github.com/likebike/go--@v0.0.0-20190911215757-0bd925d16e96/go/src/bytes/example_test.go (about)

     1  // Copyright 2011 The Go Authors. All rights reserved.
     2  // Use of this source code is governed by a BSD-style
     3  // license that can be found in the LICENSE file.
     4  
     5  package bytes_test
     6  
     7  import (
     8  	"bytes"
     9  	"encoding/base64"
    10  	"fmt"
    11  	"io"
    12  	"os"
    13  	"sort"
    14  	"unicode"
    15  )
    16  
    17  func ExampleBuffer() {
    18  	var b bytes.Buffer // A Buffer needs no initialization.
    19  	b.Write([]byte("Hello "))
    20  	fmt.Fprintf(&b, "world!")
    21  	b.WriteTo(os.Stdout)
    22  	// Output: Hello world!
    23  }
    24  
    25  func ExampleBuffer_reader() {
    26  	// A Buffer can turn a string or a []byte into an io.Reader.
    27  	buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
    28  	dec := base64.NewDecoder(base64.StdEncoding, buf)
    29  	io.Copy(os.Stdout, dec)
    30  	// Output: Gophers rule!
    31  }
    32  
    33  func ExampleBuffer_Grow() {
    34  	var b bytes.Buffer
    35  	b.Grow(64)
    36  	bb := b.Bytes()
    37  	b.Write([]byte("64 bytes or fewer"))
    38  	fmt.Printf("%q", bb[:b.Len()])
    39  	// Output: "64 bytes or fewer"
    40  }
    41  
    42  func ExampleCompare() {
    43  	// Interpret Compare's result by comparing it to zero.
    44  	var a, b []byte
    45  	if bytes.Compare(a, b) < 0 {
    46  		// a less b
    47  	}
    48  	if bytes.Compare(a, b) <= 0 {
    49  		// a less or equal b
    50  	}
    51  	if bytes.Compare(a, b) > 0 {
    52  		// a greater b
    53  	}
    54  	if bytes.Compare(a, b) >= 0 {
    55  		// a greater or equal b
    56  	}
    57  
    58  	// Prefer Equal to Compare for equality comparisons.
    59  	if bytes.Equal(a, b) {
    60  		// a equal b
    61  	}
    62  	if !bytes.Equal(a, b) {
    63  		// a not equal b
    64  	}
    65  }
    66  
    67  func ExampleCompare_search() {
    68  	// Binary search to find a matching byte slice.
    69  	var needle []byte
    70  	var haystack [][]byte // Assume sorted
    71  	i := sort.Search(len(haystack), func(i int) bool {
    72  		// Return haystack[i] >= needle.
    73  		return bytes.Compare(haystack[i], needle) >= 0
    74  	})
    75  	if i < len(haystack) && bytes.Equal(haystack[i], needle) {
    76  		// Found it!
    77  	}
    78  }
    79  
    80  func ExampleTrimSuffix() {
    81  	var b = []byte("Hello, goodbye, etc!")
    82  	b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
    83  	b = bytes.TrimSuffix(b, []byte("gopher"))
    84  	b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
    85  	os.Stdout.Write(b)
    86  	// Output: Hello, world!
    87  }
    88  
    89  func ExampleTrimPrefix() {
    90  	var b = []byte("Goodbye,, world!")
    91  	b = bytes.TrimPrefix(b, []byte("Goodbye,"))
    92  	b = bytes.TrimPrefix(b, []byte("See ya,"))
    93  	fmt.Printf("Hello%s", b)
    94  	// Output: Hello, world!
    95  }
    96  
    97  func ExampleFields() {
    98  	fmt.Printf("Fields are: %q", bytes.Fields([]byte("  foo bar  baz   ")))
    99  	// Output: Fields are: ["foo" "bar" "baz"]
   100  }
   101  
   102  func ExampleFieldsFunc() {
   103  	f := func(c rune) bool {
   104  		return !unicode.IsLetter(c) && !unicode.IsNumber(c)
   105  	}
   106  	fmt.Printf("Fields are: %q", bytes.FieldsFunc([]byte("  foo1;bar2,baz3..."), f))
   107  	// Output: Fields are: ["foo1" "bar2" "baz3"]
   108  }
   109  
   110  func ExampleContains() {
   111  	fmt.Println(bytes.Contains([]byte("seafood"), []byte("foo")))
   112  	fmt.Println(bytes.Contains([]byte("seafood"), []byte("bar")))
   113  	fmt.Println(bytes.Contains([]byte("seafood"), []byte("")))
   114  	fmt.Println(bytes.Contains([]byte(""), []byte("")))
   115  	// Output:
   116  	// true
   117  	// false
   118  	// true
   119  	// true
   120  }
   121  
   122  func ExampleContainsAny() {
   123  	fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "fÄo!"))
   124  	fmt.Println(bytes.ContainsAny([]byte("I like seafood."), "去是伟大的."))
   125  	fmt.Println(bytes.ContainsAny([]byte("I like seafood."), ""))
   126  	fmt.Println(bytes.ContainsAny([]byte(""), ""))
   127  	// Output:
   128  	// true
   129  	// true
   130  	// false
   131  	// false
   132  }
   133  
   134  func ExampleContainsRune() {
   135  	fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'f'))
   136  	fmt.Println(bytes.ContainsRune([]byte("I like seafood."), 'ö'))
   137  	fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '大'))
   138  	fmt.Println(bytes.ContainsRune([]byte("去是伟大的!"), '!'))
   139  	fmt.Println(bytes.ContainsRune([]byte(""), '@'))
   140  	// Output:
   141  	// true
   142  	// false
   143  	// true
   144  	// true
   145  	// false
   146  }
   147  
   148  func ExampleCount() {
   149  	fmt.Println(bytes.Count([]byte("cheese"), []byte("e")))
   150  	fmt.Println(bytes.Count([]byte("five"), []byte(""))) // before & after each rune
   151  	// Output:
   152  	// 3
   153  	// 5
   154  }
   155  
   156  func ExampleEqual() {
   157  	fmt.Println(bytes.Equal([]byte("Go"), []byte("Go")))
   158  	fmt.Println(bytes.Equal([]byte("Go"), []byte("C++")))
   159  	// Output:
   160  	// true
   161  	// false
   162  }
   163  
   164  func ExampleEqualFold() {
   165  	fmt.Println(bytes.EqualFold([]byte("Go"), []byte("go")))
   166  	// Output: true
   167  }
   168  
   169  func ExampleHasPrefix() {
   170  	fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("Go")))
   171  	fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("C")))
   172  	fmt.Println(bytes.HasPrefix([]byte("Gopher"), []byte("")))
   173  	// Output:
   174  	// true
   175  	// false
   176  	// true
   177  }
   178  
   179  func ExampleHasSuffix() {
   180  	fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("go")))
   181  	fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("O")))
   182  	fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("Ami")))
   183  	fmt.Println(bytes.HasSuffix([]byte("Amigo"), []byte("")))
   184  	// Output:
   185  	// true
   186  	// false
   187  	// false
   188  	// true
   189  }
   190  
   191  func ExampleIndex() {
   192  	fmt.Println(bytes.Index([]byte("chicken"), []byte("ken")))
   193  	fmt.Println(bytes.Index([]byte("chicken"), []byte("dmr")))
   194  	// Output:
   195  	// 4
   196  	// -1
   197  }
   198  
   199  func ExampleIndexByte() {
   200  	fmt.Println(bytes.IndexByte([]byte("chicken"), byte('k')))
   201  	fmt.Println(bytes.IndexByte([]byte("chicken"), byte('g')))
   202  	// Output:
   203  	// 4
   204  	// -1
   205  }
   206  
   207  func ExampleIndexFunc() {
   208  	f := func(c rune) bool {
   209  		return unicode.Is(unicode.Han, c)
   210  	}
   211  	fmt.Println(bytes.IndexFunc([]byte("Hello, 世界"), f))
   212  	fmt.Println(bytes.IndexFunc([]byte("Hello, world"), f))
   213  	// Output:
   214  	// 7
   215  	// -1
   216  }
   217  
   218  func ExampleIndexAny() {
   219  	fmt.Println(bytes.IndexAny([]byte("chicken"), "aeiouy"))
   220  	fmt.Println(bytes.IndexAny([]byte("crwth"), "aeiouy"))
   221  	// Output:
   222  	// 2
   223  	// -1
   224  }
   225  
   226  func ExampleIndexRune() {
   227  	fmt.Println(bytes.IndexRune([]byte("chicken"), 'k'))
   228  	fmt.Println(bytes.IndexRune([]byte("chicken"), 'd'))
   229  	// Output:
   230  	// 4
   231  	// -1
   232  }
   233  
   234  func ExampleLastIndex() {
   235  	fmt.Println(bytes.Index([]byte("go gopher"), []byte("go")))
   236  	fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("go")))
   237  	fmt.Println(bytes.LastIndex([]byte("go gopher"), []byte("rodent")))
   238  	// Output:
   239  	// 0
   240  	// 3
   241  	// -1
   242  }
   243  
   244  func ExampleLastIndexAny() {
   245  	fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "MüQp"))
   246  	fmt.Println(bytes.LastIndexAny([]byte("go 地鼠"), "地大"))
   247  	fmt.Println(bytes.LastIndexAny([]byte("go gopher"), "z,!."))
   248  	// Output:
   249  	// 5
   250  	// 3
   251  	// -1
   252  }
   253  
   254  func ExampleLastIndexByte() {
   255  	fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('g')))
   256  	fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('r')))
   257  	fmt.Println(bytes.LastIndexByte([]byte("go gopher"), byte('z')))
   258  	// Output:
   259  	// 3
   260  	// 8
   261  	// -1
   262  }
   263  
   264  func ExampleLastIndexFunc() {
   265  	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsLetter))
   266  	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsPunct))
   267  	fmt.Println(bytes.LastIndexFunc([]byte("go gopher!"), unicode.IsNumber))
   268  	// Output:
   269  	// 8
   270  	// 9
   271  	// -1
   272  }
   273  
   274  func ExampleJoin() {
   275  	s := [][]byte{[]byte("foo"), []byte("bar"), []byte("baz")}
   276  	fmt.Printf("%s", bytes.Join(s, []byte(", ")))
   277  	// Output: foo, bar, baz
   278  }
   279  
   280  func ExampleRepeat() {
   281  	fmt.Printf("ba%s", bytes.Repeat([]byte("na"), 2))
   282  	// Output: banana
   283  }
   284  
   285  func ExampleReplace() {
   286  	fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("k"), []byte("ky"), 2))
   287  	fmt.Printf("%s\n", bytes.Replace([]byte("oink oink oink"), []byte("oink"), []byte("moo"), -1))
   288  	// Output:
   289  	// oinky oinky oink
   290  	// moo moo moo
   291  }
   292  
   293  func ExampleRunes() {
   294  	rs := bytes.Runes([]byte("go gopher"))
   295  	for _, r := range rs {
   296  		fmt.Printf("%#U\n", r)
   297  	}
   298  	// Output:
   299  	// U+0067 'g'
   300  	// U+006F 'o'
   301  	// U+0020 ' '
   302  	// U+0067 'g'
   303  	// U+006F 'o'
   304  	// U+0070 'p'
   305  	// U+0068 'h'
   306  	// U+0065 'e'
   307  	// U+0072 'r'
   308  }
   309  
   310  func ExampleSplit() {
   311  	fmt.Printf("%q\n", bytes.Split([]byte("a,b,c"), []byte(",")))
   312  	fmt.Printf("%q\n", bytes.Split([]byte("a man a plan a canal panama"), []byte("a ")))
   313  	fmt.Printf("%q\n", bytes.Split([]byte(" xyz "), []byte("")))
   314  	fmt.Printf("%q\n", bytes.Split([]byte(""), []byte("Bernardo O'Higgins")))
   315  	// Output:
   316  	// ["a" "b" "c"]
   317  	// ["" "man " "plan " "canal panama"]
   318  	// [" " "x" "y" "z" " "]
   319  	// [""]
   320  }
   321  
   322  func ExampleSplitN() {
   323  	fmt.Printf("%q\n", bytes.SplitN([]byte("a,b,c"), []byte(","), 2))
   324  	z := bytes.SplitN([]byte("a,b,c"), []byte(","), 0)
   325  	fmt.Printf("%q (nil = %v)\n", z, z == nil)
   326  	// Output:
   327  	// ["a" "b,c"]
   328  	// [] (nil = true)
   329  }
   330  
   331  func ExampleSplitAfter() {
   332  	fmt.Printf("%q\n", bytes.SplitAfter([]byte("a,b,c"), []byte(",")))
   333  	// Output: ["a," "b," "c"]
   334  }
   335  
   336  func ExampleSplitAfterN() {
   337  	fmt.Printf("%q\n", bytes.SplitAfterN([]byte("a,b,c"), []byte(","), 2))
   338  	// Output: ["a," "b,c"]
   339  }
   340  
   341  func ExampleTitle() {
   342  	fmt.Printf("%s", bytes.Title([]byte("her royal highness")))
   343  	// Output: Her Royal Highness
   344  }
   345  
   346  func ExampleToTitle() {
   347  	fmt.Printf("%s\n", bytes.ToTitle([]byte("loud noises")))
   348  	fmt.Printf("%s\n", bytes.ToTitle([]byte("хлеб")))
   349  	// Output:
   350  	// LOUD NOISES
   351  	// ХЛЕБ
   352  }
   353  
   354  func ExampleTrim() {
   355  	fmt.Printf("[%q]", bytes.Trim([]byte(" !!! Achtung! Achtung! !!! "), "! "))
   356  	// Output: ["Achtung! Achtung"]
   357  }
   358  
   359  func ExampleTrimFunc() {
   360  	fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsLetter)))
   361  	fmt.Println(string(bytes.TrimFunc([]byte("\"go-gopher!\""), unicode.IsLetter)))
   362  	fmt.Println(string(bytes.TrimFunc([]byte("go-gopher!"), unicode.IsPunct)))
   363  	fmt.Println(string(bytes.TrimFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
   364  	// Output:
   365  	// -gopher!
   366  	// "go-gopher!"
   367  	// go-gopher
   368  	// go-gopher!
   369  }
   370  
   371  func ExampleMap() {
   372  	rot13 := func(r rune) rune {
   373  		switch {
   374  		case r >= 'A' && r <= 'Z':
   375  			return 'A' + (r-'A'+13)%26
   376  		case r >= 'a' && r <= 'z':
   377  			return 'a' + (r-'a'+13)%26
   378  		}
   379  		return r
   380  	}
   381  	fmt.Printf("%s", bytes.Map(rot13, []byte("'Twas brillig and the slithy gopher...")))
   382  	// Output: 'Gjnf oevyyvt naq gur fyvgul tbcure...
   383  }
   384  
   385  func ExampleTrimLeft() {
   386  	fmt.Print(string(bytes.TrimLeft([]byte("453gopher8257"), "0123456789")))
   387  	// Output:
   388  	// gopher8257
   389  }
   390  
   391  func ExampleTrimLeftFunc() {
   392  	fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher"), unicode.IsLetter)))
   393  	fmt.Println(string(bytes.TrimLeftFunc([]byte("go-gopher!"), unicode.IsPunct)))
   394  	fmt.Println(string(bytes.TrimLeftFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
   395  	// Output:
   396  	// -gopher
   397  	// go-gopher!
   398  	// go-gopher!567
   399  }
   400  
   401  func ExampleTrimSpace() {
   402  	fmt.Printf("%s", bytes.TrimSpace([]byte(" \t\n a lone gopher \n\t\r\n")))
   403  	// Output: a lone gopher
   404  }
   405  
   406  func ExampleTrimRight() {
   407  	fmt.Print(string(bytes.TrimRight([]byte("453gopher8257"), "0123456789")))
   408  	// Output:
   409  	// 453gopher
   410  }
   411  
   412  func ExampleTrimRightFunc() {
   413  	fmt.Println(string(bytes.TrimRightFunc([]byte("go-gopher"), unicode.IsLetter)))
   414  	fmt.Println(string(bytes.TrimRightFunc([]byte("go-gopher!"), unicode.IsPunct)))
   415  	fmt.Println(string(bytes.TrimRightFunc([]byte("1234go-gopher!567"), unicode.IsNumber)))
   416  	// Output:
   417  	// go-
   418  	// go-gopher
   419  	// 1234go-gopher!
   420  }
   421  
   422  func ExampleToUpper() {
   423  	fmt.Printf("%s", bytes.ToUpper([]byte("Gopher")))
   424  	// Output: GOPHER
   425  }
   426  
   427  func ExampleToLower() {
   428  	fmt.Printf("%s", bytes.ToLower([]byte("Gopher")))
   429  	// Output: gopher
   430  }
   431  
   432  func ExampleReader_Len() {
   433  	fmt.Println(bytes.NewReader([]byte("Hi!")).Len())
   434  	fmt.Println(bytes.NewReader([]byte("こんにちは!")).Len())
   435  	// Output:
   436  	// 3
   437  	// 16
   438  }