\documentclass[dvipsnames,14pt,t,xelatex]{beamer}
\usepackage{chessboard}
\usepackage[LSBC4,T1]{fontenc}
\usepackage{../slides}
\usepackage{../graphics}
\usepackage{../langs}

% \usepackage{../data}

\hfuzz=220pt 

%\setmonofont[Scale=.88]{Consolas}
%\newfontfamily{\consolas}{Consolas}

\lstset{language=Scala,
        style=mystyle,
        numbersep=0pt,
        numbers=none,
        xleftmargin=0mm}

\newcommand{\bl}[1]{\textcolor{blue}{#1}}     

% beamer stuff 
\renewcommand{\slidecaption}{PEP (Scala) 02, King's College London}


\begin{document}

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{frame}[t]
\frametitle{%
  \begin{tabular}{@ {}c@ {}}
  \\[5mm]
  \huge PEP Scala (2) 
  \end{tabular}}

  \normalsize
  \begin{center}
  \begin{tabular}{ll}
    Email:  & christian.urban at kcl.ac.uk\\
    Office: & N\liningnums{7.07} (North Wing, Bush House)\\
    Slides \& Code: & KEATS\medskip\\
    Office Hours: &  Mondays 12:00 -- 14:00\\
  \end{tabular}
  \end{center}


\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
\begin{frame}[c,fragile]
\frametitle{Scala on Lab Computers}

\begin{lstlisting}[language={},numbers=none,
  basicstyle=\ttfamily\small,xleftmargin=-2mm]
$ /usr/share/scala/bin/scala
  
Welcome to Scala 2.12.6 (Java HotSpot(TM) 64-Bit
Server VM, Java 10.0.1). Type in expressions for
evaluation. Or try :help.

scala>
\end{lstlisting}%$

\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%

%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
\begin{frame}[c]
\frametitle{Scala on Lab Computers}

Avoid at all costs, even in comments

\begin{itemize}
\item \texttt{var} \only<2>{$\quad\Rightarrow\;$\texttt{Var}}
\item \texttt{return} \only<2>{$\quad\Rightarrow\;$\texttt{Return}}
\item \texttt{.par}
\item \texttt{ListBuffer}
\item \texttt{mutable}  
\end{itemize}

\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
\begin{frame}[t]
\frametitle{For-Comprehensions Again}

\begin{center}
  \begin{tikzpicture}[scale=1,
                      node/.style={
                      rectangle,rounded corners=3mm,
                      very thick,draw=black!50,
                      minimum height=18mm, minimum width=20mm,
                      top color=white,bottom color=black!20}]

  \node (A0) at (0.1,0) {\texttt{\textcolor{purple}{\textbf{for}} (\alert<2->{n} <- List(}};
  \node (A1) at (2.3,0) {\texttt{\phantom{,}1,}};
  \node (A2) at (3.2,0) {\texttt{\phantom{,}2,}};
  \node (A3) at (4.1,0) {\texttt{\phantom{,}3,}};
  \node (A4) at (5.0,0) {\texttt{\phantom{,}4,}};
  \node (A5) at (5.9,0) {\texttt{\phantom{))}5))}};
  \node (A6) at (8,0) {\texttt{\textcolor{purple}{\textbf{yield}} \alert<2->{n\,*\,n}}};

  \onslide<2->{
  \node (B0) at (1.4,-3) {\texttt{List(}};
  \node (B1) at (2.3,-3) {\texttt{\phantom{,}1,}};
  \node (B2) at (3.6,-3) {\texttt{\phantom{,}4,}};
  \node (B3) at (4.9,-3) {\texttt{\phantom{,}9,}};
  \node (B4) at (6.2,-3) {\texttt{\phantom{,}16,}};
  \node (B5) at (7.5,-3) {\texttt{\phantom{,}25)}};}

  \onslide<2->{
  \draw [->,line width=1mm] (A1.south) -- (B1.north);
  \draw [->,line width=1mm] (A2.south) -- (B2.north);
  \draw [->,line width=1mm] (A3.south) -- (B3.north);
  \draw [->,line width=1mm] (A4.south) -- (B4.north);
  \draw [->,line width=1mm] (A5.south) -- (B5.north);}

  \onslide<2->{
  \node (Q1) at (-0.45,-0.1) {};
  \node (Q2) at (-0.45,-2.8) {};
  \node (Q3) at (-0.45,-2.95) {\alert<2->{\texttt{n\,*\,n:}}};
  \draw [->,red,line width=1mm] (Q1.south) -- (Q2.north);}
 \end{tikzpicture}
\end{center}

\onslide<3>{This is for when the for-comprehension\\ \textbf{yields / produces} a result.}

\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
\begin{frame}[t]
\frametitle{For-Comprehensions Again}

\begin{center}
  \begin{tikzpicture}[scale=1,
                      node/.style={
                      rectangle,rounded corners=3mm,
                      very thick,draw=black!50,
                      minimum height=18mm, minimum width=20mm,
                      top color=white,bottom color=black!20}]

  \node (A0) at (0,0)
    {\texttt{\textcolor{purple}{\textbf{for}} (n <- List(1, 2, 3, 4, 5))
             \textcolor{purple}{\textbf{yield}} n\,*\,n}};

  \node (A1) at (0,-1.5) {\LARGE\textbf{vs}};       
         
  \node (A2) at (0,-3)
    {\texttt{\textcolor{purple}{\textbf{for}} (n <- List(1, 2, 3, 4, 5)) println(n)}};
 \end{tikzpicture}
\end{center}\bigskip


The second version is in case the for \textbf{does not}
produce any result.

\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%



%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%     
\begin{frame}[t]
\frametitle{Why Scala? No null!}


\begin{itemize}
\item \large {\bf You can avoid \textcolor{blue}{\texttt{null}}}:
\end{itemize}


\begin{textblock}{6}(1,5)
  \begin{bubble}[10.5cm]\small
      ``I call it my billion-dollar mistake. It was the invention of
      the null reference in 1965. At that time, I was designing the
      first comprehensive type system for references in an object
      oriented language (ALGOL W). My goal was to ensure that all use
      of references should be absolutely safe, with checking performed
      automatically by the compiler. But I couldn't resist the
      temptation to put in a null reference, simply because it was so
      easy to implement. This has led to innumerable errors,
      vulnerabilities, and system crashes, which have probably caused
      a billion dollars of pain and damage in the last forty years.''
      \hfill Sir Tony (Hoare)
\end{bubble}
\end{textblock}
  
\begin{textblock}{5}(12.5,1.9)
\includegraphics[scale=0.05]{../pics/hoare.jpg}\\
\end{textblock}
  
\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%


%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%
\begin{frame}[c,fragile]
\frametitle{\begin{tabular}{c}\\[1cm]\alert{Questions?}\end{tabular}}

\begin{center}
\chessboard[maxfield=g7,
            color=blue!50,
            linewidth=0.2em,
            shortenstart=0.5ex,
            shortenend=0.5ex,
            markstyle=cross,
            markfields={a4, c4, Z3, d3, Z1, d1, a0, c0},
            color=red!50,
            markfields={f5, e6},
            boardfontsize=12pt,labelfontsize=8pt,
            setpieces={Ng7, Nb2},showmover=false]
\end{center}
            
\begin{center}
My Scala Office Hours: Thursdays 11 -- 13
\end{center}
\end{frame}
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%   
\end{document}


\end{document}

%%% Local Variables:  
%%% mode: latex
%%% TeX-master: t
%%% End: