Chore: use generics as possible

common/batch/batch.go

@@ -5,10 +5,10 @@ import (
 	"sync"
 )
 
-type Option = func(b *Batch)
+type Option[T any] func(b *Batch[T])
 
-type Result struct {
-	Value any
+type Result[T any] struct {
+	Value T
 	Err   error
 }
 
@@ -17,8 +17,8 @@ type Error struct {
 	Err error
 }
 
-func WithConcurrencyNum(n int) Option {
-	return func(b *Batch) {
+func WithConcurrencyNum[T any](n int) Option[T] {
+	return func(b *Batch[T]) {
 		q := make(chan struct{}, n)
 		for i := 0; i < n; i++ {
 			q <- struct{}{}
@@ -28,8 +28,8 @@ func WithConcurrencyNum(n int) Option {
 }
 
 // Batch similar to errgroup, but can control the maximum number of concurrent
-type Batch struct {
-	result map[string]Result
+type Batch[T any] struct {
+	result map[string]Result[T]
 	queue  chan struct{}
 	wg     sync.WaitGroup
 	mux    sync.Mutex
@@ -38,7 +38,7 @@ type Batch struct {
 	cancel func()
 }
 
-func (b *Batch) Go(key string, fn func() (any, error)) {
+func (b *Batch[T]) Go(key string, fn func() (T, error)) {
 	b.wg.Add(1)
 	go func() {
 		defer b.wg.Done()
@@ -59,14 +59,14 @@ func (b *Batch) Go(key string, fn func() (any, error)) {
 			})
 		}
 
-		ret := Result{value, err}
+		ret := Result[T]{value, err}
 		b.mux.Lock()
 		defer b.mux.Unlock()
 		b.result[key] = ret
 	}()
 }
 
-func (b *Batch) Wait() *Error {
+func (b *Batch[T]) Wait() *Error {
 	b.wg.Wait()
 	if b.cancel != nil {
 		b.cancel()
@@ -74,26 +74,26 @@ func (b *Batch) Wait() *Error {
 	return b.err
 }
 
-func (b *Batch) WaitAndGetResult() (map[string]Result, *Error) {
+func (b *Batch[T]) WaitAndGetResult() (map[string]Result[T], *Error) {
 	err := b.Wait()
 	return b.Result(), err
 }
 
-func (b *Batch) Result() map[string]Result {
+func (b *Batch[T]) Result() map[string]Result[T] {
 	b.mux.Lock()
 	defer b.mux.Unlock()
-	copy := map[string]Result{}
+	copyM := map[string]Result[T]{}
 	for k, v := range b.result {
-		copy[k] = v
+		copyM[k] = v
 	}
-	return copy
+	return copyM
 }
 
-func New(ctx context.Context, opts ...Option) (*Batch, context.Context) {
+func New[T any](ctx context.Context, opts ...Option[T]) (*Batch[T], context.Context) {
 	ctx, cancel := context.WithCancel(ctx)
 
-	b := &Batch{
-		result: map[string]Result{},
+	b := &Batch[T]{
+		result: map[string]Result[T]{},
 	}
 
 	for _, o := range opts {

common/batch/batch_test.go

@@ -11,14 +11,14 @@ import (
 )
 
 func TestBatch(t *testing.T) {
-	b, _ := New(context.Background())
+	b, _ := New[string](context.Background())
 
 	now := time.Now()
-	b.Go("foo", func() (any, error) {
+	b.Go("foo", func() (string, error) {
 		time.Sleep(time.Millisecond * 100)
 		return "foo", nil
 	})
-	b.Go("bar", func() (any, error) {
+	b.Go("bar", func() (string, error) {
 		time.Sleep(time.Millisecond * 150)
 		return "bar", nil
 	})
@@ -32,20 +32,20 @@ func TestBatch(t *testing.T) {
 
 	for k, v := range result {
 		assert.NoError(t, v.Err)
-		assert.Equal(t, k, v.Value.(string))
+		assert.Equal(t, k, v.Value)
 	}
 }
 
 func TestBatchWithConcurrencyNum(t *testing.T) {
-	b, _ := New(
+	b, _ := New[string](
 		context.Background(),
-		WithConcurrencyNum(3),
+		WithConcurrencyNum[string](3),
 	)
 
 	now := time.Now()
 	for i := 0; i < 7; i++ {
 		idx := i
-		b.Go(strconv.Itoa(idx), func() (any, error) {
+		b.Go(strconv.Itoa(idx), func() (string, error) {
 			time.Sleep(time.Millisecond * 100)
 			return strconv.Itoa(idx), nil
 		})
@@ -57,21 +57,21 @@ func TestBatchWithConcurrencyNum(t *testing.T) {
 
 	for k, v := range result {
 		assert.NoError(t, v.Err)
-		assert.Equal(t, k, v.Value.(string))
+		assert.Equal(t, k, v.Value)
 	}
 }
 
 func TestBatchContext(t *testing.T) {
-	b, ctx := New(context.Background())
+	b, ctx := New[string](context.Background())
 
-	b.Go("error", func() (any, error) {
+	b.Go("error", func() (string, error) {
 		time.Sleep(time.Millisecond * 100)
-		return nil, errors.New("test error")
+		return "", errors.New("test error")
 	})
 
-	b.Go("ctx", func() (any, error) {
+	b.Go("ctx", func() (string, error) {
 		<-ctx.Done()
-		return nil, ctx.Err()
+		return "", ctx.Err()
 	})
 
 	result, err := b.WaitAndGetResult()

common/cache/lrucache.go

@@ -3,19 +3,20 @@ package cache
 // Modified by https://github.com/die-net/lrucache
 
 import (
-	"container/list"
 	"sync"
 	"time"
+
+	"github.com/Dreamacro/clash/common/generics/list"
 )
 
 // Option is part of Functional Options Pattern
 type Option[K comparable, V any] func(*LruCache[K, V])
 
 // EvictCallback is used to get a callback when a cache entry is evicted
-type EvictCallback = func(key any, value any)
+type EvictCallback[K comparable, V any] func(key K, value V)
 
 // WithEvict set the evict callback
-func WithEvict[K comparable, V any](cb EvictCallback) Option[K, V] {
+func WithEvict[K comparable, V any](cb EvictCallback[K, V]) Option[K, V] {
 	return func(l *LruCache[K, V]) {
 		l.onEvict = cb
 	}
@@ -57,18 +58,18 @@ type LruCache[K comparable, V any] struct {
 	maxAge         int64
 	maxSize        int
 	mu             sync.Mutex
-	cache          map[any]*list.Element
-	lru            *list.List // Front is least-recent
+	cache          map[K]*list.Element[*entry[K, V]]
+	lru            *list.List[*entry[K, V]] // Front is least-recent
 	updateAgeOnGet bool
 	staleReturn    bool
-	onEvict        EvictCallback
+	onEvict        EvictCallback[K, V]
 }
 
 // NewLRUCache creates an LruCache
 func NewLRUCache[K comparable, V any](options ...Option[K, V]) *LruCache[K, V] {
 	lc := &LruCache[K, V]{
-		lru:   list.New(),
-		cache: make(map[any]*list.Element),
+		lru:   list.New[*entry[K, V]](),
+		cache: make(map[K]*list.Element[*entry[K, V]]),
 	}
 
 	for _, option := range options {
@@ -129,7 +130,7 @@ func (c *LruCache[K, V]) SetWithExpire(key K, value V, expires time.Time) {
 
 	if le, ok := c.cache[key]; ok {
 		c.lru.MoveToBack(le)
-		e := le.Value.(*entry[K, V])
+		e := le.Value
 		e.value = value
 		e.expires = expires.Unix()
 	} else {
@@ -154,11 +155,11 @@ func (c *LruCache[K, V]) CloneTo(n *LruCache[K, V]) {
 	n.mu.Lock()
 	defer n.mu.Unlock()
 
-	n.lru = list.New()
-	n.cache = make(map[any]*list.Element)
+	n.lru = list.New[*entry[K, V]]()
+	n.cache = make(map[K]*list.Element[*entry[K, V]])
 
 	for e := c.lru.Front(); e != nil; e = e.Next() {
-		elm := e.Value.(*entry[K, V])
+		elm := e.Value
 		n.cache[elm.key] = n.lru.PushBack(elm)
 	}
 }
@@ -172,7 +173,7 @@ func (c *LruCache[K, V]) get(key K) *entry[K, V] {
 		return nil
 	}
 
-	if !c.staleReturn && c.maxAge > 0 && le.Value.(*entry[K, V]).expires <= time.Now().Unix() {
+	if !c.staleReturn && c.maxAge > 0 && le.Value.expires <= time.Now().Unix() {
 		c.deleteElement(le)
 		c.maybeDeleteOldest()
 
@@ -180,7 +181,7 @@ func (c *LruCache[K, V]) get(key K) *entry[K, V] {
 	}
 
 	c.lru.MoveToBack(le)
-	el := le.Value.(*entry[K, V])
+	el := le.Value
 	if c.maxAge > 0 && c.updateAgeOnGet {
 		el.expires = time.Now().Unix() + c.maxAge
 	}
@@ -201,15 +202,15 @@ func (c *LruCache[K, V]) Delete(key K) {
 func (c *LruCache[K, V]) maybeDeleteOldest() {
 	if !c.staleReturn && c.maxAge > 0 {
 		now := time.Now().Unix()
-		for le := c.lru.Front(); le != nil && le.Value.(*entry[K, V]).expires <= now; le = c.lru.Front() {
+		for le := c.lru.Front(); le != nil && le.Value.expires <= now; le = c.lru.Front() {
 			c.deleteElement(le)
 		}
 	}
 }
 
-func (c *LruCache[K, V]) deleteElement(le *list.Element) {
+func (c *LruCache[K, V]) deleteElement(le *list.Element[*entry[K, V]]) {
 	c.lru.Remove(le)
-	e := le.Value.(*entry[K, V])
+	e := le.Value
 	delete(c.cache, e.key)
 	if c.onEvict != nil {
 		c.onEvict(e.key, e.value)
@@ -219,7 +220,7 @@ func (c *LruCache[K, V]) deleteElement(le *list.Element) {
 func (c *LruCache[K, V]) Clear() error {
 	c.mu.Lock()
 
-	c.cache = make(map[any]*list.Element)
+	c.cache = make(map[K]*list.Element[*entry[K, V]])
 
 	c.mu.Unlock()
 	return nil

common/cache/lrucache_test.go

@@ -52,18 +52,18 @@ func TestLRUMaxAge(t *testing.T) {
 
 	// Add one expired entry
 	c.Set("foo", "bar")
-	c.lru.Back().Value.(*entry[string, string]).expires = now
+	c.lru.Back().Value.expires = now
 
 	// Reset
 	c.Set("foo", "bar")
-	e := c.lru.Back().Value.(*entry[string, string])
+	e := c.lru.Back().Value
 	assert.True(t, e.expires >= now)
-	c.lru.Back().Value.(*entry[string, string]).expires = now
+	c.lru.Back().Value.expires = now
 
 	// Set a few and verify expiration times
 	for _, s := range entries {
 		c.Set(s.key, s.value)
-		e := c.lru.Back().Value.(*entry[string, string])
+		e := c.lru.Back().Value
 		assert.True(t, e.expires >= expected && e.expires <= expected+10)
 	}
 
@@ -77,7 +77,7 @@ func TestLRUMaxAge(t *testing.T) {
 	for _, s := range entries {
 		le, ok := c.cache[s.key]
 		if assert.True(t, ok) {
-			le.Value.(*entry[string, string]).expires = now
+			le.Value.expires = now
 		}
 	}
 
@@ -95,11 +95,11 @@ func TestLRUpdateOnGet(t *testing.T) {
 
 	// Add one expired entry
 	c.Set("foo", "bar")
-	c.lru.Back().Value.(*entry[string, string]).expires = expires
+	c.lru.Back().Value.expires = expires
 
 	_, ok := c.Get("foo")
 	assert.True(t, ok)
-	assert.True(t, c.lru.Back().Value.(*entry[string, string]).expires > expires)
+	assert.True(t, c.lru.Back().Value.expires > expires)
 }
 
 func TestMaxSize(t *testing.T) {
@@ -126,8 +126,8 @@ func TestExist(t *testing.T) {
 
 func TestEvict(t *testing.T) {
 	temp := 0
-	evict := func(key any, value any) {
-		temp = key.(int) + value.(int)
+	evict := func(key int, value int) {
+		temp = key + value
 	}
 
 	c := NewLRUCache[int, int](WithEvict[int, int](evict), WithSize[int, int](1))

common/generics/list/list.go

@@ -0,0 +1,235 @@
+// Copyright 2009 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+// Package list implements a doubly linked list.
+//
+// To iterate over a list (where l is a *List):
+//	for e := l.Front(); e != nil; e = e.Next() {
+//		// do something with e.Value
+//	}
+//
+package list
+
+// Element is an element of a linked list.
+type Element[T any] struct {
+	// Next and previous pointers in the doubly-linked list of elements.
+	// To simplify the implementation, internally a list l is implemented
+	// as a ring, such that &l.root is both the next element of the last
+	// list element (l.Back()) and the previous element of the first list
+	// element (l.Front()).
+	next, prev *Element[T]
+
+	// The list to which this element belongs.
+	list *List[T]
+
+	// The value stored with this element.
+	Value T
+}
+
+// Next returns the next list element or nil.
+func (e *Element[T]) Next() *Element[T] {
+	if p := e.next; e.list != nil && p != &e.list.root {
+		return p
+	}
+	return nil
+}
+
+// Prev returns the previous list element or nil.
+func (e *Element[T]) Prev() *Element[T] {
+	if p := e.prev; e.list != nil && p != &e.list.root {
+		return p
+	}
+	return nil
+}
+
+// List represents a doubly linked list.
+// The zero value for List is an empty list ready to use.
+type List[T any] struct {
+	root Element[T] // sentinel list element, only &root, root.prev, and root.next are used
+	len  int        // current list length excluding (this) sentinel element
+}
+
+// Init initializes or clears list l.
+func (l *List[T]) Init() *List[T] {
+	l.root.next = &l.root
+	l.root.prev = &l.root
+	l.len = 0
+	return l
+}
+
+// New returns an initialized list.
+func New[T any]() *List[T] { return new(List[T]).Init() }
+
+// Len returns the number of elements of list l.
+// The complexity is O(1).
+func (l *List[T]) Len() int { return l.len }
+
+// Front returns the first element of list l or nil if the list is empty.
+func (l *List[T]) Front() *Element[T] {
+	if l.len == 0 {
+		return nil
+	}
+	return l.root.next
+}
+
+// Back returns the last element of list l or nil if the list is empty.
+func (l *List[T]) Back() *Element[T] {
+	if l.len == 0 {
+		return nil
+	}
+	return l.root.prev
+}
+
+// lazyInit lazily initializes a zero List value.
+func (l *List[T]) lazyInit() {
+	if l.root.next == nil {
+		l.Init()
+	}
+}
+
+// insert inserts e after at, increments l.len, and returns e.
+func (l *List[T]) insert(e, at *Element[T]) *Element[T] {
+	e.prev = at
+	e.next = at.next
+	e.prev.next = e
+	e.next.prev = e
+	e.list = l
+	l.len++
+	return e
+}
+
+// insertValue is a convenience wrapper for insert(&Element{Value: v}, at).
+func (l *List[T]) insertValue(v T, at *Element[T]) *Element[T] {
+	return l.insert(&Element[T]{Value: v}, at)
+}
+
+// remove removes e from its list, decrements l.len
+func (l *List[T]) remove(e *Element[T]) {
+	e.prev.next = e.next
+	e.next.prev = e.prev
+	e.next = nil // avoid memory leaks
+	e.prev = nil // avoid memory leaks
+	e.list = nil
+	l.len--
+}
+
+// move moves e to next to at.
+func (l *List[T]) move(e, at *Element[T]) {
+	if e == at {
+		return
+	}
+	e.prev.next = e.next
+	e.next.prev = e.prev
+
+	e.prev = at
+	e.next = at.next
+	e.prev.next = e
+	e.next.prev = e
+}
+
+// Remove removes e from l if e is an element of list l.
+// It returns the element value e.Value.
+// The element must not be nil.
+func (l *List[T]) Remove(e *Element[T]) T {
+	if e.list == l {
+		// if e.list == l, l must have been initialized when e was inserted
+		// in l or l == nil (e is a zero Element) and l.remove will crash
+		l.remove(e)
+	}
+	return e.Value
+}
+
+// PushFront inserts a new element e with value v at the front of list l and returns e.
+func (l *List[T]) PushFront(v T) *Element[T] {
+	l.lazyInit()
+	return l.insertValue(v, &l.root)
+}
+
+// PushBack inserts a new element e with value v at the back of list l and returns e.
+func (l *List[T]) PushBack(v T) *Element[T] {
+	l.lazyInit()
+	return l.insertValue(v, l.root.prev)
+}
+
+// InsertBefore inserts a new element e with value v immediately before mark and returns e.
+// If mark is not an element of l, the list is not modified.
+// The mark must not be nil.
+func (l *List[T]) InsertBefore(v T, mark *Element[T]) *Element[T] {
+	if mark.list != l {
+		return nil
+	}
+	// see comment in List.Remove about initialization of l
+	return l.insertValue(v, mark.prev)
+}
+
+// InsertAfter inserts a new element e with value v immediately after mark and returns e.
+// If mark is not an element of l, the list is not modified.
+// The mark must not be nil.
+func (l *List[T]) InsertAfter(v T, mark *Element[T]) *Element[T] {
+	if mark.list != l {
+		return nil
+	}
+	// see comment in List.Remove about initialization of l
+	return l.insertValue(v, mark)
+}
+
+// MoveToFront moves element e to the front of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *List[T]) MoveToFront(e *Element[T]) {
+	if e.list != l || l.root.next == e {
+		return
+	}
+	// see comment in List.Remove about initialization of l
+	l.move(e, &l.root)
+}
+
+// MoveToBack moves element e to the back of list l.
+// If e is not an element of l, the list is not modified.
+// The element must not be nil.
+func (l *List[T]) MoveToBack(e *Element[T]) {
+	if e.list != l || l.root.prev == e {
+		return
+	}
+	// see comment in List.Remove about initialization of l
+	l.move(e, l.root.prev)
+}
+
+// MoveBefore moves element e to its new position before mark.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
+// The element and mark must not be nil.
+func (l *List[T]) MoveBefore(e, mark *Element[T]) {
+	if e.list != l || e == mark || mark.list != l {
+		return
+	}
+	l.move(e, mark.prev)
+}
+
+// MoveAfter moves element e to its new position after mark.
+// If e or mark is not an element of l, or e == mark, the list is not modified.
+// The element and mark must not be nil.
+func (l *List[T]) MoveAfter(e, mark *Element[T]) {
+	if e.list != l || e == mark || mark.list != l {
+		return
+	}
+	l.move(e, mark)
+}
+
+// PushBackList inserts a copy of another list at the back of list l.
+// The lists l and other may be the same. They must not be nil.
+func (l *List[T]) PushBackList(other *List[T]) {
+	l.lazyInit()
+	for i, e := other.Len(), other.Front(); i > 0; i, e = i-1, e.Next() {
+		l.insertValue(e.Value, l.root.prev)
+	}
+}
+
+// PushFrontList inserts a copy of another list at the front of list l.
+// The lists l and other may be the same. They must not be nil.
+func (l *List[T]) PushFrontList(other *List[T]) {
+	l.lazyInit()
+	for i, e := other.Len(), other.Back(); i > 0; i, e = i-1, e.Prev() {
+		l.insertValue(e.Value, &l.root)
+	}
+}

common/observable/iterable.go

@@ -1,3 +1,3 @@
 package observable
 
-type Iterable <-chan any
+type Iterable[T any] <-chan T

common/observable/observable.go

@@ -5,14 +5,14 @@ import (
 	"sync"
 )
 
-type Observable struct {
-	iterable Iterable
-	listener map[Subscription]*Subscriber
+type Observable[T any] struct {
+	iterable Iterable[T]
+	listener map[Subscription[T]]*Subscriber[T]
 	mux      sync.Mutex
 	done     bool
 }
 
-func (o *Observable) process() {
+func (o *Observable[T]) process() {
 	for item := range o.iterable {
 		o.mux.Lock()
 		for _, sub := range o.listener {
@@ -23,7 +23,7 @@ func (o *Observable) process() {
 	o.close()
 }
 
-func (o *Observable) close() {
+func (o *Observable[T]) close() {
 	o.mux.Lock()
 	defer o.mux.Unlock()
 
@@ -33,18 +33,18 @@ func (o *Observable) close() {
 	}
 }
 
-func (o *Observable) Subscribe() (Subscription, error) {
+func (o *Observable[T]) Subscribe() (Subscription[T], error) {
 	o.mux.Lock()
 	defer o.mux.Unlock()
 	if o.done {
-		return nil, errors.New("Observable is closed")
+		return nil, errors.New("observable is closed")
 	}
-	subscriber := newSubscriber()
+	subscriber := newSubscriber[T]()
 	o.listener[subscriber.Out()] = subscriber
 	return subscriber.Out(), nil
 }
 
-func (o *Observable) UnSubscribe(sub Subscription) {
+func (o *Observable[T]) UnSubscribe(sub Subscription[T]) {
 	o.mux.Lock()
 	defer o.mux.Unlock()
 	subscriber, exist := o.listener[sub]
@@ -55,10 +55,10 @@ func (o *Observable) UnSubscribe(sub Subscription) {
 	subscriber.Close()
 }
 
-func NewObservable(any Iterable) *Observable {
-	observable := &Observable{
-		iterable: any,
-		listener: map[Subscription]*Subscriber{},
+func NewObservable[T any](iter Iterable[T]) *Observable[T] {
+	observable := &Observable[T]{
+		iterable: iter,
+		listener: map[Subscription[T]]*Subscriber[T]{},
 	}
 	go observable.process()
 	return observable

common/observable/observable_test.go

@@ -9,8 +9,8 @@ import (
 	"go.uber.org/atomic"
 )
 
-func iterator(item []any) chan any {
-	ch := make(chan any)
+func iterator[T any](item []T) chan T {
+	ch := make(chan T)
 	go func() {
 		time.Sleep(100 * time.Millisecond)
 		for _, elm := range item {
@@ -22,8 +22,8 @@ func iterator(item []any) chan any {
 }
 
 func TestObservable(t *testing.T) {
-	iter := iterator([]any{1, 2, 3, 4, 5})
-	src := NewObservable(iter)
+	iter := iterator[int]([]int{1, 2, 3, 4, 5})
+	src := NewObservable[int](iter)
 	data, err := src.Subscribe()
 	assert.Nil(t, err)
 	count := 0
@@ -34,15 +34,15 @@ func TestObservable(t *testing.T) {
 }
 
 func TestObservable_MultiSubscribe(t *testing.T) {
-	iter := iterator([]any{1, 2, 3, 4, 5})
-	src := NewObservable(iter)
+	iter := iterator[int]([]int{1, 2, 3, 4, 5})
+	src := NewObservable[int](iter)
 	ch1, _ := src.Subscribe()
 	ch2, _ := src.Subscribe()
 	count := atomic.NewInt32(0)
 
 	var wg sync.WaitGroup
 	wg.Add(2)
-	waitCh := func(ch <-chan any) {
+	waitCh := func(ch <-chan int) {
 		for range ch {
 			count.Inc()
 		}
@@ -55,8 +55,8 @@ func TestObservable_MultiSubscribe(t *testing.T) {
 }
 
 func TestObservable_UnSubscribe(t *testing.T) {
-	iter := iterator([]any{1, 2, 3, 4, 5})
-	src := NewObservable(iter)
+	iter := iterator[int]([]int{1, 2, 3, 4, 5})
+	src := NewObservable[int](iter)
 	data, err := src.Subscribe()
 	assert.Nil(t, err)
 	src.UnSubscribe(data)
@@ -65,8 +65,8 @@ func TestObservable_UnSubscribe(t *testing.T) {
 }
 
 func TestObservable_SubscribeClosedSource(t *testing.T) {
-	iter := iterator([]any{1})
-	src := NewObservable(iter)
+	iter := iterator[int]([]int{1})
+	src := NewObservable[int](iter)
 	data, _ := src.Subscribe()
 	<-data
 
@@ -75,18 +75,18 @@ func TestObservable_SubscribeClosedSource(t *testing.T) {
 }
 
 func TestObservable_UnSubscribeWithNotExistSubscription(t *testing.T) {
-	sub := Subscription(make(chan any))
-	iter := iterator([]any{1})
-	src := NewObservable(iter)
+	sub := Subscription[int](make(chan int))
+	iter := iterator[int]([]int{1})
+	src := NewObservable[int](iter)
 	src.UnSubscribe(sub)
 }
 
 func TestObservable_SubscribeGoroutineLeak(t *testing.T) {
-	iter := iterator([]any{1, 2, 3, 4, 5})
-	src := NewObservable(iter)
+	iter := iterator[int]([]int{1, 2, 3, 4, 5})
+	src := NewObservable[int](iter)
 	max := 100
 
-	var list []Subscription
+	var list []Subscription[int]
 	for i := 0; i < max; i++ {
 		ch, _ := src.Subscribe()
 		list = append(list, ch)
@@ -94,7 +94,7 @@ func TestObservable_SubscribeGoroutineLeak(t *testing.T) {
 
 	var wg sync.WaitGroup
 	wg.Add(max)
-	waitCh := func(ch <-chan any) {
+	waitCh := func(ch <-chan int) {
 		for range ch {
 		}
 		wg.Done()
@@ -115,11 +115,11 @@ func TestObservable_SubscribeGoroutineLeak(t *testing.T) {
 }
 
 func Benchmark_Observable_1000(b *testing.B) {
-	ch := make(chan any)
-	o := NewObservable(ch)
+	ch := make(chan int)
+	o := NewObservable[int](ch)
 	num := 1000
 
-	subs := []Subscription{}
+	subs := []Subscription[int]{}
 	for i := 0; i < num; i++ {
 		sub, _ := o.Subscribe()
 		subs = append(subs, sub)
@@ -130,7 +130,7 @@ func Benchmark_Observable_1000(b *testing.B) {
 
 	b.ResetTimer()
 	for _, sub := range subs {
-		go func(s Subscription) {
+		go func(s Subscription[int]) {
 			for range s {
 			}
 			wg.Done()

common/observable/subscriber.go

@@ -4,30 +4,30 @@ import (
 	"sync"
 )
 
-type Subscription <-chan any
+type Subscription[T any] <-chan T
 
-type Subscriber struct {
-	buffer chan any
+type Subscriber[T any] struct {
+	buffer chan T
 	once   sync.Once
 }
 
-func (s *Subscriber) Emit(item any) {
+func (s *Subscriber[T]) Emit(item T) {
 	s.buffer <- item
 }
 
-func (s *Subscriber) Out() Subscription {
+func (s *Subscriber[T]) Out() Subscription[T] {
 	return s.buffer
 }
 
-func (s *Subscriber) Close() {
+func (s *Subscriber[T]) Close() {
 	s.once.Do(func() {
 		close(s.buffer)
 	})
 }
 
-func newSubscriber() *Subscriber {
-	sub := &Subscriber{
-		buffer: make(chan any, 200),
+func newSubscriber[T any]() *Subscriber[T] {
+	sub := &Subscriber[T]{
+		buffer: make(chan T, 200),
 	}
 	return sub
 }

common/picker/picker.go

@@ -9,7 +9,7 @@ import (
 // Picker provides synchronization, and Context cancelation
 // for groups of goroutines working on subtasks of a common task.
 // Inspired by errGroup
-type Picker struct {
+type Picker[T any] struct {
 	ctx    context.Context
 	cancel func()
 
@@ -17,12 +17,12 @@ type Picker struct {
 
 	once    sync.Once
 	errOnce sync.Once
-	result  any
+	result  T
 	err     error
 }
 
-func newPicker(ctx context.Context, cancel func()) *Picker {
-	return &Picker{
+func newPicker[T any](ctx context.Context, cancel func()) *Picker[T] {
+	return &Picker[T]{
 		ctx:    ctx,
 		cancel: cancel,
 	}
@@ -30,20 +30,20 @@ func newPicker(ctx context.Context, cancel func()) *Picker {
 
 // WithContext returns a new Picker and an associated Context derived from ctx.
 // and cancel when first element return.
-func WithContext(ctx context.Context) (*Picker, context.Context) {
+func WithContext[T any](ctx context.Context) (*Picker[T], context.Context) {
 	ctx, cancel := context.WithCancel(ctx)
-	return newPicker(ctx, cancel), ctx
+	return newPicker[T](ctx, cancel), ctx
 }
 
 // WithTimeout returns a new Picker and an associated Context derived from ctx with timeout.
-func WithTimeout(ctx context.Context, timeout time.Duration) (*Picker, context.Context) {
+func WithTimeout[T any](ctx context.Context, timeout time.Duration) (*Picker[T], context.Context) {
 	ctx, cancel := context.WithTimeout(ctx, timeout)
-	return newPicker(ctx, cancel), ctx
+	return newPicker[T](ctx, cancel), ctx
 }
 
 // Wait blocks until all function calls from the Go method have returned,
 // then returns the first nil error result (if any) from them.
-func (p *Picker) Wait() any {
+func (p *Picker[T]) Wait() T {
 	p.wg.Wait()
 	if p.cancel != nil {
 		p.cancel()
@@ -52,13 +52,13 @@ func (p *Picker) Wait() any {
 }
 
 // Error return the first error (if all success return nil)
-func (p *Picker) Error() error {
+func (p *Picker[T]) Error() error {
 	return p.err
 }
 
 // Go calls the given function in a new goroutine.
 // The first call to return a nil error cancels the group; its result will be returned by Wait.
-func (p *Picker) Go(f func() (any, error)) {
+func (p *Picker[T]) Go(f func() (T, error)) {
 	p.wg.Add(1)
 
 	go func() {

common/picker/picker_test.go

@@ -8,33 +8,38 @@ import (
 	"github.com/stretchr/testify/assert"
 )
 
-func sleepAndSend(ctx context.Context, delay int, input any) func() (any, error) {
-	return func() (any, error) {
+func sleepAndSend[T any](ctx context.Context, delay int, input T) func() (T, error) {
+	return func() (T, error) {
 		timer := time.NewTimer(time.Millisecond * time.Duration(delay))
 		select {
 		case <-timer.C:
 			return input, nil
 		case <-ctx.Done():
-			return nil, ctx.Err()
+			return getZero[T](), ctx.Err()
 		}
 	}
 }
 
 func TestPicker_Basic(t *testing.T) {
-	picker, ctx := WithContext(context.Background())
+	picker, ctx := WithContext[int](context.Background())
 	picker.Go(sleepAndSend(ctx, 30, 2))
 	picker.Go(sleepAndSend(ctx, 20, 1))
 
 	number := picker.Wait()
 	assert.NotNil(t, number)
-	assert.Equal(t, number.(int), 1)
+	assert.Equal(t, number, 1)
 }
 
 func TestPicker_Timeout(t *testing.T) {
-	picker, ctx := WithTimeout(context.Background(), time.Millisecond*5)
+	picker, ctx := WithTimeout[int](context.Background(), time.Millisecond*5)
 	picker.Go(sleepAndSend(ctx, 20, 1))
 
 	number := picker.Wait()
-	assert.Nil(t, number)
+	assert.Equal(t, number, getZero[int]())
 	assert.NotNil(t, picker.Error())
 }
+
+func getZero[T any]() T {
+	var result T
+	return result
+}

common/singledo/singledo.go

@@ -5,28 +5,28 @@ import (
 	"time"
 )
 
-type call struct {
+type call[T any] struct {
 	wg  sync.WaitGroup
-	val any
+	val T
 	err error
 }
 
-type Single struct {
+type Single[T any] struct {
 	mux    sync.Mutex
 	last   time.Time
 	wait   time.Duration
-	call   *call
-	result *Result
+	call   *call[T]
+	result *Result[T]
 }
 
-type Result struct {
-	Val any
+type Result[T any] struct {
+	Val T
 	Err error
 }
 
 // Do single.Do likes sync.singleFlight
 //lint:ignore ST1008 it likes sync.singleFlight
-func (s *Single) Do(fn func() (any, error)) (v any, err error, shared bool) {
+func (s *Single[T]) Do(fn func() (T, error)) (v T, err error, shared bool) {
 	s.mux.Lock()
 	now := time.Now()
 	if now.Before(s.last.Add(s.wait)) {
@@ -34,31 +34,31 @@ func (s *Single) Do(fn func() (any, error)) (v any, err error, shared bool) {
 		return s.result.Val, s.result.Err, true
 	}
 
-	if call := s.call; call != nil {
+	if callM := s.call; callM != nil {
 		s.mux.Unlock()
-		call.wg.Wait()
-		return call.val, call.err, true
+		callM.wg.Wait()
+		return callM.val, callM.err, true
 	}
 
-	call := &call{}
-	call.wg.Add(1)
-	s.call = call
+	callM := &call[T]{}
+	callM.wg.Add(1)
+	s.call = callM
 	s.mux.Unlock()
-	call.val, call.err = fn()
-	call.wg.Done()
+	callM.val, callM.err = fn()
+	callM.wg.Done()
 
 	s.mux.Lock()
 	s.call = nil
-	s.result = &Result{call.val, call.err}
+	s.result = &Result[T]{callM.val, callM.err}
 	s.last = now
 	s.mux.Unlock()
-	return call.val, call.err, false
+	return callM.val, callM.err, false
 }
 
-func (s *Single) Reset() {
+func (s *Single[T]) Reset() {
 	s.last = time.Time{}
 }
 
-func NewSingle(wait time.Duration) *Single {
-	return &Single{wait: wait}
+func NewSingle[T any](wait time.Duration) *Single[T] {
+	return &Single[T]{wait: wait}
 }

common/singledo/singledo_test.go

@@ -10,13 +10,13 @@ import (
 )
 
 func TestBasic(t *testing.T) {
-	single := NewSingle(time.Millisecond * 30)
+	single := NewSingle[int](time.Millisecond * 30)
 	foo := 0
 	shardCount := atomic.NewInt32(0)
-	call := func() (any, error) {
+	call := func() (int, error) {
 		foo++
 		time.Sleep(time.Millisecond * 5)
-		return nil, nil
+		return 0, nil
 	}
 
 	var wg sync.WaitGroup
@@ -38,32 +38,32 @@ func TestBasic(t *testing.T) {
 }
 
 func TestTimer(t *testing.T) {
-	single := NewSingle(time.Millisecond * 30)
+	single := NewSingle[int](time.Millisecond * 30)
 	foo := 0
-	call := func() (any, error) {
+	callM := func() (int, error) {
 		foo++
-		return nil, nil
+		return 0, nil
 	}
 
-	single.Do(call)
+	_, _, _ = single.Do(callM)
 	time.Sleep(10 * time.Millisecond)
-	_, _, shard := single.Do(call)
+	_, _, shard := single.Do(callM)
 
 	assert.Equal(t, 1, foo)
 	assert.True(t, shard)
 }
 
 func TestReset(t *testing.T) {
-	single := NewSingle(time.Millisecond * 30)
+	single := NewSingle[int](time.Millisecond * 30)
 	foo := 0
-	call := func() (any, error) {
+	callM := func() (int, error) {
 		foo++
-		return nil, nil
+		return 0, nil
 	}
 
-	single.Do(call)
+	_, _, _ = single.Do(callM)
 	single.Reset()
-	single.Do(call)
+	_, _, _ = single.Do(callM)
 
 	assert.Equal(t, 2, foo)
 }