Update documents to describe dynamic choice of port side

diff --git a/doc/info/attrs.html b/doc/info/attrs.html
index 58967cfb80db7d38ea7e7ee519e38ac528fffdd7..ab39cb51a245dbace46aac3198a64d0bcbd89424 100644 (file)
--- a/doc/info/attrs.html
+++ b/doc/info/attrs.html
@@ -1817,14 +1817,17 @@ the given types.
   having the given <I>portname</I>,
   or have an <A HREF=shapes.html#html>HTML-like label</A>, one of
   whose components has a <TT>PORT</TT> attribute set to <I>portname</I>.
-  In this case, the edge is aimed for the center of the corresponding
-  field.
   <P>
   If a compass point is used, it must have the form
-  <TT>"n","ne","e","se","s","sw","w","nw"</TT>. This modifies the edge
+  <TT>"n","ne","e","se","s","sw","w","nw","c","_"</TT>. This modifies the edge
   placement to aim for the corresponding compass point on the port or,
   in the second form where no <I>portname</I> is supplied, on the node
-  itself.
+  itself. The compass point "c" specifies the center of the node or port.
+  The compass point "_" specifies that an appropriate side of the port
+  adjacent to the exterior of the node should be used, if such exists.
+  Otherwise, the center is used.
+  If no compass point is used with a portname, the default value is "_".
+  <P>
   <P>
   This attribute can be attached to an edge using the
   <A HREF=#k:headport>headport</A> and

diff --git a/doc/info/lang.html b/doc/info/lang.html
index 1eb13a4fa29d178d53b0d1c1bac7d8dc840b47e0..9945075d0748f91c850444a4c1a73e2bdb5c7707 100644 (file)
--- a/doc/info/lang.html
+++ b/doc/info/lang.html
@@ -105,14 +105,15 @@ Vertical bars | separate alternatives.
 <TR>
   <TD ALIGN=RIGHT><I>compass_pt</I></TD>
   <TD ALIGN=LEFT>:</TD>
-  <TD ALIGN=LEFT>(<B>n</B> | <B>ne</B> | <B>e</B> | <B>se</B> | <B>s</B> | <B>sw</B> | <B>w</B> | <B>nw</B>)</TD>
+  <TD ALIGN=LEFT>(<B>n</B> | <B>ne</B> | <B>e</B> | <B>se</B> | <B>s</B> | <B>sw</B> | <B>w</B> | <B>nw</B> | <B>c</B> | <B>_</B>)</TD>
 </TR>
 </TABLE>
 <P>
 The keywords <B>node</B>, <B>edge</B>, <B>graph</B>, <B>digraph</B>,
 <B>subgraph</B>, and <B>strict</B> are case-independent.
 Note also that the allowed compass point values are not keywords, so
-these strings can be used elsewhere as ordinary identifiers.
+these strings can be used elsewhere as ordinary identifiers and, conversely,
+the parser will actually accept any identifier.
 <P>
 An <I>ID</I> is one of the following: 
 <MENU>