New syntax: Forks & merge polishing

docs/guide/graphs.rst

@@ -396,6 +396,33 @@ You can also create single nodes, and the api provide the same capability on sin
     graph.add_chain(..., _output="foo")
 
 
+Orphan nodes / chains
+:::::::::::::::::::::
+
+The default behaviour of `add_chain` (or `get_cursor`) is to connect the first node to the special `BEGIN` token, which
+instruct |bonobo| to call the connected node once without parameter to kickstart the data stream.
+
+This is normally what you want, but there are ways to override it, as you may want to add "orphan" nodes or chains to your graph.
+
+.. code-block:: python
+
+    import bonobo
+
+    graph = bonobo.Graph()
+
+    # using add_node will naturally add a node as "orphan"   
+    graph.add_node(a)
+
+    # using add_chain with "None" as the input will create an orphan chain
+    graph.add_chain(a, b, c, _input=None)
+
+    # using the new syntax, you can use either get_cursor(None) or the orphan() shortcut
+    graph.get_cursor(None) >> a >> b >> c
+    
+    # ... using the shortcut ...
+    graph.orphan() >> a >> b >> c
+
+
 Connecting two nodes
 ::::::::::::::::::::