github.com/q45/go@v0.0.0-20151101211701-a4fb8c13db3f/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  )
    15  
    16  func ExampleBuffer() {
    17  	var b bytes.Buffer // A Buffer needs no initialization.
    18  	b.Write([]byte("Hello "))
    19  	fmt.Fprintf(&b, "world!")
    20  	b.WriteTo(os.Stdout)
    21  	// Output: Hello world!
    22  }
    23  
    24  func ExampleBuffer_reader() {
    25  	// A Buffer can turn a string or a []byte into an io.Reader.
    26  	buf := bytes.NewBufferString("R29waGVycyBydWxlIQ==")
    27  	dec := base64.NewDecoder(base64.StdEncoding, buf)
    28  	io.Copy(os.Stdout, dec)
    29  	// Output: Gophers rule!
    30  }
    31  
    32  func ExampleCompare() {
    33  	// Interpret Compare's result by comparing it to zero.
    34  	var a, b []byte
    35  	if bytes.Compare(a, b) < 0 {
    36  		// a less b
    37  	}
    38  	if bytes.Compare(a, b) <= 0 {
    39  		// a less or equal b
    40  	}
    41  	if bytes.Compare(a, b) > 0 {
    42  		// a greater b
    43  	}
    44  	if bytes.Compare(a, b) >= 0 {
    45  		// a greater or equal b
    46  	}
    47  
    48  	// Prefer Equal to Compare for equality comparisons.
    49  	if bytes.Equal(a, b) {
    50  		// a equal b
    51  	}
    52  	if !bytes.Equal(a, b) {
    53  		// a not equal b
    54  	}
    55  }
    56  
    57  func ExampleCompare_search() {
    58  	// Binary search to find a matching byte slice.
    59  	var needle []byte
    60  	var haystack [][]byte // Assume sorted
    61  	i := sort.Search(len(haystack), func(i int) bool {
    62  		// Return haystack[i] >= needle.
    63  		return bytes.Compare(haystack[i], needle) >= 0
    64  	})
    65  	if i < len(haystack) && bytes.Equal(haystack[i], needle) {
    66  		// Found it!
    67  	}
    68  }
    69  
    70  func ExampleTrimSuffix() {
    71  	var b = []byte("Hello, goodbye, etc!")
    72  	b = bytes.TrimSuffix(b, []byte("goodbye, etc!"))
    73  	b = bytes.TrimSuffix(b, []byte("gopher"))
    74  	b = append(b, bytes.TrimSuffix([]byte("world!"), []byte("x!"))...)
    75  	os.Stdout.Write(b)
    76  	// Output: Hello, world!
    77  }
    78  
    79  func ExampleTrimPrefix() {
    80  	var b = []byte("Goodbye,, world!")
    81  	b = bytes.TrimPrefix(b, []byte("Goodbye,"))
    82  	b = bytes.TrimPrefix(b, []byte("See ya,"))
    83  	fmt.Printf("Hello%s", b)
    84  	// Output: Hello, world!
    85  }