\documentclass[../thesis.tex]{subfiles}

\input{subfilepreamble}

\begin{document}
\input{subfileprefixsmall}
\ifSubfilesClassLoaded{\chapter*{Summary}}{\chapter{Summary}}%
\label{chp:summary}%
\glsresetall%
Programming \gls{IOT} systems is complex since they are dynamic, interactive, distributed, collaborative, multi-tiered, and multitasking in nature.
The complexity is increased further by semantic friction that arises through different hardware and software characteristics between tiers.
Many computers that operate in \gls{IOT} systems are \emph{edge devices} that interact with the environment using sensors and actuators.
Edge devices often use low-cost microcontrollers designed for embedded applications.
They have little memory, unhurried processors, and are slow in communication but are also small and energy efficient.
%Hence they require additional care.

A solution is found in \gls{TOP}.
In \gls{TOP}, the main building blocks are tasks, an abstract representation of work.
During execution, the current value of the task is observable, and other tasks can act upon it.
Collaboration patterns can be modelled by combining and transforming tasks into compound tasks.
From this high-level declarative description of the work, a ready-for-work tierless application is generated that guides all operators in doing the work.
An example of a \gls{TOP} system is \gls{ITASK}, a language which describes interactive web applications.
Programming edge devices benefits from \gls{TOP} as well.
However, it is not straightforward to run \gls{TOP} systems on edge devices.

This dissertation demonstrates how to include edge devices in \gls{TOP} systems using \glspl{DSL}.
With these techniques, all tiers and their interoperation of an \gls{IOT} system is specified in a single high-level source, language, paradigm, high abstraction level, and type system.
First, I present advanced \gls{DSL} embedding techniques.
Then \gls{MTASK} is shown, a \gls{TOP} \gls{DSL} for \gls{IOT} edge devices, embedded in \gls{ITASK}.
Tasks are constructed and compiled at run time in order to allow tasks to be tailored to the current work requirements.
The task is then sent to the device for interpretation.
For a device to be used in an \gls{MTASK} system, it is programmed once with a lightweight domain-specific \gls{OS}.
This \gls{OS} executes tasks in an energy-efficient way and automates all communications and data sharing.
All aspects of the \gls{MTASK} system are shown: example applications, language design, implementation details, integration with \gls{ITASK}, and green computing facilities such as automatic sleeping.

Finally, tierless programming is compared to traditional tiered programming.
It demonstrates that when using tierless programming frameworks, the size of the code and the number of required programming languages and paradigms is reduced significantly.
Furthermore, tierless programming reduces problems such semantic friction; maintainability and robustness issues; and interoperation safety.
%This is a summary of 350--400 words.
\end{document}
