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+%
+% Copyright (C) 2015-2016 Sebastian 'tokkee' Harl <sh@tokkee.org>
+% All rights reserved.
+%
+% Redistribution and use in source and binary forms, with or without
+% modification, are permitted provided that the following conditions
+% are met:
+% 1. Redistributions of source code must retain the above copyright
+% notice, this list of conditions and the following disclaimer.
+% 2. Redistributions in binary form must reproduce the above copyright
+% notice, this list of conditions and the following disclaimer in the
+% documentation and/or other materials provided with the distribution.
+%
+% THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+% ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
+% TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
+% PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDERS OR
+% CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
+% EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
+% PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS;
+% OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY,
+% WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR
+% OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
+% ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+%
+\documentclass[presentation]{beamer}
+\uselanguage{German}
+
+\usetheme{tokkee}
+\usefonttheme{professionalfonts}
+
+\usepackage{xeCJK}
+\renewcommand\CJKfamilydefault{\CJKsfdefault}
+\setCJKsansfont{WenQuanYi Zen Hei}
+
+\setbeamercolor*{block body}{fg=black,bg=white}
+\setbeamercolor*{block title}{use=titlelike,fg=titlelike.fg!80!black,bg=black!10}
+
+\usepackage{fontspec,xunicode,polyglossia}
+\setdefaultlanguage[spelling=new]{german}
+
+\usepackage{graphicx}
+\usepackage{xcolor}
+\definecolor{darkgreen}{rgb}{0,0.39,0}
+
+\usepackage{listings}
+\lstset{
+ language=Go,
+ frame=single,
+ numbers=left,
+ keywordstyle=\bfseries\color{darkgreen},
+ commentstyle=\itshape\color{blue},
+ stringstyle=\color{red},
+ showstringspaces=false,
+ backgroundcolor=\color{lightgray!25},
+ literate=%
+ {Ö}{{\"O}}1
+ {Ä}{{\"A}}1
+ {Ü}{{\"U}}1
+ {ß}{{\ss}}1
+ {ü}{{\"u}}1
+ {ä}{{\"a}}1
+ {ö}{{\"o}}1,
+}
+
+\usepackage[overlay,absolute]{textpos}
+
+\usepackage{tikz}
+\usetikzlibrary{shadows}
+\usetikzlibrary{shapes}
+
+\title[Programmieren mit Go]{Programmieren mit Go}
+
+\titlegraphic{}
+
+\copyrightinfo{\copyright{} 2015-2016 Sebastian `tokkee' Harl}
+
+\author[Sebastian Harl]{Sebastian `tokkee' Harl\\
+ $<$sh@tokkee.org$>$}
+
+\date[2015-2016]{}
+
+\AtBeginSection[]
+{
+ \begin{frame}
+ \begin{center}
+ \Large
+ \titlebox{\secname}
+ \end{center}
+ \end{frame}
+}
+
+\begin{document}
+
+\begin{frame}[plain]
+ \titlepage
+\end{frame}
+
+\begin{frame}{Überblick}
+ \textbf{Was ist Go?}
+
+ \begin{itemize}
+ \item \url{https://golang.org/}
+ \item Open Source Programmiersprache
+ \item imperativ, Interfaces, Pakete
+ \item statisch typisiert, kompiliert
+ \item Nebenläufigkeit
+ \item Garbage Collection
+ \end{itemize}
+
+ \begin{tikzpicture}[remember picture,overlay]
+ \node[anchor=east] at (current page.east)
+ {\includegraphics[width=.7\textwidth]{gopher}};
+ \end{tikzpicture}
+\end{frame}
+
+\begin{frame}[fragile]{Hallo 世界}
+ \begin{lstlisting}
+package main
+
+import "fmt"
+
+func main() {
+ fmt.Println("Hallo 世界")
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Programm übersetzen / ausführen}
+ \begin{lstlisting}[language=bash,numbers=none]
+% go build -o hallo hallo.go
+% ./hallo
+Hallo 世界
+
+% go run hallo.go
+Hallo 世界
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}{Go Playground}
+ \begin{center}
+ \fbox{\includegraphics[width=.9\textwidth]{playground}}
+ \end{center}
+\end{frame}
+
+\begin{frame}[fragile]{Pakete / Bibliotheken}
+ \begin{lstlisting}
+package zeichenkette
+
+func Rückwärts(s string) string {
+ r := []rune(s)
+ for i := 0; i < len(r)/2; i++ {
+ j := len(r) - i - 1
+ r[j], r[i] = r[i], r[j]
+ }
+ return string(r)
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Pakete verwenden}
+ \begin{itemize}
+ \item \texttt{\$GOPATH/src} ist der Suchpfad für extra Pakete
+ \item \texttt{import "$<$paketname$>$"}
+ \end{itemize}
+
+ \begin{lstlisting}
+package main
+
+import (
+ "fmt"
+
+ zk "tokkee.org/zeichenkette"
+)
+
+func main() {
+ fmt.Println(zk.Rückwärts("Hallo 世界"))
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Arbeitsumgebung}
+ \begin{verbatim}
+$GOPATH
+ |\
+ | `- bin/
+ | \
+ | `- hallo
+ \
+ `- src/
+ \
+ `- hallo/
+ \
+ `- hallo.go
+ \end{verbatim}
+\end{frame}
+
+\begin{frame}{Arbeitsumgebung (2)}
+ \begin{itemize}
+ \item \lstinline[language=sh]{go build -o hallo_welt hallo}
+ \item \lstinline[language=sh]{go install hallo}
+ \item \lstinline[language=sh]{go doc hallo}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Fehlerbehandlung}
+ \begin{lstlisting}
+func machEs() (*Object, error) {
+ var o Object
+ if err := o.init(); err != nil {
+ return nil, err
+ }
+ return &o, nil
+}
+
+func main() {
+ o, err := machEs()
+ if err != nil {
+ log.Exitf("Fehler: %v\n", err)
+ }
+ // ...
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Komplexe Datenstrukturen}
+ \textbf{Array / Slice}
+ \begin{lstlisting}
+var array [3]string
+array[0] = "ein"
+array[1] = "String"
+fmt.Println(array)
+ \end{lstlisting}
+
+ \begin{lstlisting}
+var slice []string
+slice = array[:]
+slice = append(slice, "usw", "usf")
+slice = []string{"ein", "anderer", "String"}
+fmt.Println(slice)
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Komplexe Datenstrukturen (2)}
+ \textbf{Map}
+ \begin{lstlisting}
+var m map[string]int
+m = make(map[string]int) // Map anlegen
+m = map[string]int{ // Map initialisieren
+ "a": 1,
+ "b": 2,
+}
+m["c"] = 3
+fmt.Println(m["a"])
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Komplexe Datenstrukturen (3)}
+ \textbf{Struct}
+ \begin{lstlisting}
+type Ding struct {
+ privat float32
+ Öffentlich string
+}
+d := Ding{
+ Öffentlich: "Daten für Alle!",
+ privat: 47.11,
+}
+d.privat = 3.1415926535
+fmt.Println(d)
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Komplexe Datenstrukturen (4)}
+ \textbf{Interface / Methoden}
+ \begin{lstlisting}
+type Macher interface {
+ Mach(int, int) string
+}
+type MeinMacher struct {}
+func (m MeinMacher) Mach(a, b int) string {
+ return fmt.Sprintf("%d x %d = %d", a, b, a*b)
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}{Übung: Quadratwurzel}
+ \url{https://go-tour-de.appspot.com/flowcontrol/8}\\
+ \url{https://de.wikipedia.org/wiki/Newton-Verfahren}\\[5mm]
+
+ Berechne die Quadratwurzel (\lstinline{Wurzel(x float64)}) mit Hilfe des
+ Newton-Verfahren:
+
+ \begin{equation*}
+ z_{n+1} = z_n - \frac{z_n^2 - x}{2 * z_n}
+ \end{equation*}
+
+ Erstelle dazu ein eigenes Paket und ein Programm zum testen. Verwende
+ entweder eine Schleife mit fester Anzahl an Durchläufen oder bis sich das
+ Ergebnis nicht (kaum) mehr ändert.
+\end{frame}
+
+\begin{frame}{Die Standard-Bibliothek}
+ \url{https://golang.org/pkg/}\\[5mm]
+
+ \begin{itemize}
+ \item Crypto
+ \item Datenbanken
+ \item Go Parser
+ \item Netzwerk, HTTP, SMTP, etc.
+ \item Datenstrukturen
+ \end{itemize}
+\end{frame}
+
+\begin{frame}{Weitere Bibliotheken}
+ \url{https://godoc.org/}\\[5mm]
+
+ \begin{itemize}
+ \item Vielzahl an Open Source Bibliotheken
+ \item \lstinline[language=sh]{go get github.com/user/pkg}
+ \item \url{https://gopkg.in}
+ \begin{itemize}
+ \item Versionierung von Bibliotheken auf Github
+ \item \url{v3} zeigt auf Branch/Tag \url{v3}, \url{v3.N} oder
+ \url{v3.N.M}
+ \item \url{gopkg.in/pkg.v3} $\rightarrow$ \url{github.com/go-pkg/pkg}
+ \item \url{gopkg.in/user/pkg.v3} $\rightarrow$
+ \url{github.com/user/pkg}
+ \end{itemize}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Ein Webserver}
+ \url{https://golang.org/pkg/net/http/}
+ \begin{lstlisting}
+func main() {
+ http.HandleFunc("/hallo", sageHallo)
+ log.Fatal(http.ListenAndServe(":9999", nil))
+}
+
+func sageHallo(w http.ResponseWriter,
+ r *http.Request) {
+
+ fmt.Fprintf(w, "Hallo %s", r.RemoteAddr)
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}{Nebenläufigkeit}
+ \textbf{Alle Anfragen werden nebenläufig behandelt.}\\[5mm]
+
+ \begin{itemize}
+ \item Goroutinen
+ \begin{itemize}
+ \item \texttt{go f(args)}
+ \item leichtgewichtige Threads
+ \item hunderte oder tausende werden effizient verwaltet
+ \end{itemize}
+ \item Channels
+ \begin{itemize}
+ \item Kommunikation zwischen Goroutinen
+ \end{itemize}
+ \item \texttt{select}
+ \begin{itemize}
+ \item warten auf I/O und Channels
+ \end{itemize}
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Goroutinen}
+ \begin{lstlisting}
+errCh := make(chan error, 2)
+
+go func() {
+ errCh <- machEs()
+}()
+go func() {
+ errCh <- undDas()
+}()
+
+go machEtwasImHintergrund()
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Goroutinen (2)}
+ \url{https://golang.org/pkg/time/}
+ \begin{lstlisting}
+timeout := time.After(50*time.Millisecond)
+for i := 0; i < cap(errCh); i++ {
+ select {
+ case err := <- errCh:
+ if err != nil {
+ return err
+ }
+ case <-timeout:
+ return fmt.Errorf("timeout(%d)", i)
+ }
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Goroutinen (3)}
+ \textbf{Synchronisierung}\\
+ \url{https://golang.org/pkg/sync/}
+ \begin{lstlisting}
+daten := []Object{...}
+var wg sync.WaitGroup
+for _, d := range daten {
+ wg.Add(1)
+ go func(o Object) {
+ defer wg.Done()
+ verarbeite(o)
+ }(d) // <- !!!
+}
+wg.Wait()
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Unit Tests}
+ \url{https://golang.org/pkg/testing/}
+ \begin{lstlisting}
+package zeugs
+
+// mult multipliziert die beiden
+// übergebenen Argumente und gibt
+// das Ergebnis zurück.
+func mult(a, b int) int {
+ return a * b
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}[fragile]{Unit Tests (2)}
+ \begin{lstlisting}
+package zeugs
+func TestMult(t *testing.T) {
+ for _, test := range []struct{
+ a, b, want int
+ }{
+ {3, 4, 12},
+ {7, 8, 56},
+ } {
+ if r := mult(test.a, test.b); r != test.want {
+ t.Errorf("mult(%d, %d) = %d; want %d",
+ test.a, test.b, r, test.want)
+ }
+ }
+}
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}{Übung: Äquivalente Binärbäume}
+ \url{https://go-tour-de.appspot.com/concurrency/7}\\
+ \url{https://godoc.org/golang.org/x/tour/tree}\\
+ \url{https://de.wikipedia.org/wiki/Binärbaum}\\[5mm]
+
+ \begin{itemize}
+ \item Implementiere die \lstinline{Same(t1, t2 *tree.Tree)} Funktion aus
+ der Online-Übung.
+ \item Zusätzlich: Erstelle einen Unit-Test für die Funktion.
+ \end{itemize}
+\end{frame}
+
+\begin{frame}[fragile]{Werkzeuge}
+ \textbf{Go ist dazu gedacht, in Werkzeugen verwendet zu werden
+ (\texttt{go/ast}, etc.)}\\[5mm]
+
+ \begin{itemize}
+ \item gofmt, goimports
+ \item godoc, \url{https://godoc.org/}
+ \item IDE und Editor Unterstützung
+ \end{itemize}
+
+ \textbf{vim:}
+ \begin{lstlisting}[language=bash,morekeywords={autocmd,let}]
+autocmd filetype go
+ \ autocmd BufWritePre <buffer> Fmt
+let g:gofmt_command = "goimports"
+ \end{lstlisting}
+\end{frame}
+
+\begin{frame}{\inserttitle}
+ \begin{center}
+ Danke für die Aufmerksamkeit\\[2mm]
+ {\Large Fragen, Kommentare?}\\[6mm]
+
+ \url{https://tour.golang.org}\quad—\quad
+ \url{https://play.golang.org}
+ \end{center}
+\end{frame}
+
+\end{document}
+
+% vim: set shiftwidth=2 softtabstop=2 tabstop=8 noexpandtab spelllang=de_de :