New variables for floating-point printing control.

* lib.c (obj_print_impl): Instead of hard-coded "~s", obtain
the format string for floats from the *print-flo-format*
special variable, whose default value is "~s".

* stream.c (print_flo_digits_s, print_flo_format_s): New symbol
variables.
(formatv): Use *print-flo-digits* value for default precision
for ~f and ~e, rather than hard-coded 3.
(stream_init): Initialize print_flo_digits_s and print_flo_format_s, and
register special variables under those symbols.

* stream.h (print_flo_digits_s, print_flo_format_s): Declared.

* txr.1: Documented new specials.

1 files changed, 4 insertions, 1 deletions

diff --git a/lib.c b/lib.c
index d0cee7e6..d1f765a9 100644
--- a/lib.c
+++ b/lib.c
@@ -8406,7 +8406,10 @@ finish:
   case NUM:
   case BGNUM:
   case FLNUM:
-    format(out, lit("~s"), obj, nao);
+    {
+      val fmt = cdr(lookup_var(nil, print_flo_format_s));
+      format(out, fmt, obj, nao);
+    }
     break;
   case SYM:
     if (!pretty) {