* eval.c (force): Default the new second argument of source_loc_str.

(eval_error): Derive location of error from
the last_form_evaled, if form doesn't have it.
(eval_init): Re-register source-loc-str as binary with an optional arg.

* match.c (debuglf, sem_error, file_err, typed_error): Default new
argument of source_loc_str.

* parser.h (source_loc_str): Declaration updated.

* parser.l (source_loc_str): Take second argument which specifies
alternative value if the source loc info is not found.

* unwind.c (uw_throw): Simplify code thanks to source_loc_str
default argument.

* txr.1: Document new argument of source-loc-str.

1 files changed, 4 insertions, 4 deletions

diff --git a/parser.l b/parser.l
index b1fb63fe..2447e5fa 100644
--- a/parser.l
+++ b/parser.l
@@ -991,12 +991,12 @@ val source_loc(val form)
   return gethash(form_to_ln_hash, form);
 }
 
-val source_loc_str(val form)
+val source_loc_str(val form, val alt)
 {
   cons_bind (line, file, gethash(form_to_ln_hash, form));
-  return if3(line,
-             format(nil, lit("~a:~a"), file, line, nao),
-             lit("source location n/a"));
+  if (missingp(alt))
+    alt = lit("source location n/a");
+  return if3(line, format(nil, lit("~a:~a"), file, line, nao), alt);
 }
 
 void parser_l_init(void)