add relevant research

[msc-thesis1617.git] / methods.mtask.tex

diff --git a/methods.mtask.tex b/methods.mtask.tex
index 837933d..a35883a 100644 (file)
--- a/methods.mtask.tex
+++ b/methods.mtask.tex
@@ -1,15 +1,14 @@
-\section{mTask}
 The \gls{mTask}-\gls{EDSL} is the basis on which the system is built. The
-\gls{mTask} was created by Koopman et al.\ to support several views such as an
-\gls{iTasks} simulation and a \gls{C}-code generator. The \gls{EDSL} was
-designed to generate a ready to compile \gls{TOP}-like system for
+\gls{mTask}-\gls{EDSL} was created by Koopman et al.\ to support several views
+such as an \gls{iTasks} simulation and a \gls{C}-code generator. The \gls{EDSL}
+was designed to generate a ready to compile \gls{TOP}-like system for
 microcontrollers such as the Arduino\cite{koopman_type-safe_nodate}%
 \cite{plasmeijer_shallow_2016}.
 
 The \gls{mTask}-\gls{EDSL} is a shallowly embedded class based \gls{EDSL} and
 therefore it is very suitable to have a new backend that partly implements the
-given classes. The following subsections show the details of the \gls{EDSL}
-that are used in the extension. The parts of the \gls{EDSL} that are not used
+given classes. The following sections show the details of the \gls{EDSL}
+that are used in this extension. The parts of the \gls{EDSL} that are not used
 will not be discussed and the details of those parts can be found in the cited
 literature.
 
@@ -36,7 +35,14 @@ instance isExpr Upd
 instance isExpr Expr
 \end{lstlisting}
 
-\subsection{Expressions}
+\section{Semantics}
+\gls{mTask} do not behave like functions but more like
+\gls{iTasks}-\glspl{Task}. When an \gls{mTask} is created it returns immediatly
+and the \gls{Task} will be executed sometime in the future. \glspl{Task} can
+run at an interval and they can start other tasks.
+\todo{Meer uitwijden over de mTask semantiek}
+
+\section{Expressions}
 Expressions in the \gls{mTask}-\gls{EDSL} are divided into two types, namely
 boolean expressions and arithmetic expressions. The class of arithmetic
 language constructs also contains the function \CI{lit} that lifts a
@@ -60,10 +66,27 @@ class boolExpr v where
   (==.) infix 4 :: (v a p) (v a q) -> v Bool Expr       | ==, toCode a & ...
 \end{lstlisting}
 
-\subsection{Control flow}
-\todo{Write this}
+\section{Control flow}
+Looping of \glspl{Task} happens because \glspl{Task} are launched at regular
+intervals or relaunch themselves. Therefore there is no need for loop control
+flow functionality such as \CI{While} or \CI{For} constructions. The main
+control flow is the sequence operator and the \CI{If} statement. Both are shown
+in Listing~\ref{lst:control}. The first class of \CI{If} statements describe
+the regular if statement. The expressions given can have any role. The
+functional dependency on \CI{s} determines the return type of the statement.
+The sequence operator is very straightforward and just ties the two expressions
+together in sequence.
+
+\begin{lstlisting}[%
+       language=Clean,label={lst:control},caption={Control flow operators}]
+class If v q r ~s where
+  If :: (v Bool p) (v t q) (v t r) -> v t s | ...
+
+class seq v where
+  (:.) infixr 0 :: (v t p) (v u q) -> v u Stmt | ...
+\end{lstlisting}
 
-\subsection{Input/Output and class extensions}
+\section{Input/Output and class extensions}
 All expressions that have an \CI{Upd} role can be assigned to. Examples of such
 expressions are \glspl{SDS} and \gls{GPIO}. Moreover, class extensions can be
 created for specific peripherals such as user LEDs. The classes facilitating
@@ -109,7 +132,7 @@ class sds v where
   sds :: ((v t Upd)->In t (Main (v c s))) -> (Main (v c s)) | ...
 \end{lstlisting}
 
-\subsection{Example \gls{mTask}}
+\section{Example mTask}
 \todo{Also explain semantics about running tasks}
 Some example \glspl{mTask} using almost all of the functionality are show in
 Listing~\ref{lst:exmtask}. The \glspl{mTask} shown in the example do not belong