% add the PATH to retrieve cls and sty beamer styles files \makeatletter \providecommand*{\input@path}{} \edef\input@path{{../../support/beamer/}\input@path}% prepend \makeatother % \documentclass{pharoslides} % \documentclass[aspectratio=169]{pharoslides} % format 16/9 \documentclass[withvideo]{pharoslides} % format 16/9 + incrustation video \graphicspath{{./figures/}{../}{../../support/beamer/imgs/}} %Information to be included in the title page: \title{Reflective Operations for Live Programming} \subtitle{} \author{Damien Cassou, Stéphane Ducasse and Luc Fabresse} \institute{http://stephane.ducasse.free.fr} \date{} \slidesid{W7S04} \begin{document} \frame[plain]{\titlepage} \begin{frame}[fragile] \frametitle{Behind the Scene} \begin{itemize} \item What is happening when we recompile a class? \item What are the reflective operations that take place? \end{itemize} \end{frame} \begin{frame}[fragile] \frametitle{A Typical Scenario} \begin{itemize} \item Define one class \item Define some methods \item Create some instances \item Add an instance variable to the class \item Existing instances got mutated \item Continue working \end{itemize} \end{frame} \begin{frame}[fragile] \frametitle{Operations Supporting Interactive Coding} \begin{itemize} \item Dynamic class (re)definition \item Method recompilation \item Transparent instance migration \begin{itemize} \item Collecting instances \item Switching pointers from old to new instances \end{itemize} \end{itemize} \end{frame} \begin{frame}[fragile] \frametitle{Getting All Instances} \begin{listing}{} Dictionary allInstances size \end{listing} \begin{listing}{} Window allInstances first close \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Getting All Pointers to an Object} \begin{listing}{} anObject pointersTo \end{listing} returns all objects that store a reference to \code{anObject} \end{frame} \begin{frame}[fragile] \frametitle{Symmetric Pointer Swapping} \begin{listing}{} anObject become: anotherObject \end{listing} \begin{itemize} \item All the pointers to \code{anObject} point now to \code{anotherObject} \item And \symbol{34}the inverse\symbol{34} atomically \end{itemize} \end{frame} \begin{frame}[fragile] \frametitle{Symmetric Pointer Swapping} \begin{listing}{} | pt1 pt2 pt3 | pt1 := 0@0. pt2 := pt1. pt3 := 100@100. pt1 become: pt3. self assert: pt2 = (100@100). self assert: pt3 = (0@0). self assert: pt1 = (100@100) \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Asymmetric Pointer Swapping} Swap all the pointers from one object to the other (asymmetric) \begin{listing}{} anObject becomeForward: anotherObject \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Example: Asymmetric Pointer Swapping} \begin{listing}{} | pt1 pt2 pt3 | pt1 := 0@0. pt2 := pt1. pt3 := 100@100. pt1 becomeForward: pt3. self assert: pt1 = (100@100). self assert: pt1 == pt2. self assert: pt2 == pt3. \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Changing the Class of an Object} \begin{listing}{} Class >> adoptInstance: anInstance "Change the class of anInstance to me. Returns the class rather than the modified instance" \end{listing} \begin{itemize} \item Limited reflective feature \item Target class should have the same format as the original one \end{itemize} \end{frame} \begin{frame}[fragile] \frametitle{Essence of a Class} \begin{enumerate} \item A format i.e., a number of instance variables and types (named/indexed) \item A superclass \item A method dictionary \end{enumerate} \end{frame} \begin{frame}[fragile] \frametitle{Class initialize} \begin{listing}{} Behavior >> initialize super initialize. self superclass: Object. self methodDict: self emptyMethodDictionary. self setFormat: Object format. \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Instance Specific Behavior} \begin{listing}{} | behavior model newClass | behavior := Behavior new. behavior superclass: Model. behavior setFormat: Model format. model := Model new. model primitiveChangeClassTo: behavior new. self assert: model class = behavior. self assert: model class superclass = Model. behavior compile: 'foo ^ 2'. self assert: model foo = 2. self should: [Model new foo] raise: MessageNotUnderstood \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Instance Specific Behavior} \begin{center} \includegraphics[width=1.0\textwidth]{figures/10AnonymousClasses.png}\end{center} \end{frame} \begin{frame}[fragile] \frametitle{Anonymous Classes For Spying} \begin{listing}{} | logClass set | logClass := Behavior new. logClass superclass: Set; setFormat: Set format. logClass compile: 'add: anObject Transcript show: ''adding '', anObject printString; cr. ^ super add: anObject'. set := Set new. set add: 1. set class. set primitiveChangeClassTo: logClass basicNew. set add: 2. \end{listing} \end{frame} \begin{frame}[fragile] \frametitle{Conclusion} \begin{itemize} \item Reflection is a solid foundation for innovation and language extensibility \item Avoid using reflective operations in domain code \item Understand when you absolutely need reflection \end{itemize} \end{frame} % \setlength{\textwidth}{\originaltextwidth} \setbeamertemplate{background canvas}{\insertBorderForHandout} \begin{frame}[plain] \begin{minipage}{\originaltextwidth} \centering \large \vspace{2em} A course by \vspace{1em} \hspace{-20px}\includegraphics[height=32px]{inriaLogo}\hspace{3em}\raisebox{7px}{and}\hspace{3em}\raisebox{-6px}{\includegraphics[height=30px]{logoutop}} \vspace{2em} in collaboration with \vspace{1em} \includegraphics[height=40px]{unisciellogo}\hskip 1.5em% \raisebox{5px}{\includegraphics[height=30px]{unitlogo}}\hskip 2em% \raisebox{8px}{\includegraphics[height=24px]{univLilleLogo}}\hskip 2em% \raisebox{3px}{\includegraphics[height=29px]{logo-IMT}}\hskip 2em% \raisebox{1px}{\includegraphics[height=32px]{minesDouaiLogo}} \vspace{2.5em} \includegraphics[width=50px]{by-nc-nd} \tiny \hskip 0.5em \raisebox{5px}{Inria 2016} \medskip \tiny Except where otherwise noted, this work is licensed under CC BY-NC-ND 3.0 France \url{https://creativecommons.org/licenses/by-nc-nd/3.0/fr/} \end{minipage} \end{frame} \end{document} %%% Local Variables: %%% mode: latex %%% TeX-master: t %%% End: