range after slices and maps

src/015-range/range.go

@@ -18,3 +18,6 @@ func main() {
     }
     fmt.Println(total / float64(len(x)))
 }
+
+// todo: comment on maps
+// todo: comment on channels

src/index.txt

@@ -13,9 +13,9 @@ for
 if-else
 switch
 arrays
-range
 slices
 maps
+range
 functions
 multiple-return-values
 varadic-functions

tool/src/build-html.go

@@ -41,7 +41,7 @@ func sha1Sum(s string) string {
 
 var cacheDir = "/tmp/gbe-book-cache"
 
-func mustReadFile(path string) {
+func mustReadFile(path string) string {
     bytes, err := ioutil.ReadFile(path)
     check(err)
     return string(bytes)