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%Information to be included in the title page:
\title{Understanding the Implementation of ifTrue:ifFalse:}
\subtitle{}
\author{Damien Cassou, Stéphane Ducasse and Luc Fabresse}
\institute{http://stephane.ducasse.free.fr}
\date{}
\slidesid{W6S02}

\begin{document}

\frame[plain]{\titlepage}



\begin{frame}[fragile]

\frametitle{Yes ifTrue:ifFalse: is a message!}

\begin{listing}{}
Weather isRaining
    ifTrue: [ self takeMyUmbrella ]
    ifFalse: [ self takeMySunglasses ]
\end{listing}

\begin{itemize}
\item Conceptually \code{ifTrue:ifFalse:} is a message sent to an object: a boolean!
\item Heavily optimised by the compiler
\end{itemize}
\end{frame}



\begin{frame}[fragile]

\frametitle{Exercise}

\begin{itemize}
\item Propose an implementation of \code{ifTrue:ifFalse:}
\item You only have objects, messages and closures
\end{itemize}

\begin{listing}{}
   false ifTrue: [ 3 ] ifFalse: [ 5 ]
   -> 5

   true ifTrue: [ 3 ] ifFalse: [ 5 ]
   -> 3
\end{listing}
\end{frame}



\begin{frame}[fragile]

\frametitle{Implementing ifTrue:ifFalse:}

\begin{itemize}
\item Remember: 
\begin{itemize}
\item \code{{[} {]}} freezes body execution 
\item \code{value} kicks execution of a frozen code
\end{itemize}

\item How to implement \code{ifTrue:ifFalse:}?
\item Remember Not and Or?
\end{itemize}
\end{frame}



\begin{frame}[fragile]

\frametitle{Implementation of ifTrue:ifFalse:}

Let the receiver decide!

\begin{listing}{}
True >> ifTrue: aTrueBlock ifFalse: aFalseBlock
   ^ aTrueBlock value
\end{listing}

\begin{listing}{}
False >> ifTrue: aTrueBlock ifFalse: aFalseBlock
   ^ aFalseBlock value
\end{listing}
\end{frame}



\begin{frame}[fragile]

\frametitle{Implementation of ifTrue:ifFalse:}


\begin{center}
\includegraphics[width=1.1\textwidth]{figures/BooleanIfTrueIfFalse.png}\end{center}

\end{frame}



\begin{frame}[fragile]

\frametitle{Conclusion}

\begin{itemize}
\item Sending a message selects the right method
\item Let the receiver decide
\item \code{{[} {]}} freezes computation and \code{value} forces execution
\end{itemize}
\end{frame}




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\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}

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