parser: catch out-of-range floats.

* parser.l (out_of_range_float): New static function.
(grammar): Check for flo_str returning nil in several places;
that value is returned for out of range floats. This is not
documented!

* txr.1: Document athat flo-str returns nil for out-of-range
floats.

1 files changed, 5 insertions, 0 deletions

diff --git a/txr.1 b/txr.1
index 7f2c5cf9..89f6c32e 100644
--- a/txr.1
+++ b/txr.1
@@ -36741,6 +36741,11 @@ part denoted by the letter
 or
 .codn e ,
 an optional sign and one or more optional exponent digits.
+If the value specified by
+.meta string
+is out of range of the floating-point representation, then
+.code nil
+is returned.
 
 The
 .code num-str