src/bytes/example_test.go - go - Git at Google

 // 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"
 	"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_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 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 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 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 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 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 ExampleCount() {
 	fmt.Println(bytes.Count([]byte("cheese"), []byte("e")))
 	fmt.Println(bytes.Count([]byte("five"), []byte(""))) // before & after each rune
 	// Output:
 	// 3
 	// 5
 }

 func ExampleEqualFold() {
 	fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
 	// Output: true
 }

 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 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 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 ExampleJoin() {
 	s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
 	fmt.Printf("%s", bytes.Join(s, []byte(", ")))
 	// Output: foo, bar, baz
 }

 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 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 ExampleTrim() {
 	fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
 	// Output: ["Achtung! Achtung"]
 }

 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", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
 	// Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
 }

 func ExampleTrimSpace() {
 	fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
 	// Output: a lone gopher
 }

 func ExampleToUpper() {
 	fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
 	// Output: GOPHER
 }

 func ExampleToLower() {
 	fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
 	// Output: gopher
 }
	// 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"
	"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_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 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 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 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 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 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 ExampleCount() {
	fmt.Println(bytes.Count([]byte("cheese"), []byte("e")))
	fmt.Println(bytes.Count([]byte("five"), []byte(""))) // before & after each rune
	// Output:
	// 3
	// 5
	}

	func ExampleEqualFold() {
	fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
	// Output: true
	}

	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 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 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 ExampleJoin() {
	s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
	fmt.Printf("%s", bytes.Join(s, []byte(", ")))
	// Output: foo, bar, baz
	}

	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 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 ExampleTrim() {
	fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
	// Output: ["Achtung! Achtung"]
	}

	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", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
	// Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
	}

	func ExampleTrimSpace() {
	fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
	// Output: a lone gopher
	}

	func ExampleToUpper() {
	fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
	// Output: GOPHER
	}

	func ExampleToLower() {
	fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
	// Output: gopher
	}