added option for using clock

Author: Code-Hex

README.md

@@ -24,6 +24,9 @@ go-generics-cache is an in-memory key:value store/cache that is suitable for app
   - **Most recently used (MRU)**
     - In contrast to Least Recently Used (LRU), MRU discards the most recently used items first.
 	- See [examples](https://github.com/Code-Hex/go-generics-cache/blob/main/mru/example_test.go)
+  - **Clock**
+    - Clock is a more efficient version of FIFO than Second-chance cache algorithm.
+	- See [examples](https://github.com/Code-Hex/go-generics-cache/blob/main/clock/example_test.go)
 
 ## Requirements
 

cache.go

@@ -4,6 +4,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/Code-Hex/go-generics-cache/clock"
 	"github.com/Code-Hex/go-generics-cache/fifo"
 	"github.com/Code-Hex/go-generics-cache/lfu"
 	"github.com/Code-Hex/go-generics-cache/lru"
@@ -25,6 +26,7 @@ var (
 	_ Interface[any, any] = (*lfu.Cache[any, any])(nil)
 	_ Interface[any, any] = (*fifo.Cache[any, any])(nil)
 	_ Interface[any, any] = (*mru.Cache[any, any])(nil)
+	_ Interface[any, any] = (*clock.Cache[any, any])(nil)
 )
 
 // Item is an item
@@ -113,6 +115,13 @@ func AsMRU[K comparable, V any](opts ...mru.Option) Option[K, V] {
 	}
 }
 
+// AsClock is an option to make a new Cache as clock algorithm.
+func AsClock[K comparable, V any](opts ...clock.Option) Option[K, V] {
+	return func(o *options[K, V]) {
+		o.cache = clock.NewCache[K, *Item[K, V]](opts...)
+	}
+}
+
 // New creates a new thread safe Cache.
 //
 // There are several Cache replacement policies available with you specified any options.

example_test.go

@@ -20,6 +20,19 @@ func ExampleCache() {
 	// 0 false
 }
 
+func ExampleCacheAsClock() {
+	// use clock cache algorithm.
+	c := cache.New(cache.AsClock[string, int]())
+	c.Set("a", 1)
+	gota, aok := c.Get("a")
+	gotb, bok := c.Get("b")
+	fmt.Println(gota, aok)
+	fmt.Println(gotb, bok)
+	// Output:
+	// 1 true
+	// 0 false
+}
+
 func ExampleCacheWithExpiration() {
 	c := cache.New(cache.AsFIFO[string, int]())
 	exp := 250 * time.Millisecond