1 ;;; float-sup.el --- detect absence of floating-point support in Emacs runtime
4 ;; Last-Modified: 16 Mar 1992
6 ;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc.
8 ;; This file is part of GNU Emacs.
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 2, or (at your option)
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.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to
22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
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.
33 (error "Floating point was disabled at compile time"))
35 ;; provide an easy hook to tell if we are running with floats or not.
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...)")
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...)")
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")
49 ;; these expand to a single multiply by a float when byte compiled
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
))
58 (provide 'lisp-float-type
)
60 ;;; float-sup.el ends here