compiler: tighter code for quasiliterals.

Give the sys:fmt-simple function argument defaulting so the
generated code doesn't have to call it with all five arguments
present, four of them nil being much of the time.

* eval.c (fmt_simple): Default all but the first four
arguments.
(eval_init): Re-register sys:fmt-simple as having only one
required argument.

* parser.c (read_file_common): Load version 1 or 2 files.
We are bumping the object file version to 2 because
now when we compile files, they won't work with older
TXR in which all five arguments to sys:fmt-simple are
required.

* share/txr/stdlib/compiler.tl (expand-quasi-mods):
Generate the sys:fmt-simple call with just enough
arguments to express the modifiers that were decoded.
(sexpand-quasi-args): Reduce the trivial modifier-less
sys:fmt-simple calls to just one argument.
(%tlo-ver%): Bump major version to 2.

1 files changed, 8 insertions, 5 deletions

diff --git a/eval.c b/eval.c
index 72f98210..0b374d50 100644
--- a/eval.c
+++ b/eval.c
@@ -2692,12 +2692,15 @@ val format_field(val obj, val modifier, val filter, val eval_fun)
   return do_format_field(obj, n, sep, range_ix, plist, filter);
 }
 
-static val fmt_simple(val obj, val n_in, val sep_in,
+static val fmt_simple(val obj, val n, val sep,
                           val range_ix, val plist)
 {
-  val n = if3(null(n_in), zero, n_in);
-  val sep = if3(null(sep_in), lit(" "), sep_in);
-  return do_format_field(fmt_tostring(obj), n, sep, range_ix, plist, nil);
+  return do_format_field(fmt_tostring(obj),
+                         default_arg(n, zero),
+                         default_arg(sep, lit(" ")),
+                         default_null_arg(range_ix),
+                         default_null_arg(plist),
+                         nil);
 }
 
 static val fmt_flex(val obj, val plist, struct args *args)
@@ -6532,7 +6535,7 @@ void eval_init(void)
   reg_fun(intern(lit("tprint"), user_package), func_n2o(tprint, 1));
   reg_fun(intern(lit("display-width"), user_package), func_n1(display_width));
 
-  reg_fun(intern(lit("fmt-simple"), system_package), func_n5(fmt_simple));
+  reg_fun(intern(lit("fmt-simple"), system_package), func_n5o(fmt_simple, 1));
   reg_fun(intern(lit("fmt-flex"), system_package), func_n2v(fmt_flex));
   reg_fun(intern(lit("fmt-join"), system_package), func_n0v(fmt_join));