intro/introduction.tex

   1 \documentclass[../thesis.tex]{subfiles}
   2
   3 \begin{document}
   4 \ifSubfilesClassLoaded{
   5         \pagenumbering{arabic}
   6 }{}
   7 \chapter{Introduction}%
   8 \label{chp:introduction}
   9 %\setlength{\epigraphwidth}{.5\textwidth}%
  10 %\epigraphhead[30]{
  11 %       A \textbf{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. An air of spontaneous inspiration and a sense of improvisation make it freer in form than a set of variations.
  12 %}{%
  13 %       Wikipedia~\citep{wikipedia_contributors_rhapsody_2022}
  14 %}%
  15 The sheer number of connected devices around us is increasing exponentially.
  16 All these devices are equipped with processors, sensors, actuators, communication interfaces and much more.
  17 They
  18 The one thing they all have in common
  19 All these connected devices are driven by software and communicate with eachother, sense and interact with the world.
  20 This thesis is about \ldots
  21 \todo[inline]{introduction}
  22
  23 \section{Internet of Things}
  24 \todo[inline]{add more citations and rewrite to make modern}
  25 The \gls{IOT} is growing rapidly and it is changing the way people and machines interact with the world.
  26 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 eigthies in a speech by \citet{peter_t_lewis_speech_1985}:
  27
  28 \begin{quote}
  29         \emph{The \acrlong{IOT}, or \acrshort{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.}
  30 \end{quote}
  31
  32 CISCO states that the \gls{IOT} only started when there where as many connected devices as there were people on the globe, i.e.\ around 2008~\citep{evans_internet_2011}.
  33 Today, the \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.
  34 These connected devices are already in everyone's household in the form of smart electricity meters, smart fridges, smartphones, smart watches, home automation, \etc.
  35
  36 When describing \gls{IOT} systems, a layered, or tiered architecture is often used to compartmentalize the technology.
  37 The number of tiers heavily depends on the complexity of the model but for the intents and purposes of the thesis, the four layer architecture shown in \cref{fig:iot-layers} is used.
  38
  39 \begin{figure}[ht]
  40         \centering
  41         \includestandalone{iot-layers}
  42         \caption{The four layered \gls{IOT} architecture.}%
  43         \label{fig:iot-layers}
  44 \end{figure}
  45
  46 \begin{description}
  47         \item[Presentation layer] This presentation layer provides the interface between the user and the \gls{IOT} application.
  48                 For example, in home automation, this is often implemented as a web interface or a mobile app.
  49         \item[Application layer]
  50                 Servers often power the application layer, by providing the data storage,
  51                 One of its goals is to provide the \gls{API}, interfaces and data storage
  52         \item[Network layer] connects all layers together.
  53                 In many applications this may be implemented using conventional networking techniques such as WiFi or wire networks.
  54                 However, recently, networks tailored to the needs of \gls{IOT} applications have been increasingly popular such as \gls{BLE}, LoRa, ZigBee or LTE-M.
  55         \item[Perception layer], also called edge layer, collects the data, interacts with the environment and consists of (edge) devices equipped with various sensors and actuators.
  56                 As a special type of device, it may also contain a \gls{SN}.
  57                 A \gls{SN} is a collection of sensors connected by a mesh network or central hub.
  58 \end{description}
  59
  60 The devices are a large heterogeneous collection of different platforms, protocols and languages resulting in impedance problems or semantic friction between layers~\citep{ireland_classification_2009}.
  61 Furthermore, the perception layer often is a heterogeneous collections of microcontrollers as well, each having their own peculiarities, language of choice and hardware interfaces.
  62 The hardware needs to be cheap, small-scale and energy efficient.
  63 As a result, the \glspl{MCU} used to power these devices do not have a lot of computational power, a soup\c{c}on of memory, and little communication bandwidth.
  64 Typically the devices do not run a full fledged \gls{OS} but a compiled firmware.
  65 This firmware is often written in an imperative language that needs to be flashed to the program memory.
  66 Program memory typically is flash based and only lasts a couple of thousand writes before it wears out.
  67 While devices are getting a bit faster, smaller, and cheaper, they keep these properties to an extent.
  68 The properties of the device greatly reduce the flexibility for dynamic systems where tasks are created on the fly, executed on demand and require parallel execution.
  69 \todo{\gls{OTA} benoemen?}
  70 These problems can be mitigated by dynamically sending code to be interpreted to the \gls{MCU}.
  71 With interpretation, a specialized interpreter is flashed in the program memory once that receives the program code to execute at runtime.
  72
  73 %weiser_computer_1991
  74 \section{Domain-specific languages}
  75 % General
  76 Programming languages can be divided up into two categories: \glspl{DSL}\footnote{Historically this has been called DSEL as well.} and \glspl{GPL}~\citep{fowler_domain_2010}.
  77 Where \glspl{GPL} are not made with a demarcated area in mind, \glspl{DSL} are tailor-made for a specific domain.
  78 Writing idiomatic domain-specific code in an \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.
  79 \Glspl{DSL} come in two main flavours: standalone and embedded\footnote{Also called external and internal respectively.} of which \glspl{EDSL} can again be classified into heterogeneous and homogeneous languages (see \cref{fig:hyponymy_of_dsls} for this hyponymy).
  80
  81 \begin{figure}[ht]
  82         \centering
  83         \includestandalone{hyponymy_of_dsls}
  84         \caption{Hyponymy of \glspl{DSL} (adapted from \citet[pg.\ 2]{mernik_extensible_2013})}%
  85         \label{fig:hyponymy_of_dsls}
  86 \end{figure}
  87
  88 \subsection{Standalone and embedded}
  89 \glspl{DSL} where historically created as standalone languages, meaning all the machinery is developed solely for the language.
  90 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.
  91 Unfortunately it also means that they need to develop a compiler or interpreter for the language to be usable making standalone \glspl{DSL} costly to create.
  92 Examples of standalone \glspl{DSL} are regular expressions, make, yacc, XML, SQL, \etc.
  93
  94 A dichotomous approach is embeddding the \gls{DSL} in a host language, i.e.\ \glspl{EDSL}~\citep{hudak_modular_1998}.
  95 By defining the language as constructs in the host language, much of the machinery is inherited and the cost of creating embedded languages is very low.
  96 There is more linguistic reuse~\cite{krishnamurthi_linguistic_2001}.
  97 There are however two sides to the this coin.
  98 If the syntax of the host language is not very flexible, the syntax of the \gls{DSL} may become clumsy.
  99 Furthermore, 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}.
 100
 101 \subsection{Heterogeneity and homogeneity}
 102 Tratt applied a notion from metaprogramming~\citep{sheard_accomplishments_2001} to \glspl{EDSL} to define homogeneity and heterogeneity of \glspl{EDSL} as follows~\citep{tratt_domain_2008}:
 103 \begin{quote}
 104         \emph{a homogeneous system is one where all the components are specifically designed to work with each other, whereas in heterogeneous systems at least one of the components is largely, or completely, ignorant of the existence of the other parts of the system.}
 105 \end{quote}
 106 Homogeneous \glspl{EDSL} are therefore languages that are solely defined as an extension to their host language.
 107 They often restrict features of the host language to provide a safer interface or capture an idiomatic pattern in the host language for reuse.
 108 The difference between a library and a homogeneous \glspl{EDSL} is not always clear.
 109 Examples of homogeneous \glspl{EDSL} are libraries such as ones for sets, \glspl{GUI} creation, LISP's macro system, \etc.
 110
 111 On the other hand, heterogeneous \glspl{EDSL} are languages that are not executed in the host language.
 112 For example, Elliott et al.\ describe the language Pan, for which the final representation in the host language is a compiler that will, when executed, generate code for a completely different target platform~\citep{elliott_compiling_2003}.
 113 In fact, \gls{ITASK} and \gls{MTASK} are both heterogeneous \glspl{EDSL}\todo{reference next section?}.
 114
 115 \section{Task-oriented programming}
 116 \Gls{TOP} is a declarative programming paradigm designed to model interactive systems~\citep{plasmeijer_task-oriented_2012}.
 117 Instead of dividing problems into layers or tiers, as is done in \gls{IOT} architectures as well, it deals with separation of concerns in a novel way.
 118 From the data types, utilising various \emph{type-parametrised} concepts, all other aspects are handled (see \cref{fig:tosd}).
 119 This approach to software development is called \gls{TOSD}~\citep{wang_maintaining_2018}.
 120
 121 \begin{figure}[ht]
 122         \centering
 123         \begin{subfigure}[t]{.5\textwidth}
 124                 \centering
 125                 \includestandalone{traditional}
 126                 \caption{Traditional layered approach.}
 127         \end{subfigure}%
 128         \begin{subfigure}[t]{.5\textwidth}
 129                 \centering
 130                 \includestandalone{tosd}
 131                 \caption{\Gls{TOSD} approach.}
 132         \end{subfigure}
 133         \caption{Separation of concerns in a traditional setting and in \gls{TOSD} (adapted from~\cite[pg.\ 20]{wang_maintaining_2018}).}%
 134         \label{fig:tosd}
 135 \end{figure}
 136
 137 \begin{description}
 138         \item[Presentation layer: \gls{UI}]
 139                 The \gls{UI} of the system is automatically generated from the representation of the type.
 140 %               For instance, \gls{TOP} languages implemented in an \gls{FP} language often use generic programming or template metaprogramming to automatically achieve this.
 141 %               \Gls{TOP} languages embedded in imperative programming languages may use introspection\todo{Do I want this sentence here?}.
 142                 Even though the \gls{UI} is generated from the structure of the datatypes, in practical \gls{TOP} systems it can be tweaked afterwards to suit the specific needs of the application.
 143         \item[Business layer: tasks]
 144                 A task is an abstract representation of a piece of work that needs to be done.
 145                 It provides an intuitive abstraction over work in the real world.
 146                 Just as with real-life tasks and workflow, tasks can be combined in various ways such as in parallel or in sequence.
 147                 Furthermore, a task is observable which means it is possible to observe a---partial---result during execution and act upon it by for example starting new tasks.
 148                 Examples of tasks are filling in a form, sending an email, reading a sensor or even doing a physical task.
 149         \item[Resource access: \glspl{SDS}]
 150                 Tasks can communicate using task values but this imposes a problem in many collaboration patterns where tasks that are not necessarily related need to share data.
 151                 Tasks can also share data using \glspl{SDS}, an abstraction over any data.
 152                 An \gls{SDS} can represent typed data stored in a file, a chunk of memory, a database \etc.
 153                 \Glspl{SDS} can also represent external impure data such as the time, random numbers or sensory data.
 154                 Similar to tasks, transformation and combination of \glspl{SDS} is possible.
 155         \item[\Gls{UOD}: programming language]
 156                 The \gls{UOD} from the business layer is explicitly and separately modelled by the relations that exist in the functions of the host language.
 157 \end{description}
 158
 159 The concept of \gls{TOP} originated from the \gls{ITASK} framework, a declarative workflow language 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}.
 160 While \gls{ITASK} conceived \gls{TOP}, it is not the only \gls{TOP} language.
 161 \Gls{TOPHAT} is a fully formally specified \gls{TOP} language designed to capture the essence of \gls{TOP} formally~\citep{steenvoorden_tophat_2019}.
 162 \citet{piers_task-oriented_2016} created \textmu{}Task, a \gls{TOP} language for specifying non-interruptible embedded systems implemented as an \gls{EDSL} in \gls{HASKELL}.
 163 \citet{van_gemert_task_2022} created LTasks, a \gls{TOP} language for interactive terminal applications implemented in LUA, a dynamically typed imperative language.
 164 \citet{lijnse_toppyt_2022} created Toppyt, a \gls{TOP} language based on \gls{ITASK}, implemented in \gls{PYTHON}, but designed to be simpler and smaller.
 165 Finally there is \gls{MTASK}, \gls{TOP} language designed for defining workflow for \gls{IOT} devices~\cite{koopman_task-based_2018}.
 166 It is written in \gls{CLEAN} as an \gls{EDSL} fully integrated with \gls{ITASK} and allows the programmer to define all layers of an \gls{IOT} system from a single source.
 167
 168 \section{Outline}
 169 \todo[inline]{uitbreiden}
 170 On Wikipedia, a rhapsody is defined as follows~\citep{wikipedia_contributors_rhapsody_2022}:
 171 \begin{quote}
 172         \emph{A \textbf{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. An air of spontaneous inspiration and a sense of improvisation make it freer in form than a set of variations.}
 173 \end{quote}
 174
 175 This thesis follows the tradition and consists of three movements that are episodic yet integrated, a purely functional rhapsody.
 176 \Cref{prt:dsl} is about \gls{EDSL} techniques, \cref{prt:top} elaborates on \gls{TOP} for the \gls{IOT} and \cref{prt:tvt} compares traditional tiered \gls{IOT} architectures to a tierless architectures such as \gls{TOP}.
 177 The movements are readable independently if the reader is familiarised with the background material provided in \cref{chp:introduction}.
 178 The thesis wraps up with \cref{chp:conclusion} that provides a conclusion and an outlook on future work.
 179
 180 \subsection*{\nameref{prt:dsl}}
 181 This movement is a cumulative---paper-based---movement that focusses on techniques for embedding \glspl{DSL} in \gls{FP} lanugages.
 182 After reading the first chapter, subsequent chapters in this movement are readable as independently.
 183
 184 \subsubsection*{\fullref{chp:dsl_embedding_techniques}}
 185 This chapter shows the basic \gls{DSL} embedding techniques and compares the properties of several embedding methods.
 186 This chapter is not based on a paper and written as a extra background material for the subsequent chapters in the movement.
 187
 188 \subsubsection*{\fullref{chp:classy_deep_embedding}}
 189 This chapter is based on the paper: \emph{Deep Embedding with Class}~\todo{cite when published}.
 190
 191 During a Master's thesis supervision~\citep{amazonas_cabral_de_andrade_developing_2018}, focussing on an early version of \gls{MTASK}, a seed was planted for a novel deep embedding technique for \glspl{DSL} where the resulting language is extendible both in constructs and in interpretation using type classes and existential data types.
 192 Slowly the ideas organically grew to form the technique shown in the paper.
 193
 194 The research from this paper and writing the paper was solely performed by me.
 195 \Cref{sec:classy_reprise} was added after publication and contains a (yet) unpublished extension of the embedding technique.
 196
 197 \subsubsection*{\fullref{chp:first-class_datatypes}}
 198 This chapter is based on the paper: \emph{First-Class Data Types in Shallow Embedded Domain-Specific Languages using Metaprogramming}~\todo{cite when accepted}.
 199 It shows how to inherit data types in \glspl{EDSL} using metaprogramming.
 200
 201 The research in this paper 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.
 202
 203 \subsection*{\nameref{prt:top}}
 204 This part is a monograph focussing on \glspl{TOP} for the \gls{IOT}.
 205 Therefore, the chapters depend on eachother and are best read in order.
 206 The monograph is compiled from the following papers and revised lecture notes.
 207
 208 \begin{itemize}
 209         \item \bibentry{koopman_task-based_2018}.
 210
 211                 This was the initial \gls{TOP}/\gls{MTASK} paper.
 212                 Pieter Koopman wrote it but I helped with the software and research.
 213         \item \bibentry{lubbers_task_2018}.
 214
 215                 This paper was an extension of my Master's thesis~\citep{lubbers_task_2017}.
 216                 It shows how a simple imperative variant of \gls{MTASK} was integrated with \gls{ITASK}.
 217                 While the language was a lot different than later versions, the integration mechanism is still used in \gls{MTASK} today.
 218
 219                 The research in this paper 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.
 220         \item \bibentry{lubbers_multitasking_2019}.
 221
 222                 This paper was a short paper on the multitasking capabilities of \gls{MTASK} in contrast to traditional multitasking methods for \gls{ARDUINO}.
 223         \item \emph{Simulation of a Task-Based Embedded Domain Specific Language for the Internet of Things}~\todo{cite when published}
 224
 225                 These revised lecture notes are from a course on the \gls{MTASK} simulator was provided at the 2018 CEFP/3COWS winter school in Ko\v{s}ice, Slovakia.
 226
 227                 Pieter Koopman wrote and taught it though I helped with the software and research.
 228         \item \emph{Writing Internet of Things applications with Task Oriented Programming}~\todo{cite when published}
 229
 230                 These revised lecture notes are from a course on programming in \gls{MTASK} provided at the 2019 CEFP/3COWS summer school in Budapest, Hungary.
 231
 232                 Pieter prepared half of the lecture. I wrote the lecture notes, prepared the other half of the lecture, the assignments and practical session.
 233         \item \bibentry{lubbers_interpreting_2019}.
 234
 235                 This paper showed an implementation for \gls{MTASK} for microcontrollers in the form of a compilation scheme and informal semantics description.
 236
 237                 The research in this paper 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.
 238         \item \emph{Reducing the Power Consumption of IoT with Task-Oriented Programming}~\todo{cite when published}
 239
 240                 This paper shows how to create a scheduler so that devices running \gls{MTASK} tasks can go to sleep more automatically.
 241                 Furthermore, it shows how to integrate hardware interrupts into \gls{MTASK}.
 242                 The research was carried out by Sjoerd Crooijmans during his Master's thesis~\citep{crooijmans_reducing_2021}.
 243                 I did the daily supervision and helped with the research, Pieter Koopman was the formal supervisor and wrote most of the paper.
 244         \item \emph{Asynchronous Shared Data Sources}~\todo{cite when accepted}
 245
 246                 \todo[inline]{This paper could in theory be dropped in favour of being done sooner with the thesis}
 247
 248                 Asynchronous \glspl{SDS} are used in the current \gls{ITASK} system and allow bigger \gls{IOT} devices such as raspberry pi's to be used in a tierless \gls{ITASK} system.
 249                 The example application shown in \cref{prt:tvt} heavily uses asynchronous \glspl{SDS}.
 250                 This paper shows how to lift \glspl{SDS} to operate asynchronously independent of \gls{ITASK} or another \gls{TOP} implementation.
 251
 252                 The initial research was carried out by Haye B\"ohm during his Master's thesis~\citep{bohm_asynchronous_2019}.
 253                 I did the daily supervision and helped with the research, Pieter Koopman and Rinus Plasmeijer were the formal supervisors.
 254                 I extended and generalised the research and wrote the paper.
 255         \item \emph{Green Computing for the Internet of Things}~\todo[inline]{cite when done}
 256
 257                 These revised lecture notes are from a course on sustainable programming using \gls{MTASK} provided at the 2022 Sustrainable summer school in Rijeka, Croatia.
 258
 259                 Pieter prepared half of the lecture and wrote the introduction.
 260                 I wrote the middle part of the lecture notes, prepared the other half of the lecture, the assignments and the practical session.
 261 \end{itemize}
 262
 263 The movement is made up out of the following chapters
 264 \todo[inline]{preliminary}
 265
 266 \begin{itemize}
 267         \item The mTask language (includes informal semantics)
 268                 \begin{itemize}
 269                         \item Expressions
 270                         \item Functions
 271                         \item Tasks
 272                         \item Shares
 273                         \item Peripherals
 274                 \end{itemize}
 275         \item Interpretations/views/backends\todo{decide on terminology}
 276         \item Green computing
 277         \item Integration with iTask
 278         \item Implementation (based on IFL19 paper)
 279         \item TOP for IoT beyond microprocessors
 280 \end{itemize}
 281
 282 \subsection*{\nameref{prt:tvt}}
 283 These chapters focus on comparing traditional tiered architectures to tierless architectures and are based on a single journal paper that extended on a conference paper.
 284 The conference paper was partly funded by the Radboud-Glasgow Collaboration Fund.
 285 It does both a qualitative and a quantitative four-way comparison of a smart campus application.
 286
 287 The research in these papers and writing them was performed by all authors.
 288 I created the server application, the \gls{CLEAN}/\gls{ITASK}/\gls{MTASK} implementation (\acrshort{CWS}) and the \gls{CLEAN}/\gls{ITASK} implementation (\acrshort{CRS})
 289 Adrian Ramsingh created the micropython implementation (\acrshort{PWS}), the original python implementation (\acrshort{PRS}) and the server application were created by Jeremy Singer, Dejice Jacob and Kristian Hentschel~\citep{hentschel_supersensors:_2016}.
 290
 291 \begin{itemize}
 292         \item \bibentry{lubbers_tiered_2020}.
 293         \item \emph{Could Tierless Languages Reduce IoT Development Grief?}~\todo[inline]{cite when accepted}
 294 \end{itemize}
 295
 296 \newcounter{secondauthorcnt}
 297 \newcounter{underreviewcnt}
 298 \newcounter{plannedcnt}
 299 \newcounter{publicationscnt}
 300 \newcommand{\secondauthor}{\textsuperscript{$\ast$}\stepcounter{secondauthorcnt}}
 301 \newcommand{\underreview}{\textsuperscript{$\dagger$}\stepcounter{underreviewcnt}}
 302 \newcommand{\planned}{\textsuperscript{$\ddagger$}\stepcounter{plannedcnt}}
 303
 304 \subsection{List of publications}
 305 \begin{enumerate}
 306         \item \secondauthor{}
 307                 A Task-Based DSL for Microcomputers
 308
 309                 P. Koopman\footnote{\orcid{0000-0002-3688-0957}}, M. Lubbers\footnote{\orcid{0000-0002-4015-4878}}, and R. Plasmeijer (RWDSL 2018)~\citep{koopman_task-based_2018}.
 310         \item Task Oriented Programming and the Internet of Things
 311
 312                 M. Lubbers, P. Koopman, and R. Plasmeijer (IFL 2018)~\citep{lubbers_task_2017} (extension of Master's thesis~\citep{lubbers_task_2018}).
 313         \item Multitasking on Microcontrollers using Task Oriented Programming
 314
 315                 M. Lubbers, P. Koopman, and R. Plasmeijer (MIPRO/4COWS 2019)~\citep{lubbers_multitasking_2019}.
 316         \item \secondauthor{}
 317                 Simulation of a Task-Based Embedded Domain Specific Language for the Internet of Things
 318
 319                 P. Koopman, M. Lubbers, and R. Plasmeijer (CEFP/3COWS 2018).
 320         \item Writing Internet of Things applications with Task Oriented Programming
 321
 322                 M. Lubbers, P. Koopman, and R. Plasmeijer (CEFP/3COWS 2019).
 323         \item Interpreting Task Oriented Programs on Tiny Computers
 324
 325                 M. Lubbers, P. Koopman, and R. Plasmeijer (IFL 2019)~\citep{lubbers_interpreting_2019}.
 326         \item Tiered versus Tierless IoT Stacks: Comparing Smart Campus Software Architectures
 327
 328                 M. Lubbers, P. Koopman, A. Ramsingh\footnote{\orcid{0000-0003-3501-902X}}, J. Singer\footnote{\orcid{0000-0001-9462-6802}}, and P. Trinder\footnote{\orcid{0000-0003-0190-7010}} (IoT 2020)~\citep{lubbers_tiered_2020}.
 329
 330         % in press
 331         \item Deep Embedding with Class
 332
 333                 M. Lubbers (TFP 2022).
 334         \item \secondauthor{}
 335                 Reducing the Power Consumption of IoT with Task-Oriented Programming
 336
 337                 S. Crooijmans, M. Lubbers, and P. Koopman (TFP 2022).
 338
 339         %Under review
 340         \item \underreview{} Could Tierless Languages Reduce IoT Development Grief?
 341
 342                 M. Lubbers, P. Koopman, A. Ramsingh, J. Singer, and P. Trinder (ACM TIOT) (extension of~\citep{lubbers_tiered_2020}).
 343         \item \secondauthor\underreview{}
 344                 Strongly-Typed Multi-View Stack-Based Computations
 345
 346                 M. Lubbers and P. Koopman (IFL 2022 under review).
 347         \item \underreview{} First-Class Data Types in Shallow Embedded Domain-Specific Languages using Metaprogramming
 348
 349                 M. Lubbers, P. Koopman, and R. Plasmeijer (IFL 2022 under review).
 350         \item \underreview{} Asynchronous Shared Data Sources
 351
 352                 M. Lubbers, H. Böhm, P. Koopman, and R. Plasmeijer (IFL 2022 under review).
 353
 354         %Planned
 355         \item \planned{} Green Computing for the Internet of Things
 356
 357                 M. Lubbers, P. Koopman (Sustrainable 2022 planned).
 358
 359                 \setcounter{publicationscnt}{\value{enumi}}
 360 \end{enumerate}
 361
 362 There are \thepublicationscnt{} publications of which \thesecondauthorcnt{} I'm second author, \theunderreviewcnt{} are under review and \theplannedcnt{} are planned.
 363
 364 \input{subfilepostamble}
 365 \end{document}