// +build ignore,OMIT package main import ( "fmt" "sort" ) type Organ struct { Name string Weight Grams } func (o *Organ) String() string { return fmt.Sprintf("%v (%v)", o.Name, o.Weight) } type Grams int func (g Grams) String() string { return fmt.Sprintf("%dg", int(g)) } // PART1 OMIT 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] } // PART2 OMIT type ByName struct{ Organs } func (s ByName) Less(i, j int) bool { return s.Organs[i].Name < s.Organs[j].Name } type ByWeight struct{ Organs } func (s ByWeight) Less(i, j int) bool { return s.Organs[i].Weight < s.Organs[j].Weight } // PART3 OMIT func main() { // START OMIT s := []*Organ{ {"brain", 1340}, {"heart", 290}, {"liver", 1494}, {"pancreas", 131}, {"spleen", 162}, } sort.Sort(ByWeight{s}) // HL printOrgans("Organs by weight", s) sort.Sort(ByName{s}) // HL printOrgans("Organs by name", s) // STOP OMIT } func printOrgans(t string, s []*Organ) { fmt.Printf("%s:\n", t) for _, o := range s { fmt.Printf(" %v\n", o) } }