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// Copyright 2011 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 bytes_test
import (
"bytes"
"encoding/base64"
"fmt"
"io"
"os"
"sort"
"strconv"
"unicode"
)
func ExampleBuffer() {
var b bytes.Buffer // A Buffer needs no initialization.
b.Write([]byte("Hello "))
fmt.Fprintf(&b, "world!")
b.WriteTo(os.Stdout)
// Output: Hello world!
}
func ExampleBuffer_reader() {
// A Buffer can turn a string or a []byte into an io.Reader.
buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
dec := base64.NewDecoder(base64.StdEncoding, buf)
io.Copy(os.Stdout, dec)
// Output: Gophers rule!
}
func ExampleBuffer_Bytes() {
buf := bytes.Buffer{}
buf.Write([]byte{'h', 'e', 'l', 'l', 'o', ' ', 'w', 'o', 'r', 'l', 'd'})
os.Stdout.Write(buf.Bytes())
// Output: hello world
}
func ExampleBuffer_AvailableBuffer() {
var buf bytes.Buffer
for i := 0; i < 4; i++ {
b := buf.AvailableBuffer()
b = strconv.AppendInt(b, int64(i), 10)
b = append(b, ' ')
buf.Write(b)
}
os.Stdout.Write(buf.Bytes())
// Output: 0 1 2 3
}
func ExampleBuffer_Cap() {
buf1 := bytes.NewBuffer(make([]byte, 10))
buf2 := bytes.NewBuffer(make([]byte, 0, 10))
fmt.Println(buf1.Cap())
fmt.Println(buf2.Cap())
// Output:
// 10
// 10
}
func ExampleBuffer_Grow() {
var b bytes.Buffer
b.Grow(64)
bb := b.Bytes()
b.Write([]byte("64 bytes or fewer"))
fmt.Printf("%q", bb[:b.Len()])
// Output: "64 bytes or fewer"
}
func ExampleBuffer_Len() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
fmt.Printf("%d", b.Len())
// Output: 5
}
func ExampleBuffer_Next() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
fmt.Printf("%s\n", b.Next(2))
fmt.Printf("%s\n", b.Next(2))
fmt.Printf("%s", b.Next(2))
// Output:
// ab
// cd
// e
}
func ExampleBuffer_Read() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
rdbuf := make([]byte, 1)
n, err := b.Read(rdbuf)
if err != nil {
panic(err)
}
fmt.Println(n)
fmt.Println(b.String())
fmt.Println(string(rdbuf))
// Output:
// 1
// bcde
// a
}
func ExampleBuffer_ReadByte() {
var b bytes.Buffer
b.Grow(64)
b.Write([]byte("abcde"))
c, err := b.ReadByte()
if err != nil {
panic(err)
}
fmt.Println(c)
fmt.Println(b.String())
// Output:
// 97
// bcde
}
func ExampleClone() {
b := []byte("abc")
clone := bytes.Clone(b)
fmt.Printf("%s\n", clone)
clone[0] = 'd'
fmt.Printf("%s\n", b)
fmt.Printf("%s\n", clone)
// Output:
// abc
// abc
// dbc
}
func ExampleCompare() {
// Interpret Compare's result by comparing it to zero.
var a, b []byte
if bytes.Compare(a, b) < 0 {
// a less b
}
if bytes.Compare(a, b) <= 0 {
// a less or equal b
}
if bytes.Compare(a, b) > 0 {
// a greater b
}
if bytes.Compare(a, b) >= 0 {
// a greater or equal b
}
// Prefer Equal to Compare for equality comparisons.
if bytes.Equal(a, b) {
// a equal b
}
if !bytes.Equal(a, b) {
// a not equal b
}
}
func ExampleCompare_search() {
// Binary search to find a matching byte slice.
var needle []byte
var haystack [][]byte // Assume sorted
i := sort.Search(len(haystack), func(i int) bool {
// Return haystack[i] >= needle.
return bytes.Compare(haystack[i], needle) >= 0
})
if i < len(haystack) && bytes.Equal(haystack[i], needle) {
// Found it!
}
}
func ExampleContains() {
fmt.Println(bytes.Contains([]byte("seafood"), []byte("foo")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("bar")))
fmt.Println(bytes.Contains([]byte("seafood"), []byte("")))
fmt.Println(bytes.Contains([]byte(""), []byte("")))
// Output:
// true
// false
// true
// true
}
func ExampleContainsAny() {
fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "fÄo!"))
fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "去是伟大的."))
fmt.Println(bytes.ContainsAny([]byte("I like seafood."), ""))
fmt.Println(bytes.ContainsAny([]byte(""), ""))
// Output:
// true
// true
// false
// false
}
func ExampleContainsRune() {
fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'f'))
fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'ö'))
fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '大'))
fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '!'))
fmt.Println(bytes.ContainsRune([]byte(""), '@'))
// Output:
// true
// false
// true
// true
// false
}
func ExampleContainsFunc() {
f := func(r rune) bool {
return r >= 'a' && r <= 'z'
}
fmt.Println(bytes.ContainsFunc([]byte("HELLO"), f))
fmt.Println(bytes.ContainsFunc([]byte("World"), f))
// Output:
// false
// true
}
func ExampleCount() {
fmt.Println(bytes.Count([]byte("cheese"), []byte("e")))
fmt.Println(bytes.Count([]byte("five"), []byte(""))) // before & after each rune
// Output:
// 3
// 5
}
func ExampleCut() {
show := func(s, sep string) {
before, after, found := bytes.Cut([]byte(s), []byte(sep))
fmt.Printf("Cut(%q, %q) = %q, %q, %v\n", s, sep, before, after, found)
}
show("Gopher", "Go")
show("Gopher", "ph")
show("Gopher", "er")
show("Gopher", "Badger")
// Output:
// Cut("Gopher", "Go") = "", "pher", true
// Cut("Gopher", "ph") = "Go", "er", true
// Cut("Gopher", "er") = "Goph", "", true
// Cut("Gopher", "Badger") = "Gopher", "", false
}
func ExampleCutPrefix() {
show := func(s, sep string) {
after, found := bytes.CutPrefix([]byte(s), []byte(sep))
fmt.Printf("CutPrefix(%q, %q) = %q, %v\n", s, sep, after, found)
}
show("Gopher", "Go")
show("Gopher", "ph")
// Output:
// CutPrefix("Gopher", "Go") = "pher", true
// CutPrefix("Gopher", "ph") = "Gopher", false
}
func ExampleCutSuffix() {
show := func(s, sep string) {
before, found := bytes.CutSuffix([]byte(s), []byte(sep))
fmt.Printf("CutSuffix(%q, %q) = %q, %v\n", s, sep, before, found)
}
show("Gopher", "Go")
show("Gopher", "er")
// Output:
// CutSuffix("Gopher", "Go") = "Gopher", false
// CutSuffix("Gopher", "er") = "Goph", true
}
func ExampleEqual() {
fmt.Println(bytes.Equal([]byte("Go"), []byte("Go")))
fmt.Println(bytes.Equal([]byte("Go"), []byte("C++")))
// Output:
// true
// false
}
func ExampleEqualFold() {
fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
// Output: true
}
func ExampleFields() {
fmt.Printf("Fields are: %q", bytes.Fields([]byte(" foo bar baz ")))
// Output: Fields are: ["foo" "bar" "baz"]
}
func ExampleFieldsFunc() {
f := func(c rune) bool {
return !unicode.IsLetter(c) && !unicode.IsNumber(c)
}
fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte(" foo1;bar2,baz3..."), f))
// Output: Fields are: ["foo1" "bar2" "baz3"]
}
func ExampleHasPrefix() {
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("Go")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("C")))
fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("")))
// Output:
// true
// false
// true
}
func ExampleHasSuffix() {
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("go")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("O")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("Ami")))
fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("")))
// Output:
// true
// false
// false
// true
}
func ExampleIndex() {
fmt.Println(bytes.Index([]byte("chicken"), []byte("ken")))
fmt.Println(bytes.Index([]byte("chicken"), []byte("dmr")))
// Output:
// 4
// -1
}
func ExampleIndexByte() {
fmt.Println(bytes.IndexByte([]byte("chicken"), byte('k')))
fmt.Println(bytes.IndexByte([]byte("chicken"), byte('g')))
// Output:
// 4
// -1
}
func ExampleIndexFunc() {
f := func(c rune) bool {
return unicode.Is(unicode.Han, c)
}
fmt.Println(bytes.IndexFunc([]byte("Hello, 世界"), f))
fmt.Println(bytes.IndexFunc([]byte("Hello, world"), f))
// Output:
// 7
// -1
}
func ExampleIndexAny() {
fmt.Println(bytes.IndexAny([]byte("chicken"), "aeiouy"))
fmt.Println(bytes.IndexAny([]byte("crwth"), "aeiouy"))
// Output:
// 2
// -1
}
func ExampleIndexRune() {
fmt.Println(bytes.IndexRune([]byte("chicken"), 'k'))
fmt.Println(bytes.IndexRune([]byte("chicken"), 'd'))
// Output:
// 4
// -1
}
func ExampleJoin() {
s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
fmt.Printf("%s", bytes.Join(s, []byte(", ")))
// Output: foo, bar, baz
}
func ExampleLastIndex() {
fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("rodent")))
// Output:
// 0
// 3
// -1
}
func ExampleLastIndexAny() {
fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "MüQp"))
fmt.Println(bytes.LastIndexAny([]byte("go 地鼠"), "地大"))
fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "z,!."))
// Output:
// 5
// 3
// -1
}
func ExampleLastIndexByte() {
fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('g')))
fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('r')))
fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('z')))
// Output:
// 3
// 8
// -1
}
func ExampleLastIndexFunc() {
fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsLetter))
fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsPunct))
fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsNumber))
// Output:
// 8
// 9
// -1
}
func ExampleMap() {
rot13 := func(r rune) rune {
switch {
case r >= 'A' && r <= 'Z':
return 'A' + (r-'A'+13)%26
case r >= 'a' && r <= 'z':
return 'a' + (r-'a'+13)%26
}
return r
}
fmt.Printf("%s\n", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
// Output:
// 'Gjnf oevyyvt naq gur fyvgul tbcure...
}
func ExampleReader_Len() {
fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
// Output:
// 3
// 16
}
func ExampleRepeat() {
fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
// Output: banana
}
func ExampleReplace() {
fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("k"), []byte("ky"), 2))
fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("oink"), []byte("moo"), -1))
// Output:
// oinky oinky oink
// moo moo moo
}
func ExampleReplaceAll() {
fmt.Printf("%s\n", bytes.ReplaceAll([]byte("oink oink oink"), []byte("oink"), []byte("moo")))
// Output:
// moo moo moo
}
func ExampleRunes() {
rs := bytes.Runes([]byte("go gopher"))
for _, r := range rs {
fmt.Printf("%#U\n", r)
}
// Output:
// U+0067 'g'
// U+006F 'o'
// U+0020 ' '
// U+0067 'g'
// U+006F 'o'
// U+0070 'p'
// U+0068 'h'
// U+0065 'e'
// U+0072 'r'
}
func ExampleSplit() {
fmt.Printf("%q\n", bytes.Split([]byte("a,b,c"), []byte(",")))
fmt.Printf("%q\n", bytes.Split([]byte("a man a plan a canal panama"), []byte("a ")))
fmt.Printf("%q\n", bytes.Split([]byte(" xyz "), []byte("")))
fmt.Printf("%q\n", bytes.Split([]byte(""), []byte("Bernardo O'Higgins")))
// Output:
// ["a" "b" "c"]
// ["" "man " "plan " "canal panama"]
// [" " "x" "y" "z" " "]
// [""]
}
func ExampleSplitN() {
fmt.Printf("%q\n", bytes.SplitN([]byte("a,b,c"), []byte(","), 2))
z := bytes.SplitN([]byte("a,b,c"), []byte(","), 0)
fmt.Printf("%q (nil = %v)\n", z, z == nil)
// Output:
// ["a" "b,c"]
// [] (nil = true)
}
func ExampleSplitAfter() {
fmt.Printf("%q\n", bytes.SplitAfter([]byte("a,b,c"), []byte(",")))
// Output: ["a," "b," "c"]
}
func ExampleSplitAfterN() {
fmt.Printf("%q\n", bytes.SplitAfterN([]byte("a,b,c"), []byte(","), 2))
// Output: ["a," "b,c"]
}
func ExampleTitle() {
fmt.Printf("%s", bytes.Title([]byte("her royal highness")))
// Output: Her Royal Highness
}
func ExampleToTitle() {
fmt.Printf("%s\n", bytes.ToTitle([]byte("loud noises")))
fmt.Printf("%s\n", bytes.ToTitle([]byte("хлеб")))
// Output:
// LOUD NOISES
// ХЛЕБ
}
func ExampleToTitleSpecial() {
str := []byte("ahoj vývojári golang")
totitle := bytes.ToTitleSpecial(unicode.AzeriCase, str)
fmt.Println("Original : " + string(str))
fmt.Println("ToTitle : " + string(totitle))
// Output:
// Original : ahoj vývojári golang
// ToTitle : AHOJ VÝVOJÁRİ GOLANG
}
func ExampleToValidUTF8() {
fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("abc"), []byte("\uFFFD")))
fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("a\xffb\xC0\xAFc\xff"), []byte("")))
fmt.Printf("%s\n", bytes.ToValidUTF8([]byte("\xed\xa0\x80"), []byte("abc")))
// Output:
// abc
// abc
// abc
}
func ExampleTrim() {
fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
// Output: ["Achtung! Achtung"]
}
func ExampleTrimFunc() {
fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsLetter)))
fmt.Println(string(bytes.TrimFunc([]byte("\"go-gopher!\""), unicode.IsLetter)))
fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsPunct)))
fmt.Println(string(bytes.TrimFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
// Output:
// -gopher!
// "go-gopher!"
// go-gopher
// go-gopher!
}
func ExampleTrimLeft() {
fmt.Print(string(bytes.TrimLeft([]byte("453gopher8257"), "0123456789")))
// Output:
// gopher8257
}
func ExampleTrimLeftFunc() {
fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher"), unicode.IsLetter)))
fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher!"), unicode.IsPunct)))
fmt.Println(string(bytes.TrimLeftFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
// Output:
// -gopher
// go-gopher!
// go-gopher!567
}
func ExampleTrimPrefix() {
var b = []byte("Goodbye,, world!")
b = bytes.TrimPrefix(b, []byte("Goodbye,"))
b = bytes.TrimPrefix(b, []byte("See ya,"))
fmt.Printf("Hello%s", b)
// Output: Hello, world!
}
func ExampleTrimSpace() {
fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
// Output: a lone gopher
}
func ExampleTrimSuffix() {
var b = []byte("Hello, goodbye, etc!")
b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
b = bytes.TrimSuffix(b, []byte("gopher"))
b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
os.Stdout.Write(b)
// Output: Hello, world!
}
func ExampleTrimRight() {
fmt.Print(string(bytes.TrimRight([]byte("453gopher8257"), "0123456789")))
// Output:
// 453gopher
}
func ExampleTrimRightFunc() {
fmt.Println(string(bytes.TrimRightFunc([]byte("go-gopher"), unicode.IsLetter)))
fmt.Println(string(bytes.TrimRightFunc([]byte("go-gopher!"), unicode.IsPunct)))
fmt.Println(string(bytes.TrimRightFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
// Output:
// go-
// go-gopher
// 1234go-gopher!
}
func ExampleToLower() {
fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
// Output: gopher
}
func ExampleToLowerSpecial() {
str := []byte("AHOJ VÝVOJÁRİ GOLANG")
totitle := bytes.ToLowerSpecial(unicode.AzeriCase, str)
fmt.Println("Original : " + string(str))
fmt.Println("ToLower : " + string(totitle))
// Output:
// Original : AHOJ VÝVOJÁRİ GOLANG
// ToLower : ahoj vývojári golang
}
func ExampleToUpper() {
fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
// Output: GOPHER
}
func ExampleToUpperSpecial() {
str := []byte("ahoj vývojári golang")
totitle := bytes.ToUpperSpecial(unicode.AzeriCase, str)
fmt.Println("Original : " + string(str))
fmt.Println("ToUpper : " + string(totitle))
// Output:
// Original : ahoj vývojári golang
// ToUpper : AHOJ VÝVOJÁRİ GOLANG
}