mirror of
https://git.savannah.gnu.org/git/emacs.git
synced 2024-11-27 07:37:33 +00:00
60 lines
2.1 KiB
EmacsLisp
60 lines
2.1 KiB
EmacsLisp
;;; float-sup.el --- detect absence of floating-point support in Emacs runtime
|
|
|
|
;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc.
|
|
|
|
;; Maintainer: FSF
|
|
|
|
;; This file is part of GNU Emacs.
|
|
|
|
;; GNU Emacs is free software; you can redistribute it and/or modify
|
|
;; it under the terms of the GNU General Public License as published by
|
|
;; the Free Software Foundation; either version 2, or (at your option)
|
|
;; any later version.
|
|
|
|
;; GNU Emacs is distributed in the hope that it will be useful,
|
|
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
|
|
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
|
|
;; GNU General Public License for more details.
|
|
|
|
;; You should have received a copy of the GNU General Public License
|
|
;; along with GNU Emacs; see the file COPYING. If not, write to
|
|
;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
|
|
|
|
;;; Code:
|
|
|
|
;; Provide a meaningful error message if we are running on
|
|
;; bare (non-float) emacs.
|
|
;; Can't test for 'floatp since that may be defined by float-imitation
|
|
;; packages like float.el in this very directory.
|
|
|
|
(if (fboundp 'atan)
|
|
nil
|
|
(error "Floating point was disabled at compile time"))
|
|
|
|
;; provide an easy hook to tell if we are running with floats or not.
|
|
;; define pi and e via math-lib calls. (much less prone to killer typos.)
|
|
(defconst pi (* 4 (atan 1)) "The value of Pi (3.1415926...)")
|
|
(defconst e (exp 1) "The value of e (2.7182818...)")
|
|
|
|
;; Careful when editing this file ... typos here will be hard to spot.
|
|
;; (defconst pi 3.14159265358979323846264338327
|
|
;; "The value of Pi (3.14159265358979323846264338327...)")
|
|
|
|
(defconst degrees-to-radians (/ pi 180.0)
|
|
"Degrees to radian conversion constant")
|
|
(defconst radians-to-degrees (/ 180.0 pi)
|
|
"Radian to degree conversion constant")
|
|
|
|
;; these expand to a single multiply by a float when byte compiled
|
|
|
|
(defmacro degrees-to-radians (x)
|
|
"Convert ARG from degrees to radians."
|
|
(list '* (/ pi 180.0) x))
|
|
(defmacro radians-to-degrees (x)
|
|
"Convert ARG from radians to degrees."
|
|
(list '* (/ 180.0 pi) x))
|
|
|
|
(provide 'lisp-float-type)
|
|
|
|
;;; float-sup.el ends here
|