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1 | ;;; float-sup.el --- detect absence of floating-point support in Emacs runtime |
2 | ||
a2535589 JA |
3 | ;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc. |
4 | ||
9750e079 ER |
5 | ;; Maintainer: FSF |
6 | ||
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7 | ;; This file is part of GNU Emacs. |
8 | ||
9 | ;; GNU Emacs is free software; you can redistribute it and/or modify | |
10 | ;; it under the terms of the GNU General Public License as published by | |
e5167999 | 11 | ;; the Free Software Foundation; either version 2, or (at your option) |
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12 | ;; any later version. |
13 | ||
14 | ;; GNU Emacs is distributed in the hope that it will be useful, | |
15 | ;; but WITHOUT ANY WARRANTY; without even the implied warranty of | |
16 | ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
17 | ;; GNU General Public License for more details. | |
18 | ||
19 | ;; You should have received a copy of the GNU General Public License | |
b578f267 EN |
20 | ;; along with GNU Emacs; see the file COPYING. If not, write to the |
21 | ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330, | |
22 | ;; Boston, MA 02111-1307, USA. | |
a2535589 | 23 | |
e5167999 ER |
24 | ;;; Code: |
25 | ||
a2535589 JA |
26 | ;; Provide a meaningful error message if we are running on |
27 | ;; bare (non-float) emacs. | |
28 | ;; Can't test for 'floatp since that may be defined by float-imitation | |
29 | ;; packages like float.el in this very directory. | |
30 | ||
31 | (if (fboundp 'atan) | |
32 | nil | |
33 | (error "Floating point was disabled at compile time")) | |
34 | ||
35 | ;; provide an easy hook to tell if we are running with floats or not. | |
a2535589 JA |
36 | ;; define pi and e via math-lib calls. (much less prone to killer typos.) |
37 | (defconst pi (* 4 (atan 1)) "The value of Pi (3.1415926...)") | |
38 | (defconst e (exp 1) "The value of e (2.7182818...)") | |
39 | ||
40 | ;; Careful when editing this file ... typos here will be hard to spot. | |
41 | ;; (defconst pi 3.14159265358979323846264338327 | |
42 | ;; "The value of Pi (3.14159265358979323846264338327...)") | |
43 | ||
44 | (defconst degrees-to-radians (/ pi 180.0) | |
45 | "Degrees to radian conversion constant") | |
46 | (defconst radians-to-degrees (/ 180.0 pi) | |
47 | "Radian to degree conversion constant") | |
48 | ||
3bfd7edb | 49 | ;; these expand to a single multiply by a float when byte compiled |
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50 | |
51 | (defmacro degrees-to-radians (x) | |
52 | "Convert ARG from degrees to radians." | |
53 | (list '* (/ pi 180.0) x)) | |
54 | (defmacro radians-to-degrees (x) | |
55 | "Convert ARG from radians to degrees." | |
56 | (list '* (/ 180.0 pi) x)) | |
49116ac0 JB |
57 | |
58 | (provide 'lisp-float-type) | |
59 | ||
c0274f38 | 60 | ;;; float-sup.el ends here |