| | 1 | ;;; float-sup.el --- define some constants useful for floating point numbers. |
| | 2 | |
| | 3 | ;; Copyright (C) 1985, 1986, 1987, 2001, 2002, 2003, 2004, |
| | 4 | ;; 2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc. |
| | 5 | |
| | 6 | ;; Maintainer: FSF |
| | 7 | ;; Keywords: internal |
| | 8 | ;; Package: emacs |
| | 9 | |
| | 10 | ;; This file is part of GNU Emacs. |
| | 11 | |
| | 12 | ;; GNU Emacs is free software: you can redistribute it and/or modify |
| | 13 | ;; it under the terms of the GNU General Public License as published by |
| | 14 | ;; the Free Software Foundation, either version 3 of the License, or |
| | 15 | ;; (at your option) any later version. |
| | 16 | |
| | 17 | ;; GNU Emacs is distributed in the hope that it will be useful, |
| | 18 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of |
| | 19 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the |
| | 20 | ;; GNU General Public License for more details. |
| | 21 | |
| | 22 | ;; You should have received a copy of the GNU General Public License |
| | 23 | ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>. |
| | 24 | |
| | 25 | ;;; Commentary: |
| | 26 | |
| | 27 | ;;; Code: |
| | 28 | |
| | 29 | ;; Provide a meaningful error message if we are running on |
| | 30 | ;; bare (non-float) emacs. |
| | 31 | |
| | 32 | (if (fboundp 'atan) |
| | 33 | nil |
| | 34 | (error "Floating point was disabled at compile time")) |
| | 35 | |
| | 36 | ;; provide an easy hook to tell if we are running with floats or not. |
| | 37 | ;; define pi and e via math-lib calls. (much less prone to killer typos.) |
| | 38 | (defconst float-pi (* 4 (atan 1)) "The value of Pi (3.1415926...).") |
| | 39 | (defconst pi float-pi "Obsolete since Emacs-23.3. Use `float-pi' instead.") |
| | 40 | |
| | 41 | (defconst float-e (exp 1) "The value of e (2.7182818...).") |
| | 42 | |
| | 43 | (defconst degrees-to-radians (/ float-pi 180.0) |
| | 44 | "Degrees to radian conversion constant.") |
| | 45 | (defconst radians-to-degrees (/ 180.0 float-pi) |
| | 46 | "Radian to degree conversion constant.") |
| | 47 | |
| | 48 | ;; these expand to a single multiply by a float when byte compiled |
| | 49 | |
| | 50 | (defmacro degrees-to-radians (x) |
| | 51 | "Convert X from degrees to radians." |
| | 52 | (list '* degrees-to-radians x)) |
| | 53 | (defmacro radians-to-degrees (x) |
| | 54 | "Convert X from radians to degrees." |
| | 55 | (list '* radians-to-degrees x)) |
| | 56 | |
| | 57 | (provide 'lisp-float-type) |
| | 58 | |
| | 59 | ;; arch-tag: e7837072-a4af-4d08-9953-8a3e755abf9d |
| | 60 | ;;; float-sup.el ends here |
HCoop / bpt / emacs.git / blame_incremental