methods.tex

   1 \section{\acrlong{TOP}}
   2 \gls{TOP} is a recent new programming paradigm implemented as
   3 \gls{iTasks}\cite{achten_introduction_2015} in the pure lazy functional
   4 language \gls{Clean}\cite{brus_cleanlanguage_1987}. \gls{iTasks} is a
   5 \gls{EDSL} to model workflow tasks in the broadest sense. A \CI{Task} is just
   6 a function that, given some state, returns the observable value of the
   7 \CI{TaskValue}. A simple example is shown in Listing~\ref{lst:taskex}
   8 accompanied with Figure~\ref{fig:taskex1},~\ref{fig:taskex2} and~%
   9 \ref{fig:taskex3}.
  10
  11 \begin{lstlisting}[language=Clean,label={lst:taskex},%
  12         caption={An example \gls{Task} for entering a name}]
  13 :: Name         = { firstname :: String
  14                   , lastname  :: String
  15                                   }
  16
  17 derive class iTask Name
  18
  19 enterInformation :: String [EnterOption m] -> (Task m) | iTask m
  20
  21 enterName :: Task Name
  22 enterName = enterInformation "Enter your name" []
  23 \end{lstlisting}
  24
  25 \begin{figure}[H]
  26         \begin{subfigure}{.25\textwidth}
  27                 \centering
  28                 \includegraphics[width=.9\linewidth]{taskex1}
  29                 \caption{Initial interface}\label{fig:taskex1}
  30         \end{subfigure}
  31         \begin{subfigure}{.25\textwidth}
  32                 \centering
  33                 \includegraphics[width=.9\linewidth]{taskex2}
  34                 \caption{Incomplete entrance}\label{fig:taskex2}
  35         \end{subfigure}
  36         \begin{subfigure}{.25\textwidth}
  37                 \centering
  38                 \includegraphics[width=.9\linewidth]{taskex3}
  39                 \caption{Complete entry}\label{fig:taskex3}
  40         \end{subfigure}
  41         \caption{Example of a generated user interface}
  42 \end{figure}
  43
  44 \section{\acrlong{EDSL}s}
  45 \glspl{mTask} are expressed in a class based shallowly embedded \gls{EDSL}.
  46 There are two main types of \glspl{EDSL}.
  47 \todo{Small shallow embedded dsl intro}
  48 \todo{Small deep embedded dsl}
  49 \todo{Show that class based has the best of both worlds}
  50
  51 \section{Architecture}
  52 \section{Devices}
  53
  54 The client code for the devices is compiled from one codebase. For a device to
  55 be eligible for \glspl{mTask} it must be able to compile the shared codebase
  56 and implement (part of) the device specific interface. The shared codebase only
  57 uses standard \gls{C} and no special libraries or tricks are used. Therefore
  58 the code is compilable for almost any device or system. Note that it is not
  59 needed to implement a full interface\todo{handshake}. The full interface,
  60 listed in Appendix~\label{app:device-interface}\todo{update interface listing},
  61 also includes functions for accessing the peripherals that not every device
  62 might have. Devices can choose what to implement by setting the correct macros
  63 in the top of the file.
  64 \todo{Supported devices}
  65
  66 \subsection{Specification}
  67 Devices are stored in a record type and all devices in the system are stored in
  68 a \gls{SDS} containing all devices. From the macro settings in the interface
  69 file a profile is created for the device that describes the specification. When
  70 a connection between the server and a client is established the server will
  71 send a request for specification. The client will serialize his specs and send
  72 it to the server so that the server knows what the client is capable of. The
  73 exact specification is listed in Listing~\ref{lst:devicespec}
  74
  75 \begin{lstlisting}[language=Clean,label={lst:devicespec},
  76         caption={Device specification for \glspl{mTask}}]
  77 :: MTaskDeviceSpec =
  78         {haveLed :: Bool
  79         ,haveAio :: Bool
  80         ,haveDio :: Bool
  81         ,taskSpace :: Int // Bytes
  82         ,sdsSpace  :: Int // Bytes
  83         }
  84 \end{lstlisting}
  85 \todo{Explain specification, combine task and share space}
  86
  87 \subsection{Communication}
  88
  89 \section{mTasks}
  90 \subsection{\gls{EDSL}}
  91 The \gls{mTask}-\gls{EDSL} contains several classes that need to be implemented
  92 by a type for it to be an \gls{mTask}. For numeric and boolean arithmetic the
  93 classes \texttt{arith} and \texttt{boolExpr} are available and listed in a
  94 shortened version in Listing~\ref{lst:arithbool}. All classes are to be
  95 implemented by types of kind \texttt{*->*->*} a type \texttt{v t p},
  96 respectively a view with a type and the role.
  97
  98 \texttt{lit} lifts a constant to the \gls{mTask} domain. For a type to be a
  99 valid \gls{mTask} type it needs to implement the \texttt{mTaskType} class. The
 100 binary operators work as expected.
 101
 102 \begin{lstlisting}[language=Clean,label={lst:arithbool},
 103         caption={Basic classes for expressions}]
 104 class mTaskType a | toByteCode, fromByteCode, iTask, TC a
 105
 106 class arith v where
 107   lit :: t -> v t Expr | mTaskType t
 108   (+.) infixl 6 :: (v t p) (v t q) -> v t Expr | type, +, zero t & isExpr p & isExpr q
 109   ...
 110 class boolExpr v where
 111   (&.) infixr 3 :: (v Bool p) (v Bool q) -> v Bool Expr | isExpr p & isExpr q
 112   Not           :: (v Bool p) -> v Bool Expr | isExpr p
 113   ...
 114   (==.) infix 4 :: (v a p) (v a q) -> v Bool Expr | ==, toCode a & isExpr p & isExpr q
 115 \end{lstlisting}
 116
 117
 118 \subsection{Tasks}
 119
 120 \subsection{Shares}
 121 Shares can live on multiple clients at the same time. For every share created
 122 for an \gls{mTask} a real \gls{SDS} is created that mirrors the value on the
 123 client. All shares currently in use are stored in a system-wide \gls{SDS} in
 124 such a way that the actual share can be retrieved at any moment. All shares
 125 have a unique numeric identifier and an initial value.
 126
 127 \begin{lstlisting}[language=Clean,label={lst:sharespec}, caption={\acrlong{SDS}}]
 128 :: BCValue = E.e: BCValue e & mTaskType e
 129 :: MTaskShareType = MTaskWithShare String | MTaskLens String
 130 :: MTaskShare =
 131         {withTask :: [String]
 132         ,withDevice :: [String]
 133         ,identifier :: Int
 134         ,realShare :: MTaskShareType
 135         ,value :: BCValue
 136         }
 137
 138 sdsStore :: Shared [MTaskShare]
 139 \end{lstlisting}
 140 \todo{Do something with the sharetype}
 141
 142 \subsection{Communication}
 143 %\todo{Handshake, device specification sending, spec.c}
 144 %\todo{mTaskDevice class interface}
 145
 146 \section{mTasks}
 147 \subsection{\gls{EDSL}}
 148 \todo{Show the classes}
 149
 150 \subsection{Shares}
 151 \todo{Show the types and why}
 152
 153 Shares are used to store the values
 154
 155 Shares all have