doc add monoid example

ireina7 · May 21, 2023 · 34e6adb · 34e6adb
1 parent 18f7d5b
commit 34e6adb
Showing 1 changed file with 5 additions and 0 deletions.
diff --git a/README.md b/README.md
@@ -129,6 +129,11 @@ func main() {
 
 ## An example for `Monoid` and `Fold`
 ```go
+type Monoid[A any] interface {
+	Zero() A
+	Plus(a, b A) A
+}
+
 type MonoidString struct{}
 
 func (self *MonoidString) Zero() string {