move the average function to the correct place

ex-unsorted/ex-average.tex → ex-functions/ex-average.tex

@@ -6,5 +6,5 @@
 
 \begin{Answer}
 \Question The following function calculates the average.
-\lstinputlisting[caption=Average function in Go,linerange={3,14}]{ex-unsorted/src/ave.go}
+\lstinputlisting[caption=Average function in Go,linerange={3,14}]{ex-functions/src/ave.go}
 \end{Answer}

ex-unsorted/ex-numbercruncher.tex

@@ -25,6 +25,8 @@
 
 \begin{Answer}
 \Question 
+The following is one possibility. It uses recursion and backtracking to get
+an answer.
 \lstinputlisting[caption=Number cruncher,
 basicstyle=\tiny\ttfamily]{ex-unsorted/src/permrec.go}
 

ex-unsorted/ex-quine.tex

@@ -5,7 +5,8 @@
 \end{Exercise}
 
 \begin{Answer}
-\Question The following Quine is from Russ Cox:
+\Question 
+The following Quine is from Russ Cox:
 \begin{lstlisting}
 /* Go quine */
 package main

go-functions.tex

@@ -37,6 +37,18 @@
 "\titleref{sec:functions as values}" on page \pageref{sec:functions as values} 
 in this chapter.
 
+Recursive functions just work as in other languages:
+\begin{lstlisting}[caption=Recursive function]
+func rec(i int) {
+   if i == 10 {
+        return
+   }
+   rec(i+1)
+   fmt.Printf("%d ", i)
+}
+\end{lstlisting}
+This prints \texttt{9 8 7 6 5 4 3 2 1 0}.
+
 \section{Scope}
 Variables declared outside any functions are \first{global}{scope!local} in Go, those
 defined in functions are \first{local}{scope!local} to those functions. If names overlap --- a