linda:send() improvements

* Bumped version to 3.9.3
* new exposed variable linda.null that exposes the internal NIL_SENTINEL
marker
* linda:send() interprets send key linda.null as authorization to
silently send a single nil when not provided with anything to send
(useful when sending results of a function that can return nothing)

1 files changed, 6 insertions, 2 deletions

diff --git a/docs/index.html b/docs/index.html
index 6337647..c4a6441 100644
--- a/docs/index.html
+++ b/docs/index.html
@@ -70,7 +70,7 @@
                         </p>
 
                         <p>
-                                This document was revised on 26-Feb-14, and applies to version <tt>3.9.2</tt>.
+                                This document was revised on 27-Feb-14, and applies to version <tt>3.9.3</tt>.
                         </p>
                 </font>
         </center>
@@ -1038,7 +1038,7 @@
 <table border="1" bgcolor="#E0E0FF" cellpadding="10" style="width:50%"><tr><td><pre>
         h = lanes.linda( [opt_name, [opt_group]])
 
-        [true|lanes.cancel_error] = h:send( [timeout_secs,] key, ...)
+        [true|lanes.cancel_error] = h:send( [timeout_secs,] [h.null,] key, ...)
 
         [key, val]|[lanes.cancel_error] = h:receive( [timeout_secs,] key [, ...])
 
@@ -1071,6 +1071,10 @@
         <tt>send()</tt> returns <tt>true</tt> if the sending succeeded, and <tt>false</tt> if the queue limit was met, and the queue did not empty enough during the given timeout.
         <br/>
         (Since version 3.7.8) <tt>send()</tt> returns <tt>lanes.cancel_error</tt> if interrupted by a soft cancel request.
+        <br/>
+        If no data is provided after the key, <tt>send()</tt> raises an error. Since version 3.9.3,  if provided with <tt>linda.null</tt> before the actual key and there is no data to send, <tt>send()</tt> sends a single <tt>nil</tt>.
+        <br/>
+        Also, if <tt>linda.null</tt> is sent as data in a linda, it will be read as a <tt>nil</tt>.
 </p>
 
 <p>