lisp/calculator.el

   1 ;;; calculator.el --- a [not so] simple calculator for Emacs
   2
   3 ;; Copyright (C) 1998, 2000 by Free Software Foundation, Inc.
   4
   5 ;; Author: Eli Barzilay <eli@barzilay.org>
   6 ;; Keywords: tools, convenience
   7 ;; Time-stamp: <2001-07-15 11:04:11 pavel>
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify it
  12 ;; under the terms of the GNU General Public License as published by the
  13 ;; Free Software Foundation; either version 2, or (at your option) any
  14 ;; later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful, but
  17 ;; WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  19 ;; General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, Boston,
  24 ;; MA 02111-1307, USA.
  25
  26 ;;;=====================================================================
  27 ;;; Commentary:
  28 ;;
  29 ;; A calculator for Emacs.
  30 ;; Why should you reach for your mouse to get xcalc (calc.exe, gcalc or
  31 ;; whatever), when you have Emacs running already?
  32 ;;
  33 ;; If this is not part of your Emacs distribution, then simply bind
  34 ;; `calculator' to a key and make it an autoloaded function, e.g.:
  35 ;;   (autoload 'calculator "calculator"
  36 ;;     "Run the Emacs calculator." t)
  37 ;;   (global-set-key [(control return)] 'calculator)
  38 ;;
  39 ;; Written by Eli Barzilay: Maze is Life!  eli@barzilay.org
  40 ;;                                         http://www.barzilay.org/
  41 ;;
  42 ;; For latest version, check
  43 ;;     http://www.barzilay.org/misc/calculator.el
  44
  45 (eval-and-compile
  46   (if (fboundp 'defgroup) nil
  47     (defmacro defgroup (&rest forms) nil)
  48     (defmacro defcustom (s v d &rest r) (list 'defvar s v d))))
  49
  50 ;;;=====================================================================
  51 ;;; Customization:
  52
  53 (defgroup calculator nil
  54   "Simple Emacs calculator."
  55   :prefix "calculator"
  56   :version "21.1"
  57   :group 'tools
  58   :group 'convenience)
  59
  60 (defcustom calculator-electric-mode nil
  61   "*Run `calculator' electrically, in the echo area.
  62 Electric mode saves some place but changes the way you interact with the
  63 calculator."
  64   :type  'boolean
  65   :group 'calculator)
  66
  67 (defcustom calculator-use-menu t
  68   "*Make `calculator' create a menu.
  69 Note that this requires easymenu.  Must be set before loading."
  70   :type  'boolean
  71   :group 'calculator)
  72
  73 (defcustom calculator-bind-escape nil
  74   "*If non-nil, set escape to exit the calculator."
  75   :type  'boolean
  76   :group 'calculator)
  77
  78 (defcustom calculator-unary-style 'postfix
  79   "*Value is either 'prefix or 'postfix.
  80 This determines the default behavior of unary operators."
  81   :type    '(choice (const prefix) (const postfix))
  82   :group   'calculator)
  83
  84 (defcustom calculator-prompt "Calc=%s> "
  85   "*The prompt used by the Emacs calculator.
  86 It should contain a \"%s\" somewhere that will indicate the i/o radixes,
  87 this string will be a two-character string as described in the
  88 documentation for `calculator-mode'."
  89   :type  'string
  90   :group 'calculator)
  91
  92 (defcustom calculator-number-digits 3
  93   "*The calculator's number of digits used for standard display.
  94 Used by the `calculator-standard-display' function - it will use the
  95 format string \"%.NC\" where this number is N and C is a character given
  96 at runtime."
  97   :type  'integer
  98   :group 'calculator)
  99
 100 (defcustom calculator-remove-zeros t
 101   "*Non-nil value means delete all redundant zero decimal digits.
 102 If this value is not t, and not nil, redundant zeros are removed except
 103 for one and if it is nil, nothing is removed.
 104 Used by the `calculator-remove-zeros' function."
 105   :type  '(choice (const t) (const leave-decimal) (const nil))
 106   :group 'calculator)
 107
 108 (defcustom calculator-displayer '(std ?n)
 109   "*A displayer specification for numerical values.
 110 This is the displayer used to show all numbers in an expression.  Result
 111 values will be displayed according to the first element of
 112 `calculator-displayers'.
 113
 114 The displayer is a symbol, a string or an expression.  A symbol should
 115 be the name of a one-argument function, a string is used with a single
 116 argument and an expression will be evaluated with the variable `num'
 117 bound to whatever should be displayed.  If it is a function symbol, it
 118 should be able to handle special symbol arguments, currently 'left and
 119 'right which will be sent by special keys to modify display parameters
 120 associated with the displayer function (for example to change the number
 121 of digits displayed).
 122
 123 An exception to the above is the case of the list (std C) where C is a
 124 character, in this case the `calculator-standard-displayer' function
 125 will be used with this character for a format string.")
 126
 127 (defcustom calculator-displayers
 128   '(((std ?n) "Standard dislpay, decimal point or scientific")
 129     (calculator-eng-display "Eng display")
 130     ((std ?f) "Standard display, decimal point")
 131     ((std ?e) "Standard dislpay, scientific")
 132     ("%S"     "Emacs printer"))
 133   "*A list of displayers.
 134 Each element is a list of a displayer and a description string.  The
 135 first element is the one which is curently used, this is for the display
 136 of result values not values in expressions.  A displayer specification
 137 is the same as the values that can be stored in `calculator-displayer'.
 138
 139 `calculator-rotate-displayer' rotates this list."
 140   :type  'sexp
 141   :group 'calculator)
 142
 143 (defcustom calculator-paste-decimals t
 144   "*If non-nil, convert pasted integers so they have a decimal point.
 145 This makes it possible to paste big integers since they will be read as
 146 floats, otherwise the Emacs reader will fail on them."
 147   :type  'boolean
 148   :group 'calculator)
 149
 150 (defcustom calculator-2s-complement nil
 151   "*If non-nil, show negative numbers in 2s complement in radix modes.
 152 Otherwise show as a negative number."
 153   :type  'boolean
 154   :group 'calculator)
 155
 156 (defcustom calculator-mode-hook nil
 157   "*List of hook functions for `calculator-mode' to run."
 158   :type  'hook
 159   :group 'calculator)
 160
 161 (defcustom calculator-user-registers nil
 162   "*An association list of user-defined register bindings.
 163 Each element in this list is a list of a character and a number that
 164 will be stored in that character's register.
 165
 166 For example, use this to define the golden ratio number:
 167   (setq calculator-user-registers '((?g .  1.61803398875)))
 168 before you load calculator."
 169   :type  '(repeat (cons character number))
 170   :set   '(lambda (_ val)
 171             (and (boundp 'calculator-registers)
 172                  (setq calculator-registers
 173                        (append val calculator-registers)))
 174             (setq calculator-user-registers val))
 175   :group 'calculator)
 176
 177 (defcustom calculator-user-operators nil
 178   "*A list of additional operators.
 179 This is a list in the same format as specified in the documentation for
 180 `calculator-operators', that you can use to bind additional calculator
 181 operators.  It is probably not a good idea to modify this value with
 182 `customize' since it is too complex...
 183
 184 Examples:
 185
 186 * A very simple one, adding a postfix \"x-to-y\" conversion keys, using
 187   t as a prefix key:
 188
 189   (setq calculator-user-operators
 190         '((\"tf\" cl-to-fr (+ 32 (/ (* X 9) 5)) 1)
 191           (\"tc\" fr-to-cl (/ (* (- X 32) 5) 9) 1)
 192           (\"tp\" kg-to-lb (/ X 0.453592)       1)
 193           (\"tk\" lb-to-kg (* X 0.453592)       1)
 194           (\"tF\" mt-to-ft (/ X 0.3048)         1)
 195           (\"tM\" ft-to-mt (* X 0.3048)         1)))
 196
 197 * Using a function-like form is very simple, X for an argument (Y the
 198   second in case of a binary operator), TX is a truncated version of X
 199   and F does a recursive call, Here is a [very inefficient] Fibonacci
 200   number calculation:
 201
 202   (add-to-list 'calculator-user-operators
 203                '(\"F\" fib (if (<= TX 1)
 204                          1
 205                          (+ (F (- TX 1)) (F (- TX 2)))) 0))
 206
 207   Note that this will be either postfix or prefix, according to
 208   `calculator-unary-style'."
 209   :type  '(repeat (list string symbol sexp integer integer))
 210   :group 'calculator)
 211
 212 ;;;=====================================================================
 213 ;;; Code:
 214
 215 ;;;---------------------------------------------------------------------
 216 ;;; Variables
 217
 218 (defvar calculator-initial-operators
 219   '(;; "+"/"-" have keybindings of themselves, not calculator-ops
 220     ("=" =     identity        1 -1)
 221     (nobind "+" +  +           2  4)
 222     (nobind "-" -  -           2  4)
 223     (nobind "+" +  +          -1  9)
 224     (nobind "-" -  -          -1  9)
 225     ("(" \(    identity       -1 -1)
 226     (")" \)    identity       +1 10)
 227     ;; normal keys
 228     ("|"  or   (logior TX TY)  2  2)
 229     ("#"  xor  (logxor TX TY)  2  2)
 230     ("&"  and  (logand TX TY)  2  3)
 231     ("*"  *    *               2  5)
 232     ("/"  /    /               2  5)
 233     ("\\" div  (/ TX TY)       2  5)
 234     ("%"  rem  (% TX TY)       2  5)
 235     ("L"  log  log             2  6)
 236     ("S"  sin  (sin DX)        x  6)
 237     ("C"  cos  (cos DX)        x  6)
 238     ("T"  tan  (tan DX)        x  6)
 239     ("IS" asin (D (asin X))    x  6)
 240     ("IC" acos (D (acos X))    x  6)
 241     ("IT" atan (D (atan X))    x  6)
 242     ("Q"  sqrt sqrt            x  7)
 243     ("^"  ^    expt            2  7)
 244     ("!"  !    calculator-fact x  7)
 245     (";"  1/   (/ 1 X)         1  7)
 246     ("_"  -    -               1  8)
 247     ("~"  ~    (lognot TX)     x  8)
 248     (">"  repR calculator-repR 1  8)
 249     ("<"  repL calculator-repL 1  8)
 250     ("v"  avg  (/ (apply '+ L) (length L)) 0 8)
 251     ("l"  tot  (apply '+ L)    0 8)
 252     )
 253   "A list of initial operators.
 254 This is a list in the same format as `calculator-operators'.  Whenever
 255 `calculator' starts, it looks at the value of this variable, and if it
 256 is not empty, its contents is prepended to `calculator-operators' and
 257 the appropriate key bindings are made.
 258
 259 This variable is then reset to nil.  Don't use this if you want to add
 260 user-defined operators, use `calculator-user-operators' instead.")
 261
 262 (defvar calculator-operators nil
 263   "The calculator operators, each a list with:
 264
 265 1. The key that is bound to for this operation (usually a string);
 266
 267 2. The displayed symbol for this function;
 268
 269 3. The function symbol, or a form that uses the variables `X' and `Y',
 270    (if it is a binary operator), `TX' and `TY' (truncated integer
 271    versions), `DX' (converted to radians if degrees mode is on), `D'
 272    (function for converting radians to degrees if deg mode is on), `L'
 273    (list of saved values), `F' (function for recursive iteration calls)
 274    and evaluates to the function value - these variables are capital;
 275
 276 4. The function's arity, optional, one of: 2 => binary, -1 => prefix
 277    unary, +1 => postfix unary, 0 => a 0-arg operator func, non-number =>
 278    postfix/prefix as determined by `calculator-unary-style' (the
 279    default);
 280
 281 5. The function's precedence - should be in the range of 1 (lowest) to
 282    9 (highest) (optional, defaults to 1);
 283
 284 It it possible have a unary prefix version of a binary operator if it
 285 comes later in this list.  If the list begins with the symbol 'nobind,
 286 then no key binding will take place - this is only useful for predefined
 287 keys.
 288
 289 Use `calculator-user-operators' to add operators to this list, see its
 290 documentation for an example.")
 291
 292 (defvar calculator-stack nil
 293   "Stack contents - operations and operands.")
 294
 295 (defvar calculator-curnum nil
 296   "Current number being entered (as a string).")
 297
 298 (defvar calculator-stack-display nil
 299   "Cons of the stack and its string representation.")
 300
 301 (defvar calculator-char-radix
 302   '((?D . nil) (?B . bin) (?O . oct) (?H . hex) (?X . hex))
 303   "A table to convert input characters to corresponding radix symbols.")
 304
 305 (defvar calculator-output-radix nil
 306   "The mode for display, one of: nil (decimal), 'bin, 'oct or 'hex.")
 307
 308 (defvar calculator-input-radix nil
 309   "The mode for input, one of: nil (decimal), 'bin, 'oct or 'hex.")
 310
 311 (defvar calculator-deg nil
 312   "Non-nil if trig functions operate on degrees instead of radians.")
 313
 314 (defvar calculator-saved-list nil
 315   "A list of saved values collected.")
 316
 317 (defvar calculator-saved-ptr 0
 318   "The pointer to the current saved number.")
 319
 320 (defvar calculator-add-saved nil
 321   "Bound to t when a value should be added to the saved-list.")
 322
 323 (defvar calculator-display-fragile nil
 324   "When non-nil, we see something that the next digit should replace.")
 325
 326 (defvar calculator-buffer nil
 327   "The current calculator buffer.")
 328
 329 (defvar calculator-eng-extra nil
 330   "Internal value used by `calculator-eng-display'.")
 331
 332 (defvar calculator-eng-tmp-show nil
 333   "Internal value used by `calculator-eng-display'.")
 334
 335 (defvar calculator-last-opXY nil
 336   "The last binary operation and its arguments.
 337 Used for repeating operations in calculator-repR/L.")
 338
 339 (defvar calculator-registers ; use user-bindings first
 340   (append calculator-user-registers (list (cons ?e e) (cons ?p pi)))
 341   "The association list of calculator register values.")
 342
 343 (defvar calculator-saved-global-map nil
 344   "Saved global key map.")
 345
 346 (defvar calculator-restart-other-mode nil
 347   "Used to hack restarting with the electric mode changed.")
 348
 349 ;;;---------------------------------------------------------------------
 350 ;;; Key bindings
 351
 352 (defvar calculator-mode-map nil
 353   "The calculator key map.")
 354
 355 (or calculator-mode-map
 356   (let ((map (make-sparse-keymap)))
 357     (suppress-keymap map t)
 358     (define-key map "i" nil)
 359     (define-key map "o" nil)
 360     (let ((p
 361            '((calculator-open-paren  "[")
 362              (calculator-close-paren "]")
 363              (calculator-op-or-exp   "+" "-" [kp-add] [kp-subtract])
 364              (calculator-digit       "0" "1" "2" "3" "4" "5" "6" "7" "8"
 365                                      "9" "a" "b" "c" "d" "f"
 366                                      [kp-0] [kp-1] [kp-2] [kp-3] [kp-4]
 367                                      [kp-5] [kp-6] [kp-7] [kp-8] [kp-9])
 368              (calculator-op          [kp-divide] [kp-multiply])
 369              (calculator-decimal     "." [kp-decimal])
 370              (calculator-exp         "e")
 371              (calculator-dec/deg-mode "D")
 372              (calculator-set-register "s")
 373              (calculator-get-register "g")
 374              (calculator-radix-mode        "H" "X" "O" "B")
 375              (calculator-radix-input-mode  "id" "ih" "ix" "io" "ib"
 376                                            "iD" "iH" "iX" "iO" "iB")
 377              (calculator-radix-output-mode "od" "oh" "ox" "oo" "ob"
 378                                            "oD" "oH" "oX" "oO" "oB")
 379              (calculator-rotate-displayer      "'")
 380              (calculator-rotate-displayer-back "\"")
 381              (calculator-displayer-left        "{")
 382              (calculator-displayer-right       "}")
 383              (calculator-saved-up      [up] [?\C-p])
 384              (calculator-saved-down    [down] [?\C-n])
 385              (calculator-quit          "q" [?\C-g])
 386              (calculator-enter         [enter] [linefeed] [kp-enter]
 387                                        [return] [?\r] [?\n])
 388              (calculator-save-on-list  " " [space])
 389              (calculator-clear-saved   [?\C-c] [(control delete)])
 390              (calculator-save-and-quit [(control return)]
 391                                        [(control kp-enter)])
 392              (calculator-paste         [insert] [(shift insert)]
 393                                        [mouse-2])
 394              (calculator-clear         [delete] [?\C-?] [?\C-d])
 395              (calculator-help          [?h] [??] [f1] [help])
 396              (calculator-copy          [(control insert)])
 397              (calculator-backspace     [backspace])
 398              )))
 399       (while p
 400         ;; reverse the keys so first defs come last - makes the more
 401         ;; sensible bindings visible in the menu
 402         (let ((func (car (car p))) (keys (reverse (cdr (car p)))))
 403           (while keys
 404             (define-key map (car keys) func)
 405             (setq keys (cdr keys))))
 406         (setq p (cdr p))))
 407     (if calculator-bind-escape
 408       (progn (define-key map [?\e] 'calculator-quit)
 409              (define-key map [escape] 'calculator-quit))
 410       (define-key map [?\e ?\e ?\e] 'calculator-quit))
 411     ;; make C-h work in text-mode
 412     (or window-system (define-key map [?\C-h] 'calculator-backspace))
 413     ;; set up a menu
 414     (if (and calculator-use-menu (not (boundp 'calculator-menu)))
 415       (let ((radix-selectors
 416              (mapcar (lambda (x)
 417                        `([,(nth 0 x)
 418                           (calculator-radix-mode ,(nth 2 x))
 419                           :style radio
 420                           :keys ,(nth 2 x)
 421                           :selected
 422                           (and
 423                            (eq calculator-input-radix ',(nth 1 x))
 424                            (eq calculator-output-radix ',(nth 1 x)))]
 425                          [,(concat (nth 0 x) " Input")
 426                           (calculator-radix-input-mode ,(nth 2 x))
 427                           :keys ,(concat "i" (downcase (nth 2 x)))
 428                           :style radio
 429                           :selected
 430                           (eq calculator-input-radix ',(nth 1 x))]
 431                          [,(concat (nth 0 x) " Output")
 432                           (calculator-radix-output-mode ,(nth 2 x))
 433                           :keys ,(concat "o" (downcase (nth 2 x)))
 434                           :style radio
 435                           :selected
 436                           (eq calculator-output-radix ',(nth 1 x))]))
 437                      '(("Decimal"     nil "D")
 438                        ("Binary"      bin "B")
 439                        ("Octal"       oct "O")
 440                        ("Hexadecimal" hex "H"))))
 441             (op '(lambda (name key)
 442                         `[,name (calculator-op ,key) :keys ,key])))
 443         (easy-menu-define
 444          calculator-menu map "Calculator menu."
 445          `("Calculator"
 446            ["Help"
 447             (let ((last-command 'calculator-help)) (calculator-help))
 448             :keys "?"]
 449            "---"
 450            ["Copy"  calculator-copy]
 451            ["Paste" calculator-paste]
 452            "---"
 453            ["Electric mode"
 454             (progn (calculator-quit)
 455                    (setq calculator-restart-other-mode t)
 456                    (run-with-timer 0.1 nil '(lambda () (message nil)))
 457                    ;; the message from the menu will be visible,
 458                    ;; couldn't make it go away...
 459                    (calculator))
 460             :active (not calculator-electric-mode)]
 461            ["Normal mode"
 462             (progn (setq calculator-restart-other-mode t)
 463                    (calculator-quit))
 464             :active calculator-electric-mode]
 465            "---"
 466            ("Functions"
 467             ,(funcall op "Repeat-right" ">")
 468             ,(funcall op "Repeat-left"  "<")
 469             "------General------"
 470             ,(funcall op "Reciprocal"   ";")
 471             ,(funcall op "Log"          "L")
 472             ,(funcall op "Square-root"  "Q")
 473             ,(funcall op "Factorial"    "!")
 474             "------Trigonometric------"
 475             ,(funcall op "Sinus"        "S")
 476             ,(funcall op "Cosine"       "C")
 477             ,(funcall op "Tangent"      "T")
 478             ,(funcall op "Inv-Sinus"    "IS")
 479             ,(funcall op "Inv-Cosine"   "IC")
 480             ,(funcall op "Inv-Tangent"  "IT")
 481             "------Bitwise------"
 482             ,(funcall op "Or"           "|")
 483             ,(funcall op "Xor"          "#")
 484             ,(funcall op "And"          "&")
 485             ,(funcall op "Not"          "~"))
 486            ("Saved List"
 487             ["Eval+Save"      calculator-save-on-list]
 488             ["Prev number"    calculator-saved-up]
 489             ["Next number"    calculator-saved-down]
 490             ["Delete current" calculator-clear
 491              :active (and calculator-display-fragile
 492                           calculator-saved-list
 493                           (= (car calculator-stack)
 494                              (nth calculator-saved-ptr
 495                                   calculator-saved-list)))]
 496             ["Delete all" calculator-clear-saved]
 497             "---"
 498             ,(funcall op "List-total"   "l")
 499             ,(funcall op "List-average" "v"))
 500            ("Registers"
 501             ["Get register" calculator-get-register]
 502             ["Set register" calculator-set-register])
 503            ("Modes"
 504             ["Radians"
 505              (progn
 506                (and (or calculator-input-radix calculator-output-radix)
 507                     (calculator-radix-mode "D"))
 508                (and calculator-deg (calculator-dec/deg-mode)))
 509              :keys "D"
 510              :style radio
 511              :selected (not (or calculator-input-radix
 512                                 calculator-output-radix
 513                                 calculator-deg))]
 514             ["Degrees"
 515              (progn
 516                (and (or calculator-input-radix calculator-output-radix)
 517                     (calculator-radix-mode "D"))
 518                (or calculator-deg (calculator-dec/deg-mode)))
 519              :keys "D"
 520              :style radio
 521              :selected (and calculator-deg
 522                             (not (or calculator-input-radix
 523                                      calculator-output-radix)))]
 524             "---"
 525             ,@(mapcar 'car radix-selectors)
 526             ("Seperate I/O"
 527              ,@(mapcar (lambda (x) (nth 1 x)) radix-selectors)
 528              "---"
 529              ,@(mapcar (lambda (x) (nth 2 x)) radix-selectors)))
 530            ("Decimal Dislpay"
 531             ,@(mapcar (lambda (d)
 532                         (vector (cadr d)
 533                                 ;; Note: inserts actual object here
 534                                 `(calculator-rotate-displayer ',d)))
 535                       calculator-displayers)
 536             "---"
 537             ["Change Display Left"  calculator-displayer-left]
 538             ["Change Display Right" calculator-displayer-right])
 539            "---"
 540            ["Copy+Quit" calculator-save-and-quit]
 541            ["Quit"      calculator-quit]))))
 542     (setq calculator-mode-map map)))
 543
 544 ;;;---------------------------------------------------------------------
 545 ;;; Startup and mode stuff
 546
 547 (defun calculator-mode ()
 548   ;; this help is also used as the major help screen
 549   "A [not so] simple calculator for Emacs.
 550
 551 This calculator is used in the same way as other popular calculators
 552 like xcalc or calc.exe - but using an Emacs interface.
 553
 554 Expressions are entered using normal infix notation, parens are used as
 555 normal.  Unary functions are usually postfix, but some depends on the
 556 value of `calculator-unary-style' (if the style for an operator below is
 557 specified, then it is fixed, otherwise it depends on this variable).
 558 `+' and `-' can be used as either binary operators or prefix unary
 559 operators.  Numbers can be entered with exponential notation using `e',
 560 except when using a non-decimal radix mode for input (in this case `e'
 561 will be the hexadecimal digit).
 562
 563 Here are the editing keys:
 564 * `RET' `='      evaluate the current expression
 565 * `C-insert'     copy the whole current expression to the `kill-ring'
 566 * `C-return'     evaluate, save result the `kill-ring' and exit
 567 * `insert'       paste a number if the one was copied (normally)
 568 * `delete' `C-d' clear last argument or whole expression (hit twice)
 569 * `backspace'    delete a digit or a previous expression element
 570 * `h' `?'        pop-up a quick reference help
 571 * `ESC' `q'      exit (`ESC' can be used if `calculator-bind-escape' is
 572                  non-nil, otherwise use three consecutive `ESC's)
 573
 574 These operators are pre-defined:
 575 * `+' `-' `*' `/' the common binary operators
 576 * `\\' `%'         integer division and reminder
 577 * `_' `;'         postfix unary negation and reciprocal
 578 * `^' `L'         binary operators for x^y and log(x) in base y
 579 * `Q' `!'         unary square root and factorial
 580 * `S' `C' `T'     unary trigonometric operators - sin, cos and tan
 581 * `|' `#' `&' `~' bitwise operators - or, xor, and, not
 582
 583 The trigonometric functions can be inverted if prefixed with an `I', see
 584 below for the way to use degrees instead of the default radians.
 585
 586 Two special postfix unary operators are `>' and `<': whenever a binary
 587 operator is performed, it is remembered along with its arguments; then
 588 `>' (`<') will apply the same operator with the same right (left)
 589 argument.
 590
 591 hex/oct/bin modes can be set for input and for display separately.
 592 Another toggle-able mode is for using degrees instead of radians for
 593 trigonometric functions.
 594 The keys to switch modes are (`X' is shortcut for `H'):
 595 * `D'             switch to all-decimal mode, or toggle degrees/radians
 596 * `B' `O' `H' `X' binary/octal/hexadecimal modes for input & display
 597 * `i' `o'         followed by one of `D' `B' `O' `H' `X' (case
 598                   insensitive) sets only the input or display radix mode
 599 The prompt indicates the current modes:
 600 * \"D=\": degrees mode;
 601 * \"?=\": (? is B/O/H) this is the radix for both input and output;
 602 * \"=?\": (? is B/O/H) the display radix (when input is decimal);
 603 * \"??\": (? is D/B/O/H) 1st char for input radix, 2nd for display.
 604
 605 Also, the quote character can be used to switch display modes for
 606 decimal numbers (double-quote rotates back), and the two brace
 607 characters (\"{\" and \"}\" change display parameters that these
 608 displayers use (if they handle such).
 609
 610 Values can be saved for future reference in either a list of saved
 611 values, or in registers.
 612
 613 The list of saved values is useful for statistics operations on some
 614 collected data.  It is possible to navigate in this list, and if the
 615 value shown is the current one on the list, an indication is displayed
 616 as \"[N]\" if this is the last number and there are N numbers, or
 617 \"[M/N]\" if the M-th value is shown.
 618 * `SPC'            evaluate the current value as usual, but also adds
 619                    the result to the list of saved values
 620 * `l' `v'          computes total / average of saved values
 621 * `up' `C-p'       browse to the previous value in the list
 622 * `down' `C-n'     browse to the next value in the list
 623 * `delete' `C-d'   remove current value from the list (if it is on it)
 624 * `C-delete' `C-c' delete the whole list
 625
 626 Registers are variable-like place-holders for values:
 627 * `s' followed by a character attach the current value to that character
 628 * `g' followed by a character fetches the attached value
 629
 630 There are many variables that can be used to customize the calculator.
 631 Some interesting customization variables are:
 632 * `calculator-electric-mode'  use only the echo-area electrically.
 633 * `calculator-unary-style'    set most unary ops to pre/postfix style.
 634 * `calculator-user-registers' to define user-preset registers.
 635 * `calculator-user-operators' to add user-defined operators.
 636 See the documentation for these variables, and \"calculator.el\" for
 637 more information.
 638
 639 \\{calculator-mode-map}"
 640   (interactive)
 641   (kill-all-local-variables)
 642   (setq major-mode 'calculator-mode)
 643   (setq mode-name "Calculator")
 644   (use-local-map calculator-mode-map)
 645   (run-hooks 'calculator-mode-hook))
 646
 647 (eval-when-compile (require 'electric) (require 'ehelp))
 648
 649 ;;;###autoload
 650 (defun calculator ()
 651   "Run the Emacs calculator.
 652 See the documentation for `calculator-mode' for more information."
 653   (interactive)
 654   (if calculator-restart-other-mode
 655     (setq calculator-electric-mode (not calculator-electric-mode)))
 656   (if calculator-initial-operators
 657     (progn (calculator-add-operators calculator-initial-operators)
 658            (setq calculator-initial-operators nil)
 659            ;; don't change this since it is a customization variable,
 660            ;; its set function will add any new operators
 661            (calculator-add-operators calculator-user-operators)))
 662   (if calculator-electric-mode
 663     (save-window-excursion
 664       (progn (require 'electric) (message nil)) ; hide load message
 665       (let (old-g-map old-l-map (echo-keystrokes 0)
 666             (garbage-collection-messages nil)) ; no gc msg when electric
 667         ;; strange behavior in FSF: doesn't always select correct
 668         ;; minibuffer.  I have no idea how to fix this
 669         (setq calculator-buffer (window-buffer (minibuffer-window)))
 670         (select-window (minibuffer-window))
 671         (calculator-reset)
 672         (calculator-update-display)
 673         (setq old-l-map (current-local-map))
 674         (setq old-g-map (current-global-map))
 675         (setq calculator-saved-global-map (current-global-map))
 676         (use-local-map nil)
 677         (use-global-map calculator-mode-map)
 678         (unwind-protect
 679             (catch 'calculator-done
 680               (Electric-command-loop
 681                'calculator-done
 682                ;; can't use 'noprompt, bug in electric.el
 683                '(lambda () 'noprompt)
 684                nil
 685                (lambda (x y) (calculator-update-display))))
 686           (and calculator-buffer
 687                (catch 'calculator-done (calculator-quit)))
 688           (use-local-map old-l-map)
 689           (use-global-map old-g-map))))
 690     (progn
 691       (setq calculator-buffer
 692             (or (and (bufferp calculator-buffer)
 693                      (buffer-live-p calculator-buffer)
 694                      calculator-buffer)
 695                 (if calculator-electric-mode
 696                   (get-buffer-create "*calculator*")
 697                   (let ((split-window-keep-point nil)
 698                         (window-min-height 2))
 699                     (select-window
 700                      ;; maybe leave two lines for our window because
 701                      ;; of the normal `raised' modeline in Emacs 21
 702                      (split-window-vertically
 703                       (- (window-height)
 704                          (if (and
 705                               (fboundp 'face-attr-construct)
 706                               (plist-get (face-attr-construct 'modeline)
 707                                          :box))
 708                            3
 709                            2))))
 710                     (switch-to-buffer
 711                      (get-buffer-create "*calculator*"))))))
 712       (set-buffer calculator-buffer)
 713       (calculator-mode)
 714       (setq buffer-read-only t)
 715       (calculator-reset)
 716       (message "Hit `?' For a quick help screen.")))
 717   (if (and calculator-restart-other-mode calculator-electric-mode)
 718     (calculator)))
 719
 720 ;;;---------------------------------------------------------------------
 721 ;;; Operatos
 722
 723 (defun calculator-op-arity (op)
 724   "Return OP's arity, 2, +1 or -1."
 725   (let ((arity (or (nth 3 op) 'x)))
 726     (if (numberp arity)
 727       arity
 728       (if (eq calculator-unary-style 'postfix) +1 -1))))
 729
 730 (defun calculator-op-prec (op)
 731   "Return OP's precedence for reducing when inserting into the stack.
 732 Defaults to 1."
 733   (or (nth 4 op) 1))
 734
 735 (defun calculator-add-operators (more-ops)
 736   "This function handles operator addition.
 737 Adds MORE-OPS to `calculator-operator', called initially to handle
 738 `calculator-initial-operators' and `calculator-user-operators'."
 739   (let ((added-ops nil))
 740     (while more-ops
 741       (or (eq (car (car more-ops)) 'nobind)
 742           (let ((i -1) (key (car (car more-ops))))
 743             ;; make sure the key is undefined, so it's easy to define
 744             ;; prefix keys
 745             (while (< (setq i (1+ i)) (length key))
 746               (or (keymapp
 747                    (lookup-key calculator-mode-map
 748                                (substring key 0 (1+ i))))
 749                   (progn
 750                     (define-key
 751                       calculator-mode-map (substring key 0 (1+ i)) nil)
 752                     (setq i (length key)))))
 753             (define-key calculator-mode-map key 'calculator-op)))
 754       (setq added-ops (cons (if (eq (car (car more-ops)) 'nobind)
 755                               (cdr (car more-ops))
 756                               (car more-ops))
 757                             added-ops))
 758       (setq more-ops (cdr more-ops)))
 759     ;; added-ops come first, but in correct order
 760     (setq calculator-operators
 761           (append (nreverse added-ops) calculator-operators))))
 762
 763 ;;;---------------------------------------------------------------------
 764 ;;; Display stuff
 765
 766 (defun calculator-reset ()
 767   "Reset calculator variables."
 768   (or calculator-restart-other-mode
 769       (setq calculator-stack           nil
 770             calculator-curnum          nil
 771             calculator-stack-display   nil
 772             calculator-display-fragile nil))
 773   (setq calculator-restart-other-mode nil)
 774   (calculator-update-display))
 775
 776 (defun calculator-get-prompt ()
 777   "Return a string to display.
 778 The string is set not to exceed the screen width."
 779   (let* ((calculator-prompt
 780           (format calculator-prompt
 781                   (cond
 782                     ((or calculator-output-radix calculator-input-radix)
 783                      (if (eq calculator-output-radix
 784                              calculator-input-radix)
 785                        (concat
 786                         (char-to-string
 787                          (car (rassq calculator-output-radix
 788                                      calculator-char-radix)))
 789                         "=")
 790                        (concat
 791                         (if calculator-input-radix
 792                           (char-to-string
 793                            (car (rassq calculator-input-radix
 794                                        calculator-char-radix)))
 795                           "=")
 796                         (char-to-string
 797                          (car (rassq calculator-output-radix
 798                                      calculator-char-radix))))))
 799                     (calculator-deg "D=")
 800                     (t "=="))))
 801          (prompt
 802           (concat calculator-prompt
 803                   (cdr calculator-stack-display)
 804                   (cond (calculator-curnum
 805                          ;; number being typed
 806                          (concat calculator-curnum "_"))
 807                         ((and (= 1 (length calculator-stack))
 808                               calculator-display-fragile)
 809                          ;; only the result is shown, next number will
 810                          ;; restart
 811                          nil)
 812                         (t
 813                          ;; waiting for a number or an operator
 814                          "?"))))
 815          (trim (- (length prompt) (1- (window-width)))))
 816     (if (<= trim 0)
 817       prompt
 818       (concat calculator-prompt
 819               (substring prompt (+ trim (length calculator-prompt)))))))
 820
 821 (defun calculator-curnum-value ()
 822   "Get the numeric value of the displayed number string as a float."
 823   (if calculator-input-radix
 824     (let ((radix
 825            (cdr (assq calculator-input-radix
 826                       '((bin . 2) (oct . 8) (hex . 16)))))
 827           (i -1) (value 0))
 828       ;; assume valid input (upcased & characters in range)
 829       (while (< (setq i (1+ i)) (length calculator-curnum))
 830         (setq value
 831               (+ (let ((ch (aref calculator-curnum i)))
 832                    (- ch (if (<= ch ?9) ?0 (- ?A 10))))
 833                  (* radix value))))
 834       value)
 835     (car
 836      (read-from-string
 837       (cond
 838         ((equal "." calculator-curnum)
 839          "0.0")
 840         ((string-match "[eE][+-]?$" calculator-curnum)
 841          (concat calculator-curnum "0"))
 842         ((string-match "\\.[0-9]\\|[eE]" calculator-curnum)
 843          calculator-curnum)
 844         ((string-match "\\." calculator-curnum)
 845          ;; do this because Emacs reads "23." as an integer
 846          (concat calculator-curnum "0"))
 847         ((stringp calculator-curnum)
 848          (concat calculator-curnum ".0"))
 849         (t "0.0"))))))
 850
 851 (defun calculator-rotate-displayer (&optional new-disp)
 852   "Switch to the next displayer on the `calculator-displayers' list.
 853 Can be called with an optional argument NEW-DISP to force rotation to
 854 that argument."
 855   (interactive)
 856   (setq calculator-displayers
 857         (if (and new-disp (memq new-disp calculator-displayers))
 858           (let ((tmp nil))
 859             (while (not (eq (car calculator-displayers) new-disp))
 860               (setq tmp (cons (car calculator-displayers) tmp))
 861               (setq calculator-displayers (cdr calculator-displayers)))
 862             (setq calculator-displayers
 863                   (nconc calculator-displayers (nreverse tmp))))
 864           (nconc (cdr calculator-displayers)
 865                  (list (car calculator-displayers)))))
 866   (message "Using %s." (cadr (car calculator-displayers)))
 867   (if calculator-electric-mode
 868     (progn (sit-for 1) (message nil)))
 869   (calculator-enter))
 870
 871 (defun calculator-rotate-displayer-back ()
 872   "Like `calculator-rotate-displayer', but rotates modes back."
 873   (interactive)
 874   (calculator-rotate-displayer (car (last calculator-displayers))))
 875
 876 (defun calculator-displayer-left ()
 877   "Send the current displayer function a 'left argument.
 878 This is used to modify display arguments (if the current displayer
 879 function supports this)."
 880   (interactive)
 881   (and (car calculator-displayers)
 882        (let ((disp (caar calculator-displayers)))
 883          (cond ((symbolp disp) (funcall disp 'left))
 884                ((and (consp disp) (eq 'std (car disp)))
 885                 (calculator-standard-displayer 'left (cadr disp)))))))
 886
 887 (defun calculator-displayer-right ()
 888   "Send the current displayer function a 'right argument.
 889 This is used to modify display arguments (if the current displayer
 890 function supports this)."
 891   (interactive)
 892   (and (car calculator-displayers)
 893        (let ((disp (caar calculator-displayers)))
 894          (cond ((symbolp disp) (funcall disp 'right))
 895                ((and (consp disp) (eq 'std (car disp)))
 896                 (calculator-standard-displayer 'right (cadr disp)))))))
 897
 898 (defun calculator-remove-zeros (numstr)
 899   "Get a number string NUMSTR and remove unnecessary zeroes.
 900 the behavior of this function is controlled by
 901 `calculator-remove-zeros'."
 902   (cond ((and (eq calculator-remove-zeros t)
 903               (string-match "\\.0+\\([eE][+-]?[0-9]*\\)?$" numstr))
 904          ;; remove all redundant zeros leaving an integer
 905          (if (match-beginning 1)
 906            (concat (substring numstr 0 (match-beginning 0))
 907                    (match-string 1 numstr))
 908            (substring numstr 0 (match-beginning 0))))
 909         ((and calculator-remove-zeros
 910               (string-match
 911                "\\..\\([0-9]*[1-9]\\)?\\(0+\\)\\([eE][+-]?[0-9]*\\)?$"
 912                numstr))
 913          ;; remove zeros, except for first after the "."
 914          (if (match-beginning 3)
 915            (concat (substring numstr 0 (match-beginning 2))
 916                    (match-string 3 numstr))
 917            (substring numstr 0 (match-beginning 2))))
 918         (t numstr)))
 919
 920 (defun calculator-standard-displayer (num char)
 921   "Standard display function, used to display NUM.
 922 Its behavior is determined by `calculator-number-digits' and the given
 923 CHAR argument (both will be used to compose a format string).  If the
 924 char is \"n\" then this function will choose one between %f or %e, this
 925 is a work around %g jumping to exponential notation too fast.
 926
 927 The special 'left and 'right symbols will make it change the current
 928 number of digits displayed (`calculator-number-digits').
 929
 930 It will also remove redundant zeros from the result."
 931   (if (symbolp num)
 932     (cond ((eq num 'left)
 933            (and (> calculator-number-digits 0)
 934                 (setq calculator-number-digits
 935                       (1- calculator-number-digits))
 936                 (calculator-enter)))
 937           ((eq num 'right)
 938            (setq calculator-number-digits
 939                  (1+ calculator-number-digits))
 940            (calculator-enter)))
 941     (let ((str (format
 942                 (concat "%."
 943                         (number-to-string calculator-number-digits)
 944                         (if (eq char ?n)
 945                           (let ((n (abs num)))
 946                             (if (or (< n 0.001) (> n 1e8)) "e" "f"))
 947                           (string char)))
 948                 num)))
 949       (calculator-remove-zeros str))))
 950
 951 (defun calculator-eng-display (num)
 952   "Display NUM in engineering notation.
 953 The number of decimal digits used is controlled by
 954 `calculator-number-digits', so to change it at runtime you have to use
 955 the 'left or 'right when one of the standard modes is used."
 956   (if (symbolp num)
 957     (cond ((eq num 'left)
 958            (setq calculator-eng-extra
 959                  (if calculator-eng-extra
 960                    (1+ calculator-eng-extra)
 961                    1))
 962            (let ((calculator-eng-tmp-show t)) (calculator-enter)))
 963           ((eq num 'right)
 964            (setq calculator-eng-extra
 965                  (if calculator-eng-extra
 966                    (1- calculator-eng-extra)
 967                    -1))
 968            (let ((calculator-eng-tmp-show t)) (calculator-enter))))
 969     (let ((exp 0))
 970       (and (not (= 0 num))
 971            (progn
 972              (while (< (abs num) 1.0)
 973                (setq num (* num 1000.0)) (setq exp (- exp 3)))
 974              (while (> (abs num) 999.0)
 975                (setq num (/ num 1000.0)) (setq exp (+ exp 3)))
 976              (and calculator-eng-tmp-show
 977                   (not (= 0 calculator-eng-extra))
 978                   (let ((i calculator-eng-extra))
 979                     (while (> i 0)
 980                       (setq num (* num 1000.0)) (setq exp (- exp 3))
 981                       (setq i (1- i)))
 982                     (while (< i 0)
 983                       (setq num (/ num 1000.0)) (setq exp (+ exp 3))
 984                       (setq i (1+ i)))))))
 985       (or calculator-eng-tmp-show (setq calculator-eng-extra nil))
 986       (let ((str (format (concat "%." calculator-number-digits "f")
 987                          num)))
 988         (concat (let ((calculator-remove-zeros
 989                        ;; make sure we don't leave integers
 990                        (and calculator-remove-zeros 'x)))
 991                   (calculator-remove-zeros str))
 992                 "e" (number-to-string exp))))))
 993
 994 (defun calculator-num-to-string (num)
 995   "Convert NUM to a displayable string."
 996   (cond
 997     ((and (numberp num) calculator-output-radix)
 998      ;; print with radix - for binary I convert the octal number
 999      (let ((str (format (if (eq calculator-output-radix 'hex) "%x" "%o")
1000                         (calculator-truncate
1001                          (if calculator-2s-complement num (abs num))))))
1002        (if (eq calculator-output-radix 'bin)
1003          (let ((i -1) (s ""))
1004            (while (< (setq i (1+ i)) (length str))
1005              (setq s
1006                    (concat s
1007                            (cdr (assq (aref str i)
1008                                       '((?0 . "000") (?1 . "001")
1009                                         (?2 . "010") (?3 . "011")
1010                                         (?4 . "100") (?5 . "101")
1011                                         (?6 . "110") (?7 . "111")))))))
1012            (string-match "^0*\\(.+\\)" s)
1013            (setq str (match-string 1 s))))
1014        (upcase
1015         (if (and (not calculator-2s-complement) (< num 0))
1016           (concat "-" str)
1017           str))))
1018     ((and (numberp num) (car calculator-displayers))
1019      (let ((disp (if (= 1 (length calculator-stack))
1020                    ;; customizable display for a single value
1021                    (caar calculator-displayers)
1022                    calculator-displayer)))
1023        (cond ((stringp disp) (format disp num))
1024              ((symbolp disp) (funcall disp num))
1025              ((and (consp disp)
1026                    (eq 'std (car disp)))
1027                              (calculator-standard-displayer
1028                               num (cadr disp)))
1029              ((listp disp)   (eval disp))
1030              (t              (prin1-to-string num t)))))
1031     ;; operators are printed here
1032     (t (prin1-to-string (nth 1 num) t))))
1033
1034 (defun calculator-update-display (&optional force)
1035   "Update the display.
1036 If optional argument FORCE is non-nil, don't use the cached string."
1037   (set-buffer calculator-buffer)
1038   ;; update calculator-stack-display
1039   (if (or force
1040           (not (eq (car calculator-stack-display) calculator-stack)))
1041     (setq calculator-stack-display
1042           (cons calculator-stack
1043                 (if calculator-stack
1044                   (concat
1045                    (mapconcat 'calculator-num-to-string
1046                               (reverse calculator-stack)
1047                               " ")
1048                    " "
1049                    (and calculator-display-fragile
1050                         calculator-saved-list
1051                         (= (car calculator-stack)
1052                            (nth calculator-saved-ptr
1053                                 calculator-saved-list))
1054                         (if (= 0 calculator-saved-ptr)
1055                           (format "[%s]" (length calculator-saved-list))
1056                           (format "[%s/%s]"
1057                                   (- (length calculator-saved-list)
1058                                      calculator-saved-ptr)
1059                                   (length calculator-saved-list)))))
1060                   ""))))
1061   (let ((inhibit-read-only t))
1062     (erase-buffer)
1063     (insert (calculator-get-prompt)))
1064   (set-buffer-modified-p nil)
1065   (if calculator-display-fragile
1066     (goto-char (1+ (length calculator-prompt)))
1067     (goto-char (1- (point)))))
1068
1069 ;;;---------------------------------------------------------------------
1070 ;;; Stack computations
1071
1072 (defun calculator-reduce-stack (prec)
1073   "Reduce the stack using top operator.
1074 PREC is a precedence - reduce everything with higher precedence."
1075   (while
1076       (cond
1077         ((and (cdr (cdr calculator-stack))         ; have three values
1078               (consp   (nth 0 calculator-stack))   ; two operators & num
1079               (numberp (nth 1 calculator-stack))
1080               (consp   (nth 2 calculator-stack))
1081               (eq '\) (nth 1 (nth 0 calculator-stack)))
1082               (eq '\( (nth 1 (nth 2 calculator-stack))))
1083          ;; reduce "... ( x )" --> "... x"
1084          (setq calculator-stack
1085                (cons (nth 1 calculator-stack)
1086                      (nthcdr 3 calculator-stack)))
1087          ;; another iteration
1088          t)
1089         ((and (cdr (cdr calculator-stack))         ; have three values
1090               (numberp (nth 0 calculator-stack))   ; two nums & operator
1091               (consp   (nth 1 calculator-stack))
1092               (numberp (nth 2 calculator-stack))
1093               (= 2 (calculator-op-arity            ; binary operator
1094                     (nth 1 calculator-stack)))
1095               (<= prec                             ; with higher prec.
1096                   (calculator-op-prec (nth 1 calculator-stack))))
1097          ;; reduce "... x op y" --> "... r", r is the result
1098          (setq calculator-stack
1099                (cons (calculator-funcall
1100                       (nth 2 (nth 1 calculator-stack))
1101                       (nth 2 calculator-stack)
1102                       (nth 0 calculator-stack))
1103                      (nthcdr 3 calculator-stack)))
1104          ;; another iteration
1105          t)
1106         ((and (>= (length calculator-stack) 2)     ; have two values
1107               (numberp (nth 0 calculator-stack))   ; number & operator
1108               (consp   (nth 1 calculator-stack))
1109               (= -1 (calculator-op-arity           ; prefix-unary op
1110                      (nth 1 calculator-stack)))
1111               (<= prec                             ; with higher prec.
1112                   (calculator-op-prec (nth 1 calculator-stack))))
1113          ;; reduce "... op x" --> "... r" for prefix op
1114          (setq calculator-stack
1115                (cons (calculator-funcall
1116                       (nth 2 (nth 1 calculator-stack))
1117                       (nth 0 calculator-stack))
1118                      (nthcdr 2 calculator-stack)))
1119          ;; another iteration
1120          t)
1121         ((and (cdr calculator-stack)               ; have two values
1122               (consp   (nth 0 calculator-stack))   ; operator & number
1123               (numberp (nth 1 calculator-stack))
1124               (= +1 (calculator-op-arity           ; postfix-unary op
1125                      (nth 0 calculator-stack)))
1126               (<= prec                             ; with higher prec.
1127                   (calculator-op-prec (nth 0 calculator-stack))))
1128          ;; reduce "... x op" --> "... r" for postfix op
1129          (setq calculator-stack
1130                (cons (calculator-funcall
1131                       (nth 2 (nth 0 calculator-stack))
1132                       (nth 1 calculator-stack))
1133                      (nthcdr 2 calculator-stack)))
1134          ;; another iteration
1135          t)
1136         ((and calculator-stack                     ; have one value
1137               (consp (nth 0 calculator-stack))     ; an operator
1138               (= 0 (calculator-op-arity            ; 0-ary op
1139                     (nth 0 calculator-stack))))
1140          ;; reduce "... op" --> "... r" for 0-ary op
1141          (setq calculator-stack
1142                (cons (calculator-funcall
1143                       (nth 2 (nth 0 calculator-stack)))
1144                      (nthcdr 1 calculator-stack)))
1145          ;; another iteration
1146          t)
1147         ((and (cdr calculator-stack)               ; have two values
1148               (numberp (nth 0 calculator-stack))   ; both numbers
1149               (numberp (nth 1 calculator-stack)))
1150          ;; get rid of redundant numbers:
1151          ;;   reduce "... y x" --> "... x"
1152          ;; needed for 0-ary ops that puts more values
1153          (setcdr calculator-stack (cdr (cdr calculator-stack))))
1154         (t ;; no more iterations
1155            nil))))
1156
1157 (defun calculator-funcall (f &optional X Y)
1158   "If F is a symbol, evaluate (F X Y).
1159 Otherwise, it should be a list, evaluate it with X, Y bound to the
1160 arguments."
1161   ;; remember binary ops for calculator-repR/L
1162   (if Y (setq calculator-last-opXY (list f X Y)))
1163   (condition-case nil
1164       ;; there used to be code here that returns 0 if the result was
1165       ;; smaller than calculator-epsilon (1e-15).  I don't think this is
1166       ;; necessary now.
1167       (if (symbolp f)
1168         (cond ((and X Y) (funcall f X Y))
1169               (X         (funcall f X))
1170               (t         (funcall f)))
1171         ;; f is an expression
1172         (let* ((__f__ f) ; so we can get this value below...
1173                (TX (calculator-truncate X))
1174                (TY (and Y (calculator-truncate Y)))
1175                (DX (if calculator-deg (/ (* X pi) 180) X))
1176                (L  calculator-saved-list)
1177                (Fbound (fboundp 'F))
1178                (Fsave  (and Fbound (symbol-function 'F)))
1179                (Dbound (fboundp 'D))
1180                (Dsave  (and Dbound (symbol-function 'D))))
1181           ;; a shortened version of flet
1182           (fset 'F (function
1183                     (lambda (&optional x y)
1184                       (calculator-funcall __f__ x y))))
1185           (fset 'D (function
1186                     (lambda (x)
1187                       (if calculator-deg (/ (* x 180) pi) x))))
1188           (unwind-protect (eval f)
1189             (if Fbound (fset 'F Fsave) (fmakunbound 'F))
1190             (if Dbound (fset 'D Dsave) (fmakunbound 'D)))))
1191     (error 0)))
1192
1193 (eval-when-compile ; silence the compiler
1194   (or (fboundp 'event-key)
1195       (defun event-key (&rest _) nil))
1196   (or (fboundp 'key-press-event-p)
1197       (defun key-press-event-p (&rest _) nil)))
1198
1199 ;;;---------------------------------------------------------------------
1200 ;;; Input interaction
1201
1202 (defun calculator-last-input (&optional keys)
1203   "Last char (or event or event sequence) that was read.
1204 Optional string argument KEYS will force using it as the keys entered."
1205   (let ((inp (or keys (this-command-keys))))
1206     (if (or (stringp inp) (not (arrayp inp)))
1207       inp
1208       ;; this translates kp-x to x and [tries to] create a string to
1209       ;; lookup operators
1210       (let* ((i -1) (converted-str (make-string (length inp) ? )) k)
1211         ;; converts an array to a string the ops lookup with keypad
1212         ;; input
1213         (while (< (setq i (1+ i)) (length inp))
1214           (setq k (aref inp i))
1215           ;; if Emacs will someday have a event-key, then this would
1216           ;; probably be modified anyway
1217           (and (fboundp 'event-key) (key-press-event-p k)
1218                (event-key k) (setq k (event-key k)))
1219           ;; assume all symbols are translatable with an ascii-character
1220           (and (symbolp k)
1221                (setq k (or (get k 'ascii-character) ? )))
1222           (aset converted-str i k))
1223         converted-str))))
1224
1225 (defun calculator-clear-fragile (&optional op)
1226   "Clear the fragile flag if it was set, then maybe reset all.
1227 OP is the operator (if any) that caused this call."
1228   (if (and calculator-display-fragile
1229            (or (not op)
1230                (= -1 (calculator-op-arity op))
1231                (= 0 (calculator-op-arity op))))
1232     ;; reset if last calc finished, and now get a num or prefix or 0-ary
1233     ;; op
1234     (calculator-reset))
1235   (setq calculator-display-fragile nil))
1236
1237 (defun calculator-digit ()
1238   "Enter a single digit."
1239   (interactive)
1240   (let ((inp (aref (calculator-last-input) 0)))
1241     (if (and (or calculator-display-fragile
1242                  (not (numberp (car calculator-stack))))
1243              (cond
1244                ((not calculator-input-radix)     (<= inp ?9))
1245                ((eq calculator-input-radix 'bin) (<= inp ?1))
1246                ((eq calculator-input-radix 'oct) (<= inp ?7))
1247                (t t)))
1248       ;; enter digit if starting a new computation or have an op on the
1249       ;; stack
1250       (progn
1251         (calculator-clear-fragile)
1252         (let ((digit (upcase (char-to-string inp))))
1253           (if (equal calculator-curnum "0")
1254             (setq calculator-curnum nil))
1255           (setq calculator-curnum
1256                 (concat (or calculator-curnum "") digit)))
1257         (calculator-update-display)))))
1258
1259 (defun calculator-decimal ()
1260   "Enter a decimal period."
1261   (interactive)
1262   (if (and (not calculator-input-radix)
1263            (or calculator-display-fragile
1264                (not (numberp (car calculator-stack))))
1265            (not (and calculator-curnum
1266                      (string-match "[.eE]" calculator-curnum))))
1267     ;; enter the period on the same condition as a digit, only if no
1268     ;; period or exponent entered yet
1269     (progn
1270       (calculator-clear-fragile)
1271       (setq calculator-curnum (concat (or calculator-curnum "0") "."))
1272       (calculator-update-display))))
1273
1274 (defun calculator-exp ()
1275   "Enter an `E' exponent character, or a digit in hex input mode."
1276   (interactive)
1277   (if calculator-input-radix
1278     (calculator-digit)
1279     (if (and (or calculator-display-fragile
1280                  (not (numberp (car calculator-stack))))
1281              (not (and calculator-curnum
1282                        (string-match "[eE]" calculator-curnum))))
1283       ;; same condition as above, also no E so far
1284       (progn
1285         (calculator-clear-fragile)
1286         (setq calculator-curnum (concat (or calculator-curnum "1") "e"))
1287         (calculator-update-display)))))
1288
1289 (defun calculator-op (&optional keys)
1290   "Enter an operator on the stack, doing all necessary reductions.
1291 Optional string argument KEYS will force using it as the keys entered."
1292   (interactive)
1293   (catch 'op-error
1294     (let* ((last-inp (calculator-last-input keys))
1295            (op (assoc last-inp calculator-operators)))
1296       (calculator-clear-fragile op)
1297       (if (and calculator-curnum (/= (calculator-op-arity op) 0))
1298         (setq calculator-stack
1299               (cons (calculator-curnum-value) calculator-stack)))
1300       (setq calculator-curnum nil)
1301       (if (and (= 2 (calculator-op-arity op))
1302                (not (and calculator-stack
1303                          (numberp (nth 0 calculator-stack)))))
1304         ;; we have a binary operator but no number - search for a prefix
1305         ;; version
1306         (let ((rest-ops calculator-operators))
1307           (while (not (equal last-inp (car (car rest-ops))))
1308             (setq rest-ops (cdr rest-ops)))
1309           (setq op (assoc last-inp (cdr rest-ops)))
1310           (if (not (and op (= -1 (calculator-op-arity op))))
1311             ;;(error "Binary operator without a first operand")
1312             (progn
1313               (message "Binary operator without a first operand")
1314               (if calculator-electric-mode
1315                 (progn (sit-for 1) (message nil)))
1316               (throw 'op-error nil)))))
1317       (calculator-reduce-stack
1318        (cond ((eq (nth 1 op) '\() 10)
1319              ((eq (nth 1 op) '\)) 0)
1320              (t (calculator-op-prec op))))
1321       (if (or (and (= -1 (calculator-op-arity op))
1322                    (numberp (car calculator-stack)))
1323               (and (/= (calculator-op-arity op) -1)
1324                    (/= (calculator-op-arity op) 0)
1325                    (not (numberp (car calculator-stack)))))
1326         ;;(error "Unterminated expression")
1327         (progn
1328           (message "Unterminated expression")
1329           (if calculator-electric-mode
1330             (progn (sit-for 1) (message nil)))
1331           (throw 'op-error nil)))
1332       (setq calculator-stack (cons op calculator-stack))
1333       (calculator-reduce-stack (calculator-op-prec op))
1334       (and (= (length calculator-stack) 1)
1335            (numberp (nth 0 calculator-stack))
1336            ;; the display is fragile if it contains only one number
1337            (setq calculator-display-fragile t)
1338            ;; add number to the saved-list
1339            calculator-add-saved
1340            (if (= 0 calculator-saved-ptr)
1341              (setq calculator-saved-list
1342                    (cons (car calculator-stack) calculator-saved-list))
1343              (let ((p (nthcdr (1- calculator-saved-ptr)
1344                               calculator-saved-list)))
1345                (setcdr p (cons (car calculator-stack) (cdr p))))))
1346       (calculator-update-display))))
1347
1348 (defun calculator-op-or-exp ()
1349   "Either enter an operator or a digit.
1350 Used with +/- for entering them as digits in numbers like 1e-3 (there is
1351 no need for negative numbers since these are handled by unary
1352 operators)."
1353   (interactive)
1354   (if (and (not calculator-display-fragile)
1355            calculator-curnum
1356            (string-match "[eE]$" calculator-curnum))
1357     (calculator-digit)
1358     (calculator-op)))
1359
1360 ;;;---------------------------------------------------------------------
1361 ;;; Input/output modes (not display)
1362
1363 (defun calculator-dec/deg-mode ()
1364   "Set decimal mode for display & input, if decimal, toggle deg mode."
1365   (interactive)
1366   (if calculator-curnum
1367     (setq calculator-stack
1368           (cons (calculator-curnum-value) calculator-stack)))
1369   (setq calculator-curnum nil)
1370   (if (or calculator-input-radix calculator-output-radix)
1371     (progn (setq calculator-input-radix nil)
1372            (setq calculator-output-radix nil))
1373     ;; already decimal - toggle degrees mode
1374     (setq calculator-deg (not calculator-deg)))
1375   (calculator-update-display t))
1376
1377 (defun calculator-radix-mode (&optional keys)
1378   "Set input and display radix modes.
1379 Optional string argument KEYS will force using it as the keys entered."
1380   (interactive)
1381   (calculator-radix-input-mode keys)
1382   (calculator-radix-output-mode keys))
1383
1384 (defun calculator-radix-input-mode (&optional keys)
1385   "Set input radix modes.
1386 Optional string argument KEYS will force using it as the keys entered."
1387   (interactive)
1388   (if calculator-curnum
1389     (setq calculator-stack
1390           (cons (calculator-curnum-value) calculator-stack)))
1391   (setq calculator-curnum nil)
1392   (setq calculator-input-radix
1393         (let ((inp (calculator-last-input keys)))
1394           (cdr (assq (upcase (aref inp (1- (length inp))))
1395                      calculator-char-radix))))
1396   (calculator-update-display))
1397
1398 (defun calculator-radix-output-mode (&optional keys)
1399   "Set display radix modes.
1400 Optional string argument KEYS will force using it as the keys entered."
1401   (interactive)
1402   (if calculator-curnum
1403     (setq calculator-stack
1404           (cons (calculator-curnum-value) calculator-stack)))
1405   (setq calculator-curnum nil)
1406   (setq calculator-output-radix
1407         (let ((inp (calculator-last-input keys)))
1408           (cdr (assq (upcase (aref inp (1- (length inp))))
1409                      calculator-char-radix))))
1410   (calculator-update-display t))
1411
1412 ;;;---------------------------------------------------------------------
1413 ;;; Saved values list
1414
1415 (defun calculator-save-on-list ()
1416   "Evaluate current expression, put result on the saved values list."
1417   (interactive)
1418   (let ((calculator-add-saved t)) ; marks the result to be added
1419     (calculator-enter)))
1420
1421 (defun calculator-clear-saved ()
1422   "Clear the list of saved values in `calculator-saved-list'."
1423   (interactive)
1424   (setq calculator-saved-list nil)
1425   (setq calculator-saved-ptr 0)
1426   (calculator-update-display t))
1427
1428 (defun calculator-saved-move (n)
1429   "Go N elements up the list of saved values."
1430   (interactive)
1431   (and calculator-saved-list
1432        (or (null calculator-stack) calculator-display-fragile)
1433        (progn
1434          (setq calculator-saved-ptr
1435                (max (min (+ n calculator-saved-ptr)
1436                          (length calculator-saved-list))
1437                     0))
1438          (if (nth calculator-saved-ptr calculator-saved-list)
1439            (setq calculator-stack
1440                  (list (nth calculator-saved-ptr calculator-saved-list))
1441                  calculator-display-fragile t)
1442            (calculator-reset))
1443          (calculator-update-display))))
1444
1445 (defun calculator-saved-up ()
1446   "Go up the list of saved values."
1447   (interactive)
1448   (calculator-saved-move +1))
1449
1450 (defun calculator-saved-down ()
1451   "Go down the list of saved values."
1452   (interactive)
1453   (calculator-saved-move -1))
1454
1455 ;;;---------------------------------------------------------------------
1456 ;;; Misc functions
1457
1458 (defun calculator-open-paren ()
1459   "Equivalents of `(' use this."
1460   (interactive)
1461   (calculator-op "("))
1462
1463 (defun calculator-close-paren ()
1464   "Equivalents of `)' use this."
1465   (interactive)
1466   (calculator-op ")"))
1467
1468 (defun calculator-enter ()
1469   "Evaluate current expression."
1470   (interactive)
1471   (calculator-op "="))
1472
1473 (defun calculator-backspace ()
1474   "Backward delete a single digit or a stack element."
1475   (interactive)
1476   (if calculator-curnum
1477     (setq calculator-curnum
1478           (if (> (length calculator-curnum) 1)
1479             (substring calculator-curnum
1480                        0 (1- (length calculator-curnum)))
1481             nil))
1482     (setq calculator-stack (cdr calculator-stack)))
1483   (calculator-update-display))
1484
1485 (defun calculator-clear ()
1486   "Clear current number."
1487   (interactive)
1488   (setq calculator-curnum nil)
1489   (cond
1490     ;; if the current number is from the saved-list - remove it
1491     ((and calculator-display-fragile
1492           calculator-saved-list
1493           (= (car calculator-stack)
1494              (nth calculator-saved-ptr calculator-saved-list)))
1495      (if (= 0 calculator-saved-ptr)
1496        (setq calculator-saved-list (cdr calculator-saved-list))
1497        (let ((p (nthcdr (1- calculator-saved-ptr)
1498                         calculator-saved-list)))
1499          (setcdr p (cdr (cdr p)))
1500          (setq calculator-saved-ptr (1- calculator-saved-ptr))))
1501      (if calculator-saved-list
1502        (setq calculator-stack
1503              (list (nth calculator-saved-ptr calculator-saved-list)))
1504        (calculator-reset)))
1505     ;; reset if fragile or double clear
1506     ((or calculator-display-fragile (eq last-command this-command))
1507      (calculator-reset)))
1508   (calculator-update-display))
1509
1510 (defun calculator-copy ()
1511   "Copy current number to the `kill-ring'."
1512   (interactive)
1513   (calculator-enter)
1514   ;; remove trailing spaces and and an index
1515   (let ((s (cdr calculator-stack-display)))
1516     (if (string-match "^\\([^ ]+\\) *\\(\\[[0-9/]+\\]\\)? *$" s)
1517       (setq s (match-string 1 s)))
1518     (kill-new s)))
1519
1520 (defun calculator-set-register (reg)
1521   "Set a register value for REG."
1522   (interactive "cRegister to store into: ")
1523   (let* ((as  (assq reg calculator-registers))
1524          (val (progn (calculator-enter) (car calculator-stack))))
1525     (if as
1526       (setcdr as val)
1527       (setq calculator-registers
1528             (cons (cons reg val) calculator-registers)))
1529     (message (format "[%c] := %S" reg val))))
1530
1531 (defun calculator-put-value (val)
1532   "Paste VAL as if entered.
1533 Used by `calculator-paste' and `get-register'."
1534   (if (and (numberp val)
1535            ;; (not calculator-curnum)
1536            (or calculator-display-fragile
1537                (not (numberp (car calculator-stack)))))
1538     (progn
1539       (calculator-clear-fragile)
1540       (setq calculator-curnum (calculator-num-to-string val))
1541       (calculator-update-display))))
1542
1543 (defun calculator-paste ()
1544   "Paste a value from the `kill-ring'."
1545   (interactive)
1546   (calculator-put-value
1547    (let ((str (current-kill 0)))
1548      (and calculator-paste-decimals
1549           (string-match "\\([0-9]+\\)\\(\\.[0-9]+\\)?\\(e[0-9]+\\)?"
1550                         str)
1551           (or (match-string 1 str)
1552               (match-string 2 str)
1553               (match-string 3 str))
1554           (setq str (concat (match-string 1 str)
1555                             (or (match-string 2 str) ".0")
1556                             (match-string 3 str))))
1557      (condition-case nil (car (read-from-string str))
1558        (error nil)))))
1559
1560 (defun calculator-get-register (reg)
1561   "Get a value from a register REG."
1562   (interactive "cRegister to get value from: ")
1563   (calculator-put-value (cdr (assq reg calculator-registers))))
1564
1565 (defun calculator-help ()
1566   ;; this is used as the quick reference screen you get with `h'
1567   "Quick reference:
1568 * numbers/operators/parens/./e - enter expressions
1569   + - * / \\(div) %(rem) _(-X,postfix) ;(1/X,postfix) ^(exp) L(og)
1570   Q(sqrt) !(fact) S(in) C(os) T(an) |(or) #(xor) &(and) ~(not)
1571 * >/< repeats last binary operation with its 2nd (1st) arg as postfix op
1572 * I inverses next trig function        * '/\"/{} - display/display args
1573 * D         - switch to all-decimal, or toggle deg/rad mode
1574 * B/O/H/X   - binary/octal/hex mode for i/o (X is a shortcut for H)
1575 * i/o       - prefix for d/b/o/x - set only input/output modes
1576 * enter/=   - evaluate current expr.   * s/g      - set/get a register
1577 * space     - evaluate & save on list  * l/v      - list total/average
1578 * up/down/C-p/C-n - browse saved       * C-delete - clear all saved
1579 * C-insert  - copy whole expr.         * C-return - evaluate, copy, exit
1580 * insert    - paste a number           * backspace- delete backwards
1581 * delete    - clear argument or list value or whole expression (twice)
1582 * escape/q  - exit."
1583   (interactive)
1584   (if (eq last-command 'calculator-help)
1585     (let ((mode-name "Calculator")
1586           (major-mode 'calculator-mode)
1587           (g-map (current-global-map))
1588           (win (selected-window)))
1589       (require 'ehelp)
1590       (if calculator-electric-mode
1591         (use-global-map calculator-saved-global-map))
1592       (if (or (not calculator-electric-mode)
1593               ;; XEmacs has a problem with electric-describe-mode
1594               (string-match "XEmacs" (emacs-version)))
1595         (describe-mode)
1596         (electric-describe-mode))
1597       (if calculator-electric-mode
1598         (use-global-map g-map))
1599       (select-window win) ; these are for XEmacs (also below)
1600       (message nil))
1601     (let ((one (one-window-p t))
1602           (win (selected-window))
1603           (help-buf (get-buffer-create "*Help*")))
1604       (save-window-excursion
1605         (with-output-to-temp-buffer "*Help*"
1606           (princ (documentation 'calculator-help)))
1607         (if one
1608           (shrink-window-if-larger-than-buffer
1609            (get-buffer-window help-buf)))
1610         (message
1611          "`%s' again for more help, any other key continues normally."
1612          (calculator-last-input))
1613         (select-window win)
1614         (sit-for 360))
1615       (select-window win))))
1616
1617 (defun calculator-quit ()
1618   "Quit calculator."
1619   (interactive)
1620   (set-buffer calculator-buffer)
1621   (let ((inhibit-read-only t)) (erase-buffer))
1622   (if (not calculator-electric-mode)
1623     (progn
1624       (condition-case nil
1625           (while (get-buffer-window calculator-buffer)
1626             (delete-window (get-buffer-window calculator-buffer)))
1627         (error nil))
1628       (kill-buffer calculator-buffer)))
1629   (setq calculator-buffer nil)
1630   (message "Calculator done.")
1631   (if calculator-electric-mode (throw 'calculator-done nil)))
1632
1633 (defun calculator-save-and-quit ()
1634   "Quit the calculator, saving the result on the `kill-ring'."
1635   (interactive)
1636   (calculator-enter)
1637   (calculator-copy)
1638   (calculator-quit))
1639
1640 (defun calculator-repR (x)
1641   "Repeats the last binary operation with its second argument and X.
1642 To use this, apply a binary operator (evaluate it), then call this."
1643   (if calculator-last-opXY
1644     ;; avoid rebinding calculator-last-opXY
1645     (let ((calculator-last-opXY calculator-last-opXY))
1646       (calculator-funcall
1647        (car calculator-last-opXY) x (nth 2 calculator-last-opXY)))
1648     x))
1649
1650 (defun calculator-repL (x)
1651   "Repeats the last binary operation with its first argument and X.
1652 To use this, apply a binary operator (evaluate it), then call this."
1653   (if calculator-last-opXY
1654     ;; avoid rebinding calculator-last-opXY
1655     (let ((calculator-last-opXY calculator-last-opXY))
1656       (calculator-funcall
1657        (car calculator-last-opXY) (nth 1 calculator-last-opXY) x))
1658     x))
1659
1660 (defun calculator-fact (x)
1661   "Simple factorial of X."
1662   (let ((r (if (<= x 10) 1 1.0)))
1663     (while (> x 0)
1664       (setq r (* r (truncate x)))
1665       (setq x (1- x)))
1666     r))
1667
1668 (defun calculator-truncate (n)
1669   "Truncate N, return 0 in case of overflow."
1670   (condition-case nil (truncate n) (error 0)))
1671
1672
1673 (provide 'calculator)
1674
1675 ;;; calculator.el ends here