libgo/go/sort/example_test.go

   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 sort_test
   6
   7 import (
   8         "fmt"
   9         "math"
  10         "sort"
  11 )
  12
  13 func ExampleInts() {
  14         s := []int{5, 2, 6, 3, 1, 4} // unsorted
  15         sort.Ints(s)
  16         fmt.Println(s)
  17         // Output: [1 2 3 4 5 6]
  18 }
  19
  20 func ExampleIntsAreSorted() {
  21         s := []int{1, 2, 3, 4, 5, 6} // sorted ascending
  22         fmt.Println(sort.IntsAreSorted(s))
  23
  24         s = []int{6, 5, 4, 3, 2, 1} // sorted descending
  25         fmt.Println(sort.IntsAreSorted(s))
  26
  27         s = []int{3, 2, 4, 1, 5} // unsorted
  28         fmt.Println(sort.IntsAreSorted(s))
  29
  30         // Output: true
  31         // false
  32         // false
  33 }
  34
  35 func ExampleFloat64s() {
  36         s := []float64{5.2, -1.3, 0.7, -3.8, 2.6} // unsorted
  37         sort.Float64s(s)
  38         fmt.Println(s)
  39
  40         s = []float64{math.Inf(1), math.NaN(), math.Inf(-1), 0.0} // unsorted
  41         sort.Float64s(s)
  42         fmt.Println(s)
  43
  44         // Output: [-3.8 -1.3 0.7 2.6 5.2]
  45         // [NaN -Inf 0 +Inf]
  46 }
  47
  48 func ExampleFloat64sAreSorted() {
  49         s := []float64{0.7, 1.3, 2.6, 3.8, 5.2} // sorted ascending
  50         fmt.Println(sort.Float64sAreSorted(s))
  51
  52         s = []float64{5.2, 3.8, 2.6, 1.3, 0.7} // sorted descending
  53         fmt.Println(sort.Float64sAreSorted(s))
  54
  55         s = []float64{5.2, 1.3, 0.7, 3.8, 2.6} // unsorted
  56         fmt.Println(sort.Float64sAreSorted(s))
  57
  58         // Output: true
  59         // false
  60         // false
  61 }
  62
  63 func ExampleReverse() {
  64         s := []int{5, 2, 6, 3, 1, 4} // unsorted
  65         sort.Sort(sort.Reverse(sort.IntSlice(s)))
  66         fmt.Println(s)
  67         // Output: [6 5 4 3 2 1]
  68 }
  69
  70 func ExampleSlice() {
  71         people := []struct {
  72                 Name string
  73                 Age  int
  74         }{
  75                 {"Gopher", 7},
  76                 {"Alice", 55},
  77                 {"Vera", 24},
  78                 {"Bob", 75},
  79         }
  80         sort.Slice(people, func(i, j int) bool { return people[i].Name < people[j].Name })
  81         fmt.Println("By name:", people)
  82
  83         sort.Slice(people, func(i, j int) bool { return people[i].Age < people[j].Age })
  84         fmt.Println("By age:", people)
  85         // Output: By name: [{Alice 55} {Bob 75} {Gopher 7} {Vera 24}]
  86         // By age: [{Gopher 7} {Vera 24} {Alice 55} {Bob 75}]
  87 }
  88
  89 func ExampleSliceStable() {
  90
  91         people := []struct {
  92                 Name string
  93                 Age  int
  94         }{
  95                 {"Alice", 25},
  96                 {"Elizabeth", 75},
  97                 {"Alice", 75},
  98                 {"Bob", 75},
  99                 {"Alice", 75},
 100                 {"Bob", 25},
 101                 {"Colin", 25},
 102                 {"Elizabeth", 25},
 103         }
 104
 105         // Sort by name, preserving original order
 106         sort.SliceStable(people, func(i, j int) bool { return people[i].Name < people[j].Name })
 107         fmt.Println("By name:", people)
 108
 109         // Sort by age preserving name order
 110         sort.SliceStable(people, func(i, j int) bool { return people[i].Age < people[j].Age })
 111         fmt.Println("By age,name:", people)
 112
 113         // Output: By name: [{Alice 25} {Alice 75} {Alice 75} {Bob 75} {Bob 25} {Colin 25} {Elizabeth 75} {Elizabeth 25}]
 114         // By age,name: [{Alice 25} {Bob 25} {Colin 25} {Elizabeth 25} {Alice 75} {Alice 75} {Bob 75} {Elizabeth 75}]
 115 }
 116
 117 func ExampleStrings() {
 118         s := []string{"Go", "Bravo", "Gopher", "Alpha", "Grin", "Delta"}
 119         sort.Strings(s)
 120         fmt.Println(s)
 121         // Output: [Alpha Bravo Delta Go Gopher Grin]
 122 }