lisp/calculator.el

   1 ;;; calculator.el --- a calculator for Emacs  -*- lexical-binding: t -*-
   2
   3 ;; Copyright (C) 1998, 2000-2017 Free Software Foundation, Inc.
   4
   5 ;; Author: Eli Barzilay <eli@barzilay.org>
   6 ;; Keywords: tools, convenience
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software: you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation, either version 3 of the License, or
  13 ;; (at your option) any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.
  22
  23 ;;;=====================================================================
  24 ;;; Commentary:
  25 ;;
  26 ;; A calculator for Emacs.
  27 ;; Why should you reach for your mouse to get xcalc (calc.exe, gcalc or
  28 ;; whatever), when you have Emacs running already?
  29 ;;
  30 ;; If this is not part of your Emacs distribution, then simply bind
  31 ;; `calculator' to a key and make it an autoloaded function, e.g.:
  32 ;;   (autoload 'calculator "calculator"
  33 ;;     "Run the Emacs calculator." t)
  34 ;;   (global-set-key [(control return)] 'calculator)
  35 ;;
  36 ;; Written by Eli Barzilay, eli@barzilay.org
  37 ;;
  38
  39 ;;;=====================================================================
  40 ;;; Customization:
  41
  42 (defgroup calculator nil
  43   "Simple Emacs calculator."
  44   :prefix "calculator"
  45   :version "21.1"
  46   :group 'tools
  47   :group 'applications)
  48
  49 (defcustom calculator-electric-mode nil
  50   "Run `calculator' electrically, in the echo area.
  51 Electric mode saves some place but changes the way you interact with the
  52 calculator."
  53   :type  'boolean
  54   :group 'calculator)
  55
  56 (defcustom calculator-use-menu t
  57   "Make `calculator' create a menu.
  58 Note that this requires easymenu.  Must be set before loading."
  59   :type  'boolean
  60   :group 'calculator)
  61
  62 (defcustom calculator-bind-escape nil
  63   "If non-nil, set escape to exit the calculator."
  64   :type  'boolean
  65   :group 'calculator)
  66
  67 (defcustom calculator-unary-style 'postfix
  68   "Value is either `prefix' or `postfix'.
  69 This determines the default behavior of unary operators."
  70   :type    '(choice (const prefix) (const postfix))
  71   :group   'calculator)
  72
  73 (defcustom calculator-prompt "Calc=%s> "
  74   "The prompt used by the Emacs calculator.
  75 It should contain a \"%s\" somewhere that will indicate the i/o radixes;
  76 this will be a two-character string as described in the documentation
  77 for `calculator-mode'."
  78   :type  'string
  79   :group 'calculator)
  80
  81 (defcustom calculator-number-digits 3
  82   "The calculator's number of digits used for standard display.
  83 Used by the `calculator-standard-display' function - it will use the
  84 format string \"%.NC\" where this number is N and C is a character given
  85 at runtime."
  86   :type  'integer
  87   :group 'calculator)
  88
  89 (defcustom calculator-radix-grouping-mode t
  90   "Use digit grouping in radix output mode.
  91 If this is set, chunks of `calculator-radix-grouping-digits' characters
  92 will be separated by `calculator-radix-grouping-separator' when in radix
  93 output mode is active (determined by `calculator-output-radix')."
  94   :type  'boolean
  95   :group 'calculator)
  96
  97 (defcustom calculator-radix-grouping-digits 4
  98   "The number of digits used for grouping display in radix modes.
  99 See `calculator-radix-grouping-mode'."
 100   :type  'integer
 101   :group 'calculator)
 102
 103 (defcustom calculator-radix-grouping-separator "'"
 104   "The separator used in radix grouping display.
 105 See `calculator-radix-grouping-mode'."
 106   :type  'string
 107   :group 'calculator)
 108
 109 (defcustom calculator-remove-zeros t
 110   "Non-nil value means delete all redundant zero decimal digits.
 111 If this value is not t and not nil, redundant zeros are removed except
 112 for one.
 113 Used by the `calculator-remove-zeros' function."
 114   :type  '(choice (const t) (const leave-decimal) (const nil))
 115   :group 'calculator)
 116
 117 (defcustom calculator-displayer '(std ?n)
 118   "A displayer specification for numerical values.
 119 This is the displayer used to show all numbers in an expression.  Result
 120 values will be displayed according to the first element of
 121 `calculator-displayers'.
 122
 123 The displayer is a symbol, a string or an expression.  A symbol should
 124 be the name of a one-argument function, a string is used with a single
 125 argument and an expression will be evaluated with the variable `num'
 126 bound to whatever should be displayed.  If it is a function symbol, it
 127 should be able to handle special symbol arguments, currently `left' and
 128 `right' which will be sent by special keys to modify display parameters
 129 associated with the displayer function (for example to change the number
 130 of digits displayed).
 131
 132 An exception to the above is the case of the list (std C [G]) where C is
 133 a character and G is an optional boolean, in this case the
 134 `calculator-standard-displayer' function will be used with these as
 135 arguments."
 136   :type '(choice (function) (string) (sexp)
 137                  (list (const std) character)
 138                  (list (const std) character boolean))
 139   :group 'calculator)
 140
 141 (defcustom calculator-displayers
 142   '(((std ?n) "Standard display, decimal point or scientific")
 143     (calculator-eng-display "Eng display")
 144     ((std ?f t) "Standard display, decimal point with grouping")
 145     ((std ?e) "Standard display, scientific")
 146     ("%S"     "Emacs printer"))
 147   "A list of displayers.
 148 Each element is a list of a displayer and a description string.  The
 149 first element is the one which is currently used, this is for the
 150 display of result values not values in expressions.  A displayer
 151 specification is the same as the values that can be stored in
 152 `calculator-displayer'.
 153
 154 `calculator-rotate-displayer' rotates this list."
 155   :type  'sexp
 156   :group 'calculator)
 157
 158 (defcustom calculator-paste-decimals t
 159   "If non-nil, convert pasted integers so they have a decimal point.
 160 This makes it possible to paste big integers since they will be read as
 161 floats, otherwise the Emacs reader will fail on them."
 162   :type  'boolean
 163   :group 'calculator)
 164 (make-obsolete-variable 'calculator-paste-decimals
 165                         "it is no longer used." nil)
 166
 167 (defcustom calculator-copy-displayer nil
 168   "If non-nil, this is any value that can be used for
 169 `calculator-displayer', to format a string before copying it with
 170 `calculator-copy'.  If nil, then `calculator-displayer's normal value is
 171 used."
 172   :type  'boolean
 173   :group 'calculator)
 174
 175 (defcustom calculator-2s-complement nil
 176   "If non-nil, show negative numbers in 2s complement in radix modes.
 177 Otherwise show as a negative number."
 178   :type  'boolean
 179   :group 'calculator)
 180
 181 (defcustom calculator-mode-hook nil
 182   "List of hook functions for `calculator-mode' to run.
 183 Note: if `calculator-electric-mode' is on, then this hook will get
 184 activated in the minibuffer -- in that case it should not do much more
 185 than local key settings and other effects that will change things
 186 outside the scope of calculator related code."
 187   :type  'hook
 188   :group 'calculator)
 189
 190 (defcustom calculator-user-registers nil
 191   "An association list of user-defined register bindings.
 192 Each element in this list is a list of a character and a number that
 193 will be stored in that character's register.
 194
 195 For example, use this to define the golden ratio number:
 196   (setq calculator-user-registers \\='((?g .  1.61803398875)))
 197 before you load calculator."
 198   :type  '(repeat (cons character number))
 199   :set   (lambda (_ val)
 200            (when (boundp 'calculator-registers)
 201              (setq calculator-registers
 202                    (append val calculator-registers)))
 203            (setq calculator-user-registers val))
 204   :group 'calculator)
 205
 206 (defcustom calculator-user-operators nil
 207   "A list of additional operators.
 208 This is a list in the same format as specified in the documentation for
 209 `calculator-operators', that you can use to bind additional calculator
 210 operators.  It is probably not a good idea to modify this value with
 211 `customize' since it is too complex...
 212
 213 Examples:
 214
 215 * A very simple one, adding a postfix \"x-to-y\" conversion keys, using
 216   t as a prefix key:
 217
 218   (setq calculator-user-operators
 219         \\='((\"tf\" cl-to-fr (+ 32 (/ (* X 9) 5)) 1)
 220           (\"tc\" fr-to-cl (/ (* (- X 32) 5) 9) 1)
 221           (\"tp\" kg-to-lb (/ X 0.453592)       1)
 222           (\"tk\" lb-to-kg (* X 0.453592)       1)
 223           (\"tF\" mt-to-ft (/ X 0.3048)         1)
 224           (\"tM\" ft-to-mt (* X 0.3048)         1)))
 225
 226 * Using a function-like form is simple: use `X' for the argument (`Y'
 227   for a second one in case of a binary operator), `TX' is a truncated
 228   version of `X' and `F' for a recursive call.  Here is a [very
 229   inefficient] Fibonacci number operator:
 230
 231   (add-to-list \\='calculator-user-operators
 232                \\='(\"F\" fib
 233                  (if (<= TX 1) 1 (+ (F (- TX 1)) (F (- TX 2))))))
 234
 235   Note that this will be either postfix or prefix, according to
 236   `calculator-unary-style'."
 237   :type  '(repeat (list string symbol sexp integer integer))
 238   :group 'calculator)
 239
 240 ;;;=====================================================================
 241 ;;; Code:
 242
 243 (eval-when-compile (require 'cl-lib))
 244
 245 ;;;---------------------------------------------------------------------
 246 ;;; Variables
 247
 248 (defvar calculator-initial-operators
 249   '(;; "+"/"-" have keybindings of their own, not calculator-ops
 250     ("=" =     identity        1 -1)
 251     (nobind "+" +  +           2  4)
 252     (nobind "-" -  -           2  4)
 253     (nobind "+" +  +          -1  9)
 254     (nobind "-" -  -          -1  9)
 255     ("(" \(    identity       -1 -1)
 256     (")" \)    identity       +1 10)
 257     ;; normal keys
 258     ("|"  or   (logior TX TY)  2  2)
 259     ("#"  xor  (logxor TX TY)  2  2)
 260     ("&"  and  (logand TX TY)  2  3)
 261     ("*"  *    *               2  5)
 262     ("/"  /    /               2  5)
 263     ("\\" div  (/ TX TY)       2  5)
 264     ("%"  rem  (% TX TY)       2  5)
 265     ("L"  log  log             2  6)
 266     ("S"  sin  (sin DX)        x  6)
 267     ("C"  cos  (cos DX)        x  6)
 268     ("T"  tan  (tan DX)        x  6)
 269     ("IS" asin (D (asin X))    x  6)
 270     ("IC" acos (D (acos X))    x  6)
 271     ("IT" atan (D (atan X))    x  6)
 272     ("Q"  sqrt sqrt            x  7)
 273     ("^"  ^    calculator-expt 2  7)
 274     ("!"  !    calculator-fact x  7)
 275     (";"  1/   (/ 1 X)         1  7)
 276     ("_"  -    -               1  8)
 277     ("~"  ~    (lognot TX)     x  8)
 278     (">"  repR calculator-repR 1  8)
 279     ("<"  repL calculator-repL 1  8)
 280     ("v"  avg  (/ (apply '+ L) (length L)) 0 8)
 281     ("l"  tot  (apply '+ L)    0 8)
 282     )
 283   "A list of initial operators.
 284 This is a list in the same format as `calculator-operators'.  Whenever
 285 `calculator' starts, it looks at the value of this variable, and if it
 286 is not empty, its contents is prepended to `calculator-operators' and
 287 the appropriate key bindings are made.
 288
 289 This variable is then reset to nil.  Don't use this if you want to add
 290 user-defined operators, use `calculator-user-operators' instead.")
 291
 292 (defvar calculator-operators nil
 293   "The calculator operators, each a list with:
 294
 295 1. The key(s) that is bound to for this operation, a string that is
 296    used with `kbd';
 297
 298 2. The displayed symbol for this function;
 299
 300 3. The function symbol, or a form that uses the variables `X' and `Y',
 301    (if it is a binary operator), `TX' and `TY' (truncated integer
 302    versions), `DX' (converted to radians if degrees mode is on), `D'
 303    (function for converting radians to degrees if deg mode is on), `L'
 304    (list of saved values), `F' (function for recursive iteration calls)
 305    and evaluates to the function value -- these variables are capital;
 306
 307 4. The function's arity, optional, one of: 2 => binary, -1 => prefix
 308    unary, +1 => postfix unary, 0 => a 0-arg operator func (note that
 309    using such a function replaces the currently entered number, if any),
 310    non-number (the default) => postfix or prefix as determined by
 311    `calculator-unary-style';
 312
 313 5. The function's precedence -- should be in the range of 1 (lowest) to
 314    9 (highest) (optional, defaults to 1);
 315
 316 It it possible have a unary prefix version of a binary operator if it
 317 comes later in this list.  If the list begins with the symbol `nobind',
 318 then no key binding will take place -- this is only used for predefined
 319 keys.
 320
 321 Use `calculator-user-operators' to add operators to this list, see its
 322 documentation for an example.")
 323
 324 (defvar calculator-stack nil
 325   "Stack contents -- operations and operands.")
 326
 327 (defvar calculator-curnum nil
 328   "Current number being entered (as a string).")
 329
 330 (defvar calculator-stack-display nil
 331   "Cons of the stack and its string representation.")
 332
 333 (defvar calculator-char-radix
 334   '((?D . nil) (?B . bin) (?O . oct) (?H . hex) (?X . hex))
 335   "A table to convert input characters to corresponding radix symbols.")
 336
 337 (defvar calculator-output-radix nil
 338   "The mode for display, one of: nil (decimal), `bin', `oct' or `hex'.")
 339
 340 (defvar calculator-input-radix nil
 341   "The mode for input, one of: nil (decimal), `bin', `oct' or `hex'.")
 342
 343 (defvar calculator-deg nil
 344   "Non-nil if trig functions operate on degrees instead of radians.")
 345
 346 (defvar calculator-saved-list nil
 347   "A list of saved values collected.")
 348
 349 (defvar calculator-saved-ptr 0
 350   "The pointer to the current saved number.")
 351
 352 (defvar calculator-add-saved nil
 353   "Bound to t when a value should be added to the saved-list.")
 354
 355 (defvar calculator-display-fragile nil
 356   "When non-nil, we see something that the next digit should replace.")
 357
 358 (defvar calculator-buffer nil
 359   "The current calculator buffer.")
 360
 361 (defvar calculator-eng-extra nil
 362   "Internal value used by `calculator-eng-display'.")
 363
 364 (defvar calculator-eng-tmp-show nil
 365   "Internal value used by `calculator-eng-display'.")
 366
 367 (defvar calculator-last-opXY nil
 368   "The last binary operation and its arguments.
 369 Used for repeating operations in calculator-repR/L.")
 370
 371 (defvar calculator-registers ; use user-bindings first
 372   (append calculator-user-registers
 373           (list (cons ?e float-e) (cons ?p float-pi)))
 374   "The association list of calculator register values.")
 375
 376 (defvar calculator-restart-other-mode nil
 377   "Used to hack restarting with the electric mode changed.")
 378
 379 ;;;---------------------------------------------------------------------
 380 ;;; Key bindings
 381
 382 (defun calculator-define-key (key cmd map)
 383   ;; Arranges for unbound alphabetic keys to be used as their un/shifted
 384   ;; versions if those are bound (mimics the usual Emacs global bindings).
 385   ;; FIXME: We should adjust Emacs's native "fallback to unshifted binding"
 386   ;; such that it can also be used here, rather than having to use a hack like
 387   ;; this one.
 388   (let* ((key  (if (stringp key) (kbd key) key))
 389          (omap (keymap-parent map)))
 390     (define-key map key cmd)
 391     ;; "other" map, used for case-flipped bindings
 392     (unless omap
 393       (setq omap (make-sparse-keymap))
 394       (suppress-keymap omap t)
 395       (set-keymap-parent map omap))
 396     (let ((m omap))
 397       ;; Bind all case-flipped versions.
 398       (dotimes (i (length key))
 399         (let* ((c (aref key i))
 400                (k (vector c))
 401                (b (lookup-key m k))
 402                (defkey (lambda (x)
 403                          (define-key m k x)
 404                          (when (and (characterp c)
 405                                     (or (<= ?A c ?Z) (<= ?a c ?z)))
 406                            (define-key m (vector (logxor 32 c)) x)))))
 407           (cond ((= i (1- (length key)))
 408                  ;; Prefer longer sequences.
 409                  (unless (keymapp b) (funcall defkey cmd)))
 410                 ((keymapp b) (setq m b))
 411                 (t (let ((sub (make-sparse-keymap)))
 412                      (funcall defkey sub)
 413                      (setq m sub)))))))))
 414
 415 (defvar calculator-mode-map
 416   (let ((map (make-sparse-keymap)))
 417     (suppress-keymap map t)
 418     (dolist (x '((calculator-digit
 419                   "0" "1" "2" "3" "4" "5" "6" "7" "8" "9" "a" "b" "c"
 420                   "d" "f" "<kp-0>" "<kp-1>" "<kp-2>" "<kp-3>" "<kp-4>"
 421                   "<kp-5>" "<kp-6>" "<kp-7>" "<kp-8>" "<kp-9>")
 422                  (calculator-open-paren  "[")
 423                  (calculator-close-paren "]")
 424                  (calculator-op-or-exp   "+" "-"
 425                                          "<kp-add>" "<kp-subtract>")
 426                  (calculator-op          "<kp-divide>" "<kp-multiply>")
 427                  (calculator-decimal     "." "<kp-decimal>")
 428                  (calculator-exp         "e")
 429                  (calculator-dec/deg-mode "D")
 430                  (calculator-set-register "s")
 431                  (calculator-get-register "g")
 432                  (calculator-radix-mode        "H" "X" "O" "B")
 433                  (calculator-radix-input-mode  "iD" "iH" "iX" "iO" "iB")
 434                  (calculator-radix-output-mode "oD" "oH" "oX" "oO" "oB")
 435                  (calculator-rotate-displayer      "'")
 436                  (calculator-rotate-displayer-back "\"")
 437                  (calculator-displayer-prev        "{")
 438                  (calculator-displayer-next        "}")
 439                  (calculator-saved-up     "<up>" "C-p")
 440                  (calculator-saved-down   "<down>" "C-n")
 441                  (calculator-quit         "q" "C-g")
 442                  (calculator-enter        "<enter>" "<linefeed>"
 443                                           "<kp-enter>" "<return>"
 444                                           "RET" "LFD")
 445                  (calculator-save-on-list "SPC" "<space>")
 446                  (calculator-clear-saved  "C-c" "<C-delete>")
 447                  (calculator-save-and-quit "<C-return>" "<C-kp-enter>")
 448                  (calculator-paste        "<insert>" "<S-insert>"
 449                                           "<paste>" "<mouse-2>" "C-y")
 450                  (calculator-clear        "<delete>" "DEL" "C-d")
 451                  (calculator-help         "h" "?" "<f1>" "<help>")
 452                  (calculator-copy         "<C-insert>" "<copy>")
 453                  (calculator-backspace    "<backspace>")
 454                  ))
 455       ;; reverse the keys so earlier definitions come last -- makes the
 456       ;; more sensible bindings visible in the menu
 457       (dolist (k (reverse (cdr x)))
 458         (calculator-define-key k (car x) map)))
 459     (if calculator-bind-escape
 460       (progn (calculator-define-key "ESC" 'calculator-quit map)
 461              (calculator-define-key "<escape>" 'calculator-quit map))
 462       (calculator-define-key "ESC ESC ESC" 'calculator-quit map))
 463     ;; make C-h work in text-mode
 464     (unless window-system
 465       (calculator-define-key "C-h" 'calculator-backspace map))
 466     ;; set up a menu
 467     (when (and calculator-use-menu (not (boundp 'calculator-menu)))
 468       (let ((radix-selectors
 469              (mapcar (lambda (x)
 470                        `([,(nth 0 x)
 471                           (calculator-radix-mode ,(nth 2 x))
 472                           :style radio
 473                           :keys ,(nth 2 x)
 474                           :selected
 475                           (and
 476                            (eq calculator-input-radix ',(nth 1 x))
 477                            (eq calculator-output-radix ',(nth 1 x)))]
 478                          [,(concat (nth 0 x) " Input")
 479                           (calculator-radix-input-mode ,(nth 2 x))
 480                           :keys ,(concat "i" (downcase (nth 2 x)))
 481                           :style radio
 482                           :selected
 483                           (eq calculator-input-radix ',(nth 1 x))]
 484                          [,(concat (nth 0 x) " Output")
 485                           (calculator-radix-output-mode ,(nth 2 x))
 486                           :keys ,(concat "o" (downcase (nth 2 x)))
 487                           :style radio
 488                           :selected
 489                           (eq calculator-output-radix ',(nth 1 x))]))
 490                      '(("Decimal"     nil "D")
 491                        ("Binary"      bin "B")
 492                        ("Octal"       oct "O")
 493                        ("Hexadecimal" hex "H"))))
 494             (op (lambda (name key)
 495                   `[,name (calculator-op ,key) :keys ,key])))
 496         (easy-menu-define
 497           calculator-menu map "Calculator menu."
 498           `("Calculator"
 499             ["Help"
 500              (let ((last-command 'calculator-help)) (calculator-help))
 501              :keys "?"]
 502             "---"
 503             ["Copy"  calculator-copy]
 504             ["Paste" calculator-paste]
 505             "---"
 506             ["Electric mode"
 507              (progn (calculator-quit)
 508                     (setq calculator-restart-other-mode t)
 509                     (run-with-timer 0.1 nil (lambda () (message nil)))
 510                     ;; the message from the menu will be visible,
 511                     ;; couldn't make it go away...
 512                     (calculator))
 513              :active (not calculator-electric-mode)]
 514             ["Normal mode"
 515              (progn (setq calculator-restart-other-mode t)
 516                     (calculator-quit))
 517              :active calculator-electric-mode]
 518             "---"
 519             ("Functions"
 520              ,(funcall op "Repeat-right" ">")
 521              ,(funcall op "Repeat-left"  "<")
 522              "------General------"
 523              ,(funcall op "Reciprocal"   ";")
 524              ,(funcall op "Log"          "L")
 525              ,(funcall op "Square-root"  "Q")
 526              ,(funcall op "Factorial"    "!")
 527              "------Trigonometric------"
 528              ,(funcall op "Sinus"        "S")
 529              ,(funcall op "Cosine"       "C")
 530              ,(funcall op "Tangent"      "T")
 531              ,(funcall op "Inv-Sinus"    "IS")
 532              ,(funcall op "Inv-Cosine"   "IC")
 533              ,(funcall op "Inv-Tangent"  "IT")
 534              "------Bitwise------"
 535              ,(funcall op "Or"           "|")
 536              ,(funcall op "Xor"          "#")
 537              ,(funcall op "And"          "&")
 538              ,(funcall op "Not"          "~"))
 539             ("Saved List"
 540              ["Eval+Save"      calculator-save-on-list]
 541              ["Prev number"    calculator-saved-up]
 542              ["Next number"    calculator-saved-down]
 543              ["Delete current" calculator-clear
 544               :active (and calculator-display-fragile
 545                            calculator-saved-list
 546                            (= (car calculator-stack)
 547                               (nth calculator-saved-ptr
 548                                    calculator-saved-list)))]
 549              ["Delete all" calculator-clear-saved]
 550              "---"
 551              ,(funcall op "List-total"   "l")
 552              ,(funcall op "List-average" "v"))
 553             ("Registers"
 554              ["Get register" calculator-get-register]
 555              ["Set register" calculator-set-register])
 556             ("Modes"
 557              ["Radians"
 558               (progn
 559                 (when (or calculator-input-radix calculator-output-radix)
 560                   (calculator-radix-mode "D"))
 561                 (when calculator-deg (calculator-dec/deg-mode)))
 562               :keys "D"
 563               :style radio
 564               :selected (not (or calculator-input-radix
 565                                  calculator-output-radix
 566                                  calculator-deg))]
 567              ["Degrees"
 568               (progn
 569                 (when (or calculator-input-radix calculator-output-radix)
 570                   (calculator-radix-mode "D"))
 571                 (unless calculator-deg (calculator-dec/deg-mode)))
 572               :keys "D"
 573               :style radio
 574               :selected (and calculator-deg
 575                              (not (or calculator-input-radix
 576                                       calculator-output-radix)))]
 577              "---"
 578              ,@(mapcar 'car radix-selectors)
 579              ("Separate I/O"
 580               ,@(mapcar (lambda (x) (nth 1 x)) radix-selectors)
 581               "---"
 582               ,@(mapcar (lambda (x) (nth 2 x)) radix-selectors)))
 583             ("Decimal Display"
 584              ,@(mapcar (lambda (d)
 585                          (vector (cadr d)
 586                                  ;; Note: inserts actual object here
 587                                  `(calculator-rotate-displayer ',d)))
 588                        calculator-displayers)
 589              "---"
 590              ["Change Prev Display" calculator-displayer-prev]
 591              ["Change Next Display" calculator-displayer-next])
 592             "---"
 593             ["Copy+Quit" calculator-save-and-quit]
 594             ["Quit"      calculator-quit]))))
 595     map)
 596   "The calculator key map.")
 597
 598 ;;;---------------------------------------------------------------------
 599 ;;; Startup and mode stuff
 600
 601 (define-derived-mode calculator-mode fundamental-mode "Calculator"
 602   ;; this help is also used as the major help screen
 603   "A [not so] simple calculator for Emacs.
 604
 605 This calculator is used in the same way as other popular calculators
 606 like xcalc or calc.exe -- but using an Emacs interface.
 607
 608 Expressions are entered using normal infix notation, parens are used as
 609 normal.  Unary functions are usually postfix, but some depends on the
 610 value of `calculator-unary-style' (if the style for an operator below is
 611 specified, then it is fixed, otherwise it depends on this variable).
 612 `+' and `-' can be used as either binary operators or prefix unary
 613 operators.  Numbers can be entered with exponential notation using `e',
 614 except when using a non-decimal radix mode for input (in this case `e'
 615 will be the hexadecimal digit).
 616
 617 Here are the editing keys:
 618 * `RET' `='      evaluate the current expression
 619 * `C-insert'     copy the whole current expression to the `kill-ring'
 620 * `C-return'     evaluate, save result the `kill-ring' and exit
 621 * `insert'       paste a number if the one was copied (normally)
 622 * `delete' `C-d' clear last argument or whole expression (hit twice)
 623 * `backspace'    delete a digit or a previous expression element
 624 * `h' `?'        pop-up a quick reference help
 625 * `ESC' `q'      exit (`ESC' can be used if `calculator-bind-escape' is
 626                  non-nil, otherwise use three consecutive `ESC's)
 627
 628 These operators are pre-defined:
 629 * `+' `-' `*' `/' the common binary operators
 630 * `\\' `%'         integer division and reminder
 631 * `_' `;'         postfix unary negation and reciprocal
 632 * `^' `L'         binary operators for x^y and log(x) in base y
 633 * `Q' `!'         unary square root and factorial
 634 * `S' `C' `T'     unary trigonometric operators: sin, cos and tan
 635 * `|' `#' `&' `~' bitwise operators: or, xor, and, not
 636
 637 The trigonometric functions can be inverted if prefixed with an `I', see
 638 below for the way to use degrees instead of the default radians.
 639
 640 Two special postfix unary operators are `>' and `<': whenever a binary
 641 operator is performed, it is remembered along with its arguments; then
 642 `>' (`<') will apply the same operator with the same right (left)
 643 argument.
 644
 645 hex/oct/bin modes can be set for input and for display separately.
 646 Another toggle-able mode is for using degrees instead of radians for
 647 trigonometric functions.
 648 The keys to switch modes are (both `H' and `X' are for hex):
 649 * `D'             switch to all-decimal mode, or toggle degrees/radians
 650 * `B' `O' `H' `X' binary/octal/hexadecimal modes for input & display
 651 * `i' `o'         followed by one of `D' `B' `O' `H' `X' (case
 652                   insensitive) sets only the input or display radix mode
 653 The prompt indicates the current modes:
 654 * \"==\": decimal mode (using radians);
 655 * \"D=\": decimal mode using degrees;
 656 * \"?=\": ? is B/O/H, the radix for both input and output;
 657 * \"=?\": ? is B/O/H, the display radix (with decimal input);
 658 * \"??\": ? is D/B/O/H, 1st char for input radix, 2nd for display.
 659
 660 Also, the quote key can be used to switch display modes for decimal
 661 numbers (double-quote rotates back), and the two brace characters
 662 \(\"{\" and \"}\" change display parameters that these displayers use,
 663 if they handle such).  If output is using any radix mode, then these
 664 keys toggle digit grouping mode and the chunk size.
 665
 666 Values can be saved for future reference in either a list of saved
 667 values, or in registers.
 668
 669 The list of saved values is useful for statistics operations on some
 670 collected data.  It is possible to navigate in this list, and if the
 671 value shown is the current one on the list, an indication is displayed
 672 as \"[N]\" if this is the last number and there are N numbers, or
 673 \"[M/N]\" if the M-th value is shown.
 674 * `SPC'            evaluate the current value as usual, but also adds
 675                    the result to the list of saved values
 676 * `l' `v'          computes total / average of saved values
 677 * `up' `C-p'       browse to the previous value in the list
 678 * `down' `C-n'     browse to the next value in the list
 679 * `delete' `C-d'   remove current value from the list (if it is on it)
 680 * `C-delete' `C-c' delete the whole list
 681
 682 Registers are variable-like place-holders for values:
 683 * `s' followed by a character attach the current value to that character
 684 * `g' followed by a character fetches the attached value
 685
 686 There are many variables that can be used to customize the calculator.
 687 Some interesting customization variables are:
 688 * `calculator-electric-mode'  use only the echo-area electrically.
 689 * `calculator-unary-style'    set most unary ops to pre/postfix style.
 690 * `calculator-user-registers' to define user-preset registers.
 691 * `calculator-user-operators' to add user-defined operators.
 692 See the documentation for these variables, and \"calculator.el\" for
 693 more information.
 694
 695 \\{calculator-mode-map}")
 696
 697 (declare-function Electric-command-loop "electric"
 698                   (return-tag &optional prompt inhibit-quitting
 699                               loop-function loop-state))
 700
 701 ;;;###autoload
 702 (defun calculator ()
 703   "Run the Emacs calculator.
 704 See the documentation for `calculator-mode' for more information."
 705   (interactive)
 706   (when calculator-restart-other-mode
 707     (setq calculator-electric-mode (not calculator-electric-mode)))
 708   (when calculator-initial-operators
 709     (calculator-add-operators calculator-initial-operators)
 710     (setq calculator-initial-operators nil)
 711     ;; don't change this since it is a customization variable,
 712     ;; its set function will add any new operators
 713     (calculator-add-operators calculator-user-operators))
 714   (setq calculator-buffer (get-buffer-create "*calculator*"))
 715   (if calculator-electric-mode
 716     (save-window-excursion
 717       (require 'electric) (message nil) ; hide load message
 718       (let ((old-buf (window-buffer (minibuffer-window)))
 719             (echo-keystrokes 0)
 720             (garbage-collection-messages nil)) ; no gc msg when electric
 721         (set-window-buffer (minibuffer-window) calculator-buffer)
 722         (select-window (minibuffer-window))
 723         (calculator-reset)
 724         (calculator-update-display)
 725         (use-local-map calculator-mode-map)
 726         (run-hooks 'calculator-mode-hook)
 727         (unwind-protect
 728             (catch 'calculator-done
 729               (Electric-command-loop
 730                'calculator-done
 731                ;; can't use 'noprompt, bug in electric.el
 732                (lambda () 'noprompt)
 733                nil
 734                (lambda (_x _y) (calculator-update-display))))
 735           (set-window-buffer (minibuffer-window) old-buf)
 736           (kill-buffer calculator-buffer))))
 737     (progn
 738       (cond
 739         ((not (get-buffer-window calculator-buffer))
 740          (let ((window-min-height 2))
 741            ;; maybe leave two lines for our window because of the
 742            ;; normal `raised' mode line
 743            (select-window (split-window-below
 744                            (if (calculator-need-3-lines) -3 -2)))
 745            (switch-to-buffer calculator-buffer)))
 746         ((not (eq (current-buffer) calculator-buffer))
 747          (select-window (get-buffer-window calculator-buffer))))
 748       (calculator-mode)
 749       (setq buffer-read-only t)
 750       (calculator-reset)
 751       (message "Hit `?' For a quick help screen.")))
 752   (when (and calculator-restart-other-mode calculator-electric-mode)
 753     (calculator)))
 754
 755 (defun calculator-need-3-lines ()
 756   ;; If the mode line might interfere with the calculator buffer, use 3
 757   ;; lines instead.
 758   (let* ((dh (face-attribute 'default :height))
 759          (mh (face-attribute 'mode-line :height)))
 760     ;; if the mode line is shorter than the default, stick with 2 lines
 761     ;; (it may be necessary to check how much shorter)
 762     (and (not (or (and (integerp dh) (integerp mh) (< mh dh))
 763                   (and (numberp mh) (not (integerp mh)) (< mh 1))))
 764          (or ;; if the mode line is taller than the default, use 3 lines
 765              (and (integerp dh) (integerp mh) (> mh dh))
 766              (and (numberp mh) (not (integerp mh)) (> mh 1))
 767              ;; if the mode line has a box with non-negative line-width,
 768              ;; use 3 lines
 769              (let* ((bx (face-attribute 'mode-line :box))
 770                     (lh (plist-get bx :line-width)))
 771                (and bx (or (not lh) (> lh 0))))
 772              ;; if the mode line has an overline, use 3 lines
 773              (not (memq (face-attribute 'mode-line :overline)
 774                         '(nil unspecified)))))))
 775
 776 (defun calculator-message (string &rest arguments)
 777   "Same as `message', but also handle electric mode."
 778   (apply 'message string arguments)
 779   (when calculator-electric-mode (sit-for 1) (message nil)))
 780
 781 ;;;---------------------------------------------------------------------
 782 ;;; Operators
 783
 784 (defun calculator-op-arity (op)
 785   "Return OP's arity.
 786 Current results are one of 2 (binary), +1 (postfix), -1 (prefix), or
 787 0 (nullary)."
 788   (let ((arity (nth 3 op)))
 789     (cond ((numberp arity)                      arity)
 790           ((eq calculator-unary-style 'postfix) +1)
 791           (t                                    -1))))
 792
 793 (defun calculator-op-prec (op)
 794   "Return OP's precedence for reducing when inserting into the stack.
 795 Defaults to 1."
 796   (or (nth 4 op) 1))
 797
 798 (defun calculator-add-operators (more-ops)
 799   "This function handles operator addition.
 800 Adds MORE-OPS to `calculator-operator', called initially to handle
 801 `calculator-initial-operators' and `calculator-user-operators'."
 802   (let ((added-ops nil))
 803     (dolist (op more-ops)
 804       (unless (eq (car op) 'nobind)
 805         (calculator-define-key (car op) 'calculator-op calculator-mode-map))
 806       (push (if (eq (car op) 'nobind) (cdr op) op)
 807             added-ops))
 808     ;; added-ops come first, but in correct order
 809     (setq calculator-operators
 810           (append (nreverse added-ops) calculator-operators))))
 811
 812 ;;;---------------------------------------------------------------------
 813 ;;; Display stuff
 814
 815 (defun calculator-reset ()
 816   "Reset calculator variables."
 817   (unless calculator-restart-other-mode
 818     (setq calculator-stack           nil
 819           calculator-curnum          nil
 820           calculator-stack-display   nil
 821           calculator-display-fragile nil))
 822   (setq calculator-restart-other-mode nil)
 823   (calculator-update-display))
 824
 825 (defun calculator-get-display ()
 826   "Return a string to display.
 827 The result should not exceed the screen width."
 828   (let* ((in-r  (and calculator-input-radix
 829                      (char-to-string
 830                       (car (rassq calculator-input-radix
 831                                   calculator-char-radix)))))
 832          (out-r (and calculator-output-radix
 833                      (char-to-string
 834                       (car (rassq calculator-output-radix
 835                                   calculator-char-radix)))))
 836          (prompt (format calculator-prompt
 837                          (cond ((or in-r out-r)
 838                                 (concat (or in-r "=")
 839                                         (if (equal in-r out-r) "="
 840                                             (or out-r "D"))))
 841                                (calculator-deg "D=")
 842                                (t "=="))))
 843          (expr
 844           (concat (cdr calculator-stack-display)
 845                   (cond
 846                     ;; entering a number
 847                     (calculator-curnum (concat calculator-curnum "_"))
 848                     ;; showing a result
 849                     ((and (= 1 (length calculator-stack))
 850                           calculator-display-fragile)
 851                      nil)
 852                     ;; waiting for a number or an operator
 853                     (t "?"))))
 854          (trim (+ (length expr) (length prompt) 1 (- (window-width)))))
 855     (concat prompt (if (<= trim 0) expr (substring expr trim)))))
 856
 857 (defun calculator-string-to-number (str)
 858   "Convert the given STR to a number, according to the value of
 859 `calculator-input-radix'."
 860   (if calculator-input-radix
 861     (string-to-number str (cadr (assq calculator-input-radix
 862                                       '((bin 2) (oct 8) (hex 16)))))
 863     (let* ((str (replace-regexp-in-string
 864                  "\\.\\([^0-9].*\\)?$" ".0\\1" str))
 865            (str (replace-regexp-in-string
 866                  "[eE][+-]?\\([^0-9].*\\)?$" "e0\\1" str)))
 867       (string-to-number str))))
 868
 869 (defun calculator-push-curnum ()
 870   "Push the numeric value of the displayed number to the stack."
 871   (when calculator-curnum
 872     (push (calculator-string-to-number calculator-curnum)
 873           calculator-stack)
 874     (setq calculator-curnum nil)))
 875
 876 (defun calculator-rotate-displayer (&optional new-disp)
 877   "Switch to the next displayer on the `calculator-displayers' list.
 878 Can be called with an optional argument NEW-DISP to force rotation to
 879 that argument.
 880 If radix output mode is active, toggle digit grouping."
 881   (interactive)
 882   (cond
 883     (calculator-output-radix
 884      (setq calculator-radix-grouping-mode
 885            (not calculator-radix-grouping-mode))
 886      (calculator-message
 887       "Digit grouping mode %s."
 888       (if calculator-radix-grouping-mode "ON" "OFF")))
 889     (t
 890      (setq calculator-displayers
 891            (if (and new-disp (memq new-disp calculator-displayers))
 892              (let ((tmp nil))
 893                (while (not (eq (car calculator-displayers) new-disp))
 894                  (push (pop calculator-displayers) tmp))
 895                (setq calculator-displayers
 896                      (nconc calculator-displayers (nreverse tmp))))
 897              (nconc (cdr calculator-displayers)
 898                     (list (car calculator-displayers)))))
 899      (calculator-message
 900       "Using %s." (cadr (car calculator-displayers)))))
 901   (calculator-enter))
 902
 903 (defun calculator-rotate-displayer-back ()
 904   "Like `calculator-rotate-displayer', but rotates modes back.
 905 If radix output mode is active, toggle digit grouping."
 906   (interactive)
 907   (calculator-rotate-displayer (car (last calculator-displayers))))
 908
 909 (defun calculator-displayer-prev ()
 910   "Send the current displayer function a `left' argument.
 911 This is used to modify display arguments (if the current displayer
 912 function supports this).
 913 If radix output mode is active, increase the grouping size."
 914   (interactive)
 915   (if calculator-output-radix
 916     (progn (setq calculator-radix-grouping-digits
 917                  (1+ calculator-radix-grouping-digits))
 918            (calculator-enter))
 919     (when (car calculator-displayers)
 920       (let ((disp (caar calculator-displayers)))
 921         (cond ((symbolp disp) (funcall disp 'left))
 922               ((and (consp disp) (eq 'std (car disp)))
 923                (calculator-standard-displayer 'left)))))))
 924
 925 (defun calculator-displayer-next ()
 926   "Send the current displayer function a `right' argument.
 927 This is used to modify display arguments (if the current displayer
 928 function supports this).
 929 If radix output mode is active, decrease the grouping size."
 930   (interactive)
 931   (if calculator-output-radix
 932     (progn (setq calculator-radix-grouping-digits
 933                  (max 2 (1- calculator-radix-grouping-digits)))
 934            (calculator-enter))
 935     (when (car calculator-displayers)
 936       (let ((disp (caar calculator-displayers)))
 937         (cond ((symbolp disp) (funcall disp 'right))
 938               ((and (consp disp) (eq 'std (car disp)))
 939                (calculator-standard-displayer 'right)))))))
 940
 941 (defun calculator-remove-zeros (numstr)
 942   "Get a number string NUMSTR and remove unnecessary zeros.
 943 The behavior of this function is controlled by
 944 `calculator-remove-zeros'."
 945   (let* ((s (if (not (eq calculator-remove-zeros t)) numstr
 946                 ;; remove all redundant zeros leaving an integer
 947                 (replace-regexp-in-string
 948                  "\\.0+\\([eE].*\\)?$" "\\1" numstr)))
 949          (s (if (not calculator-remove-zeros) s
 950                 ;; remove zeros, except for first after the "."
 951                 (replace-regexp-in-string
 952                  "\\(\\..[0-9]*?\\)0+\\([eE].*\\)?$" "\\1\\2" s))))
 953     s))
 954
 955 (defun calculator-groupize-number (str n sep &optional fromleft)
 956   "Return the input string STR with occurrences of SEP that separate
 957 every N characters starting from the right, or from the left if
 958 FROMLEFT is true."
 959   (let* ((len (length str)) (i (/ len n)) (j (% len n))
 960          (r (if (or (not fromleft) (= j 0)) '()
 961                 (list (substring str (- len j))))))
 962     (while (> i 0)
 963       (let* ((e (* i n)) (e (if fromleft e (+ e j))))
 964         (push (substring str (- e n) e) r))
 965       (setq i (1- i)))
 966     (when (and (not fromleft) (> j 0))
 967       (push (substring str 0 j) r))
 968     (mapconcat 'identity r sep)))
 969
 970 (defun calculator-standard-displayer (num &optional char group-p)
 971   "Standard display function, used to display NUM.
 972 Its behavior is determined by `calculator-number-digits' and the given
 973 CHAR argument (both will be used to compose a format string).  If the
 974 char is \"n\" then this function will choose one between %f or %e, this
 975 is a work around %g jumping to exponential notation too fast.
 976
 977 It will also split digit sequences into comma-separated groups
 978 and/or remove redundant zeros.
 979
 980 The special `left' and `right' symbols will make it change the current
 981 number of digits displayed (`calculator-number-digits')."
 982   (if (symbolp num)
 983     (cond ((eq num 'left)
 984            (when (> calculator-number-digits 0)
 985              (setq calculator-number-digits
 986                    (1- calculator-number-digits))
 987              (calculator-enter)))
 988           ((eq num 'right)
 989            (setq calculator-number-digits
 990                  (1+ calculator-number-digits))
 991            (calculator-enter)))
 992     (let* ((s (if (eq char ?n)
 993                 (let ((n (abs num)))
 994                   (if (or (and (< 0 n) (< n 0.001)) (< 1e8 n)) ?e ?f))
 995                 char))
 996            (s (format "%%.%s%c" calculator-number-digits s))
 997            (s (calculator-remove-zeros (format s num)))
 998            (s (if (or (not group-p) (string-match-p "[eE]" s)) s
 999                   (replace-regexp-in-string
1000                    "\\([0-9]+\\)\\(?:\\..*\\|$\\)"
1001                    (lambda (_) (calculator-groupize-number
1002                                 (match-string 1 s) 3 ","))
1003                    s nil nil 1))))
1004       s)))
1005
1006 (defun calculator-eng-display (num)
1007   "Display NUM in engineering notation.
1008 The number of decimal digits used is controlled by
1009 `calculator-number-digits', so to change it at runtime you have to use
1010 the `left' or `right' when one of the standard modes is used."
1011   (if (symbolp num)
1012     (cond ((eq num 'left)
1013            (setq calculator-eng-extra
1014                  (if calculator-eng-extra (1+ calculator-eng-extra) 1))
1015            (let ((calculator-eng-tmp-show t)) (calculator-enter)))
1016           ((eq num 'right)
1017            (setq calculator-eng-extra
1018                  (if calculator-eng-extra (1- calculator-eng-extra) -1))
1019            (let ((calculator-eng-tmp-show t)) (calculator-enter))))
1020     (let ((exp 0))
1021       (unless (= 0 num)
1022         (while (< (abs num) 1.0)
1023           (setq num (* num 1000.0)) (setq exp (- exp 3)))
1024         (while (> (abs num) 999.0)
1025           (setq num (/ num 1000.0)) (setq exp (+ exp 3)))
1026         (when (and calculator-eng-tmp-show
1027                    (not (= 0 calculator-eng-extra)))
1028           (let ((i calculator-eng-extra))
1029             (while (> i 0)
1030               (setq num (* num 1000.0)) (setq exp (- exp 3))
1031               (setq i (1- i)))
1032             (while (< i 0)
1033               (setq num (/ num 1000.0)) (setq exp (+ exp 3))
1034               (setq i (1+ i))))))
1035       (unless calculator-eng-tmp-show (setq calculator-eng-extra nil))
1036       (let ((str (format (format "%%.%sf" calculator-number-digits)
1037                          num)))
1038         (concat (let ((calculator-remove-zeros
1039                        ;; make sure we don't leave integers
1040                        (and calculator-remove-zeros 'x)))
1041                   (calculator-remove-zeros str))
1042                 "e" (number-to-string exp))))))
1043
1044 (defun calculator-number-to-string (num)
1045   "Convert NUM to a displayable string."
1046   (cond
1047     ;; operators are printed here, the rest is for numbers
1048     ((not (numberp num)) (prin1-to-string (nth 1 num) t))
1049     ;; %f/%e handle these, but avoid them in radix or in user displayers
1050     ((and (floatp num) (isnan num)) "NaN")
1051     ((<= 1.0e+INF num) "Inf")
1052     ((<= num -1.0e+INF) "-Inf")
1053     (calculator-output-radix
1054      ;; print with radix -- for binary, convert the octal number
1055      (let* ((fmt (if (eq calculator-output-radix 'hex) "%x" "%o"))
1056             (str (if calculator-2s-complement num (abs num)))
1057             (str (format fmt (calculator-truncate str)))
1058             (bins '((?0 "000") (?1 "001") (?2 "010") (?3 "011")
1059                     (?4 "100") (?5 "101") (?6 "110") (?7 "111")))
1060             (str (if (not (eq calculator-output-radix 'bin)) str
1061                      (replace-regexp-in-string
1062                       "^0+\\(.\\)" "\\1"
1063                       (apply 'concat (mapcar (lambda (c)
1064                                                (cadr (assq c bins)))
1065                                      str)))))
1066             (str (if (not calculator-radix-grouping-mode) str
1067                      (calculator-groupize-number
1068                       str calculator-radix-grouping-digits
1069                       calculator-radix-grouping-separator))))
1070        (upcase (if (or calculator-2s-complement (>= num 0)) str
1071                    (concat "-" str)))))
1072     ((stringp calculator-displayer) (format calculator-displayer num))
1073     ((symbolp calculator-displayer) (funcall calculator-displayer num))
1074     ((eq 'std (car-safe calculator-displayer))
1075      (apply 'calculator-standard-displayer
1076             num (cdr calculator-displayer)))
1077     ((listp calculator-displayer)
1078      (eval `(let ((num ',num)) ,calculator-displayer) t))
1079     ;; nil (or bad) displayer
1080     (t (prin1-to-string num t))))
1081
1082 (defun calculator-update-display (&optional force)
1083   "Update the display.
1084 If optional argument FORCE is non-nil, don't use the cached string."
1085   (set-buffer calculator-buffer)
1086   ;; update calculator-stack-display
1087   (when (or force (not (eq (car calculator-stack-display)
1088                            calculator-stack)))
1089     (setq calculator-stack-display
1090           (cons calculator-stack
1091                 (if calculator-stack
1092                   (concat
1093                    (let ((calculator-displayer
1094                           (if (and calculator-displayers
1095                                    (= 1 (length calculator-stack)))
1096                             ;; customizable display for a single value
1097                             (caar calculator-displayers)
1098                             calculator-displayer)))
1099                      (mapconcat 'calculator-number-to-string
1100                                 (reverse calculator-stack)
1101                                 " "))
1102                    " "
1103                    (and calculator-display-fragile
1104                         calculator-saved-list
1105                         ;; Hack: use `eq' to compare the number: it's a
1106                         ;; flonum, so `eq' means that its the actual
1107                         ;; number rather than a computation that had an
1108                         ;; equal result (eg, enter 1,3,2, use "v" to see
1109                         ;; the average -- it now shows "2" instead of
1110                         ;; "2 [3]").
1111                         (eq (car calculator-stack)
1112                             (nth calculator-saved-ptr
1113                                  calculator-saved-list))
1114                         (if (= 0 calculator-saved-ptr)
1115                           (format "[%s]" (length calculator-saved-list))
1116                           (format "[%s/%s]"
1117                                   (- (length calculator-saved-list)
1118                                      calculator-saved-ptr)
1119                                   (length calculator-saved-list)))))
1120                   ""))))
1121   (let ((inhibit-read-only t))
1122     (erase-buffer)
1123     (insert (calculator-get-display)))
1124   (set-buffer-modified-p nil)
1125   (goto-char (if calculator-display-fragile
1126                (1+ (length calculator-prompt))
1127                (1- (point)))))
1128
1129 ;;;---------------------------------------------------------------------
1130 ;;; Stack computations
1131
1132 (defun calculator-reduce-stack-once (prec)
1133   "Worker for `calculator-reduce-stack'."
1134   (cl-flet ((check (ar op)        (and (listp op)
1135                                        (<= prec (calculator-op-prec op))
1136                                        (= ar (calculator-op-arity op))))
1137             (call (op &rest args) (apply 'calculator-funcall
1138                                          (nth 2 op) args)))
1139     (pcase calculator-stack
1140       ;; reduce "... ( x )" --> "... x"
1141       (`((,_ \) . ,_) ,(and X (pred numberp)) (,_ \( . ,_) . ,rest)
1142        (cons X rest))
1143       ;; reduce "... x op y" --> "... r", r is the result
1144       (`(,(and Y (pred numberp))
1145          ,(and O (pred (check 2)))
1146          ,(and X (pred numberp))
1147          . ,rest)
1148        (cons (call O X Y) rest))
1149       ;; reduce "... op x" --> "... r" for prefix op
1150       (`(,(and X (pred numberp)) ,(and O (pred (check -1))) . ,rest)
1151        (cons (call O X) rest))
1152       ;; reduce "... x op" --> "... r" for postfix op
1153       (`(,(and O (pred (check +1))) ,(and X (pred numberp)) . ,rest)
1154        (cons (call O X) rest))
1155       ;; reduce "... op" --> "... r" for 0-ary op
1156       (`(,(and O (pred (check 0))) . ,rest)
1157        (cons (call O) rest))
1158       ;; reduce "... y x" --> "... x"
1159       ;; (needed for 0-ary ops: replace current number with result)
1160       (`(,(and X (pred numberp)) ,(and _Y (pred numberp)) . ,rest)
1161        (cons X rest))
1162       (_ nil)))) ; nil = done
1163
1164 (defun calculator-reduce-stack (prec)
1165   "Reduce the stack using top operators as long as possible.
1166 PREC is a precedence -- reduce everything with higher precedence."
1167   (let ((new nil))
1168     (while (setq new (calculator-reduce-stack-once prec))
1169       (setq calculator-stack new))))
1170
1171 (defun calculator-funcall (f &optional X Y)
1172   "If F is a symbol, evaluate (F X Y).
1173 Otherwise, it should be a list, evaluate it with X, Y bound to the
1174 arguments."
1175   ;; remember binary ops for calculator-repR/L
1176   (when Y (setq calculator-last-opXY (list f X Y)))
1177   (if (symbolp f)
1178     (cond ((and X Y) (funcall f X Y))
1179           (X         (funcall f X))
1180           (t         (funcall f)))
1181     ;; f is an expression
1182     (let ((TX (and X (calculator-truncate X)))
1183           (TY (and Y (calculator-truncate Y)))
1184           (DX (if (and X calculator-deg) (degrees-to-radians X) X))
1185           (L  calculator-saved-list)
1186           (fF `(calculator-funcall ',f x y))
1187           (fD `(if calculator-deg (radians-to-degrees x) x)))
1188       (eval `(cl-flet ((F (&optional x y) ,fF) (D (x) ,fD))
1189                (let ((X ,X) (Y ,Y) (DX ,DX) (TX ,TX) (TY ,TY) (L ',L))
1190                  ,f))
1191             t))))
1192
1193 ;;;---------------------------------------------------------------------
1194 ;;; Input interaction
1195
1196 (defun calculator-last-input (&optional keys)
1197   "Return the last key sequence that was used to invoke this command, or
1198 the input KEYS.  Uses the `function-key-map' translate keypad numbers to
1199 plain ones."
1200   (let* ((inp (or keys (this-command-keys)))
1201          (inp (or (and (arrayp inp) (not (stringp inp))
1202                        (lookup-key function-key-map inp))
1203                   inp)))
1204     (if (or (not inp) (stringp inp) (not (arrayp inp))
1205             (catch 'done ; any non-chars?
1206               (dotimes (i (length inp))
1207                 (unless (characterp (aref inp i)) (throw 'done t)))
1208               nil))
1209       inp
1210       (concat inp))))
1211
1212 (defun calculator-clear-fragile (&optional op)
1213   "Clear the fragile flag if it was set, then maybe reset all.
1214 OP is the operator (if any) that caused this call."
1215   (when (and calculator-display-fragile
1216              (or (not op) (memq (calculator-op-arity op) '(-1 0))))
1217     ;; reset if last calc finished, and now get a num or prefix or 0-ary
1218     ;; op
1219     (calculator-reset))
1220   (setq calculator-display-fragile nil))
1221
1222 (defun calculator-digit ()
1223   "Enter a single digit."
1224   (interactive)
1225   (let ((inp (aref (calculator-last-input) 0)))
1226     (when (and (or calculator-display-fragile
1227                    (not (numberp (car calculator-stack))))
1228                (<= inp (pcase calculator-input-radix
1229                          (`nil ?9) (`bin ?1) (`oct ?7) (_ 999))))
1230       (calculator-clear-fragile)
1231       (setq calculator-curnum
1232             (concat (if (equal calculator-curnum "0") ""
1233                         calculator-curnum)
1234                     (list (upcase inp))))
1235       (calculator-update-display))))
1236
1237 (defun calculator-decimal ()
1238   "Enter a decimal period."
1239   (interactive)
1240   (when (and (not calculator-input-radix)
1241              (or calculator-display-fragile
1242                  (not (numberp (car calculator-stack))))
1243              (not (and calculator-curnum
1244                        (string-match-p "[.eE]" calculator-curnum))))
1245     ;; enter the period on the same condition as a digit, only if no
1246     ;; period or exponent entered yet
1247     (calculator-clear-fragile)
1248     (setq calculator-curnum (concat (or calculator-curnum "0") "."))
1249     (calculator-update-display)))
1250
1251 (defun calculator-exp ()
1252   "Enter an exponent, or an \"E\" digit in hex input mode."
1253   (interactive)
1254   (cond
1255     (calculator-input-radix (calculator-digit))
1256     ((and (or calculator-display-fragile
1257               (not (numberp (car calculator-stack))))
1258           (not (and calculator-curnum
1259                     (string-match-p "[eE]" calculator-curnum))))
1260      ;; same condition as above, also no E so far
1261      (calculator-clear-fragile)
1262      (setq calculator-curnum (concat (or calculator-curnum "1") "e"))
1263      (calculator-update-display))))
1264
1265 (defun calculator-op (&optional keys)
1266   "Enter an operator on the stack, doing all necessary reductions.
1267 Optional string argument KEYS will force using it as the keys entered."
1268   (interactive)
1269   (catch 'op-error
1270     (let* ((last-inp (calculator-last-input keys))
1271            (op (assoc last-inp calculator-operators)))
1272       (calculator-clear-fragile op)
1273       (calculator-push-curnum)
1274       (when (and (= 2 (calculator-op-arity op))
1275                  (not (numberp (car calculator-stack))))
1276         ;; we have a binary operator but no number -- search for a
1277         ;; prefix version
1278         (setq op (assoc last-inp (cdr (memq op calculator-operators))))
1279         (unless (and op (= -1 (calculator-op-arity op)))
1280           (calculator-message "Binary operator without a first operand")
1281           (throw 'op-error nil)))
1282       (calculator-reduce-stack
1283        (cond ((eq (nth 1 op) '\() 10)
1284              ((eq (nth 1 op) '\)) 0)
1285              (t (calculator-op-prec op))))
1286       (when (let ((hasnum (numberp (car calculator-stack))))
1287               (pcase (calculator-op-arity op)
1288                 (-1 hasnum)
1289                 ((or 1 2) (not hasnum))))
1290         (calculator-message "Incomplete expression")
1291         (throw 'op-error nil))
1292       (push op calculator-stack)
1293       (calculator-reduce-stack (calculator-op-prec op))
1294       (when (and (= (length calculator-stack) 1)
1295                  (numberp (car calculator-stack)))
1296         ;; the display is fragile if it contains only one number
1297         (setq calculator-display-fragile t)
1298         (when calculator-add-saved ; add number to the saved-list
1299           (push (car calculator-stack)
1300                 (nthcdr calculator-saved-ptr calculator-saved-list))))
1301       (calculator-update-display))))
1302
1303 (defun calculator-op-or-exp ()
1304   "Either enter an operator or a digit.
1305 Used with +/- for entering them as digits in numbers like 1e-3 (there is
1306 no need for negative numbers since these are handled by unary
1307 operators)."
1308   (interactive)
1309   (if (and (not calculator-input-radix)
1310            (not calculator-display-fragile)
1311            calculator-curnum
1312            (string-match-p "[eE]$" calculator-curnum))
1313     (calculator-digit)
1314     (calculator-op)))
1315
1316 ;;;---------------------------------------------------------------------
1317 ;;; Input/output modes (not display)
1318
1319 (defun calculator-dec/deg-mode ()
1320   "Set decimal mode for display & input, if decimal, toggle deg mode."
1321   (interactive)
1322   (calculator-push-curnum)
1323   (if (or calculator-input-radix calculator-output-radix)
1324     (setq calculator-input-radix nil
1325           calculator-output-radix nil)
1326     ;; already decimal -- toggle degrees mode
1327     (setq calculator-deg (not calculator-deg)))
1328   (calculator-update-display t))
1329
1330 (defun calculator-radix-mode (&optional keys)
1331   "Set input and display radix modes.
1332 Optional string argument KEYS will force using it as the keys entered."
1333   (interactive)
1334   (calculator-radix-input-mode keys)
1335   (calculator-radix-output-mode keys))
1336
1337 (defun calculator-radix-input-mode (&optional keys)
1338   "Set input radix modes.
1339 Optional string argument KEYS will force using it as the keys entered."
1340   (interactive)
1341   (calculator-push-curnum)
1342   (setq calculator-input-radix
1343         (let ((inp (calculator-last-input keys)))
1344           (cdr (assq (upcase (aref inp (1- (length inp))))
1345                      calculator-char-radix))))
1346   (calculator-update-display))
1347
1348 (defun calculator-radix-output-mode (&optional keys)
1349   "Set display radix modes.
1350 Optional string argument KEYS will force using it as the keys entered."
1351   (interactive)
1352   (calculator-push-curnum)
1353   (setq calculator-output-radix
1354         (let ((inp (calculator-last-input keys)))
1355           (cdr (assq (upcase (aref inp (1- (length inp))))
1356                      calculator-char-radix))))
1357   (calculator-update-display t))
1358
1359 ;;;---------------------------------------------------------------------
1360 ;;; Saved values list
1361
1362 (defun calculator-save-on-list ()
1363   "Evaluate current expression, put result on the saved values list."
1364   (interactive)
1365   (let ((calculator-add-saved t)) ; marks the result to be added
1366     (calculator-enter)))
1367
1368 (defun calculator-clear-saved ()
1369   "Clear the list of saved values in `calculator-saved-list'."
1370   (interactive)
1371   (setq calculator-saved-list nil
1372         calculator-saved-ptr 0)
1373   (calculator-update-display t))
1374
1375 (defun calculator-saved-move (n)
1376   "Go N elements up the list of saved values."
1377   (interactive)
1378   (when (and calculator-saved-list
1379              (or (null calculator-stack) calculator-display-fragile))
1380     (setq calculator-saved-ptr
1381           (max (min (+ n calculator-saved-ptr)
1382                     (length calculator-saved-list))
1383                0))
1384     (if (nth calculator-saved-ptr calculator-saved-list)
1385       (setq calculator-stack (list (nth calculator-saved-ptr
1386                                         calculator-saved-list))
1387             calculator-display-fragile t)
1388       (calculator-reset))
1389     (calculator-update-display)))
1390
1391 (defun calculator-saved-up ()
1392   "Go up the list of saved values."
1393   (interactive)
1394   (calculator-saved-move +1))
1395
1396 (defun calculator-saved-down ()
1397   "Go down the list of saved values."
1398   (interactive)
1399   (calculator-saved-move -1))
1400
1401 ;;;---------------------------------------------------------------------
1402 ;;; Misc functions
1403
1404 (defun calculator-open-paren ()
1405   "Equivalents of `(' use this."
1406   (interactive)
1407   (calculator-op "("))
1408
1409 (defun calculator-close-paren ()
1410   "Equivalents of `)' use this."
1411   (interactive)
1412   (calculator-op ")"))
1413
1414 (defun calculator-enter ()
1415   "Evaluate current expression."
1416   (interactive)
1417   (calculator-op "="))
1418
1419 (defun calculator-backspace ()
1420   "Backward delete a single digit or a stack element."
1421   (interactive)
1422   (if calculator-curnum
1423     (setq calculator-curnum
1424           (if (> (length calculator-curnum) 1)
1425             (substring calculator-curnum
1426                        0 (1- (length calculator-curnum)))
1427             nil))
1428     (setq calculator-stack (cdr calculator-stack)))
1429   (calculator-update-display))
1430
1431 (defun calculator-clear ()
1432   "Clear current number."
1433   (interactive)
1434   (setq calculator-curnum nil)
1435   (cond
1436     ;; if the current number is from the saved-list remove it
1437     ((and calculator-display-fragile
1438           calculator-saved-list
1439           (= (car calculator-stack)
1440              (nth calculator-saved-ptr calculator-saved-list)))
1441      (if (= 0 calculator-saved-ptr)
1442        (setq calculator-saved-list (cdr calculator-saved-list))
1443        (let ((p (nthcdr (1- calculator-saved-ptr)
1444                         calculator-saved-list)))
1445          (setcdr p (cddr p))
1446          (setq calculator-saved-ptr (1- calculator-saved-ptr))))
1447      (if calculator-saved-list
1448        (setq calculator-stack
1449              (list (nth calculator-saved-ptr calculator-saved-list)))
1450        (calculator-reset)))
1451     ;; reset if fragile or double clear
1452     ((or calculator-display-fragile (eq last-command this-command))
1453      (calculator-reset)))
1454   (calculator-update-display))
1455
1456 (defun calculator-copy ()
1457   "Copy current number to the `kill-ring'."
1458   (interactive)
1459   (let ((calculator-displayer
1460          (or calculator-copy-displayer calculator-displayer))
1461         (calculator-displayers
1462          (if calculator-copy-displayer nil calculator-displayers)))
1463     (calculator-enter)
1464     ;; remove trailing spaces and an index
1465     (let ((s (cdr calculator-stack-display)))
1466       (when s
1467         (kill-new (replace-regexp-in-string
1468                    "^\\([^ ]+\\) *\\(\\[[0-9/]+\\]\\)? *$" "\\1" s))))))
1469
1470 (defun calculator-put-value (val)
1471   "Paste VAL as if entered.
1472 Used by `calculator-paste' and `get-register'."
1473   (when (and (numberp val)
1474              ;; (not calculator-curnum)
1475              (or calculator-display-fragile
1476                  (not (numberp (car calculator-stack)))))
1477     (calculator-clear-fragile)
1478     (setq calculator-curnum
1479           (let ((calculator-displayer "%S")
1480                 (calculator-radix-grouping-mode nil)
1481                 (calculator-output-radix calculator-input-radix))
1482             (calculator-number-to-string val)))
1483     (calculator-update-display)))
1484
1485 (defun calculator-paste (arg)
1486   "Paste a value from the `kill-ring'.
1487
1488 With a prefix argument, paste the raw string as a sequence of key
1489 presses, which can be used to paste expressions.  Note that this
1490 is literal; examples: spaces will store values, pasting \"1+2\"
1491 will not produce 3 if it's done you're entering a number or after
1492 a multiplication."
1493   (interactive "P")
1494   (let ((str (current-kill 0)))
1495     (if arg
1496       (setq unread-command-events
1497             `(,@(listify-key-sequence str) ,@unread-command-events))
1498       (calculator-put-value (calculator-string-to-number str)))))
1499
1500 (defun calculator-register-read-with-preview (prompt)
1501   "Similar to `register-read-with-preview' but for calculator
1502 registers."
1503   (let ((register-alist calculator-registers)
1504         (register-preview-delay 1)
1505         (register-preview-function
1506          (lambda (r)
1507            (format "%s: %s\n"
1508                    (single-key-description (car r))
1509                    (calculator-number-to-string (cdr r))))))
1510     (register-read-with-preview prompt)))
1511
1512 (defun calculator-set-register (reg)
1513   "Set a register value for REG."
1514   (interactive (list (calculator-register-read-with-preview
1515                       "Register to store value into: ")))
1516   (let* ((as  (assq reg calculator-registers))
1517          (val (progn (calculator-enter) (car calculator-stack))))
1518     (if as
1519       (setcdr as val)
1520       (push (cons reg val) calculator-registers))
1521     (calculator-message "[%c] := %S" reg val)))
1522
1523 (defun calculator-get-register (reg)
1524   "Get a value from a register REG."
1525   (interactive (list (calculator-register-read-with-preview
1526                       "Register to get value from: ")))
1527   (calculator-put-value (cdr (assq reg calculator-registers))))
1528
1529 (declare-function electric-describe-mode "ehelp" ())
1530
1531 (defun calculator-help ()
1532   ;; this is used as the quick reference screen you get with `h'
1533   "Quick reference:
1534 * numbers/operators/parens/./e - enter expressions
1535   + - * / \\(div) %(rem) _(-X,postfix) ;(1/X,postfix) ^(exp) L(og)
1536   Q(sqrt) !(fact) S(in) C(os) T(an) |(or) #(xor) &(and) ~(not)
1537 * >/< repeats last binary operation with its 2nd (1st) arg as postfix op
1538 * I inverse the next trig function     \
1539 * \\='/\"/{/}  - display/display args
1540 * D         - switch to all-decimal, or toggle deg/rad mode
1541 * B/O/H/X   - binary/octal/hex mode for i/o (both H and X are for hex)
1542 * i/o       - prefix for D/B/O/X - set only input/output modes
1543 * enter/=   - evaluate current expr.   * s/g      - set/get a register
1544 * space     - evaluate & save on list  * l/v      - list total/average
1545 * up/down/C-p/C-n - browse saved       * C-delete - clear all saved
1546 * C-insert  - copy whole expr.         * C-return - evaluate, copy, exit
1547 * insert    - paste a number           * backspace- delete backwards
1548 * delete    - clear argument or list value or whole expression (twice)
1549 * escape/q  - exit."
1550   (interactive)
1551   (if (eq last-command 'calculator-help)
1552     (let ((mode-name "Calculator")
1553           (major-mode 'calculator-mode)
1554           (win (selected-window)))
1555       (require 'ehelp)
1556       (if (not calculator-electric-mode)
1557         (describe-mode)
1558         (electric-describe-mode))
1559       (select-window win)
1560       (message nil))
1561     (let ((one (one-window-p t))
1562           (win (selected-window))
1563           (help-buf (get-buffer-create "*Help*")))
1564       (save-window-excursion
1565         (with-output-to-temp-buffer "*Help*"
1566           (princ (documentation 'calculator-help)))
1567         (when one (shrink-window-if-larger-than-buffer
1568                    (get-buffer-window help-buf)))
1569         (message "`%s' again for more help, %s."
1570                  (calculator-last-input)
1571                  "any other key continues normally")
1572         (select-window win)
1573         (sit-for 360))
1574       (select-window win))))
1575
1576 (defun calculator-quit ()
1577   "Quit calculator."
1578   (interactive)
1579   (set-buffer calculator-buffer)
1580   (let ((inhibit-read-only t)) (erase-buffer))
1581   (unless calculator-electric-mode
1582     (ignore-errors
1583       (while (get-buffer-window calculator-buffer)
1584         (delete-window (get-buffer-window calculator-buffer)))))
1585   (kill-buffer calculator-buffer)
1586   (message "Calculator done.")
1587   (if calculator-electric-mode
1588     (throw 'calculator-done nil) ; will kill the buffer
1589     (setq calculator-buffer nil)))
1590
1591 (defun calculator-save-and-quit ()
1592   "Quit the calculator, saving the result on the `kill-ring'."
1593   (interactive)
1594   (calculator-enter)
1595   (calculator-copy)
1596   (calculator-quit))
1597
1598 (defun calculator-repR (x)
1599   "Repeat the last binary operation with its second argument and X.
1600 To use this, apply a binary operator (evaluate it), then call this."
1601   (if calculator-last-opXY
1602     ;; avoid rebinding calculator-last-opXY
1603     (let ((calculator-last-opXY calculator-last-opXY))
1604       (calculator-funcall
1605        (car calculator-last-opXY) x (nth 2 calculator-last-opXY)))
1606     x))
1607
1608 (defun calculator-repL (x)
1609   "Repeat the last binary operation with its first argument and X.
1610 To use this, apply a binary operator (evaluate it), then call this."
1611   (if calculator-last-opXY
1612     ;; avoid rebinding calculator-last-opXY
1613     (let ((calculator-last-opXY calculator-last-opXY))
1614       (calculator-funcall
1615        (car calculator-last-opXY) (nth 1 calculator-last-opXY) x))
1616     x))
1617
1618 (defun calculator-expt (x y)
1619   "Compute X^Y, dealing with errors appropriately."
1620   (condition-case nil
1621       (expt x y)
1622     (domain-error 0.0e+NaN)
1623     (range-error
1624      (cond ((and (< x 1.0) (> x -1.0))
1625             ;; For small x, the range error comes from large y.
1626             0.0)
1627            ((and (> x 0.0) (< y 0.0))
1628             ;; For large positive x and negative y, the range error
1629             ;; comes from large negative y.
1630             0.0)
1631            ((and (> x 0.0) (> y 0.0))
1632             ;; For large positive x and positive y, the range error
1633             ;; comes from large y.
1634             1.0e+INF)
1635            ;; For the rest, x must be large and negative.
1636            ;; The range errors come from large integer y.
1637            ((< y 0.0)
1638             0.0)
1639            ((eq (logand (truncate y) 1) 1)   ; expansion of cl `oddp'
1640             ;; If y is odd
1641             -1.0e+INF)
1642            (t
1643             ;;
1644             1.0e+INF)))
1645     (error 0.0e+NaN)))
1646
1647 (defun calculator-fact (x)
1648   "Simple factorial of X."
1649   (cond ((>= x 1.0e+INF) x)
1650         ((or (and (floatp x) (isnan x)) (< x 0)) 0.0e+NaN)
1651         ((>= (calculator-expt (/ x 3.0) x) 1.0e+INF) 1.0e+INF)
1652         (t (let ((x (truncate x)) (r 1.0))
1653              (while (> x 0) (setq r (* r x) x (1- x)))
1654              r))))
1655
1656 (defun calculator-truncate (n)
1657   "Truncate N, return 0 in case of overflow."
1658   (condition-case nil (truncate n) (range-error 0)))
1659
1660
1661 (provide 'calculator)
1662
1663 ;;; calculator.el ends here