X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=methods.top.tex;h=c05165a705ce513af7bcb7434aacc18ace7e33df;hb=5f23e1fc77da5ea47ca9e1f71f7c2e862e0e0df2;hp=bc940034f96fa504108217928d8d97f1ea932323;hpb=c1a2d537de7ff3d730d26658daa822b2f03ea110;p=msc-thesis1617.git diff --git a/methods.top.tex b/methods.top.tex index bc94003..c05165a 100644 --- a/methods.top.tex +++ b/methods.top.tex @@ -1,10 +1,9 @@ -\section{\acrlong{TOP}} -\subsection{\gls{iTasks}} +\section{iTasks} \gls{TOP} is a 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{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 +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 @@ -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 -\CI{Stable} and can not be changed any further. +\CI{Stable} and cannot be changed any further. \begin{figure}[H] \centering @@ -66,19 +65,20 @@ functions that are 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. -\subsection{Combinators} +\section{Combinators} \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 - 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 @@ -117,7 +117,7 @@ basic combinators are shown in Listing~\ref{lst:combinators}. (-&&-) infixr 4 :: (Task a) (Task b) -> Task (a,b) | iTask a & iTask b \end{lstlisting} -\subsection{\acrlongpl{SDS}} +\section{\acrlongpl{SDS}} \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