set-command-flag 'clear-message)
        (if math-working-step
            (if math-working-step-2
                (setq msg (format "[%d/%d] %s"
                                  math-working-step math-working-step-2 msg))
              (setq msg (format "[%d] %s" math-working-step msg))))
        (message "Working... %s = %s" msg
                 (math-showing-full-precision (math-format-number arg))))))


;;; Compute A modulo B, defined in terms of truncation toward minus infinity.
(defun math-mod (a b)   ; [R R R] [Public]
  (cond ((and (Math-zerop a) (not (eq (car-safe a) 'mod))) a)
        ((Math-zerop b)
         (math-reject-arg a "*Division by zero"))
        ((and (Math-natnump a) (Math-natnump b))
         (math-imod a b))
        ((and (Math-anglep a) (Math-anglep b))
         (math-sub a (math-mul (math-floor (math-div a b)) b)))
        (t (require 'calc-ext)
           (math-mod-fancy a b))))



;;; General exponentiation.

(defun math-pow (a b)   ; [O O N] [Public]
  (cond ((equal b '(var nan var-nan))
         b)
        ((Math-zerop a)
         (if (and (Math-scalarp b) (Math-posp b))
             (if (math-floatp b) (math-float a) a)
           (require 'calc-ext)
           (math-pow-of-zero a b)))
        ((or (eq a 1) (eq b 1)) a)
        ((or (equal a '(float 1 0)) (equal b '(float 1 0))) a)
        ((Math-zerop b)
         (if (Math-scalarp a)
             (if (or (math-floatp a) (math-floatp b))
                 '(float 1 0) 1)
           (require 'calc-ext)
           (math-pow-zero a b)))
        ((and (Math-integerp b) (or (Math-numberp a) (Math-vectorp a)))
         (if (and (equal a '(float 1 1)) (integerp b))
             (math-make-float 1 b)
           (math-with-extra-prec 2
             (math-ipow a b))))
        (t
         (require 'calc-ext)
         (math-pow-fancy a b))))

(defun math-ipow (a n)   ; [O O I] [Public]
  (cond ((Math-integer-negp n)
         (math-ipow (math-div 1 a) (Math-integer-neg n)))
        ((not (consp n))
         (if (and (Math-ratp a) (> n 20))
             (math-iipow-show a n)
           (math-iipow a n)))
        ((math-evenp n)
         (math-ipow (math-mul a a) (math-div2 n)))
        (t
         (math-mul a (math-ipow (math-mul a a)
                                (math-div2 (math-add n -1)))))))

(defun math-iipow (a n)   ; [O O S]
  (cond ((= n 0) 1)
        ((= n 1) a)
        ((= (% n 2) 0) (math-iipow (math-mul a a) (/ n 2)))
        (t (math-mul a (math-iipow (math-mul a a) (/ n 2))))))

(defun math-iipow-show (a n)   ; [O O S]
  (math-working "pow" a)
  (let ((val (cond
              ((= n 0) 1)
              ((= n 1) a)
              ((= (% n 2) 0) (math-iipow-show (math-mul a a) (/ n 2)))
              (t (math-mul a (math-iipow-show (math-mul a a) (/ n 2)))))))
    (math-working "pow" val)
    val))


(defun math-read-radix-digit (dig)   ; [D S; Z S]
  (if (> dig ?9)
      (if (< dig ?A)
          nil
        (- dig 55))
    (if (>= dig ?0)
        (- dig ?0)
      nil)))


;;; Bug reporting

(defun report-calc-bug ()
  "Report a bug in Calc, the GNU Emacs calculator.
Prompts for bug subject.  Leaves you in a mail buffer."
  (interactive)
  (let ((reporter-prompt-for-summary-p t))
    (reporter-submit-bug-report calc-bug-address "Calc" '(calc-version)
                                nil nil
                                "Please describe exactly what actions triggered the bug and the
precise symptoms of the bug.  If possible, include a backtrace by
doing 'M-x toggle-debug-on-error', then reproducing the bug.
" )))
(defalias 'calc-report-bug 'report-calc-bug)

(provide 'calc-misc)

;;; arch-tag: 7984d9d0-62e5-41dc-afb8-e904b975f250
;;; calc-misc.el ends here