X-Git-Url: https://git.martlubbers.net/?a=blobdiff_plain;f=concl%2Fconcl.tex;h=b2ce8e5719ac3048f6fb719b95ba2a2d46b1d500;hb=7af43f4cbbc7792ec22553a84468cde77f429a11;hp=17a7828d218d5d62be88c089410b0a224cd09b4c;hpb=b6db6f555ad33c9b0b6ea958b5319b32365018dd;p=phd-thesis.git diff --git a/concl/concl.tex b/concl/concl.tex index 17a7828..b2ce8e5 100644 --- a/concl/concl.tex +++ b/concl/concl.tex @@ -15,44 +15,46 @@ \section{Reflections} This dissertation shed light on orchestrating complete \gls{IOT} systems using \gls{TOP}. - The term \gls{IOT} refers to the interconnected network of physical devices that are connected to each other and the internet. -The edge, or perception, layer of an \gls{IOT} systems is often powered by microcontrollers. +The edge, or perception, layer of an \gls{IOT} system is often powered by microcontrollers. These small and cheap computers do not have powerful hardware but are energy efficient and support many sensors and actuators. While the term \gls{IOT} has already been known for almost thirty years, only recently, the exponential growth of the number of \gls{IOT} edge devices is really ramping up. Programming \gls{IOT} systems is very complex because each layer of the system is built with different computers, hardware architectures, programming languages, programming paradigms, and abstraction levels. This generates a lot of semantic friction. -Furthermore, \gls{IOT} systems become convoluted because they are dynamic, multi-tiered, multi-user, multitasking, interactive, distributed, and collaborative. +Furthermore, \gls{IOT} systems become convoluted because they are dynamic, multi-tiered, multi-user, multitasking, interactive, distributed, and collaborative in nature. \Gls{TOP} proves a suitable programming paradigm that allows the declarative specification of exactly such systems. However, edge devices are often too computationally restricted to be able to run a full-fledged \gls{TOP} system such as \gls{ITASK}. - The dissertation is structured as a purely functional rhapsody in three episodes. -It shows different techniques that aid crafting the tools required, i.e.\ creating the programming languages. -Then it shows the tool, \gls{MTASK}, a \gls{TOP} system for \gls{IOT} edge devices. -Finally it compares how this tool compares to existing tools. + +In order to get \gls{TOP} to resource-constraind edge devices we use special tools: \glspl{DSL}. +The dissertation shows several techniques for creating \glspl{EDSL}. +Then it shows a tool, \gls{MTASK}, a \gls{TOP} system for \gls{IOT} edge devices. +Finally it compares how this approach compares to existing approaches for programming \gls{IOT} systems. \subsection{Tool craft} -First some techniques for tool crafting are presented in \cref{prt:dsl} that are useful for creating \gls{TOP} languages for \gls{IOT} edge devices. -It presents two novel techniques for embedding \glspl{DSL} in \gls{FP} languages: +\Cref{prt:dsl} presents some tool crafting techniques that are useful for creating \gls{TOP} languages for \gls{IOT} edge devices. +It presents two novel techniques for embedding \glspl{DSL} in \gls{FP} languages. + Classy deep embedding is a novel \gls{EDSL} embedding technique. -In \gls{DSL} embedding techniques, one always has to make concessions. -Either it is easy to extend the language in language constructs or in interpretations but never both. +When embedding \glspl{DSL}, one always has to make concessions. +It is either easy to add language constructs, or to add interpretations of the terms, but never both. +Some advanced embedding techniques found ways of mitigate this issue. Tagless-final embedding offers a way of extending a shallowly embedded \gls{DSL} both in constructs and interpretations. Classy deep embedding is the organically grown counterpart for deep embedding a \gls{DSL}. It allows orthogonal extension of language constructs and interpretations with minimal boilerplate and no advanced type system extensions. -When embedding a \gls{DSL} in a language, much, but not all, of the machinery is inherited -For example, data types are not automatically useable in the \gls{DSL} because the interfaces such as constructors, deconstructors and constructor predicates are not inherited. -I show how to automatically generate boilerplate for \glspl{DSL} in order to make data types first-class citizens in the \gls{DSL}. -The scaffolding is generated using template metaprogramming and quasiquotation is used to alleviate the programmer from the syntax burden. +When embedding a \gls{DSL} in a language, much, but not all, of the machinery is inherited. +An example of this are host-language data types. +They are not automatically useable in the \gls{DSL} because the interfaces such as constructors, deconstructors, constructor predicates, and pattern matching are not inherited. +I show how to automatically generate the required boilerplate for shallowly embedded \glspl{DSL} in order to make data types from the host language first-class citizens in the \gls{DSL}. +The scaffolding is generated using template metaprogramming and quasiquotation is used to alleviate the programmer from the syntax burden and support pattern matching. \subsection{Tools} -General-purpose \gls{TOP} systems cannot run on edge devices due to their sizeable hardware requirements. -However, using advanced \gls{DSL} embedding techniques, \glspl{DSL} can be created that can be executed on edge devices while maintaining the high abstraction level. -By embedding domain-specific knowledge into the language and execution platform, and leaving out general-purpose functionality \gls{TOP} languages can be made suitable for edge devices. +General-purpose \gls{TOP} systems cannot run on edge devices due to their significant hardware requirements. +However, with the right techniques, \glspl{DSL} can be created that can be executed on edge devices while maintaining the high abstraction level. +By embedding domain-specific knowledge into the language and execution platform, and leaving out general-purpose functionality, \gls{TOP} languages can be made suitable for edge devices. \Cref{prt:top} contains a complete overview of such a tool: the \gls{MTASK} system. -Its design, integration with \gls{ITASK}, implementation, and green computing facilities are shown. The \gls{MTASK} language is a unique domain-specific \gls{TOP} \gls{EDSL} designed system for edge devices. The \gls{MTASK} system is fully integrated with the \gls{ITASK} system, a \gls{TOP} system for programming distributed web applications. In the \gls{ITASK} system, there are abstractions for details such as user interfaces, data storage, client-side platforms, and persistent workflows. @@ -60,35 +62,34 @@ The \gls{MTASK} language abstracts away from edge device specific details such a Tasks in the \gls{MTASK} system are compiled at run time and sent to the device dynamically in order to support create dynamic systems where tasks are tailor-made for the current work requirements. This tight integration makes programming full \gls{IOT} systems using \gls{TOP} possible without major compromises. Using only three simple functions, devices are connected to \gls{ITASK} servers, \gls{MTASK} tasks are integrated in \gls{ITASK}, and \gls{ITASK} \glspl{SDS} accessed from within \gls{MTASK} tasks. +Its design, integration with \gls{ITASK}, implementation, and green computing facilities are shown. \subsection{Comparison} -Previous episodes show that it is possible to program all layers of an \gls{IOT} systems using \gls{TOP}. Using tierless programming, many issues that arise with tiered programming are mitigated. This has already been observed in web applications. -The question whether this novel approach to programming tiered systems also reduces the develop grief is answered in \cref{prt:tvt}. -This episode presents a four-way qualitatively and quantitatively comparison of the following systems: -\begin{enumerate*} - \item \gls{PRS}, a tiered system based on resource-rich edge devices powered by \gls{PYTHON}; - \item \gls{PWS}, a tiered system based on resource-constrained edge devices by \gls{MICROPYTHON}; - \item \gls{CRS}, a tierless system based on resource-rich edge devices powered by \gls{ITASK}; - \item \gls{CWS}, a tierless system based on resource-constrained edge devices powered by \imtask{}. -\end{enumerate*} +The \gls{MTASK} system show that it is possible to program edge devices of a \gls{IOT} systems using \gls{TOP}. +Furthermore, when used together with \gls{ITASK}, entire \gls{IOT} systems can be programmed tierlessly. +The question whether this novel approach to programming tiered systems also reduces the \gls{IOT} develop grief is answered in \cref{prt:tvt}. +This episode presents a four-way qualitative and quantitative comparison of the following systems: +\gls{PRS}, a tiered system based on resource-rich edge devices powered by \gls{PYTHON}; +\gls{PWS}, a tiered system based on resource-constrained edge devices by \gls{MICROPYTHON}; +\gls{CRS}, a tierless system based on resource-rich edge devices powered by \gls{ITASK}; +\gls{CWS}, a tierless system based on resource-constrained edge devices powered by \gls{MTASK}. This comparison shows that when using a programming paradigm that is available both for resource-rich and resource-constrained edge devices, there is little difference in developer grief. On the other hand, using a tierless system compared to a tiered system reduces the developer grief significantly. -Using either \imtask{} when dealing with resource-constrained devices such as microcontrollers or just \gls{ITASK} for all layers all layers of the entire \gls{IOT} system are specified in a single source, the same strong type system, and similar high abstraction level. +Every layer of the entire \gls{IOT} system is specified in a single source, the same strong type system, and similar high abstraction level. The tierless approach results in fewer \gls{SLOC}, files, programming languages and programming paradigms. All code is simultaneously checked by a single compiler, reducing interoperability problems. Furthermore, all communication and integration is automatically generated, reducing interoperability issues even more. -% + However, it is not a silver bullet, there are some disadvantages as well. Tierless languages are novel, and hence often lack tooling and community support. They contain high-level tierless abstractions that the programmer has to master. The low-level specific semantics of the final application may become more difficult to distill from the specification. Finally, the system is more monolithic compared to tiered approaches. -Changing components within the system is easy if it already is supported in the \gls{EDSL}. -Adding new components to the system requires the programmer to add it to all complex components of the languages such as the compiler, and \gls{RTS}. +Changing components within the system is easy if it already is supported in the \gls{EDSL}, but adding new components to the system requires the programmer to add it to all complex components of the languages such as the compiler, and \gls{RTS}. \input{subfilepostamble} \end{document}