Applied patch #1635: Float patch for inf and nan on Windows (and other platforms).

The patch unifies float("inf") and repr(float("inf")) on all platforms.

Doc/c-api/utilities.rst

@@ -1066,7 +1066,7 @@ The following functions provide locale-independent string to number conversions.
 
    .. versionadded:: 2.4
 
-
+ 
 .. cfunction:: double PyOS_ascii_atof(const char *nptr)
 
    Convert a string to a :ctype:`double` in a locale-independent way.
@@ -1075,6 +1075,22 @@ The following functions provide locale-independent string to number conversions.
 
    See the Unix man page :manpage:`atof(2)` for details.
 
+   
+.. cfunction:: char * PyOS_stricmp(char *s1, char *s2)
+
+   Case insensitive comparsion of strings. The functions works almost
+   identical to :cfunc:`strcmp` except that it ignores the case.
+
+   .. versionadded:: 2.6
+
+
+.. cfunction:: char * PyOS_strnicmp(char *s1, char *s2, Py_ssize_t  size)
+
+   Case insensitive comparsion of strings. The functions works almost
+   identical to :cfunc:`strncmp` except that it ignores the case.
+
+   .. versionadded:: 2.6
+
 
 .. _reflection:
 

Doc/library/functions.rst

@@ -434,7 +434,8 @@ available.  They are listed here in alphabetical order.
 
    Convert a string or a number to floating point.  If the argument is a string, it
    must contain a possibly signed decimal or floating point number, possibly
-   embedded in whitespace. Otherwise, the argument may be a plain or long integer
+   embedded in whitespace. The argument may also be [+|-]nan or [+|-]inf.
+   Otherwise, the argument may be a plain or long integer
    or a floating point number, and a floating point number with the same value
    (within Python's floating point precision) is returned.  If no argument is
    given, returns ``0.0``.
@@ -446,9 +447,10 @@ available.  They are listed here in alphabetical order.
          single: Infinity
 
       When passing in a string, values for NaN and Infinity may be returned, depending
-      on the underlying C library.  The specific set of strings accepted which cause
+      on the underlying C library.  Float accepts the strings nan, inf and -inf for
-      these values to be returned depends entirely on the C library and is known to
+      NaN and positive or negative infinity. The case and a leading + are ignored as
-      vary.
+      well as a leading - is ignored for NaN. Float always represents NaN and infinity
+      as nan, inf or -inf.
 
    The float type is described in :ref:`typesnumeric`.
 

Doc/library/stdtypes.rst

@@ -298,7 +298,7 @@ numeric operations have a higher priority than comparison operations):
 +--------------------+---------------------------------+--------+
 | ``long(x)``        | *x* converted to long integer   | \(2)   |
 +--------------------+---------------------------------+--------+
-| ``float(x)``       | *x* converted to floating point |        |
+| ``float(x)``       | *x* converted to floating point | \(6)   |
 +--------------------+---------------------------------+--------+
 | ``complex(re,im)`` | a complex number with real part |        |
 |                    | *re*, imaginary part *im*.      |        |
@@ -355,6 +355,13 @@ Notes:
    Also referred to as integer division.  The resultant value is a whole integer,
    though the result's type is not necessarily int.
 
+(6)
+   float also accepts the strings "nan" and "inf" with an optional prefix "+" 
+   or "-" for Not a Number (NaN) and positive or negative infinity.
+   
+   .. versionadded:: 2.6
+
+   
 .. % XXXJH exceptions: overflow (when? what operations?) zerodivision
 
 

Include/Python.h

@@ -129,6 +129,7 @@
 #include "eval.h"
 
 #include "pystrtod.h"
+#include "pystrcmp.h"
 
 /* _Py_Mangle is defined in compile.c */
 PyAPI_FUNC(PyObject*) _Py_Mangle(PyObject *p, PyObject *name);

Include/pyport.h

@@ -349,6 +349,17 @@ extern "C" {
 #define Py_SAFE_DOWNCAST(VALUE, WIDE, NARROW) (NARROW)(VALUE)
 #endif
 
+/* High precision defintion of pi and e (Euler)
+ * The values are taken from libc6's math.h.
+ */
+#ifndef Py_MATH_PI
+#define Py_MATH_PI 3.1415926535897932384626433832795029L
+#endif
+
+#ifndef Py_MATH_E
+#define Py_MATH_E 2.7182818284590452353602874713526625L
+#endif
+
 /* Py_IS_NAN(X)
  * Return 1 if float or double arg is a NaN, else 0.
  * Caution:
@@ -358,8 +369,12 @@ extern "C" {
  *     a platform where it doesn't work.
  */
 #ifndef Py_IS_NAN
+#ifdef HAVE_ISNAN
+#define Py_IS_NAN(X) isnan(X)
+#else
 #define Py_IS_NAN(X) ((X) != (X))
 #endif
+#endif
 
 /* Py_IS_INFINITY(X)
  * Return 1 if float or double arg is an infinity, else 0.
@@ -370,8 +385,12 @@ extern "C" {
  *    Override in pyconfig.h if you have a better spelling on your platform.
  */
 #ifndef Py_IS_INFINITY
+#ifdef HAVE_ISINF
+#define Py_IS_INFINITY(X) isinf(X)
+#else
 #define Py_IS_INFINITY(X) ((X) && (X)*0.5 == (X))
 #endif
+#endif
 
 /* Py_IS_FINITE(X)
  * Return 1 if float or double arg is neither infinite nor NAN, else 0.
@@ -379,8 +398,12 @@ extern "C" {
  * macro for this particular test is useful
  */
 #ifndef Py_IS_FINITE
+#ifdef HAVE_ISFINITE
+#define Py_IS_FINITE(X) isfinite
+#else
 #define Py_IS_FINITE(X) (!Py_IS_INFINITY(X) && !Py_IS_NAN(X))
 #endif
+#endif
 
 /* HUGE_VAL is supposed to expand to a positive double infinity.  Python
  * uses Py_HUGE_VAL instead because some platforms are broken in this
@@ -393,6 +416,15 @@ extern "C" {
 #define Py_HUGE_VAL HUGE_VAL
 #endif
 
+/* Py_NAN
+ * A value that evaluates to a NaN. On IEEE 754 platforms INF*0 or
+ * INF/INF works. Define Py_NO_NAN in pyconfig.h if your platform
+ * doesn't support NaNs.
+ */
+#if !defined(Py_NAN) && !defined(Py_NO_NAN)
+#define Py_NAN (Py_HUGE_VAL * 0.)
+#endif
+
 /* Py_OVERFLOWED(X)
  * Return 1 iff a libm function overflowed.  Set errno to 0 before calling
  * a libm function, and invoke this macro after, passing the function

Include/pystrcmp.h

@@ -0,0 +1,23 @@
+#ifndef Py_STRCMP_H
+#define Py_STRCMP_H
+
+#ifdef __cplusplus
+extern "C" {
+#endif
+
+PyAPI_FUNC(int) PyOS_mystrnicmp(const char *, const char *, Py_ssize_t);
+PyAPI_FUNC(int) PyOS_mystricmp(const char *, const char *);
+
+#ifdef MS_WINDOWS
+#define PyOS_strnicmp strnicmp
+#define PyOS_stricmp stricmp
+#else
+#define PyOS_strnicmp PyOS_mystrnicmp
+#define PyOS_stricmp PyOS_mystricmp
+#endif
+
+#ifdef __cplusplus
+}
+#endif
+
+#endif /* !Py_STRCMP_H */

Lib/test/test_float.py

@@ -3,6 +3,12 @@ import unittest, struct
 import os
 from test import test_support
 
+def isinf(x):
+    return x * 0.5 == x
+
+def isnan(x):
+    return x != x
+
 class FormatFunctionsTestCase(unittest.TestCase):
 
     def setUp(self):
@@ -128,13 +134,78 @@ class ReprTestCase(unittest.TestCase):
             self.assertEqual(v, eval(repr(v)))
         floats_file.close()
 
+# Beginning with Python 2.6 float has cross platform compatible
+# ways to create and representate inf and nan
+class InfNanTest(unittest.TestCase):
+    def test_inf_from_str(self):
+        self.assert_(isinf(float("inf")))
+        self.assert_(isinf(float("+inf")))
+        self.assert_(isinf(float("-inf")))
+
+        self.assertEqual(repr(float("inf")), "inf")
+        self.assertEqual(repr(float("+inf")), "inf")
+        self.assertEqual(repr(float("-inf")), "-inf")
+
+        self.assertEqual(repr(float("INF")), "inf")
+        self.assertEqual(repr(float("+Inf")), "inf")
+        self.assertEqual(repr(float("-iNF")), "-inf")
+
+        self.assertEqual(str(float("inf")), "inf")
+        self.assertEqual(str(float("+inf")), "inf")
+        self.assertEqual(str(float("-inf")), "-inf")
+
+        self.assertRaises(ValueError, float, "info")
+        self.assertRaises(ValueError, float, "+info")
+        self.assertRaises(ValueError, float, "-info")
+        self.assertRaises(ValueError, float, "in")
+        self.assertRaises(ValueError, float, "+in")
+        self.assertRaises(ValueError, float, "-in")
+
+    def test_inf_as_str(self):
+        self.assertEqual(repr(1e300 * 1e300), "inf")
+        self.assertEqual(repr(-1e300 * 1e300), "-inf")
+
+        self.assertEqual(str(1e300 * 1e300), "inf")
+        self.assertEqual(str(-1e300 * 1e300), "-inf")
+
+    def test_nan_from_str(self):
+        self.assert_(isnan(float("nan")))
+        self.assert_(isnan(float("+nan")))
+        self.assert_(isnan(float("-nan")))
+
+        self.assertEqual(repr(float("nan")), "nan")
+        self.assertEqual(repr(float("+nan")), "nan")
+        self.assertEqual(repr(float("-nan")), "nan")
+
+        self.assertEqual(repr(float("NAN")), "nan")
+        self.assertEqual(repr(float("+NAn")), "nan")
+        self.assertEqual(repr(float("-NaN")), "nan")
+
+        self.assertEqual(str(float("nan")), "nan")
+        self.assertEqual(str(float("+nan")), "nan")
+        self.assertEqual(str(float("-nan")), "nan")
+
+        self.assertRaises(ValueError, float, "nana")
+        self.assertRaises(ValueError, float, "+nana")
+        self.assertRaises(ValueError, float, "-nana")
+        self.assertRaises(ValueError, float, "na")
+        self.assertRaises(ValueError, float, "+na")
+        self.assertRaises(ValueError, float, "-na")
+
+    def test_nan_as_str(self):
+        self.assertEqual(repr(1e300 * 1e300 * 0), "nan")
+        self.assertEqual(repr(-1e300 * 1e300 * 0), "nan")
+
+        self.assertEqual(str(1e300 * 1e300 * 0), "nan")
+        self.assertEqual(str(-1e300 * 1e300 * 0), "nan")
 
 def test_main():
     test_support.run_unittest(
         FormatFunctionsTestCase,
         UnknownFormatTestCase,
         IEEEFormatTestCase,
-        #ReprTestCase
+        ReprTestCase,
+        InfNanTest,
         )
 
 if __name__ == '__main__':

Makefile.pre.in

@@ -275,6 +275,7 @@ PYTHON_OBJS=	\
 		Python/sysmodule.o \
 		Python/traceback.o \
 		Python/getopt.o \
+		Python/pystrcmp.o \
 		Python/pystrtod.o \
 		Python/$(DYNLOADFILE) \
 		$(LIBOBJS) \
@@ -554,6 +555,8 @@ PYTHON_HEADERS= \
 		Include/pymem.h \
 		Include/pyport.h \
 		Include/pystate.h \
+		Include/pystrtod.h \
+		Include/pystrcmp.h \
 		Include/pythonrun.h \
 		Include/rangeobject.h \
                 Include/setobject.h \

Misc/NEWS

@@ -12,6 +12,13 @@ What's New in Python 2.6 alpha 1?
 Core and builtins
 -----------------
 
+- Issue #1635: Platform independent creation and representation of NaN
+  and INF. float("nan"), float("inf") and float("-inf") now work on every
+  platform with IEEE 754 semantics.
+
+- Added case insensitive comparsion methods ``PyOS_stricmp(char*, char*)``
+  and ``PyOS_strnicmp(char*, char*, Py_ssize_t)``.
+
 - Compiler now generates simpler and faster code for dictionary literals.
   The oparg for BUILD_MAP now indicates an estimated dictionary size.
   There is a new opcode, STORE_MAP, for adding entries to the dictionary.

Objects/floatobject.c

@@ -128,7 +128,7 @@ still supported but now *officially* useless:  if pend is not NULL,
 PyObject *
 PyFloat_FromString(PyObject *v, char **pend)
 {
-	const char *s, *last, *end;
+	const char *s, *last, *end, *sp;
 	double x;
 	char buffer[256]; /* for errors */
 #ifdef Py_USING_UNICODE
@@ -171,6 +171,7 @@ PyFloat_FromString(PyObject *v, char **pend)
 		PyErr_SetString(PyExc_ValueError, "empty string for float()");
 		return NULL;
 	}
+	sp = s;
 	/* We don't care about overflow or underflow.  If the platform supports
 	 * them, infinities and signed zeroes (on underflow) are fine.
 	 * However, strtod can return 0 for denormalized numbers, where atof
@@ -186,7 +187,26 @@ PyFloat_FromString(PyObject *v, char **pend)
 	   byte at the end of the string, when the input is inf(inity). */
 	if (end > last)
 		end = last;
+	/* Check for inf and nan. This is done late because it rarely happens. */
 	if (end == s) {
+		char *p = (char*)sp;
+		int sign = 1;
+
+		if (*p == '-') {
+			sign = -1;
+			p++;
+		}
+		if (*p == '+') {
+			p++;
+		}
+		if (PyOS_strnicmp(p, "inf", 4) == 0) {
+			return PyFloat_FromDouble(sign * Py_HUGE_VAL);
+		}
+#ifdef Py_NAN
+		if(PyOS_strnicmp(p, "nan", 4) == 0) {
+			return PyFloat_FromDouble(Py_NAN);
+		}
+#endif
 		PyOS_snprintf(buffer, sizeof(buffer),
 			      "invalid literal for float(): %.200s", s);
 		PyErr_SetString(PyExc_ValueError, buffer);
@@ -271,6 +291,8 @@ format_float(char *buf, size_t buflen, PyFloatObject *v, int precision)
 {
 	register char *cp;
 	char format[32];
+	int i;
+
 	/* Subroutine for float_repr and float_print.
 	   We want float numbers to be recognizable as such,
 	   i.e., they should contain a decimal point or an exponent.
@@ -293,7 +315,33 @@ format_float(char *buf, size_t buflen, PyFloatObject *v, int precision)
 		*cp++ = '.';
 		*cp++ = '0';
 		*cp++ = '\0';
+		return;
 	}
+	/* Checking the next three chars should be more than enough to
+	 * detect inf or nan, even on Windows. We check for inf or nan
+	 * at last because they are rare cases.
+	 */
+	for (i=0; *cp != '\0' && i<3; cp++, i++) {
+		if (isdigit(Py_CHARMASK(*cp)) || *cp == '.')
+			continue;
+		/* found something that is neither a digit nor point
+		 * it might be a NaN or INF
+		 */
+#ifdef Py_NAN
+		if (Py_IS_NAN(v->ob_fval)) {
+			strcpy(buf, "nan");
+		}
+                else
+#endif
+		if (Py_IS_INFINITY(v->ob_fval)) {
+			cp = buf;
+			if (*cp == '-')
+				cp++;
+			strcpy(cp, "inf");
+		}
+		break;
+	}
+
 }
 
 /* XXX PyFloat_AsStringEx should not be a public API function (for one

PC/pyconfig.h

@@ -386,6 +386,15 @@ Py_NO_ENABLE_SHARED to find out.  Also support MS_NO_COREDLL for b/w compat */
 
 /* Fairly standard from here! */
 
+/* Define to 1 if you have the `copysign' function. */
+/* #define HAVE_COPYSIGN 1*/
+
+/* Define to 1 if you have the `isinf' function. */
+#define HAVE_ISINF 1
+
+/* Define to 1 if you have the `isnan' function. */
+#define HAVE_ISNAN 1
+
 /* Define if on AIX 3.
    System headers sometimes define this.
    We just want to avoid a redefinition error message.  */

PCbuild/pythoncore.vcproj

@@ -700,6 +700,10 @@
 		<File
 			RelativePath="..\Python\pystate.c">
 		</File>
+		<File
+			RelativePath="..\Python\pystrcmp.c"
+			>
+		</File>
 		<File
 			RelativePath="..\Python\pystrtod.c">
 		</File>

PCbuild8/pythoncore/pythoncore.vcproj

@@ -735,6 +735,10 @@
 				RelativePath="..\..\Python\pystate.c"
 				>
 			</File>
+			<File
+				RelativePath="..\..\Python\pystrcmp.c"
+				>
+			</File>
 			<File
 				RelativePath="..\..\Python\pystrtod.c"
 				>
@@ -1193,6 +1197,10 @@
 				RelativePath="..\..\Include\pystate.h"
 				>
 			</File>
+			<File
+				RelativePath="..\..\Include\pystrcmp.h"
+				>
+			</File>
 			<File
 				RelativePath="..\..\Include\pystrtod.h"
 				>

PCbuild9/pythoncore.vcproj

@@ -874,6 +874,10 @@
 				RelativePath="..\Include\pystate.h"
 				>
 			</File>
+			<File
+				RelativePath="..\Include\pystrcmp.h"
+				>
+			</File>
 			<File
 				RelativePath="..\Include\pystrtod.h"
 				>
@@ -1714,6 +1718,10 @@
 				RelativePath="..\Python\pystate.c"
 				>
 			</File>
+			<File
+				RelativePath="..\Python\pystrcmp.c"
+				>
+			</File>
 			<File
 				RelativePath="..\Python\pystrtod.c"
 				>

Python/pystrcmp.c

@@ -0,0 +1,25 @@
+/* Cross platform case insenstive string compare functions
+ */
+
+#include "Python.h"
+
+int
+PyOS_mystrnicmp(const char *s1, const char *s2, Py_ssize_t size)
+{
+	if (size == 0)
+		return 0;
+	while ((--size > 0) && (tolower(*s1) == tolower(*s2))) {
+		if (!*s1++ || !*s2++)
+			break;
+	}
+	return tolower(*s1) - tolower(*s2);
+}
+
+int
+PyOS_mystricmp(const char *s1, const char *s2)
+{
+	while (*s1 && (tolower(*s1++) == tolower(*s2++))) {
+		;
+	}
+	return (tolower(*s1) - tolower(*s2));
+}

configure

@@ -1,5 +1,5 @@
 #! /bin/sh
-# From configure.in Revision: 59484 .
+# From configure.in Revision: 59533 .
 # Guess values for system-dependent variables and create Makefiles.
 # Generated by GNU Autoconf 2.61 for python 2.6.
 #
@@ -20368,6 +20368,9 @@ echo "${ECHO_T}default LIBC=\"$LIBC\"" >&6; }
 fi
 
 
+# ************************************
+# * Check for mathematical functions *
+# ************************************
 # check for hypot() in math library
 LIBS_SAVE=$LIBS
 LIBS="$LIBS $LIBM"
@@ -20473,6 +20476,105 @@ fi
 done
 
 
+
+
+
+
+
+for ac_func in copysign isfinite isnan isinf
+do
+as_ac_var=`echo "ac_cv_func_$ac_func" | $as_tr_sh`
+{ echo "$as_me:$LINENO: checking for $ac_func" >&5
+echo $ECHO_N "checking for $ac_func... $ECHO_C" >&6; }
+if { as_var=$as_ac_var; eval "test \"\${$as_var+set}\" = set"; }; then
+  echo $ECHO_N "(cached) $ECHO_C" >&6
+else
+  cat >conftest.$ac_ext <<_ACEOF
+/* confdefs.h.  */
+_ACEOF
+cat confdefs.h >>conftest.$ac_ext
+cat >>conftest.$ac_ext <<_ACEOF
+/* end confdefs.h.  */
+/* Define $ac_func to an innocuous variant, in case <limits.h> declares $ac_func.
+   For example, HP-UX 11i <limits.h> declares gettimeofday.  */
+#define $ac_func innocuous_$ac_func
+
+/* System header to define __stub macros and hopefully few prototypes,
+    which can conflict with char $ac_func (); below.
+    Prefer <limits.h> to <assert.h> if __STDC__ is defined, since
+    <limits.h> exists even on freestanding compilers.  */
+
+#ifdef __STDC__
+# include <limits.h>
+#else
+# include <assert.h>
+#endif
+
+#undef $ac_func
+
+/* Override any GCC internal prototype to avoid an error.
+   Use char because int might match the return type of a GCC
+   builtin and then its argument prototype would still apply.  */
+#ifdef __cplusplus
+extern "C"
+#endif
+char $ac_func ();
+/* The GNU C library defines this for functions which it implements
+    to always fail with ENOSYS.  Some functions are actually named
+    something starting with __ and the normal name is an alias.  */
+#if defined __stub_$ac_func || defined __stub___$ac_func
+choke me
+#endif
+
+int
+main ()
+{
+return $ac_func ();
+  ;
+  return 0;
+}
+_ACEOF
+rm -f conftest.$ac_objext conftest$ac_exeext
+if { (ac_try="$ac_link"
+case "(($ac_try" in
+  *\"* | *\`* | *\\*) ac_try_echo=\$ac_try;;
+  *) ac_try_echo=$ac_try;;
+esac
+eval "echo \"\$as_me:$LINENO: $ac_try_echo\"") >&5
+  (eval "$ac_link") 2>conftest.er1
+  ac_status=$?
+  grep -v '^ *+' conftest.er1 >conftest.err
+  rm -f conftest.er1
+  cat conftest.err >&5
+  echo "$as_me:$LINENO: \$? = $ac_status" >&5
+  (exit $ac_status); } && {
+	 test -z "$ac_c_werror_flag" ||
+	 test ! -s conftest.err
+       } && test -s conftest$ac_exeext &&
+       $as_test_x conftest$ac_exeext; then
+  eval "$as_ac_var=yes"
+else
+  echo "$as_me: failed program was:" >&5
+sed 's/^/| /' conftest.$ac_ext >&5
+
+	eval "$as_ac_var=no"
+fi
+
+rm -f core conftest.err conftest.$ac_objext conftest_ipa8_conftest.oo \
+      conftest$ac_exeext conftest.$ac_ext
+fi
+ac_res=`eval echo '${'$as_ac_var'}'`
+	       { echo "$as_me:$LINENO: result: $ac_res" >&5
+echo "${ECHO_T}$ac_res" >&6; }
+if test `eval echo '${'$as_ac_var'}'` = yes; then
+  cat >>confdefs.h <<_ACEOF
+#define `echo "HAVE_$ac_func" | $as_tr_cpp` 1
+_ACEOF
+
+fi
+done
+
+
 LIBS=$LIBS_SAVE
 
 # check for wchar.h

configure.in

@@ -2974,10 +2974,16 @@ else AC_MSG_ERROR([proper usage is --with-libc=STRING])
 fi],
 [AC_MSG_RESULT(default LIBC="$LIBC")])
 
+# ************************************
+# * Check for mathematical functions *
+# ************************************
 # check for hypot() in math library
 LIBS_SAVE=$LIBS
 LIBS="$LIBS $LIBM"
 AC_REPLACE_FUNCS(hypot)
+
+AC_CHECK_FUNCS(copysign isfinite isnan isinf)
+
 LIBS=$LIBS_SAVE
 
 # check for wchar.h

pyconfig.h.in

@@ -85,6 +85,9 @@
 /* Define to 1 if you have the <conio.h> header file. */
 #undef HAVE_CONIO_H
 
+/* Define to 1 if you have the `copysign' function. */
+#undef HAVE_COPYSIGN
+
 /* Define to 1 if you have the `ctermid' function. */
 #undef HAVE_CTERMID
 
@@ -288,6 +291,15 @@
 /* Define to 1 if you have the <io.h> header file. */
 #undef HAVE_IO_H
 
+/* Define to 1 if you have the `isfinite' function. */
+#undef HAVE_ISFINITE
+
+/* Define to 1 if you have the `isinf' function. */
+#undef HAVE_ISINF
+
+/* Define to 1 if you have the `isnan' function. */
+#undef HAVE_ISNAN
+
 /* Define to 1 if you have the `kill' function. */
 #undef HAVE_KILL
 
@@ -1028,3 +1040,4 @@
 
 #endif /*Py_PYCONFIG_H*/
 
+