Argument of flush-stream now optional.

* stream.c (flush_stream): Default the argument to
std_output.
(stream_init): Register flush-stream as having one
optional arg.

* txr.1: Updated flush-stream description.

2 files changed, 10 insertions, 3 deletions

diff --git a/stream.c b/stream.c
index 358c6eac..86a6cb60 100644
--- a/stream.c
+++ b/stream.c
@@ -3222,8 +3222,9 @@ val put_lines(val lines, val stream)
   return t;
 }
 
-val flush_stream(val stream)
+val flush_stream(val stream_in)
 {
+  val stream = default_arg(stream_in, std_output);
   struct strm_ops *ops = coerce(struct strm_ops *, cobj_ops(stream, stream_s));
   return ops->flush(stream);
 }
@@ -3963,7 +3964,7 @@ void stream_init(void)
   reg_fun(intern(lit("put-strings"), user_package), func_n2o(put_strings, 1));
   reg_fun(intern(lit("unget-char"), user_package), func_n2o(unget_char, 1));
   reg_fun(intern(lit("unget-byte"), user_package), func_n2o(unget_byte, 1));
-  reg_fun(intern(lit("flush-stream"), user_package), func_n1(flush_stream));
+  reg_fun(intern(lit("flush-stream"), user_package), func_n1o(flush_stream, 0));
   reg_fun(intern(lit("seek-stream"), user_package), func_n3(seek_stream));
   reg_fun(intern(lit("truncate-stream"), user_package), func_n2(truncate_stream));
   reg_fun(intern(lit("streamp"), user_package), func_n1(streamp));
diff --git a/txr.1 b/txr.1
index 1007bf6d..8b1b3d60 100644
--- a/txr.1
+++ b/txr.1
@@ -34519,7 +34519,7 @@ Both functions return
 
 .coNP Function @ flush-stream
 .synb
-.mets (flush-stream << stream )
+.mets (flush-stream <> [ stream ])
 .syne
 .desc
 This function is meaningful for output streams which accumulate data
@@ -34533,6 +34533,12 @@ to the operating system. If called on streams for which this function is not
 meaningful, it does nothing, and returns
 .codn nil .
 
+If
+.meta stream
+is omitted, the current value of
+.code *stdout*
+is used.
+
 .coNP Function @ seek-stream
 .synb
 .mets (seek-stream < stream < offset << whence )