Update spec: Registry

Author: qnikst

doc/semantics/CloudHaskellSemantics.tex

@@ -700,6 +700,23 @@ \subsection{Ordering and Typed Channels}
 for all messages from $P$ to $Q$, rather than using an ordered connection per
 typed channel plus one for direct messages.
 
+\subsection{Registry}
+The identifiers of both local and remote processes can be stored in the Registry.
+The operation \texttt{registerRemoteAsync} can register processes at remote nodes.
+When a message is sent to a remote node using \texttt{nsendRemote} there is no
+guarantee that the process that should receive the message is located at the
+node; thus it may be necessary to relay the message to a process on yet another node.
+
+Both operations \texttt{nsend} and \texttt{nsendRemote} discard the messages if
+no process is registered with the given name, or already dead.
+
+Both \texttt{nsend} and \texttt{nsendRemote} guarantee ordering between messages
+sent between two processes using one of those mechanism, however ordering between
+messages sent by \texttt{send} and \texttt{nsend} is not preserved.
+
+Current implementation for monitoring processes that are stored in registry
+are left unspecified, this may be changed in future.
+
 \bibliographystyle{apalike}
 \bibliography{references}