helicopter in presentation

[msc-thesis1617.git] / mtaskext.sdssem.tex

diff --git a/mtaskext.sdssem.tex b/mtaskext.sdssem.tex
index 5ba33ad..c4f2c2b 100644 (file)
--- a/mtaskext.sdssem.tex
+++ b/mtaskext.sdssem.tex
@@ -2,14 +2,17 @@
 of regular \gls{iTasks}-\glspl{SDS}. However, the same freedom that an
 \gls{SDS} has in the \gls{iTasks}-system is not given for \glspl{SDS} that
 reside on the client. Not all types are suitable to be located on a client,
-simply because it needs to be representable on clients. Moreover, \glspl{SDS}
-behave a little different in an \gls{mTask} device compared to in the
-\gls{iTasks} system. In an \gls{iTasks} system, when the \gls{SDS} is updated,
-a broadcast to all watching \glspl{Task} in the system is made to notify them
-of the update. \glspl{SDS} can update often and the update might not be the
-final value it will get. Implementing the same functionality on the \gls{mTask}
-client would result in a lot of expensive unneeded bandwidth usage.  Therefore
-a device must publish the \gls{SDS} explicitly to save bandwidth.
+simply because it needs to be representable on clients. Also, not all \gls{SDS}
+types are possible to have on a device. Moreover, \glspl{SDS} behave a little
+different in an \gls{mTask} device compared to in the \gls{iTasks} system. In
+an \gls{iTasks} system, when the \gls{SDS} is updated, a broadcast to all
+watching \glspl{Task} in the system is made to notify them of the update.
+\glspl{SDS} can update often and the update might not be the final value it
+will get. Implementing the same functionality on the \gls{mTask} client would
+result in a lot of expensive unneeded bandwidth usage. Therefore a device must
+publish the \gls{SDS} explicitly to save bandwidth. Note that this means that
+the \gls{SDS} value on the device can be different compared to the value of the
+same \gls{SDS} on the server.
 
 To add this functionality, the \CI{sds} class could be extended. However, this
 would result in having to update all existing views that use the \CI{sds}
@@ -21,3 +24,18 @@ signature:
 class sdspub v where
   pub :: (v t Upd) -> v t Expr | type t
 \end{lstlisting}
+
+Moreover, \glspl{SDS} in the \gls{mTask}-\gls{EDSL} are always anonymous. There
+is no way of labeling it since it is not a real entity, it is just a function.
+When an \gls{SDS} is sent to the device it must be retrievable and
+identifiable.  It is not always clear which instantiated \gls{SDS} is which.
+Therefore, an added class named \CI{namedsds} is added that provides the exact
+same functionality as the \gls{SDS} class but adds a \CI{String} parameter that
+can later be used to identify an \gls{SDS}. The types for this class are as
+follows:
+
+\begin{lstlisting}[caption={The \texttt{namedsds} class}]
+class namedsds v where
+  namedsds :: ((v t Upd)->In (Named t String) (Main (v c s))) -> (Main (v c s)) | type, mTaskType, toCode t
+:: Named a b = Named infix 1 a b
+\end{lstlisting}