Several fixes for formatting bignums

* src/bignum.c: Include stdlib.h, for abs.
(bignum_bufsize, bignum_to_c_string): New functions.
* src/bignum.c (bignum_to_string):
* src/print.c (print_vectorlike): Use them.
* src/editfns.c (styled_format): Instead of having a separate
buffer for sprintf (which does not work for bignums), just append
to the main buffer.  When formatting bignums, add support for the
standard integer flags -, #, 0, + and space.  Fix some comments.
Capitalize properly when formatting bignums with %X.  Use
functions like c_isdigit rather than reinventing the wheel.
Simplify computation of excess precision.
* src/print.c: Do not include bignum.h; no longer needed.
(print_vectorlike): Avoid recalculating string length.
* test/src/editfns-tests.el (format-bignum):
Test some of the above fixes.

1 files changed, 4 insertions, 1 deletions

diff --git a/src/lisp.h b/src/lisp.h
index c5b51ba3b35..36ca32c3c05 100644
--- a/src/lisp.h
+++ b/src/lisp.h
@@ -3278,9 +3278,12 @@ set_sub_char_table_contents (Lisp_Object table, ptrdiff_t idx, Lisp_Object val)
   XSUB_CHAR_TABLE (table)->contents[idx] = val;
 }
 
-/* Defined in bignum.c.  */
+/* Defined in bignum.c.  This part of bignum.c's API does not require
+   the caller to access bignum internals; see bignum.h for that.  */
 extern intmax_t bignum_to_intmax (Lisp_Object);
 extern uintmax_t bignum_to_uintmax (Lisp_Object);
+extern ptrdiff_t bignum_bufsize (Lisp_Object, int);
+extern ptrdiff_t bignum_to_c_string (char *, ptrdiff_t, Lisp_Object, int);
 extern Lisp_Object bignum_to_string (Lisp_Object, int);
 extern Lisp_Object make_bignum_str (char const *, int);
 extern Lisp_Object double_to_bignum (double);