And as computers, they require software to operate.
An increasing amount of these connected devices are so-called \emph{edge devices} that operate in the \gls{IOT}.
+Edge devices are the leafs of the \gls{IOT} systems, they perform the interaction with the physical world.
Typically, these edge devices are powered by microcontrollers.
These miniature computers contain integrated circuits that accomodates a microprocessor designed for use in embedded applications.
-Typically, microcontrollers are therefore tiny in size; have little memory; contain a slow, but energy-efficient processor; and allow for a lot of connectivity to connect peripherals such as sensors and actuators in order to interact with their surroundings.
+Typically, microcontrollers are therefore tiny in size; have little memory; contain a slow, but energy-efficient processor; and allow for a lot of connectivity for integrating peripherals such as sensors and actuators in order to interact with their surroundings.
%
%\begin{figure}[ht]
% \centering
% \label{fig:esp_prototype}
%\end{figure}
-Programming and maintaining \gls{IOT} systems is a complex and error-prone process.
-Unlike the conductor in the orchestra waving their baton to orchestrate the ensemble of instruments in an orchestra, in the universe of software there is room for little error.
-An \gls{IOT} programmer has to program each device and their interoperation using different programming paradigms, programming languages, and abstraction levels resulting in semantic friction.
+Unlike the conductor in the orchestra waving their baton to instruct the ensemble of instruments, in the universe of software there is room for little error.
+In the traditional setting, an \gls{IOT} engineer has to program each device and their interoperation using different programming paradigms, programming languages, and abstraction levels.
+Thus resulting in semantic friction, making programming and maintaining \gls{IOT} systems is a complex and error-prone process.
This thesis describes the research carried out around orchestrating these complex \gls{IOT} systems using \gls{TOP}.
-\Gls{TOP} is an innovative tierless programming paradigm for interactive multi-tier systems.
-By utilising advanced compiler technologies, much of the internals, communications, and interoperations of the applications are automatically generated.
-From a single declarative specification of the work required, the compiler makes a ready-for-work application.
+\Gls{TOP} is an innovative tierless programming paradigm for interactive multi-layered systems.
+By utilising advanced compiler technologies, much of the internals, communications, and interoperations between the tiers\slash{}layers of the applications is automatically generated.
+From a single declarative specification of the work required, the compiler makes a ready-for-work application consisting of interconnected components for all tiers.
For example, the \gls{TOP} system \gls{ITASK} can be used to program all layers of a multi-user distributed web applications from a single source specification.
-Unfortunately, because the abstraction level is so demanding, the hardware requirements are excessive for \gls{TOP} systems such as \gls{ITASK}.
+It is implemented in \gls{CLEAN} and executes also in \gls{CLEAN}'s run time.
+The final executable is very low level and contains all these abstraction levels, this results in increased hardware requirements.
The high hardware requirements are no problem for regular computers but impractical for the average edge device.
-This is where \glspl{DSL} are must be brought into play.
+This is where \glspl{DSL} must be brought into play.
\Glspl{DSL} are programming languages created with a specific domain in mind.
Consequently, jargon does not have to be expressed in the language itself, but they can be built-in features.
As a result, hardware requirements can be drastically lowered, even with high levels of abstraction for the specified domain.
A \emph{rhapsody} in music is a one-movement work that is episodic yet integrated, free-flowing in structure, featuring a range of highly contrasted moods, colour, and tonality.}
\end{quote}
%The three episodes in this thesis are barded by the introduction and conclusion (\cref{chp:introduction,chp:conclusion}).
-\Cref{prt:dsl} is a paper-based---otherwise known as cumulative---episode providing insights in advanced \gls{DSL} embedding techniques for \gls{FP} languages.
+\Cref{prt:dsl} is a paper-based---otherwise known as cumulative---episode containing chapters that provide insight in advanced \gls{DSL} embedding techniques for \gls{FP} languages.
The chapters are readable independently.
\Cref{prt:top} is a monograph showing \gls{MTASK}, a \gls{TOP} \gls{DSL} for the \gls{IOT}.
+It introduces \gls{IOT} edge device programming, shows the complete \gls{MTASK} language, provides details on how \gls{MTASK} is integrated with \gls{ITASK}, shows how the byte code compiler is implemented, and concludes with a guide for green computing with \gls{ITASK}.
Hence, the chapters are best read in order.
-\Cref{prt:tvt} is a journal article in which traditional tiered \gls{IOT} programming is qualitatively and quantitatively compared to tierless programming using a real-world application.
+\Cref{prt:tvt} is a single chapter based on a journal article in which traditional tiered \gls{IOT} programming is qualitatively and quantitatively compared to tierless programming using a real-world application.
The chapter is readable independently.
-The following sections provide background material on the \gls{IOT}, \glspl{DSL}, and \gls{TOP} after which a detailed overview of the contributions is presented.
+The following sections in this prelude provide background material on the \gls{IOT}, \glspl{DSL}, and \gls{TOP} after which a detailed overview of the contributions is presented.
Text typeset as \texttt{teletype} represents source code.
Standalone source code listings are marked by the programming language used, e.g.\ \gls{CLEAN}\footnotemark, \gls{HASKELL}, \gls{CPP}, \etc.
\footnotetext{\Cref{chp:clean_for_haskell_programmers} contains a guide for \gls{CLEAN} tailored to \gls{HASKELL} programmers.}
\section{\texorpdfstring{\Glsxtrlong{IOT}}{Internet of things}}%
\label{sec:back_iot}
-The \gls{IOT} is growing rapidly and it is changing the way people and machines interact with the world.
+The \gls{IOT} is growing rapidly and it is changing the way people and machines interact with each other and the world.
While the term \gls{IOT} briefly gained interest around 1999 to describe the communication of \gls{RFID} devices \citep{ashton_internet_1999,ashton_that_2009}, it probably already popped up halfway the eighties in a speech by \citet{peter_t_lewis_speech_1985}:
\begin{quote}
\emph{The \glsxtrlong{IOT}, or \glsxtrshort{IOT}, is the integration of people, processes and technology with connectable devices and sensors to enable remote monitoring, status, manipulation and evaluation of trends of such devices.}
\end{quote}
-CISCO states that the \gls{IOT} started when there were as many connected devices as there were people on the globe, i.e.\ around 2008 \citep{evans_internet_2011}.
+Much later, CISCO states that the \gls{IOT} started when there were as many connected devices as there were people on the globe, i.e.\ around 2008 \citep{evans_internet_2011}.
Today, \gls{IOT} is the term for a system of devices that sense the environment, act upon it and communicate with each other and the world they live in.
These connected devices are already in households all around us in the form of smart electricity meters, fridges, phones, watches, home automation, \etc.
When describing \gls{IOT} systems, a tiered---or layered---architecture is often used for compartmentalisation.
-The number of tiers heavily depends on the required complexity of the model but for the intents and purposes of this thesis, the layered architecture as shown in \cref{fig:iot-layers} is used.
+The number of tiers heavily depends on the required complexity of the model.
+For the intents and purposes of this thesis, the layered architecture as shown in \cref{fig:iot-layers} is used.
\begin{figure}
\centering
The perception layer---also called edge layer---collects the data and interacts with the environment.
It consists of edge devices such as microcontrollers equipped with various sensors and actuators.
-In home automation this layer consists of all the devices hosting sensors and actuators such as smart light bulbs, actuators to open doors or a temperature and humidity sensors.
+In home automation this layer consists of all the devices hosting sensors and actuators such as smart light bulbs, actuators to open doors, or temperature and humidity sensors.
All layers are connected using the network layer.
In some applications this is implemented using conventional networking techniques such as WiFi or Ethernet.
-However, networks or layers on top of it---tailored to the needs of the specific interconnection between the two layers---have become increasingly popular.
-Examples of this are BLE, LoRa, ZigBee, LTE-M, or \gls{MQTT} for connecting the perception layer to the application layer and techniques such as HTTP, AJAX, and WebSocket for connecting the presentation layer to the application layer.
+However, network technology that is tailored to the needs of the specific interconnection between the two layers have become increasingly popular.
+Examples of this are BLE, LoRa, ZigBee, and LTE-M as a transport for connecting the perception layer to the application layer using \gls{IOT} protocols such as \gls{MQTT}.
+Protocols such as HTTP, AJAX, and WebSocket connecting the presentation layer to the application layer that are designed for the use in web applications.
Across the layers, the devices are a large heterogeneous collection of different platforms, protocols, paradigms, and programming languages often resulting in impedance problems or semantic friction between layers when programming \citep{ireland_classification_2009}.
Even more so, the perception layer itself is often a heterogeneous collections of microcontrollers in itself, each having their own peculiarities, language of choice, and hardware interfaces.
-Insofar, as edge hardware needs to be cheap, small-scale, and energy efficient, the microcontrollers used to power them do not have a lot of computational power, only a soup\c{c}on of memory, and little communication bandwidth.
+As edge hardware needs to be cheap, small-scale, and energy efficient, the microcontrollers used to power them do not have a lot of computational power, only a soup\c{c}on of memory, and little communication bandwidth.
Typically these devices are unable to run a full-fledged general-purpose \gls{OS}.
-Rather they employ compiled firmware written in imperative languages.
+Rather they employ compiled firmware written in imperative languages that combines all tasks on the device in a single program.
While devices are getting a bit faster, smaller, and cheaper, they keep these properties to an extent, greatly reducing the flexibility for dynamic systems when tasks are created on the fly, executed on demand, or require parallel execution.
As program memory is mostly flash-based and only lasts a couple of thousand writes before it wears out, it is not suitable for rapid reconfiguring and reprogramming.
These problems can be mitigated by dynamically sending code to be interpreted to the microcontroller.
With interpretation, a specialized interpreter is flashed in the program memory once it receives the program code to execute at run time.
-Interpretation always comes with an overhead, making it challenging to create them for small edge devices.
-However, the hardware requirements can be reduced by embedding domain-specific data into the programming language to be interpreted, so-called \glspl{DSL}.
+Therefore, as the programs are not stored in the flash memory, it does not wear out.
+It is challenging to create interpreters for small edge devices due to the severe hardware restrictions.
+However, the hardware requirements can be reduced by embedding domain-specific data into the langauge, so called \gls{DSL}; and the interpreter, a domain-specific \gls{OS}.
\section{\texorpdfstring{\Glsxtrlongpl{DSL}}{Domain-specific languages}}%
\label{sec:back_dsl}
Programming languages can be divided up into two categories: \glspl{DSL}\footnotemark\ and \glspl{GPL} \citep{fowler_domain_2010}.
\footnotetext{Historically \glsxtrshortpl{DSL} have been called DSELs as well.}
Where \glspl{GPL} are not made with a demarcated area in mind, \glspl{DSL} are tailor-made for a specific domain.
-Writing idiomatic domain-specific code in a \gls{DSL} is easy but this may come at the cost of the \gls{DSL} being less expressive to an extent that it may not even be Turing complete.
-\Glspl{DSL} come in two main flavours: standalone and embedded (\cref{sec:standalone_embedded})\footnote{Standalone and embedded are also called external and internal respectively.} of which \glspl{EDSL} can further be classified into heterogeneous and homogeneous languages (\cref{sec:hetero_homo}).
+Writing idiomatic domain-specific code in a \gls{DSL} is easier and requires less background knowledge about a \gls{GPL}.
+This does come at the cost of the \gls{DSL} being sometimes less expressive to an extent that it may not even be Turing complete.
+\Glspl{DSL} come in two main flavours: standalone and embedded (\cref{sec:standalone_embedded})\footnote{Standalone and embedded are also called external and internal respectively.}.
+Standalone languages are languages for which the complete toolchain has been developed, just as for any other \gls{GPL}.
+Embedded languages piggyback on an existing \gls{GPL}, they are defined in terms of their host language.
+\Glspl{EDSL} can further be classified into heterogeneous and homogeneous languages (\cref{sec:hetero_homo}).
+In homogeneous languages all components are integrated whereas in heterogeneous \glspl{DSL}, some parts are ignorant of the other systems, e.g.\ a \gls{DSL} that generates code that is compiled by an existing compiler.
This hyponymy is shown in \cref{fig:hyponymy_of_dsls}.
\begin{figure}
\label{sec:standalone_embedded}
\glspl{DSL} where historically created as standalone languages, meaning that all machinery is developed solely for the language.
The advantage of this approach is that the language designer is free to define the syntax and type system of the language as they wish, not being restricted by any constraint.
-Unfortunately it also means that they need to develop a compiler or interpreter for the language, making standalone \glspl{DSL} costly to create.
+Unfortunately it also means that they need to develop a compiler or interpreter, and all the scaffolding for the language, making standalone \glspl{DSL} costly to create.
Examples of standalone \glspl{DSL} are regular expressions, make, yacc, XML, SQL, \etc.
The dichotomous approach is embedding the \gls{DSL} in a host language, i.e.\ \glspl{EDSL} \citep{hudak_modular_1998}.
However, there are two sides to this coin.
If the syntax of the host language is not very flexible, the syntax of the \gls{DSL} may become clumsy.
Furthermore, \gls{DSL} errors shown to the programmer may be larded with host language errors, making it difficult for a non-expert of the host language to work with the \gls{DSL}.
-\Gls{FP} languages are especially suitable for hosting embedded \glspl{DSL} because they often have strong and versatile type systems, minimal but flexible syntax and offer referential transparency.
+\Gls{FP} languages are especially suitable for hosting embedded \glspl{DSL}.
+They offer tooling for building abstraction levels by a strong and versatile type systems, minimal but flexible syntax, and offer referential transparency.
\subsection{Heterogeneity and homogeneity}%
\label{sec:hetero_homo}
\section{\texorpdfstring{\Glsxtrlong{TOP}}{Task-oriented programming}}%
\label{sec:back_top}
\Gls{TOP} is a recent declarative programming paradigm for modelling interactive systems \citep{plasmeijer_task-oriented_2012}.
-\Citet{steenvoorden_tophat_2022} defines two instruments for \gls{TOP}: \gls{TOP} languages and \gls{TOP} engines.
-The language is the \emph{formal} language for specifying interactive systems.
-The engine is the software or hardware that executes these specifications as a ready-for-work application.
In \gls{TOP} languages, tasks are the basic building blocks and they represent the actual work.
Instead of dividing problems into \gls{LSOC} \gls{TOP} deals with separation of concerns in a novel way.
From the data types, utilising various \emph{type-parametrised} concepts, all other aspects are handled automatically (see \cref{fig:tosd}).
This approach to software development is called \gls{TOSD} \citep{wang_maintaining_2018}.
+After describing the layers, the link to the \gls{IOT} architecture is explained.\todo{dit om vast te primen}
\begin{figure}
\centering
- \begin{subfigure}[t]{.5\textwidth}
- \centering
- \includestandalone{traditional}
- \caption{\Gls{LSOC} approach.}
- \end{subfigure}%
- \begin{subfigure}[t]{.5\textwidth}
- \centering
- \includestandalone{tosd}
- \caption{\Gls{TOSD} approach.}
- \end{subfigure}
- \caption{Separation of concerns in a traditional setting compared to \gls{TOSD} (adapted from \citep[\citepage{20}]{wang_maintaining_2018}).}%
+ \includestandalone{tosd}
+ \caption{Separation of concerns in \gls{TOSD} (adapted from \citep[\citepage{20}]{wang_maintaining_2018}).}%
\label{fig:tosd}
\end{figure}
An \gls{SDS} can represent typed data stored in a file, a chunk of memory, a database \etc.
\Glspl{SDS} can also represent external impure data such as the time, random numbers or sensor data.
In many \gls{TOP} langauges, combinators are available to filter, combine, transform, and focus \glspl{SDS}.
- \item[Programming language (\glsxtrshort{UOD}):]
+ \item[\Glsxtrshort{UOD} (programming language):]
The \gls{UOD} is explicitly and separately modelled by the relations that exist in the functions of the host language.
+ \todo{uit\-brei\-den}
\end{description}
-%Applying the concepts of \gls{LSOC} to \gls{IOT} systems can be done in two ways.
-%Firstly, edge devices can be seen as simple resources, thus accessed through the resource access layer.
-%The second view is that edge devices contain miniature \gls{LSOC} systems in itself as well.
-%In \gls{TOSD} the same can be applied.
-%The individual components in the miniature systems, the tasks, the \glspl{SDS}, are connected to the main system.
-%\t odo{Is deze \P\ dui\-de\-lijk genoeg of \"uberhaupt nodig?}
-
+This figure differs from the presented \gls{IOT} architecture because they represent separate concepts.
+The \gls{IOT} architecture from \cref{fig:iot} describes an execution architecture wheras the \gls{TOSD} figure describes a softwared development model.
+E.g.\ from a software development perspective, a task is a task, whether it is executed on a microcontroller, a server or a client.
+Though some concepts can be mapped upon eachother.
+Applying the concepts of \gls{TOSD} to \gls{IOT} systems can be done in two ways.
+Firstly, edge devices can be seen as simple resources, thus accessed through \glspl{SDS}.
+The second view is that edge devices contain miniature \gls{TOP} systems in itself.
+The individual components in the miniature systems, the tasks, the \glspl{SDS}, are, in the eventual execution, connected to the main system.
+\todo{legt dit de link goed genoeg uit?}
+
+%\Citet{steenvoorden_tophat_2022} distinguishes two instruments for \gls{TOP}: \gls{TOP} languages and \gls{TOP} engines.
+%The language is the \emph{formal} language for specifying interactive systems.
+%The engine is the software or hardware that executes these specifications as a ready-for-work application.
+%\todo{uit\-brei\-den, ver\-wij\-de\-ren?}
+%
\subsection{\texorpdfstring{\Gls{ITASK}}{ITask}}
The concept of \gls{TOP} originated from the \gls{ITASK} framework, a declarative interactive systems language and \gls{TOP} engine for defining multi-user distributed web applications implemented as an \gls{EDSL} in the lazy pure \gls{FP} language \gls{CLEAN} \citep{plasmeijer_itasks:_2007,plasmeijer_task-oriented_2012}.
From the structural properties of the data types, the entire user interface is automatically generated.
Browsers are powering \gls{ITASK}'s perception layer.
-The framework is written using standard web techniques such as JavaScript, HTML, and CSS, \gls{ITASK} code running in the browser relies on an interpreter that operates on \gls{CLEAN}'s intermediate language \gls{ABC} \citep{staps_lazy_2019}.
-
-As an example, \cref{lst:enter_person,fig:enter_person} show the \gls{ITASK} code and the corresponding \gls{UI} for a simple task for entering information about a person and viewing the entered result after completion.
-From the data type definitions (\cref{lst:dt_fro,lst:dt_to}), using generic programming (\cref{lst:dt_derive}), the \glspl{UI} for the data types are automatically generated.
-Using task combinators (e.g.\ \cleaninline{>>!} at \cref{lst:task_comb}), the tasks can be combined in sequence.
-Only when the user enters a complete value in the web editor, then the continue button enables and the result can be viewed.
-Special combinators (e.g.\ \cleaninline{@>>} at \cref{lst:task_ui}) are used to tweak the \gls{UI} so that informative labels are displayed.
+The framework is built on top of standard web techniques such as JavaScript, HTML, and {CSS}.
+\Gls{ITASK} code running in the browser relies on an interpreter that operates on \gls{CLEAN}'s intermediate language \gls{ABC} \citep{staps_lazy_2019}.
+Tasks in \gls{ITASK} have either \emph{no value}, an \emph{unstable} or a \emph{stable} task value.
+The allowed task value transitions are shown in \cref{fig:taskvalue}.
\begin{figure}
- \includegraphics[width=.325\linewidth]{person0g}
- \includegraphics[width=.325\linewidth]{person1g}
- \includegraphics[width=.325\linewidth]{person2g}
- \caption{The \gls{UI} for entering a person in \gls{ITASK}.}%
- \label{fig:enter_person}
+ \centering
+ \includestandalone{taskvalue}
+ \caption{Transition diagram for task values in \gls{ITASK}.}%
+ \label{fig:taskvalue}
\end{figure}
-\begin{lstClean}[numbers=left,caption={The code for entering a person in \gls{ITASK}.},label={lst:enter_person}]
-:: Person = { name :: String, gender :: Gender, dateOfBirth :: Date }[+\label{lst:dt_fro}+]
-:: Gender = Male | Female | Other String[+\label{lst:dt_to}+]
+As an example, \cref{lst:todo,fig:todo} show the code and \gls{UI} for an interactive to-do list application.
+The user can modify a shared to-do list through an editor directly or using some of the predefined actions.
+Furthermore, in parallel, the length of the list is shown to demonstrate \glspl{SDS}.
+From the data type definitions (\cref{lst:todo_dt}), using generic programming (\cref{lst:todo_derive}), the \glspl{UI} for the data types are automatically generated.
+Then, using the parallel task combinator (\cleaninline{-\|\|}) that uses the left-hand side's result the task for updating the todos (\cref{lst:todo_update}) and the task for viewing the length are combined (\cref{lst:todo_length}).
+Both tasks operate on the todo \gls{SDS} (\cref{lst:todo_sds}).
+The task for updating the todo list is just an editor (\cref{lst:todo_editor}) combined using a step combinator (\crefrange{lst:todo_contfro}{lst:todo_contto}).
+The actions either change the value, sorting or clearing it, or terminates the task by returning the current value of the \gls{SDS}.
+Special combinators (e.g.\ \cleaninline{@>>} at \cref{lst:todo_ui}) are used to tweak the \gls{UI} to display informative labels.
-derive class iTask Person, Gender[+\label{lst:dt_derive}+]
+\begin{figure}
+ \centering
+ \includegraphics[width=.75\linewidth]{todo0g}
+ \caption{The \gls{UI} for the shared to-do list \gls{ITASK}.}%
+ \label{fig:todo}
+\end{figure}
-enterPerson :: Task Person
-enterPerson
- = Hint "Enter a person:" @>> enterInformation [][+\label{lst:task_ui}+]
- >>! \result->Hint "You Entered:" @>> viewInformation [] result[+\label{lst:task_comb}+]
-\end{lstClean}
+\cleaninputlisting[firstline=6,lastline=22,tabsize=3,numbers=left,caption={The code for a shared to-do list in \gls{ITASK}.},label={lst:todo}]{lst/sharedlist.icl}
\subsection{\texorpdfstring{\Gls{MTASK}}{MTask}}
\Gls{ITASK} seems an obvious candidate at first glance for extending \gls{TOP} to \gls{IOT} edge devices.
\Gls{MTASK} is seamlessly integrated with \gls{ITASK}: \gls{MTASK} tasks are integrated in such a way that they function as \gls{ITASK} tasks, and \glspl{SDS} in on the device can tether an \gls{ITASK} \gls{SDS}.
Using \gls{MTASK}, the programmer can define all layers of an \gls{IOT} system as a single declarative specification.
-\Cref{lst:intro_blink,fig:intro_blink} shows the code and a screenshot of an interactive \imtask{} application for blinking \pgls{LED} on the microcontroller every user-specified interval.
-\Crefrange{lst:intro:itask_fro}{lst:intro:itask_to} show the \gls{ITASK} part.
-First \pgls{SDS} is defined to communicate the blinking interval, then the \gls{MTASK} is connected using \cleaninline{withDevice}.
+\Cref{lst:intro_blink,fig:intro_blink} shows the \gls{ITASK} part of the code and a screenshot of an interactive \imtask{} application for blinking \pgls{LED} on the microcontroller every dynamically changeable interval.
+Using \cleaninline{enterInformation}, the connection specification of the \gls{TCP} device is queried (\cref{lst:intro_enterDevice}).
+\Cref{lst:intro_withshared} defines \pgls{SDS} to communicate the blinking interval.
+Then the \gls{MTASK} is connected using \cleaninline{withDevice} at \cref{lst:intro_withdevice}.
Once connected, the \cleaninline{intBlink} task is sent to the device (\cref{lst:intro_liftmtask}) and, in parallel, an editor is shown that updates the value of the interval \gls{SDS} (\cref{lst:intro_editor}).
+To allow ending the task, the \gls{ITASK} task ends with a sequential operation that returns a constant value when the button is pressed, making the task stable.
-\begin{lstClean}[numbers=left,caption={\Imtask{} interactive blinking.},label={lst:intro_blink}]
-interactiveBlink :: Task Int[+\label{lst:intro:itask_fro}+]
-interactiveBlink =
- withShared 500 \iInterval->[+\label{lst:intro_withshared}+]
- withDevice {TCPSettings | host = ..., port = ...} \dev->
- liftmTask (intBlink iInterval) dev[+\label{lst:intro_liftmtask}+]
- -|| Hint "Interval (ms)" @>> updateSharedInformation [] iInterval[+\label{lst:intro_editor}+][+\label{lst:intro:itask_to}+]
-\end{lstClean}
+\cleaninputlisting[firstline=10,lastline=18,numbers=left,caption={\Imtask{} interactive blinking.},label={lst:intro_blink}]{lst/blink.icl}
\begin{figure}
\centering
- \includegraphics[width=.3\textwidth]{blink}
- \caption{Screenshot for the interactive blink application.}%
+ \begin{subfigure}{.5\textwidth}
+ \centering
+ \includegraphics[width=.975\linewidth]{blink1g}
+ \caption{Device selection.}
+ \end{subfigure}%
+ \begin{subfigure}{.5\textwidth}
+ \centering
+ \includegraphics[width=.975\linewidth]{blink2g}
+ \caption{Changing the interval.}
+ \end{subfigure}
+ \caption{Screenshots for the interactive blink application.}%
\label{fig:intro_blink}
\end{figure}
The main expression of the program calls the \cleaninline{blink} function with an initial state.
This function on \crefrange{lst:intro:blink_fro}{lst:intro:blink_to} first reads the interval \gls{SDS}, waits the specified delay, writes the state to the \gls{GPIO} pin and calls itself recursively using the inverse of the state.
-\begin{lstClean}[numbers=left,caption={\Gls{MTASK} part of the interactive blinking application.},label={lst:intro_blink_mtask}]
-intBlink :: (Shared sds Int) -> MTask v Int | mtask, liftsds v & RWShared sds[+\label{lst:intro:mtask_fro}+]
-intBlink iInterval =
- declarePin D13 PMOutput \d13->[+\label{lst:intro:declarePin}+]
- liftsds \mInterval=iInterval[+\label{lst:intro:liftsds}+]
- In fun \blink=(\st->[+\label{lst:intro:blink_fro}+]
- getSds mInterval >>=. \i->delay i
- >>|. writeD d13 st >>|. blink (Not st))[+\label{lst:intro:blink_to}+]
- In {main = blink true}[+\label{lst:intro:mtask_to}+]
-\end{lstClean}
+\begin{lstClean}[numbers=left,belowskip=0pt]
+intBlink :: (Shared sds Int) -> Main (MTask v Int) | mtask v & ...\end{lstClean}
+\cleaninputlisting[aboveskip=0pt,firstnumber=3,firstline=22,numbers=left,caption={\Gls{MTASK} part of the interactive blinking application.},label={lst:intro_blink_mtask}]{lst/blink.icl}
\subsection{Other \texorpdfstring{\glsxtrshort{TOP}}{TOP} languages}
While \gls{ITASK} conceived \gls{TOP}, it is not the only \gls{TOP} system.
Some \gls{TOP} systems arose from Master's and Bachelor's thesis projects.
For example, \textmu{}Task \citep{piers_task-oriented_2016}, a \gls{TOP} language for modelling non-interruptible embedded systems in \gls{HASKELL}, and LTasks \citep{van_gemert_task_2022}, a \gls{TOP} language written in the dynamically typed programming language {LUA}.
-Some \gls{TOP} languages were created to solve a practical problem.
-Toppyt \citep{lijnse_toppyt_2022} is a general purpose \gls{TOP} language written in \gls{PYTHON} used to host frameworks for modelling C2 systems, and hTask \citep{lubbers_htask_2022}, a vessel for experimenting with asynchronous \glspl{SDS}.
+Some \gls{TOP} languages were created to fill a gap encountered in practise.
+Toppyt \citep{lijnse_toppyt_2022} is a general purpose \gls{TOP} language written in \gls{PYTHON} used to host frameworks for modelling \emph{Command\&Control} systems, and hTask \citep{lubbers_htask_2022}, a vessel for experimenting with asynchronous \glspl{SDS}.
Finally there are \gls{TOP} languages with strong academic foundations.
\Gls{TOPHAT} is a fully formally specified \gls{TOP} language designed to capture the essence of \gls{TOP} formally \citep{steenvoorden_tophat_2019}.
Such a formal specification allows for symbolic execution, hint generation, but also the translation to \gls{ITASK} for actually performing the work \citep{steenvoorden_tophat_2022}.
\end{enumerate}
\paragraph{Other publications on \texorpdfstring{\glspl{EDSL}}{eDSLs}:}
-Furthermore, I co-authored another paper that is worth mentioning but did not really fit in this dissertation.
+Furthermore, I co-authored another paper that is worth mentioning but is not part of the \gls{MTASK} system yet and hence not part of the dissertation.
\begin{enumerate}[resume]
\item \emph{Strongly-Typed Multi-View Stack-Based Computations} \citep{koopman_strongly-typed_2022} shows how to create type-safe \glspl{EDSL} representing stack-based computations.
The research in these papers and writing the paper was performed by me, though there were weekly meetings with Pieter Koopman and Rinus Plasmeijer in which we discussed and refined the ideas for paper~\ref{enum:first-class}.
\subsection{\Fullref{prt:top}}
-This episode is a monograph compiled from the following publications and shows the design, properties, implementation and usage of the \gls{MTASK} system and \gls{TOP} for the \gls{IOT}.
+This episode is a monograph that shows the design, properties, implementation and usage of the \gls{MTASK} system and \gls{TOP} for the \gls{IOT}.
+It is compiled from the following publications:
\begin{enumerate}[resume]
\item \emph{A Task-Based \glsxtrshort{DSL} for Microcomputers} \citep{koopman_task-based_2018}
repositories / phd-thesis.git / blobdiff