doc: provide example filepath.Walk for go1

R=golang-dev, r, r
CC=golang-dev
https://golang.org/cl/5674067

doc/go1.html

@@ -1540,12 +1540,24 @@ <h3 id="path_filepath">The path/filepath package</h3>
 The <code>WalkFunc</code> function will be called even for files or directories that could not be opened;
 in such cases the error argument will describe the failure.
 If a directory's contents are to be skipped,
-the function should return the value <code>SkipDir</code>.
+the function should return the value <a href="/pkg/path/filepath/#variables"><code>filepath.SkipDir</code></a>
 </p>
 
-<p>
-<font color="red">TODO: add an example?</font>
-</p>
+<pre><!--{{code "progs/go1.go" `/STARTWALK/` `/ENDWALK/`}}
+--> markFn := func(path string, info os.FileInfo, err error) error {
+ if path == &#34;pictures&#34; { // Will skip walking of directory pictures and its contents.
+ return filepath.SkipDir
+ }
+ if err != nil {
+ return err
+ }
+ log.Println(path)
+ return nil
+ }
+ err := filepath.Walk(&#34;.&#34;, markFn)
+ if err != nil {
+ log.Fatal(err)
+ }</pre>
 
 <p>
 <em>Updating</em>:

doc/go1.tmpl

@@ -1439,12 +1439,10 @@ instead of a <code>Visitor</code> interface value.
 The <code>WalkFunc</code> function will be called even for files or directories that could not be opened;
 in such cases the error argument will describe the failure.
 If a directory's contents are to be skipped,
-the function should return the value <code>SkipDir</code>.
+the function should return the value <a href="/pkg/path/filepath/#variables"><code>filepath.SkipDir</code></a>
 </p>
 
-<p>
-<font color="red">TODO: add an example?</font>
-</p>
+{{code "progs/go1.go" `/STARTWALK/` `/ENDWALK/`}}
 
 <p>
 <em>Updating</em>:

doc/progs/go1.go

@@ -12,6 +12,7 @@ import (
  "fmt"
  "log"
  "os"
+ "path/filepath"
  "testing"
  "time"
  "unicode"
@@ -28,6 +29,7 @@ func main() {
  runeType()
  errorExample()
  timePackage()
+ walkExample()
  osIsExist()
 }
 
@@ -183,6 +185,25 @@ func timePackage() {
  sleepUntil(time.Now().Add(123 * time.Millisecond))
 }
 
+func walkExample() {
+ // STARTWALK OMIT
+ markFn := func(path string, info os.FileInfo, err error) error {
+ if path == "pictures" { // Will skip walking of directory pictures and its contents.
+ return filepath.SkipDir
+ }
+ if err != nil {
+ return err
+ }
+ log.Println(path)
+ return nil
+ }
+ err := filepath.Walk(".", markFn)
+ if err != nil {
+ log.Fatal(err)
+ }
+ // ENDWALK OMIT
+}
+
 func initializationFunction(c chan int) {
  c <- 1
 }