1 \section{\acrlong{TOP
}}
2 \subsection{\gls{iTasks
}}
3 \gls{TOP
} is a recent new programming paradigm implemented as
4 \gls{iTasks
}\cite{achten_introduction_2015
} in the pure lazy functional
5 language
\gls{Clean
}\cite{brus_cleanlanguage_1987
}.
\gls{iTasks
} is a
6 \gls{EDSL
} to model workflow tasks in the broadest sense. A
\CI{Task
} is just
7 a function that, given some state, returns the observable
\CI{TaskValue
}. The
8 \CI{TaskValue
} of a
\CI{Task
} can have different states. Not all state
9 transitions are possible as shown in Figure~
\ref{fig:taskvalue
}. Once a value
10 has gone stable it can never become unstable again. Stability is often reached
11 by pressing a confirmation button or for
\glspl{Task
} that offer a constant
12 value. A simple example is shown in Listing~
\ref{lst:taskex
} accompanied with
13 Figure~
\ref{fig:taskex1
},~
\ref{fig:taskex2
} and~
\ref{fig:taskex3
}. In this
14 example the first image in is the
\CI{NoValue
} state, the second and third
15 image are in the
\CI{Unstable
} state. When the user presses
\emph{Continue
} the
16 value becomes
\CI{Stable
}.
20 \includegraphics[width=
.5\linewidth]{fig-taskvalue
}
21 \caption{The states of a
\CI{TaskValue
}}\label{fig:taskvalue
}
24 \begin{lstlisting
}[language=Clean,label=
{lst:taskex
},
%
25 caption=
{An example
\gls{Task
} for entering a name
}]
26 :: Name =
{ firstname :: String
30 derive class iTask Name
32 enterInformation :: String
[EnterOption m
] -> (Task m) | iTask m
34 enterName :: Task Name
35 enterName = enterInformation "Enter your name"
[]
39 \begin{subfigure
}{.25\textwidth}
41 \includegraphics[width=
.9\linewidth]{taskex1
}
42 \caption{Initial interface
}\label{fig:taskex1
}
44 \begin{subfigure
}{.25\textwidth}
46 \includegraphics[width=
.9\linewidth]{taskex2
}
47 \caption{Incomplete entrance
}\label{fig:taskex2
}
49 \begin{subfigure
}{.25\textwidth}
51 \includegraphics[width=
.9\linewidth]{taskex3
}
52 \caption{Complete entry
}\label{fig:taskex3
}
54 \caption{Example of a generated user interface
}
57 For a type to be suitable it must have instances for a collection of generic
58 functions that are captured in the class
\CI{iTask
}. Basic types have
59 specialization instances for these functions and show an according interface.
60 Generated interfaces can be modified with decoration operators.
62 \subsection{Combinators
}
63 \todo{Stukje over combinators, in ieder geval bind en paralel
}