\documentclass[dvipsnames,14pt,t,xelatex]{beamer}+ −
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\lstset{language=Scala,+ −
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xleftmargin=0mm}+ −
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\newcommand{\bl}[1]{\textcolor{blue}{#1}} + −
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% beamer stuff + −
\renewcommand{\slidecaption}{PEP (Scala) 02, King's College London}+ −
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\begin{document}+ −
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
\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}+ −
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\end{frame}+ −
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\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}%$+ −
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\end{frame}+ −
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
\begin{frame}[c]+ −
\frametitle{Assignments}+ −
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Don't change anything with the templates!\bigskip+ −
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Avoid at all costs:+ −
+ −
\begin{itemize}+ −
\item \texttt{var} + −
\item \texttt{return} + −
\item \texttt{ListBuffer}+ −
\item \texttt{mutable}+ −
\item \texttt{.par} + −
\end{itemize}\pause\bigskip+ −
+ −
+ −
\mbox{}\hfill\textit{``Scala --- \underline{S}lowly \underline{c}ompiled + −
\underline{a}cademic \underline{la}nguage''}\smallskip\\+ −
\mbox{}\hfill\textit{ --- a joke(?) found on Twitter}\bigskip+ −
\end{frame}+ −
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\begin{frame}[t]+ −
\frametitle{Email: Hate 'val'}+ −
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\mbox{}\\[-25mm]\mbox{}+ −
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\begin{center}+ −
\begin{bubble}[10.5cm]+ −
Subject: \textbf{Hate '\textbf{\texttt{val}}'}\hfill 01:00 AM\medskip\\+ −
+ −
Hello Mr Urban,\medskip\\+ −
+ −
I just wanted to ask, how are we suppose to work+ −
with the completely useless \textbf{\texttt{val}}, that can’t be changed ever? Why is+ −
this rule active at all? I’ve spent 4 hours not thinking on the+ −
coursework, but how to bypass this annoying rule. What’s the whole+ −
point of all these coursework, when we can’t use everything Scala+ −
gives us?!?\medskip\\+ −
+ −
Regards.\\+ −
\mbox{}\hspace{5mm}\textcolor{black!50}{<<deleted>>}\\+ −
\end{bubble}+ −
\end{center}+ −
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\def\firstcircle{(0,0) circle (1.4cm)}+ −
\def\secondcircle{(0:2cm) circle (1.4cm)}+ −
\colorlet{circle edge}{blue!50}+ −
\colorlet{circle area}{blue!20}+ −
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\tikzset{filled/.style={fill=circle area, draw=circle edge, thick},+ −
outline/.style={draw=circle edge, thick}}+ −
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\begin{frame}[c,fragile]+ −
\frametitle{Par: Intersections}+ −
+ −
\begin{textblock}{6}(1,2)+ −
\begin{tikzpicture}+ −
\draw[outline] \firstcircle node {$A$};+ −
\node[anchor=south] at (current bounding box.north)+ −
{$A = \{1,2,3,\ldots,1000\}$};+ −
\end{tikzpicture}+ −
\end{textblock}+ −
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\begin{textblock}{6}(8,2)+ −
\begin{tikzpicture}+ −
\draw[outline] \secondcircle node {$B$};+ −
\node[anchor=south] at (current bounding box.north)+ −
{$B = \{1,5,9,13,\ldots,997\}$};+ −
\end{tikzpicture}+ −
\end{textblock}+ −
+ −
\begin{textblock}{6}(3.3,9)+ −
\begin{tikzpicture}+ −
\begin{scope}+ −
\clip \firstcircle;+ −
\fill[filled] \secondcircle;+ −
\end{scope}+ −
\draw[outline] \firstcircle node {$A$};+ −
\draw[outline] \secondcircle node {$B$};+ −
\node[anchor=north] at (current bounding box.south)+ −
{How many elements are in $A \cap B$?};+ −
\end{tikzpicture}+ −
\end{textblock} + −
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\end{frame}+ −
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\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}]+ −
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\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)}};}+ −
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\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);}+ −
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\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);}+ −
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\end{center}+ −
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\onslide<3>{This is for when the for-comprehension\\ \textbf{yields / produces} a result.}+ −
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\end{frame}+ −
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\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}}; + −
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\node (A2) at (0,-3)+ −
{\texttt{\textcolor{purple}{\textbf{for}} (n <- List(1, 2, 3, 4, 5)) println(n)}};+ −
\end{tikzpicture}+ −
\end{center}\bigskip+ −
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The second version is in case the for \textbf{does not}+ −
produce any result.+ −
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\end{frame}+ −
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%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
\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}+ −
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\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%+ −
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\begin{frame}[c,fragile]+ −
\frametitle{\begin{tabular}{c}\\[1cm]\alert{Questions?}\end{tabular}}+ −
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%\begin{center}+ −
%\chessboard[maxfield=g7,+ −
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%\end{center}+ −
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\begin{center}+ −
My Office Hours: Mondays 12 -- 14+ −
\end{center}+ −
\end{frame}+ −
%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%%% + −
\end{document}+ −
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\end{document}+ −
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