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Diffstat (limited to 'src/sort/example_wrapper_test.go')
-rw-r--r-- | src/sort/example_wrapper_test.go | 77 |
1 files changed, 77 insertions, 0 deletions
diff --git a/src/sort/example_wrapper_test.go b/src/sort/example_wrapper_test.go new file mode 100644 index 0000000..cf6d74c --- /dev/null +++ b/src/sort/example_wrapper_test.go @@ -0,0 +1,77 @@ +// 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 sort_test + +import ( + "fmt" + "sort" +) + +type Grams int + +func (g Grams) String() string { return fmt.Sprintf("%dg", int(g)) } + +type Organ struct { + Name string + Weight Grams +} + +type Organs []*Organ + +func (s Organs) Len() int { return len(s) } +func (s Organs) Swap(i, j int) { s[i], s[j] = s[j], s[i] } + +// ByName implements sort.Interface by providing Less and using the Len and +// Swap methods of the embedded Organs value. +type ByName struct{ Organs } + +func (s ByName) Less(i, j int) bool { return s.Organs[i].Name < s.Organs[j].Name } + +// ByWeight implements sort.Interface by providing Less and using the Len and +// Swap methods of the embedded Organs value. +type ByWeight struct{ Organs } + +func (s ByWeight) Less(i, j int) bool { return s.Organs[i].Weight < s.Organs[j].Weight } + +func Example_sortWrapper() { + s := []*Organ{ + {"brain", 1340}, + {"heart", 290}, + {"liver", 1494}, + {"pancreas", 131}, + {"prostate", 62}, + {"spleen", 162}, + } + + sort.Sort(ByWeight{s}) + fmt.Println("Organs by weight:") + printOrgans(s) + + sort.Sort(ByName{s}) + fmt.Println("Organs by name:") + printOrgans(s) + + // Output: + // Organs by weight: + // prostate (62g) + // pancreas (131g) + // spleen (162g) + // heart (290g) + // brain (1340g) + // liver (1494g) + // Organs by name: + // brain (1340g) + // heart (290g) + // liver (1494g) + // pancreas (131g) + // prostate (62g) + // spleen (162g) +} + +func printOrgans(s []*Organ) { + for _, o := range s { + fmt.Printf("%-8s (%v)\n", o.Name, o.Weight) + } +} |