[bpt/emacs.git] / lisp / float-sup.el

;;; float-sup.el --- detect absence of floating-point support in Emacs runtime

;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc.

;; 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 1, 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.

;; 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
Commit	Line	Data
c0274f38 ER	1	;;; float-sup.el --- detect absence of floating-point support in Emacs runtime
c0274f38 ER	2
a2535589 JA	3	;; Copyright (C) 1985, 1986, 1987 Free Software Foundation, Inc.
	4
	5	;; This file is part of GNU Emacs.
	6
	7	;; GNU Emacs is free software; you can redistribute it and/or modify
	8	;; it under the terms of the GNU General Public License as published by
	9	;; the Free Software Foundation; either version 1, or (at your option)
	10	;; any later version.
	11
	12	;; GNU Emacs is distributed in the hope that it will be useful,
	13	;; but WITHOUT ANY WARRANTY; without even the implied warranty of
	14	;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
	15	;; GNU General Public License for more details.
	16
	17	;; You should have received a copy of the GNU General Public License
	18	;; along with GNU Emacs; see the file COPYING. If not, write to
	19	;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
	20
	21	;; Provide a meaningful error message if we are running on
	22	;; bare (non-float) emacs.
	23	;; Can't test for 'floatp since that may be defined by float-imitation
	24	;; packages like float.el in this very directory.
	25
	26	(if (fboundp 'atan)
	27	nil
	28	(error "Floating point was disabled at compile time"))
	29
	30	;; provide an easy hook to tell if we are running with floats or not.
a2535589 JA	31	;; define pi and e via math-lib calls. (much less prone to killer typos.)
	32	(defconst pi (* 4 (atan 1)) "The value of Pi (3.1415926...)")
	33	(defconst e (exp 1) "The value of e (2.7182818...)")
	34
	35	;; Careful when editing this file ... typos here will be hard to spot.
	36	;; (defconst pi 3.14159265358979323846264338327
	37	;; "The value of Pi (3.14159265358979323846264338327...)")
	38
	39	(defconst degrees-to-radians (/ pi 180.0)
	40	"Degrees to radian conversion constant")
	41	(defconst radians-to-degrees (/ 180.0 pi)
	42	"Radian to degree conversion constant")
	43
3bfd7edb	44	;; these expand to a single multiply by a float when byte compiled
a2535589 JA	45
	46	(defmacro degrees-to-radians (x)
	47	"Convert ARG from degrees to radians."
	48	(list '* (/ pi 180.0) x))
	49	(defmacro radians-to-degrees (x)
	50	"Convert ARG from radians to degrees."
	51	(list '* (/ 180.0 pi) x))
49116ac0 JB	52
	53	(provide 'lisp-float-type)
	54
c0274f38	55	;;; float-sup.el ends here