module/rnrs/arithmetic/flonums.scm

   1 ;;; flonums.scm --- The R6RS flonums arithmetic library
   2
   3 ;;      Copyright (C) 2010, 2011 Free Software Foundation, Inc.
   4 ;;
   5 ;; This library is free software; you can redistribute it and/or
   6 ;; modify it under the terms of the GNU Lesser General Public
   7 ;; License as published by the Free Software Foundation; either
   8 ;; version 3 of the License, or (at your option) any later version.
   9 ;;
  10 ;; This library is distributed in the hope that it will be useful,
  11 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  12 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU
  13 ;; Lesser General Public License for more details.
  14 ;;
  15 ;; You should have received a copy of the GNU Lesser General Public
  16 ;; License along with this library; if not, write to the Free Software
  17 ;; Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA
  18 \f
  19
  20 (library (rnrs arithmetic flonums (6))
  21   (export flonum?
  22           real->flonum
  23
  24           fl=? fl<? fl<=? fl>? fl>=?
  25
  26           flinteger? flzero? flpositive? flnegative? flodd? fleven? flfinite?
  27           flinfinite? flnan?
  28
  29           flmax flmin
  30
  31           fl+ fl* fl- fl/
  32
  33           flabs
  34
  35           fldiv-and-mod
  36           fldiv
  37           flmod
  38           fldiv0-and-mod0
  39           fldiv0
  40           flmod0
  41
  42           flnumerator
  43           fldenominator
  44
  45           flfloor flceiling fltruncate flround
  46
  47           flexp fllog flsin flcos fltan flacos flasin flatan
  48
  49           flsqrt flexpt
  50
  51           &no-infinities
  52           make-no-infinities-violation
  53           no-infinities-violation?
  54
  55           &no-nans
  56           make-no-nans-violation
  57           no-nans-violation?
  58
  59           fixnum->flonum)
  60   (import (ice-9 optargs)
  61           (only (guile) inf?)
  62           (rnrs arithmetic fixnums (6))
  63           (rnrs base (6))
  64           (rnrs control (6))
  65           (rnrs conditions (6))
  66           (rnrs exceptions (6))
  67           (rnrs lists (6))
  68           (rnrs r5rs (6)))
  69
  70   (define (flonum? obj) (and (real? obj) (inexact? obj)))
  71   (define (assert-flonum . args)
  72     (or (for-all flonum? args) (raise (make-assertion-violation))))
  73   (define (assert-iflonum . args)
  74     (or (for-all (lambda (i) (and (flonum? i) (integer? i))) args)
  75         (raise (make-assertion-violation))))
  76
  77   (define (ensure-flonum z)
  78     (cond ((real? z) z)
  79           ((zero? (imag-part z)) (real-part z))
  80           (else +nan.0)))
  81
  82   (define (real->flonum x)
  83     (or (real? x) (raise (make-assertion-violation)))
  84     (exact->inexact x))
  85
  86   (define (fl=? . args) (apply assert-flonum args) (apply = args))
  87   (define (fl<? . args) (apply assert-flonum args) (apply < args))
  88   (define (fl<=? . args) (apply assert-flonum args) (apply <= args))
  89   (define (fl>? . args) (apply assert-flonum args) (apply > args))
  90   (define (fl>=? . args) (apply assert-flonum args) (apply >= args))
  91
  92   (define (flinteger? fl) (assert-flonum fl) (integer? fl))
  93   (define (flzero? fl) (assert-flonum fl) (zero? fl))
  94   (define (flpositive? fl) (assert-flonum fl) (positive? fl))
  95   (define (flnegative? fl) (assert-flonum fl) (negative? fl))
  96   (define (flodd? ifl) (assert-iflonum ifl) (odd? ifl))
  97   (define (fleven? ifl) (assert-iflonum ifl) (even? ifl))
  98   (define (flfinite? fl) (assert-flonum fl) (not (or (inf? fl) (nan? fl))))
  99   (define (flinfinite? fl) (assert-flonum fl) (inf? fl))
 100   (define (flnan? fl) (assert-flonum fl) (nan? fl))
 101
 102   (define (flmax fl1 . args)
 103     (let ((flargs (cons fl1 args)))
 104       (apply assert-flonum flargs)
 105       (apply max flargs)))
 106
 107   (define (flmin fl1 . args)
 108     (let ((flargs (cons fl1 args)))
 109       (apply assert-flonum flargs)
 110       (apply min flargs)))
 111
 112   (define (fl+ . args)
 113     (apply assert-flonum args)
 114     (if (null? args) 0.0 (apply + args)))
 115
 116   (define (fl* . args)
 117     (apply assert-flonum args)
 118     (if (null? args) 1.0 (apply * args)))
 119
 120   (define (fl- fl1 . args)
 121     (let ((flargs (cons fl1 args)))
 122       (apply assert-flonum flargs)
 123       (apply - flargs)))
 124
 125   (define (fl/ fl1 . args)
 126     (let ((flargs (cons fl1 args)))
 127       (apply assert-flonum flargs)
 128       (apply / flargs)))
 129
 130   (define (flabs fl) (assert-flonum fl) (abs fl))
 131
 132   (define (fldiv-and-mod fl1 fl2)
 133     (assert-iflonum fl1 fl2)
 134     (div-and-mod fl1 fl2))
 135
 136   (define (fldiv fl1 fl2)
 137     (assert-iflonum fl1 fl2)
 138     (div fl1 fl2))
 139
 140   (define (flmod fl1 fl2)
 141     (assert-iflonum fl1 fl2)
 142     (mod fl1 fl2))
 143
 144   (define (fldiv0-and-mod0 fl1 fl2)
 145     (assert-iflonum fl1 fl2)
 146     (div0-and-mod0 fl1 fl2))
 147
 148   (define (fldiv0 fl1 fl2)
 149     (assert-iflonum fl1 fl2)
 150     (div0 fl1 fl2))
 151
 152   (define (flmod0 fl1 fl2)
 153     (assert-iflonum fl1 fl2)
 154     (mod0 fl1 fl2))
 155
 156   (define (flnumerator fl)
 157     (assert-flonum fl)
 158     (case fl
 159       ((+inf.0) +inf.0)
 160       ((-inf.0) -inf.0)
 161       (else (numerator fl))))
 162
 163   (define (fldenominator fl)
 164     (assert-flonum fl)
 165     (case fl
 166       ((+inf.0) 1.0)
 167       ((-inf.0) 1.0)
 168       (else (denominator fl))))
 169
 170   (define (flfloor fl) (assert-flonum fl) (floor fl))
 171   (define (flceiling fl) (assert-flonum fl) (ceiling fl))
 172   (define (fltruncate fl) (assert-flonum fl) (truncate fl))
 173   (define (flround fl) (assert-flonum fl) (round fl))
 174
 175   (define (flexp fl) (assert-flonum fl) (exp fl))
 176   (define fllog
 177     (case-lambda
 178       ((fl)
 179        (assert-flonum fl)
 180        ;; add 0.0 to fl, to change -0.0 to 0.0,
 181        ;; so that (fllog -0.0) will be -inf.0, not -inf.0+pi*i.
 182        (ensure-flonum (log (+ fl 0.0))))
 183       ((fl fl2)
 184        (assert-flonum fl fl2)
 185        (ensure-flonum (/ (log (+ fl 0.0))
 186                          (log (+ fl2 0.0)))))))
 187
 188   (define (flsin fl) (assert-flonum fl) (sin fl))
 189   (define (flcos fl) (assert-flonum fl) (cos fl))
 190   (define (fltan fl) (assert-flonum fl) (tan fl))
 191   (define (flasin fl) (assert-flonum fl) (ensure-flonum (asin fl)))
 192   (define (flacos fl) (assert-flonum fl) (ensure-flonum (acos fl)))
 193   (define flatan
 194     (case-lambda
 195       ((fl) (assert-flonum fl) (atan fl))
 196       ((fl fl2) (assert-flonum fl fl2) (atan fl fl2))))
 197
 198   (define (flsqrt fl) (assert-flonum fl) (ensure-flonum (sqrt fl)))
 199   (define (flexpt fl1 fl2) (assert-flonum fl1 fl2) (ensure-flonum (expt fl1 fl2)))
 200
 201   (define-condition-type &no-infinities
 202     &implementation-restriction
 203     make-no-infinities-violation
 204     no-infinities-violation?)
 205
 206   (define-condition-type &no-nans
 207     &implementation-restriction
 208     make-no-nans-violation
 209     no-nans-violation?)
 210
 211   (define (fixnum->flonum fx)
 212     (or (fixnum? fx) (raise (make-assertion-violation)))
 213     (exact->inexact fx))
 214 )