add parametric lens reference and todo

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

diff --git a/methods.top.tex b/methods.top.tex
index 174a783..b54b50f 100644 (file)
--- a/methods.top.tex
+++ b/methods.top.tex
@@ -1,10 +1,9 @@
-\section{\acrlong{TOP}}
-\subsection{\gls{iTasks}}
-\gls{TOP} is a recent programming paradigm implemented as
+\section{iTasks}
+\gls{TOP} is a modern recent programming paradigm implemented as

 \gls{iTasks}\cite{achten_introduction_2015} in the pure lazy functional
 language \gls{Clean}\cite{brus_cleanlanguage_1987}. \gls{iTasks} is a
 \gls{iTasks}\cite{achten_introduction_2015} in the pure lazy functional
 language \gls{Clean}\cite{brus_cleanlanguage_1987}. \gls{iTasks} is a

-\gls{EDSL} to model workflow tasks in the broadest sense. A \CI{Task} is just
-a function that, given some state, returns the observable \CI{TaskValue}. The
+\gls{EDSL} to model workflow tasks in the broadest sense. A \gls{Task} is just
+a function that --- given some state --- returns the observable \CI{TaskValue}. The

 \CI{TaskValue} of a \CI{Task} can have different states. Not all state
 transitions are possible as shown in Figure~\ref{fig:taskvalue}. Once a value
 is stable it can never become unstable again. Stability is often reached
 \CI{TaskValue} of a \CI{Task} can have different states. Not all state
 transitions are possible as shown in Figure~\ref{fig:taskvalue}. Once a value
 is stable it can never become unstable again. Stability is often reached


@@ -20,7 +19,7 @@ image in the \CI{NoValue} state, the second image does not have all the fields
 filled in and therefore the \CI{TaskValue} remains \CI{Unstable}. In the third
 image all fields are entered and the \CI{TaskValue} transitions to the
 \CI{Unstable} state. When the user presses \emph{Continue} the value becomes
 filled in and therefore the \CI{TaskValue} remains \CI{Unstable}. In the third
 image all fields are entered and the \CI{TaskValue} transitions to the
 \CI{Unstable} state. When the user presses \emph{Continue} the value becomes

-\CI{Stable} and can not be changed any further.
+\CI{Stable} and cannot be changed any further.

 
 \begin{figure}[H]
        \centering
 
 \begin{figure}[H]
        \centering


@@ -28,7 +27,7 @@ image all fields are entered and the \CI{TaskValue} transitions to the
        \caption{The states of a \CI{TaskValue}}\label{fig:taskvalue}
 \end{figure}
 
        \caption{The states of a \CI{TaskValue}}\label{fig:taskvalue}
 \end{figure}
 

-\begin{lstlisting}[language=Clean,label={lst:taskex},%
+\begin{lstlisting}[label={lst:taskex},%

        caption={An example \gls{Task} for entering a name}]
 :: Name = { firstname :: String
           , lastname  :: String
        caption={An example \gls{Task} for entering a name}]
 :: Name = { firstname :: String
           , lastname  :: String


@@ -43,6 +42,7 @@ enterName = enterInformation "Enter your name" []
 \end{lstlisting}
 
 \begin{figure}[H]
 \end{lstlisting}
 
 \begin{figure}[H]

+       \centering

        \begin{subfigure}{.25\textwidth}
                \centering
                \includegraphics[width=.9\linewidth]{taskex1}
        \begin{subfigure}{.25\textwidth}
                \centering
                \includegraphics[width=.9\linewidth]{taskex1}


@@ -61,24 +61,26 @@ enterName = enterInformation "Enter your name" []
        \caption{Example of a generated user interface}
 \end{figure}
 
        \caption{Example of a generated user interface}
 \end{figure}
 

-For a type to be suitable it must have instances for a collection of generic
-functions that are captured in the class \CI{iTask}. Basic types have
+For a type to be suitable, it must have instances for a collection of generic
+functions that is captured in the class \CI{iTask}. Basic types have

 specialization instances for these functions and show an according interface.
 Generated interfaces can be modified with decoration operators.
 
 specialization instances for these functions and show an according interface.
 Generated interfaces can be modified with decoration operators.
 

-\subsection{Combinators}
+\section{Combinators}
+\todo{check and refine}

 \Glspl{Task} can be combined using so called \gls{Task}-combinators.
 Combinators describe relations between \glspl{Task}. \Glspl{Task} can be
 combined in parallel, sequenced and their result values can be converted to
 \Glspl{Task} can be combined using so called \gls{Task}-combinators.
 Combinators describe relations between \glspl{Task}. \Glspl{Task} can be
 combined in parallel, sequenced and their result values can be converted to

-\glspl{SDS}. Moreover, a very important combinator is the step combinator that
-starts a new task according to the \CI{TaskValue}. The type signatures of the
-basic combinators are shown in Listing~\ref{lst:combinators}.
+\glspl{SDS}. Moreover, a very important combinator is the step combinator which
+starts a new task according to specified predicates on the \CI{TaskValue}.
+Type signatures of the basic combinators are shown in
+Listing~\ref{lst:combinators}.

 
 \begin{itemize}
        \item Step:
 
                The step combinator is used to start \glspl{Task} when a predicate on
 
 \begin{itemize}
        \item Step:
 
                The step combinator is used to start \glspl{Task} when a predicate on

-               the \CI{TaskValue} holds or an action has been taken place. The bind
+               the \CI{TaskValue} holds or an action has taken place. The bind

                operator can be written as a step combinator.
                \begin{lstlisting}[language=Clean]
 (>>=) infixl 1 :: (Task a) (a -> (Task b)) -> (Task b) | iTask a & iTask b
                operator can be written as a step combinator.
                \begin{lstlisting}[language=Clean]
 (>>=) infixl 1 :: (Task a) (a -> (Task b)) -> (Task b) | iTask a & iTask b


@@ -87,8 +89,8 @@ basic combinators are shown in Listing~\ref{lst:combinators}.
         onValue (Value a _)     = Just (f a)
         onValue _               = Nothing
 
         onValue (Value a _)     = Just (f a)
         onValue _               = Nothing
 

-               onStable (Value a True) = Just (f a)
-               onStable _              = Nothing
+        onStable (Value a True) = Just (f a)
+        onStable _              = Nothing

                \end{lstlisting}
        \item Parallel:
 
                \end{lstlisting}
        \item Parallel:
 


@@ -98,7 +100,7 @@ basic combinators are shown in Listing~\ref{lst:combinators}.
                dictates.
 \end{itemize}
 
                dictates.
 \end{itemize}
 

-\begin{lstlisting}[language=Clean,%
+\begin{lstlisting}[%

        caption={\Gls{Task}-combinators},label={lst:combinators}]
 //Step combinator
 (>>*)  infixl 1 :: (Task a) [TaskCont a (Task b)] -> Task b     | iTask a & iTask b
        caption={\Gls{Task}-combinators},label={lst:combinators}]
 //Step combinator
 (>>*)  infixl 1 :: (Task a) [TaskCont a (Task b)] -> Task b     | iTask a & iTask b


@@ -117,5 +119,38 @@ basic combinators are shown in Listing~\ref{lst:combinators}.
 (-&&-) infixr 4 :: (Task a) (Task b)              -> Task (a,b) | iTask a & iTask b
 \end{lstlisting}
 
 (-&&-) infixr 4 :: (Task a) (Task b)              -> Task (a,b) | iTask a & iTask b
 \end{lstlisting}
 

-\subsection{\acrlongpl{SDS}}
-
+\section{Shared Data Sources}
+\Glspl{SDS} are an abstraction over resources that are available in the world
+or in the \gls{iTasks} system. The shared data can be a file on disk, it can be
+the time, a random integer or just some data stored in memory. The actual
+\gls{SDS} is just a record containing functions on how to read and write the
+source. In these functions the \CI{*IWorld} which in turn contains the real
+program \CI{*World}. Accessing the outside world is required for interacting
+with it and thus the functions can access files on disk, raw memory, other
+shares and combine shares.
+
+The basic operations for \glspl{SDS} are get, set and update. The signatures
+for these functions are shown in Listing~\ref{lst:shares}. By default, all
+shares are files containing a \gls{JSON} encoded version of the object and thus
+are persistent between restarts of the program. Library functions for shares
+residing in memory are available as well. The three main operations on shares
+are atomic in the sense that during reading no other tasks are executed.
+
+The basic type for \glspl{SDS} has three \todo{parametric
+lenses}\cite{domoszlai_parametric_2014}.
+
+\begin{lstlisting}[%
+       label={lst:shares},caption={\Gls{SDS} functions}]
+:: RWShared p r w = ... 
+:: ReadWriteShared r w :== RWShared () r w
+:: ROShared p r :== RWShared p () r
+:: ReadOnlyShared r :== ROShared () r
+
+:: Shared r :== ReadWriteShared r r
+
+get ::          (ReadWriteShared r w)           -> Task r | iTask r
+set :: w        (ReadWriteShared r w)           -> Task w | iTask w
+upd :: (r -> w) (ReadWriteShared r w)           -> Task w | iTask r & iTask w
+
+sharedStore :: String a -> Shared a | JSONEncode{|*|}, JSONDecode{|*|}
+\end{lstlisting}