--- a/handouts/pep-ho.tex	Fri Jan 19 14:09:08 2018 +0000
+++ b/handouts/pep-ho.tex	Fri Feb 23 22:26:42 2018 +0000
@@ -6,10 +6,65 @@
 %cheat sheet
 %http://worldline.github.io/scala-cheatsheet/
 
+% case class, apply, unappy
+% see https://medium.com/@thejasbabu/scala-pattern-matching-9c9e73ba9a8a
+
 \begin{document}
 
 \section*{A Crash-Course in Scala}
 
+
+Scala is a programming language that combines functional and
+object-oriented programming-styles. It has received quite a bit of
+attention in the last five or so years. One reason for this attention
+is that, like the Java programming language, Scala compiles to the
+Java Virtual Machine (JVM) and therefore Scala programs can run under
+MacOSX, Linux and Windows.\footnote{There are also experimental
+  backends for Android and JavaScript; and also work is under way to
+  have a native compiler, see
+  \url{https://github.com/scala-native/scala-native}.} Unlike Java,
+however, Scala often allows programmers to write very concise and
+elegant code.  Some therefore say: ``Scala is the better
+Java''.\footnote{\url{https://www.slideshare.net/maximnovak/joy-of-scala}}
+Also a number of companies (the Guardian, Twitter, Coursera,
+FourSquare, LinkedIn to name a few) either use Scala exclusively in
+production code, or at least to some substantial degree. Scala seems
+also to be useful in job-interviews (in Data Science) according to
+this anecdotal report
+
+\begin{quote}\small
+\url{https://techcrunch.com/2016/06/14/scala-is-the-new-golden-child/}
+\end{quote}
+
+\noindent
+The official Scala compiler can be downloaded from
+
+\begin{quote}
+\url{http://www.scala-lang.org}
+\end{quote}
+
+\noindent
+A ready-made bundle with the Eclipse IDE is at
+
+\begin{quote}
+\url{http://scala-ide.org/download/sdk.html}
+\end{quote}
+
+\noindent
+When developing Scala programs, I personally prefer to use Emacs
+or Sublime as my environment, since they provide an easy access
+to the Scala REPL (see below).  But it is also possible to work
+completely on the command line and also with heavy-duty IDEs
+like Eclipse of IntelliJ. There is even an online editor and
+environment for developing Scala programs called ScalaFiddle
+
+\begin{quote}
+\url{https://scalafiddle.io}
+\end{quote}
+  
+
+
+
 \subsection*{The Very Basics}
 
 One advantage of Scala over Java is that it includes an interpreter (a
@@ -17,6 +72,7 @@
 \underline{R}ead-\underline{E}val-\underline{P}rint-\underline{L}oop)
 with which you can run and test small code-snippets without the need
 of a compiler. This helps a lot with interactively developing
+programs. This is really the preferred way of writing small Scala
 programs. Once you installed Scala, you can start the interpreter by
 typing on the command line: