moar interfaces

Author: gunjan5

day18-interfaces/shuffeler.go

@@ -0,0 +1,49 @@
+package main
+
+import (
+	"fmt"
+	"math/rand"
+)
+
+type shuffler interface {
+	Len() int
+	Swap(i, j int)
+}
+
+func shuffle(s shuffler) {
+	for i := 0; i < s.Len(); i++ {
+		j := rand.Intn(s.Len() - i)
+		s.Swap(i, j)
+
+	}
+}
+
+type intSlice []int
+
+func (is intSlice) Len() int {
+	return len(is)
+}
+
+func (is intSlice) Swap(i, j int) {
+	is[i], is[j] = is[j], is[i]
+}
+
+type stringSlice []string
+
+func (ss stringSlice) Len() int {
+	return len(ss)
+}
+
+func (ss stringSlice) Swap(i, j int) {
+	ss[i], ss[j] = ss[j], ss[i]
+}
+
+func main() {
+	ii := intSlice{1, 2, 3, 4, 5, 6}
+	shuffle(ii)
+	fmt.Printf("%v\n", ii)
+
+	si := stringSlice{"interfaces", "are", "awesome", "!"}
+	shuffle(si)
+	fmt.Printf("%v\n", si)
+}