infinities are no longer integers

* libguile/numbers.c (scm_is_integer): Infinities are not integers, per
  the R6RS.
  (scm_even_p, scm_odd_p): Passing an infinity to even? or odd? is an
  error.

* test-suite/tests/numbers.test ("integer?"): Adapt test.
  ("expt"): Add tests for +inf.0 and -inf.0 exponents.

* NEWS: Add NEWS entries.

diff --git a/NEWS b/NEWS
index f10da91..c2bb1c1 100644 (file)
--- a/NEWS
+++ b/NEWS
@@ -10,6 +10,11 @@ latest prerelease, and a full NEWS corresponding to 1.8 -> 2.0.
 
 Changes in 1.9.15 (since the 1.9.14 prerelease):
 
+** Infinities are no longer integers.
+
+Following the R6RS, infinities (+inf.0 and -inf.0) are no longer
+considered to be integers.
+
 ** New reader option: `hungry-eol-escapes'
 
 Guile's string syntax is more compatible with R6RS when the

diff --git a/doc/ref/api-data.texi b/doc/ref/api-data.texi
index 659dc5c..17b32bb 100755 (executable)
--- a/doc/ref/api-data.texi
+++ b/doc/ref/api-data.texi
@@ -303,10 +303,6 @@ representation where the required number does not fit in the native
 form.  Conversion between these two representations is automatic and
 completely invisible to the Scheme level programmer.
 
-The infinities @samp{+inf.0} and @samp{-inf.0} are considered to be
-inexact integers.  They are explained in detail in the next section,
-together with reals and rationals.
-
 C has a host of different integer types, and Guile offers a host of
 functions to convert between them and the @code{SCM} representation.
 For example, a C @code{int} can be handled with @code{scm_to_int} and
@@ -537,7 +533,8 @@ infinity, depending on the sign of the divided number.
 
 The infinities are written @samp{+inf.0} and @samp{-inf.0},
 respectively.  This syntax is also recognized by @code{read} as an
-extension to the usual Scheme syntax.
+extension to the usual Scheme syntax.  The infinities are considered to
+be inexact, non-integer values.
 
 Dividing zero by zero yields something that is not a number at all:
 @samp{+nan.0}.  This is the special `not a number' value.
@@ -548,9 +545,8 @@ are implemented using the corresponding @acronym{IEEE} 754 values.
 They behave in arithmetic operations like @acronym{IEEE} 754 describes
 it, i.e., @code{(= +nan.0 +nan.0)} @result{} @code{#f}.
 
-The infinities are inexact integers and are considered to be both even
-and odd.  While @samp{+nan.0} is not @code{=} to itself, it is
-@code{eqv?} to itself.
+While @samp{+nan.0} is not @code{=} to itself, it is @code{eqv?} to
+itself.
 
 To test for the special values, use the functions @code{inf?} and
 @code{nan?}.

diff --git a/libguile/numbers.c b/libguile/numbers.c
index 21f2383..88b225c 100644 (file)
--- a/libguile/numbers.c
+++ b/libguile/numbers.c
@@ -1,4 +1,4 @@
-/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005, 2006, 2007, 2008, 2009, 2010 Free Software Foundation, Inc.
+/* Copyright (C) 1995,1996,1997,1998,1999,2000,2001,2002,2003,2004,2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
  *
  * Portions Copyright 1990, 1991, 1992, 1993 by AT&T Bell Laboratories
  * and Bellcore.  See scm_divide.
@@ -530,7 +530,7 @@ SCM_DEFINE (scm_odd_p, "odd?", 1, 0, 0,
       return scm_from_bool (odd_p);
     }
   else if (scm_is_true (scm_inf_p (n)))
-    return SCM_BOOL_T;
+    SCM_WRONG_TYPE_ARG (1, n);
   else if (SCM_REALP (n))
     {
       double rem = fabs (fmod (SCM_REAL_VALUE(n), 2.0));
@@ -565,7 +565,7 @@ SCM_DEFINE (scm_even_p, "even?", 1, 0, 0,
       return scm_from_bool (even_p);
     }
   else if (scm_is_true (scm_inf_p (n)))
-    return SCM_BOOL_T;
+    SCM_WRONG_TYPE_ARG (1, n);
   else if (SCM_REALP (n))
     {
       double rem = fabs (fmod (SCM_REAL_VALUE(n), 2.0));
@@ -3333,7 +3333,8 @@ SCM_DEFINE (scm_integer_p, "integer?", 1, 0, 0,
   if (SCM_COMPLEXP (x))
     return SCM_BOOL_F;
   r = SCM_REAL_VALUE (x);
-  /* +/-inf passes r==floor(r), making those #t */
+  if (isinf (r))
+    return SCM_BOOL_F;
   if (r == floor (r))
     return SCM_BOOL_T;
   return SCM_BOOL_F;

diff --git a/test-suite/tests/numbers.test b/test-suite/tests/numbers.test
index b548ad8..5ea4764 100644 (file)
--- a/test-suite/tests/numbers.test
+++ b/test-suite/tests/numbers.test
@@ -1,5 +1,5 @@
 ;;;; numbers.test --- tests guile's numbers     -*- scheme -*-
-;;;; Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2009, 2010 Free Software Foundation, Inc.
+;;;; Copyright (C) 2000, 2001, 2003, 2004, 2005, 2006, 2009, 2010, 2011 Free Software Foundation, Inc.
 ;;;;
 ;;;; This library is free software; you can redistribute it and/or
 ;;;; modify it under the terms of the GNU Lesser General Public
@@ -1508,8 +1508,8 @@
   (pass-if (and (= 3+0i (round 3+0i)) (integer? 3+0i)))
   (pass-if (and (= 1.0 (round 1.0)) (integer? 1.0)))
   (pass-if (not (integer? 1.3)))
-  (pass-if (integer? +inf.0))
-  (pass-if (integer? -inf.0))
+  (pass-if (not (integer? +inf.0)))
+  (pass-if (not (integer? -inf.0)))
   (pass-if (not (integer? +nan.0)))
   (pass-if (not (integer? 3+4i)))
   (pass-if (not (integer? #\a)))
@@ -2949,7 +2949,11 @@
   (pass-if (eqv? (* -1.0 12398 12398) (expt +12398i 2.0)))
   (pass-if (eqv-loosely? +i (expt -1 0.5)))
   (pass-if (eqv-loosely? +i (expt -1 1/2)))
-  (pass-if (eqv-loosely? 1.0+1.7320508075688i (expt -8 1/3))))
+  (pass-if (eqv-loosely? 1.0+1.7320508075688i (expt -8 1/3)))
+  (pass-if (eqv? +inf.0 (expt 2 +inf.0)))
+  (pass-if (eqv? +inf.0 (expt 2.0 +inf.0)))
+  (pass-if (eqv? 0.0 (expt 2 -inf.0)))
+  (pass-if (eqv? 0.0 (expt 2.0 -inf.0))))
 
 
 ;;;