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diff --git a/src/bufio/example_test.go b/src/bufio/example_test.go
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+// Copyright 2013 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package bufio_test
+
+import (
+	"bufio"
+	"bytes"
+	"fmt"
+	"os"
+	"strconv"
+	"strings"
+)
+
+func ExampleWriter() {
+	w := bufio.NewWriter(os.Stdout)
+	fmt.Fprint(w, "Hello, ")
+	fmt.Fprint(w, "world!")
+	w.Flush() // Don't forget to flush!
+	// Output: Hello, world!
+}
+
+func ExampleWriter_AvailableBuffer() {
+	w := bufio.NewWriter(os.Stdout)
+	for _, i := range []int64{1, 2, 3, 4} {
+		b := w.AvailableBuffer()
+		b = strconv.AppendInt(b, i, 10)
+		b = append(b, ' ')
+		w.Write(b)
+	}
+	w.Flush()
+	// Output: 1 2 3 4
+}
+
+// The simplest use of a Scanner, to read standard input as a set of lines.
+func ExampleScanner_lines() {
+	scanner := bufio.NewScanner(os.Stdin)
+	for scanner.Scan() {
+		fmt.Println(scanner.Text()) // Println will add back the final '\n'
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "reading standard input:", err)
+	}
+}
+
+// Return the most recent call to Scan as a []byte.
+func ExampleScanner_Bytes() {
+	scanner := bufio.NewScanner(strings.NewReader("gopher"))
+	for scanner.Scan() {
+		fmt.Println(len(scanner.Bytes()) == 6)
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "shouldn't see an error scanning a string")
+	}
+	// Output:
+	// true
+}
+
+// Use a Scanner to implement a simple word-count utility by scanning the
+// input as a sequence of space-delimited tokens.
+func ExampleScanner_words() {
+	// An artificial input source.
+	const input = "Now is the winter of our discontent,\nMade glorious summer by this sun of York.\n"
+	scanner := bufio.NewScanner(strings.NewReader(input))
+	// Set the split function for the scanning operation.
+	scanner.Split(bufio.ScanWords)
+	// Count the words.
+	count := 0
+	for scanner.Scan() {
+		count++
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "reading input:", err)
+	}
+	fmt.Printf("%d\n", count)
+	// Output: 15
+}
+
+// Use a Scanner with a custom split function (built by wrapping ScanWords) to validate
+// 32-bit decimal input.
+func ExampleScanner_custom() {
+	// An artificial input source.
+	const input = "1234 5678 1234567901234567890"
+	scanner := bufio.NewScanner(strings.NewReader(input))
+	// Create a custom split function by wrapping the existing ScanWords function.
+	split := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
+		advance, token, err = bufio.ScanWords(data, atEOF)
+		if err == nil && token != nil {
+			_, err = strconv.ParseInt(string(token), 10, 32)
+		}
+		return
+	}
+	// Set the split function for the scanning operation.
+	scanner.Split(split)
+	// Validate the input
+	for scanner.Scan() {
+		fmt.Printf("%s\n", scanner.Text())
+	}
+
+	if err := scanner.Err(); err != nil {
+		fmt.Printf("Invalid input: %s", err)
+	}
+	// Output:
+	// 1234
+	// 5678
+	// Invalid input: strconv.ParseInt: parsing "1234567901234567890": value out of range
+}
+
+// Use a Scanner with a custom split function to parse a comma-separated
+// list with an empty final value.
+func ExampleScanner_emptyFinalToken() {
+	// Comma-separated list; last entry is empty.
+	const input = "1,2,3,4,"
+	scanner := bufio.NewScanner(strings.NewReader(input))
+	// Define a split function that separates on commas.
+	onComma := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
+		for i := 0; i < len(data); i++ {
+			if data[i] == ',' {
+				return i + 1, data[:i], nil
+			}
+		}
+		if !atEOF {
+			return 0, nil, nil
+		}
+		// There is one final token to be delivered, which may be the empty string.
+		// Returning bufio.ErrFinalToken here tells Scan there are no more tokens after this
+		// but does not trigger an error to be returned from Scan itself.
+		return 0, data, bufio.ErrFinalToken
+	}
+	scanner.Split(onComma)
+	// Scan.
+	for scanner.Scan() {
+		fmt.Printf("%q ", scanner.Text())
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "reading input:", err)
+	}
+	// Output: "1" "2" "3" "4" ""
+}
+
+// Use a Scanner with a custom split function to parse a comma-separated
+// list with an empty final value but stops at the token "STOP".
+func ExampleScanner_earlyStop() {
+	onComma := func(data []byte, atEOF bool) (advance int, token []byte, err error) {
+		i := bytes.IndexByte(data, ',')
+		if i == -1 {
+			if !atEOF {
+				return 0, nil, nil
+			}
+			// If we have reached the end, return the last token.
+			return 0, data, bufio.ErrFinalToken
+		}
+		// If the token is "STOP", stop the scanning and ignore the rest.
+		if string(data[:i]) == "STOP" {
+			return i + 1, nil, bufio.ErrFinalToken
+		}
+		// Otherwise, return the token before the comma.
+		return i + 1, data[:i], nil
+	}
+	const input = "1,2,STOP,4,"
+	scanner := bufio.NewScanner(strings.NewReader(input))
+	scanner.Split(onComma)
+	for scanner.Scan() {
+		fmt.Printf("Got a token %q\n", scanner.Text())
+	}
+	if err := scanner.Err(); err != nil {
+		fmt.Fprintln(os.Stderr, "reading input:", err)
+	}
+	// Output:
+	// Got a token "1"
+	// Got a token "2"
+}