Added Listener generic type.

Author: mikestefanello

README.md

@@ -25,19 +25,7 @@ type User struct {
 var HookUserInsert = hooks.NewHook[User]("user.insert")
 ```
 
-2) Dispatch the data to the hook _listeners_:
-
-```go
-func (u *User) Insert() {
-    db.Insert("INSERT INTO users ...")
-    
-    HookUserInsert.Dispatch(&u)
-}
-```
-
-Or, dispatch all listeners asynchronously with `HookUserInsert.DispatchAsync(u)`.
-
-3) Listen to a hook:
+2Listen to a hook:
 
 ```go
 package greeter
@@ -49,6 +37,18 @@ func init() {
 }
 ```
 
+3) Dispatch the data to the hook _listeners_:
+
+```go
+func (u *User) Insert() {
+    db.Insert("INSERT INTO users ...")
+
+    HookUserInsert.Dispatch(&u)
+}
+```
+
+Or, dispatch all listeners asynchronously with `HookUserInsert.DispatchAsync(u)`.
+
 ### Things to know
 
 - The `Listen()` callback does not have to be an anonymous function. You can also do:
@@ -206,15 +206,16 @@ Hook listeners can also provide validation or other similar input on data that i
 ```go
 type UserValidation struct {
     User User
-    Errors []error
+    Errors *[]error
 }
 
 var HookUserValidate = hooks.NewHook[UserValidation]("user.validate")
 
 func (u *User) Validate() []error {
-    uv := &UserValidation{
-        User: &u,
-        Errors: make([]error, 0)
+    errs := make([]error, 0)
+    uv := UserValidation{
+        User:   *u,
+        Errors: &errs,
     }
 
     if u.Email == "" {

hook.go

@@ -4,13 +4,16 @@ import (
 	"sync"
 )
 
+// Listener is a function that can listen and react to a hook event
+type Listener[T any] func(event Event[T])
+
 // Hook is a mechanism which supports the ability to dispatch data to arbitrary listener callbacks
 type Hook[T any] struct {
 	// name stores the name of the hook
 	name string
 
 	// listeners stores the functions which will be invoked during dispatch
-	listeners []func(event Event[T])
+	listeners []Listener[T]
 
 	// mu stores the mutex to provide concurrency-safe operations
 	mu sync.RWMutex
@@ -22,7 +25,7 @@ func NewHook[T any](name string) *Hook[T] {
 
 	return &Hook[T]{
 		name:      name,
-		listeners: make([]func(event Event[T]), 0),
+		listeners: make([]Listener[T], 0),
 		mu:        sync.RWMutex{},
 	}
 }
@@ -33,7 +36,7 @@ func (h *Hook[T]) GetName() string {
 }
 
 // Listen registers a callback function to be invoked when the hook dispatches data
-func (h *Hook[T]) Listen(callback func(event Event[T])) {
+func (h *Hook[T]) Listen(callback Listener[T]) {
 	h.mu.Lock()
 	defer h.mu.Unlock()