Make the Lisp reader and string-to-float more consistent.

* data.c (atof): Remove decl; no longer used or needed.
(Fstring_to_number): Use new string_to_float function, to be
consistent with how the Lisp reader treats infinities and NaNs.
Do not assume that floating-point numbers represent EMACS_INT
without losing information; this is not true on most 64-bit hosts.
Avoid double-rounding errors, by insisting on integers when
parsing non-base-10 numbers, as the documentation specifies.
Report integer overflow instead of silently converting to
integers.
* lisp.h (string_to_float): New decl, replacing ...
(isfloat_string): Remove.
* lread.c (read1): Do not accept +. and -. as integers; this
appears to have been a coding error.  Similarly, do not accept
strings like +-1e0 as floating point numbers.  Do not report
overflow for some integer overflows and not others; instead,
report them all.  Break out the floating-point parsing into a new
function string_to_float, so that Fstring_to_number parses
floating point numbers consistently with the Lisp reader.
(string_to_float): New function, replacing isfloat_string.
This function checks for valid syntax and produces the resulting
Lisp float number too.

1 files changed, 25 insertions, 0 deletions

diff --git a/src/ChangeLog b/src/ChangeLog
index 4a675cc96c6..c232c242fd7 100644
--- a/src/ChangeLog
+++ b/src/ChangeLog
@@ -1,3 +1,28 @@
+2011-04-20  Paul Eggert  <eggert@cs.ucla.edu>
+
+        Make the Lisp reader and string-to-float more consistent.
+        * data.c (atof): Remove decl; no longer used or needed.
+        (Fstring_to_number): Use new string_to_float function, to be
+        consistent with how the Lisp reader treats infinities and NaNs.
+        Do not assume that floating-point numbers represent EMACS_INT
+        without losing information; this is not true on most 64-bit hosts.
+        Avoid double-rounding errors, by insisting on integers when
+        parsing non-base-10 numbers, as the documentation specifies.
+        Report integer overflow instead of silently converting to
+        integers.
+        * lisp.h (string_to_float): New decl, replacing ...
+        (isfloat_string): Remove.
+        * lread.c (read1): Do not accept +. and -. as integers; this
+        appears to have been a coding error.  Similarly, do not accept
+        strings like +-1e0 as floating point numbers.  Do not report
+        overflow for some integer overflows and not others; instead,
+        report them all.  Break out the floating-point parsing into a new
+        function string_to_float, so that Fstring_to_number parses
+        floating point numbers consistently with the Lisp reader.
+        (string_to_float): New function, replacing isfloat_string.
+        This function checks for valid syntax and produces the resulting
+        Lisp float number too.
+
 2011-04-19  Eli Zaretskii  <eliz@gnu.org>
 
         * syntax.h (SETUP_SYNTAX_TABLE_FOR_OBJECT): Fix setting of