* stream.c (put_line): Default string argument to empty string.

(stream_init): Change how put_line is registered to take advantage of
new optional parameter.

* txr.1: Updated.

3 files changed, 13 insertions, 4 deletions

diff --git a/ChangeLog b/ChangeLog
index 1ad8d631..8d14ecdc 100644
--- a/ChangeLog
+++ b/ChangeLog
@@ -1,3 +1,11 @@
+2014-03-05  Kaz Kylheku  <kaz@kylheku.com>
+
+	* stream.c (put_line): Default string argument to empty string.
+	(stream_init): Change how put_line is registered to take advantage of
+	new optional parameter.
+
+	* txr.1: Updated.
+
 2014-03-04  Kaz Kylheku  <kaz@kylheku.com>
 
 	* arith.c (logten): New function.
diff --git a/stream.c b/stream.c
index 3a3d2d77..5761894e 100644
--- a/stream.c
+++ b/stream.c
@@ -1968,7 +1968,7 @@ val put_byte(val byte, val stream)
 
 val put_line(val string, val stream)
 {
-  return (put_string(string, stream), put_char(chr('\n'), stream));
+  return (put_string(default_arg(string, null_string), stream), put_char(chr('\n'), stream));
 }
 
 val flush_stream(val stream)
@@ -2678,7 +2678,7 @@ void stream_init(void)
   reg_fun(intern(lit("get-char"), user_package), func_n1o(get_char, 0));
   reg_fun(intern(lit("get-byte"), user_package), func_n1o(get_byte, 0));
   reg_fun(intern(lit("put-string"), user_package), func_n2o(put_string, 1));
-  reg_fun(intern(lit("put-line"), user_package), func_n2o(put_line, 1));
+  reg_fun(intern(lit("put-line"), user_package), func_n2o(put_line, 0));
   reg_fun(intern(lit("put-char"), user_package), func_n2o(put_char, 1));
   reg_fun(intern(lit("put-byte"), user_package), func_n2o(put_byte, 1));
   reg_fun(intern(lit("unget-char"), user_package), func_n2o(unget_char, 1));
diff --git a/txr.1 b/txr.1
index deff8d86..dcbbd92c 100644
--- a/txr.1
+++ b/txr.1
@@ -11628,7 +11628,7 @@ indeterminate.
 .TP
 Syntax:
 
-  (put-line <string> [<stream>])
+  (put-line [<string> [<stream>]])
   (put-string <string> [<stream>])
   (put-char <char> [<stream>])
   (put-byte <byte> [<stream>])
@@ -11645,7 +11645,8 @@ stream is based on bytes, then the character is encoded into UTF-8 and multiple
 bytes are written. Streams which support put-char also support put-line, and
 put-string. The put-string function writes the characters of a string out to
 the stream as if by multiple calls to put-char. The put-line function is like
-put-string, but also writes an additional newline character.
+put-string, but also writes an additional newline character. The string
+is optional in put-line, and defaults to the empty string.
 
 The put-byte function writes a raw byte given by the <byte> argument
 to <stream>, if <stream> supports a byte write operation. The byte