Test Comparable interface

common/cache/lrucache.go

@@ -6,6 +6,7 @@ import (
 	"sync"
 	"time"
 
+	"github.com/sagernet/sing/common"
 	"github.com/sagernet/sing/common/x/list"
 )
 
@@ -69,8 +70,7 @@ func New[K comparable, V any](options ...Option[K, V]) *LruCache[K, V] {
 func (c *LruCache[K, V]) Load(key K) (V, bool) {
 	entry := c.get(key)
 	if entry == nil {
-		var defaultValue V
-		return defaultValue, false
+		return common.DefaultValue[V](), false
 	}
 	value := entry.value
 
@@ -154,8 +154,7 @@ create:
 func (c *LruCache[K, V]) LoadWithExpire(key K) (V, time.Time, bool) {
 	entry := c.get(key)
 	if entry == nil {
-		var defaultValue V
-		return defaultValue, time.Time{}, false
+		return common.DefaultValue[V](), time.Time{}, false
 	}
 
 	return entry.value, time.Unix(entry.expires, 0), true

common/comparable.go

@@ -0,0 +1,40 @@
+package common
+
+type Comparable[T any] interface {
+	Equals(other T) bool
+}
+
+func Equals[T Comparable[T]](obj T, other T) bool {
+	var anyObj any = obj
+	var anyOther any = other
+	if anyObj == nil && anyOther == nil {
+		return true
+	} else if anyObj == nil || anyOther == nil {
+		return false
+	}
+	return obj.Equals(other)
+}
+
+func IsEmptyByEquals[T Comparable[T]](obj T) bool {
+	return obj.Equals(DefaultValue[T]())
+}
+
+func ComparablePtrEquals[T comparable](obj *T, other *T) bool {
+	return *obj == *other
+}
+
+func PtrEquals[T Comparable[T]](obj *T, other *T) bool {
+	return Equals(*obj, *other)
+}
+
+func ComparableSliceEquals[T comparable](arr []T, otherArr []T) bool {
+	return len(arr) == len(otherArr) && AllIndexed(arr, func(index int, it T) bool {
+		return it == otherArr[index]
+	})
+}
+
+func SliceEquals[T Comparable[T]](arr []T, otherArr []T) bool {
+	return len(arr) == len(otherArr) && AllIndexed(arr, func(index int, it T) bool {
+		return Equals(it, otherArr[index])
+	})
+}

common/cond.go

@@ -16,6 +16,15 @@ func Any[T any](array []T, block func(it T) bool) bool {
 	return false
 }
 
+func AnyIndexed[T any](array []T, block func(index int, it T) bool) bool {
+	for i, it := range array {
+		if block(i, it) {
+			return true
+		}
+	}
+	return false
+}
+
 func All[T any](array []T, block func(it T) bool) bool {
 	for _, it := range array {
 		if !block(it) {
@@ -25,6 +34,15 @@ func All[T any](array []T, block func(it T) bool) bool {
 	return true
 }
 
+func AllIndexed[T any](array []T, block func(index int, it T) bool) bool {
+	for i, it := range array {
+		if !block(i, it) {
+			return false
+		}
+	}
+	return true
+}
+
 func Contains[T comparable](arr []T, target T) bool {
 	for i := range arr {
 		if target == arr[i] {
@@ -66,8 +84,7 @@ func Find[T any](arr []T, block func(it T) bool) T {
 			return it
 		}
 	}
-	var defaultValue T
-	return defaultValue
+	return DefaultValue[T]()
 }
 
 //go:norace
@@ -164,15 +181,18 @@ func PtrOrNil[T any](ptr *T) any {
 
 func PtrValueOrDefault[T any](ptr *T) T {
 	if ptr == nil {
-		var defaultValue T
-		return defaultValue
+		return DefaultValue[T]()
 	}
 	return *ptr
 }
 
 func IsEmpty[T comparable](obj T) bool {
+	return obj == DefaultValue[T]()
+}
+
+func DefaultValue[T any]() T {
 	var defaultValue T
-	return obj == defaultValue
+	return defaultValue
 }
 
 func Close(closers ...any) error {

common/upstream.go

@@ -11,6 +11,5 @@ func Cast[T any](obj any) (T, bool) {
 	if u, ok := obj.(WithUpstream); ok {
 		return Cast[T](u.Upstream())
 	}
-	var defaultValue T
-	return defaultValue, false
+	return DefaultValue[T](), false
 }

common/x/list/cond.go

@@ -1,13 +1,18 @@
 package list
 
+import "github.com/sagernet/sing/common"
+
+func (l List[T]) Size() int {
+	return l.len
+}
+
 func (l List[T]) IsEmpty() bool {
 	return l.len == 0
 }
 
 func (l *List[T]) PopBack() T {
 	if l.len == 0 {
-		var defaultValue T
-		return defaultValue
+		return common.DefaultValue[T]()
 	}
 	entry := l.root.prev
 	l.remove(entry)
@@ -16,8 +21,7 @@ func (l *List[T]) PopBack() T {
 
 func (l *List[T]) PopFront() T {
 	if l.len == 0 {
-		var defaultValue T
-		return defaultValue
+		return common.DefaultValue[T]()
 	}
 	entry := l.root.next
 	l.remove(entry)

common/x/list/list.go

@@ -130,7 +130,7 @@ func (l *List[T]) move(e, at *Element[T]) {
 // 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]) any {
+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