doc: adding go playground examples

README.md

@@ -392,6 +392,8 @@ lop.Map([]int64{1, 2, 3, 4}, func(x int64, _ int) string {
 // []string{"1", "2", "3", "4"}
 ```
 
+[[play](https://go.dev/play/p/sCJaB3quRMC)]
+
 Mutable: like `lo.Map()`, but the slice is updated in place.
 
 ```go
@@ -404,6 +406,8 @@ lom.Map(list, func(x int) int {
 // []int{2, 4, 6, 8}
 ```
 
+[[play](https://go.dev/play/p/0jY3Z0B7O_5)]
+
 ### UniqMap
 
 Manipulates a slice and transforms it to a slice of another type with unique values.
@@ -421,6 +425,8 @@ names := lo.UniqMap(users, func(u User, index int) string {
 // []string{"Alex", "Bob", "Alice"}
 ```
 
+[[play](https://go.dev/play/p/fygzLBhvUdB)]
+
 ### FilterMap
 
 Returns a slice which obtained after both filtering and mapping using the given callback function.
@@ -616,6 +622,8 @@ groups := lo.GroupByMap([]int{0, 1, 2, 3, 4, 5}, func(i int) (int, int) {
 // map[int][]int{0: []int{0, 6}, 1: []int{2, 8}, 2: []int{4, 10}}
 ```
 
+[[play](https://go.dev/play/p/iMeruQ3_W80)]
+
 ### Chunk
 
 Returns an array of elements split into groups the length of size. If array can't be split evenly, the final chunk will be the remaining elements.
@@ -634,7 +642,7 @@ lo.Chunk([]int{0}, 2)
 // [][]int{{0}}
 ```
 
-[[play](https://go.dev/play/p/EeKl0AuTehH)]
+[[play](https://go.dev/play/p/kEMkFbdu85g)]
 
 ### PartitionBy
 
@@ -853,6 +861,8 @@ result := lo.FilterSliceToMap(list, func(str string) (string, int, bool) {
 // map[string][int]{"aa":2 "aaa":3}
 ```
 
+[[play](https://go.dev/play/p/2z0rDz2ZSGU)]
+
 ### Keyify
 
 Returns a map with each unique element of the slice as a key.
@@ -862,6 +872,8 @@ set := lo.Keyify([]int{1, 1, 2, 3, 4})
 // map[int]struct{}{1:{}, 2:{}, 3:{}, 4:{}}
 ```
 
+[[play](https://go.dev/play/p/RYhhM_csqIG)]
+
 ### Drop
 
 Drops n elements from the beginning of a slice or array.
@@ -1360,7 +1372,7 @@ entries := lo.Entries(map[string]int{"foo": 1, "bar": 2})
 // }
 ```
 
-[[play](https://go.dev/play/p/3Dhgx46gawJ)]
+[[play](https://go.dev/play/p/_t4Xe34-Nl5)]
 
 ### FromEntries (alias: FromPairs)
 
@@ -1678,6 +1690,8 @@ mean := lo.MeanBy([]float64{}, mapper)
 // 0
 ```
 
+[[play](https://go.dev/play/p/j7TsVwBOZ7P)]
+
 
 ### Mode
 
@@ -1773,7 +1787,7 @@ str := lo.PascalCase("hello_world")
 // HelloWorld
 ```
 
-[[play](https://go.dev/play/p/iZkdeLP9oiB)]
+[[play](https://go.dev/play/p/Dy_V_6DUYhe)]
 
 ### CamelCase
 
@@ -1784,7 +1798,7 @@ str := lo.CamelCase("hello_world")
 // helloWorld
 ```
 
-[[play](https://go.dev/play/p/dtyFB58MBRp)]
+[[play](https://go.dev/play/p/Go6aKwUiq59)]
 
 ### KebabCase
 
@@ -1795,7 +1809,7 @@ str := lo.KebabCase("helloWorld")
 // hello-world
 ```
 
-[[play](https://go.dev/play/p/2YTuPafwECA)]
+[[play](https://go.dev/play/p/96gT_WZnTVP)]
 
 ### SnakeCase
 
@@ -1806,7 +1820,7 @@ str := lo.SnakeCase("HelloWorld")
 // hello_world
 ```
 
-[[play](https://go.dev/play/p/QVKJG9nOnDg)]
+[[play](https://go.dev/play/p/ziB0V89IeVH)]
 
 ### Words
 
@@ -1817,7 +1831,7 @@ str := lo.Words("helloWorld")
 // []string{"hello", "world"}
 ```
 
-[[play](https://go.dev/play/p/2P4zhqqq61g)]
+[[play](https://go.dev/play/p/-f3VIQqiaVw)]
 
 ### Capitalize
 
@@ -1828,6 +1842,8 @@ str := lo.Capitalize("heLLO")
 // Hello
 ```
 
+[[play](https://go.dev/play/p/uLTZZQXqnsa)]
+
 ### Ellipsis
 
 Trims and truncates a string to a specified length in `bytes` and appends an ellipsis if truncated. If the string contains non-ASCII characters (which may occupy multiple bytes in UTF-8), truncating by byte length may split a character in the middle, potentially resulting in garbled output.
@@ -1843,6 +1859,8 @@ str := lo.Ellipsis("Lorem Ipsum", 3)
 // ...
 ```
 
+[[play](https://go.dev/play/p/qE93rgqe1TW)]
+
 ### T2 -> T9
 
 Creates a tuple from a list of values.
@@ -1968,6 +1986,8 @@ duration := lo.Duration(func() {
 // 3s
 ```
 
+[[play](https://go.dev/play/p/HQfbBbAXaFP)]
+
 ### Duration0 -> Duration10
 
 Returns the time taken to execute a function.
@@ -2028,6 +2048,8 @@ for i := range children {
 }
 ```
 
+[[play](https://go.dev/play/p/UZGu2wVg3J2)]
+
 Many distributions strategies are available:
 
 - [lo.DispatchingStrategyRoundRobin](./channel.go): Distributes messages in a rotating sequential manner.
@@ -2088,6 +2110,8 @@ for v := range lo.SliceToChannel(2, list) {
 // prints 1, then 2, then 3, then 4, then 5
 ```
 
+[[play](https://go.dev/play/p/lIbSY3QmiEg)]
+
 ### ChannelToSlice
 
 Returns a slice built from channels items. Blocks until channel closes.
@@ -2274,6 +2298,8 @@ present := lo.Contains([]int{0, 1, 2, 3, 4, 5}, 5)
 // true
 ```
 
+[[play](https://go.dev/play/p/W1EvyqY6t9j)]
+
 ### ContainsBy
 
 Returns true if the predicate function returns `true`.
@@ -2308,6 +2334,8 @@ b := EveryBy([]int{1, 2, 3, 4}, func(x int) bool {
 // true
 ```
 
+[[play](https://go.dev/play/p/dn1-vhHsq9x)]
+
 ### Some
 
 Returns true if at least 1 element of a subset is contained into a collection.
@@ -2316,6 +2344,9 @@ If the subset is empty Some returns false.
 ```go
 ok := lo.Some([]int{0, 1, 2, 3, 4, 5}, []int{0, 6})
 // true
+```
+
+[[play](https://go.dev/play/p/Lj4ceFkeT9V)]
 
 ok := lo.Some([]int{0, 1, 2, 3, 4, 5}, []int{-1, 6})
 // false
@@ -2344,6 +2375,8 @@ b := None([]int{0, 1, 2, 3, 4, 5}, []int{-1, 6})
 // true
 ```
 
+[[play](https://go.dev/play/p/fye7JsmxzPV)]
+
 ### NoneBy
 
 Returns true if the predicate returns true for none of the elements in the collection or if the collection is empty.
@@ -2355,6 +2388,8 @@ b := NoneBy([]int{1, 2, 3, 4}, func(x int) bool {
 // true
 ```
 
+[[play](https://go.dev/play/p/O64WZ32H58S)]
+
 ### Intersect
 
 Returns the intersection between two collections.
@@ -2385,6 +2420,8 @@ left, right := lo.Difference([]int{0, 1, 2, 3, 4, 5}, []int{0, 1, 2, 3, 4, 5})
 // []int{}, []int{}
 ```
 
+[[play](https://go.dev/play/p/pKE-JgzqRpz)]
+
 ### Union
 
 Returns all distinct elements from given collections. Result will not change the order of elements relatively.
@@ -2499,6 +2536,8 @@ notFound := lo.IndexOf([]int{0, 1, 2, 1, 2, 3}, 6)
 // -1
 ```
 
+[[play](https://go.dev/play/p/Eo7W0lvKTky)]
+
 ### LastIndexOf
 
 Returns the index at which the last occurrence of a value is found in an array or return -1 if the value cannot be found.
@@ -2527,6 +2566,8 @@ str, ok := lo.Find([]string{"foobar"}, func(i string) bool {
 // "", false
 ```
 
+[[play](https://go.dev/play/p/Eo7W0lvKTky)]
+
 ### FindIndexOf
 
 FindIndexOf searches an element in a slice based on a predicate and returns the index and true. It returns -1 and false if the element is not found.
@@ -2543,6 +2584,8 @@ str, index, ok := lo.FindIndexOf([]string{"foobar"}, func(i string) bool {
 // "", -1, false
 ```
 
+[[play](https://go.dev/play/p/XWSEM4Ic_t0)]
+
 ### FindLastIndexOf
 
 FindLastIndexOf searches an element in a slice based on a predicate and returns the index and true. It returns -1 and false if the element is not found.
@@ -2559,6 +2602,8 @@ str, index, ok := lo.FindLastIndexOf([]string{"foobar"}, func(i string) bool {
 // "", -1, false
 ```
 
+[[play](https://go.dev/play/p/dPiMRtJ6cUx)]
+
 ### FindOrElse
 
 Search an element in a slice based on a predicate. It returns the element if found or a given fallback value otherwise.
@@ -2666,6 +2711,8 @@ min := lo.Min([]time.Duration{time.Second, time.Hour})
 // 1s
 ```
 
+[[play](https://go.dev/play/p/r6e-Z8JozS8)]
+
 ### MinIndex
 
 Search the minimum value of a collection and the index of the minimum value.
@@ -2985,6 +3032,8 @@ lo.Sample([]string{})
 // ""
 ```
 
+[[play](https://go.dev/play/p/FYA45LcpfM2)]
+
 
 
 ### SampleBy
@@ -3215,6 +3264,8 @@ ptr := lo.ToPtr("hello world")
 // *string{"hello world"}
 ```
 
+[[play](https://go.dev/play/p/P2sD0PMXw4F)]
+
 ### Nil
 
 Returns a nil pointer of type.
@@ -3503,6 +3554,8 @@ f(42)
 // 47
 ```
 
+[[play](https://go.dev/play/p/Sy1gAQiQZ3v)]
+
 ### Partial2 -> Partial5
 
 Returns new function that, when called, has its first argument set to the provided value.
@@ -3518,6 +3571,8 @@ f(42, -4)
 // 80
 ```
 
+[[play](https://go.dev/play/p/-xiPjy4JChJ)]
+
 ### Attempt
 
 Invokes a function N times until it returns valid output. Returns either the caught error or nil.
@@ -3606,7 +3661,7 @@ count1, err1 := lo.AttemptWhile(5, func(i int) (error, bool) {
 
 For more advanced retry strategies (delay, exponential backoff...), please take a look on [cenkalti/backoff](https://github.com/cenkalti/backoff).
 
-[[play](https://go.dev/play/p/M2wVq24PaZM)]
+[[play](https://go.dev/play/p/1VS7HxlYMOG)]
 
 ### AttemptWhileWithDelay
 
@@ -3631,7 +3686,7 @@ count1, time1, err1 := lo.AttemptWhileWithDelay(5, time.Millisecond, func(i int,
 
 For more advanced retry strategies (delay, exponential backoff...), please take a look on [cenkalti/backoff](https://github.com/cenkalti/backoff).
 
-[[play](https://go.dev/play/p/cfcmhvLO-nv)]
+[[play](https://go.dev/play/p/mhufUjJfLEF)]
 
 ### Debounce
 
@@ -3876,6 +3931,8 @@ iterations, duration, ok := lo.WaitFor(laterTrue, 10*time.Millisecond, 5*time.Mi
 // false
 ```
 
+[[play](https://go.dev/play/p/t_wTDmubbK3)]
+
 ### WaitForWithContext
 
 Runs periodically until a condition is validated or context is invalid.
@@ -3918,6 +3975,8 @@ iterations, duration, ok := lo.WaitForWithContext(expiringCtx, alwaysFalse, 100*
 // false
 ```
 
+[[play](https://go.dev/play/p/t_wTDmubbK3)]
+
 ### Validate
 
 Helper function that creates an error when a condition is not met.

channel.go

@@ -14,6 +14,7 @@ type DispatchingStrategy[T any] func(msg T, index uint64, channels []<-chan T) i
 // ChannelDispatcher distributes messages from input channels into N child channels.
 // Close events are propagated to children.
 // Underlying channels can have a fixed buffer capacity or be unbuffered when cap is 0.
+// Play: https://go.dev/play/p/UZGu2wVg3J2
 func ChannelDispatcher[T any](stream <-chan T, count int, channelBufferCap int, strategy DispatchingStrategy[T]) []<-chan T {
 	children := createChannels[T](count, channelBufferCap)
 
@@ -73,6 +74,7 @@ func channelIsNotFull[T any](ch <-chan T) bool {
 
 // DispatchingStrategyRoundRobin distributes messages in a rotating sequential manner.
 // If the channel capacity is exceeded, the next channel will be selected and so on.
+// Play: https://go.dev/play/p/UZGu2wVg3J2
 func DispatchingStrategyRoundRobin[T any](msg T, index uint64, channels []<-chan T) int {
 	for {
 		i := int(index % uint64(len(channels)))
@@ -87,6 +89,7 @@ func DispatchingStrategyRoundRobin[T any](msg T, index uint64, channels []<-chan
 
 // DispatchingStrategyRandom distributes messages in a random manner.
 // If the channel capacity is exceeded, another random channel will be selected and so on.
+// Play: https://go.dev/play/p/GEyGn3TdGk4
 func DispatchingStrategyRandom[T any](msg T, index uint64, channels []<-chan T) int {
 	for {
 		i := rand.IntN(len(channels))
@@ -100,6 +103,7 @@ func DispatchingStrategyRandom[T any](msg T, index uint64, channels []<-chan T)
 
 // DispatchingStrategyWeightedRandom distributes messages in a weighted manner.
 // If the channel capacity is exceeded, another random channel will be selected and so on.
+// Play: https://go.dev/play/p/v0eMh8NZG2L
 func DispatchingStrategyWeightedRandom[T any](weights []int) DispatchingStrategy[T] {
 	seq := []int{}
 
@@ -123,6 +127,7 @@ func DispatchingStrategyWeightedRandom[T any](weights []int) DispatchingStrategy
 
 // DispatchingStrategyFirst distributes messages in the first non-full channel.
 // If the capacity of the first channel is exceeded, the second channel will be selected and so on.
+// Play: https://go.dev/play/p/OrJCvOmk42f
 func DispatchingStrategyFirst[T any](msg T, index uint64, channels []<-chan T) int {
 	for {
 		for i := range channels {
@@ -136,6 +141,7 @@ func DispatchingStrategyFirst[T any](msg T, index uint64, channels []<-chan T) i
 }
 
 // DispatchingStrategyLeast distributes messages in the emptiest channel.
+// Play: https://go.dev/play/p/ypy0jrRcEe7
 func DispatchingStrategyLeast[T any](msg T, index uint64, channels []<-chan T) int {
 	seq := Range(len(channels))
 
@@ -146,6 +152,7 @@ func DispatchingStrategyLeast[T any](msg T, index uint64, channels []<-chan T) i
 
 // DispatchingStrategyMost distributes messages in the fullest channel.
 // If the channel capacity is exceeded, the next channel will be selected and so on.
+// Play: https://go.dev/play/p/erHHone7rF9
 func DispatchingStrategyMost[T any](msg T, index uint64, channels []<-chan T) int {
 	seq := Range(len(channels))
 
@@ -155,6 +162,7 @@ func DispatchingStrategyMost[T any](msg T, index uint64, channels []<-chan T) in
 }
 
 // SliceToChannel returns a read-only channels of collection elements.
+// Play: https://go.dev/play/p/lIbSY3QmiEg
 func SliceToChannel[T any](bufferSize int, collection []T) <-chan T {
 	ch := make(chan T, bufferSize)
 
@@ -170,6 +178,7 @@ func SliceToChannel[T any](bufferSize int, collection []T) <-chan T {
 }
 
 // ChannelToSlice returns a slice built from channels items. Blocks until channel closes.
+// Play: https://go.dev/play/p/lIbSY3QmiEg
 func ChannelToSlice[T any](ch <-chan T) []T {
 	collection := []T{}
 
@@ -181,6 +190,7 @@ func ChannelToSlice[T any](ch <-chan T) []T {
 }
 
 // Generator implements the generator design pattern.
+// Play: https://go.dev/play/p/lIbSY3QmiEg
 func Generator[T any](bufferSize int, generator func(yield func(T))) <-chan T {
 	ch := make(chan T, bufferSize)
 
@@ -198,6 +208,7 @@ func Generator[T any](bufferSize int, generator func(yield func(T))) <-chan T {
 
 // Buffer creates a slice of n elements from a channel. Returns the slice and the slice length.
 // @TODO: we should probably provide an helper that reuse the same buffer.
+// Play: https://go.dev/play/p/gPQ-6xmcKQI
 func Buffer[T any](ch <-chan T, size int) (collection []T, length int, readTime time.Duration, ok bool) {
 	buffer := make([]T, 0, size)
 	index := 0
@@ -224,6 +235,7 @@ func Batch[T any](ch <-chan T, size int) (collection []T, length int, readTime t
 
 // BufferWithContext creates a slice of n elements from a channel, with context. Returns the slice and the slice length.
 // @TODO: we should probably provide an helper that reuse the same buffer.
+// Play: https://go.dev/play/p/oRfOyJWK9YF
 func BufferWithContext[T any](ctx context.Context, ch <-chan T, size int) (collection []T, length int, readTime time.Duration, ok bool) {
 	buffer := make([]T, 0, size)
 	now := time.Now()
@@ -246,6 +258,7 @@ func BufferWithContext[T any](ctx context.Context, ch <-chan T, size int) (colle
 }
 
 // BufferWithTimeout creates a slice of n elements from a channel, with timeout. Returns the slice and the slice length.
+// Play: https://go.dev/play/p/sxyEM3koo4n
 func BufferWithTimeout[T any](ch <-chan T, size int, timeout time.Duration) (collection []T, length int, readTime time.Duration, ok bool) {
 	ctx, cancel := context.WithTimeout(context.Background(), timeout)
 	defer cancel()
@@ -261,6 +274,7 @@ func BatchWithTimeout[T any](ch <-chan T, size int, timeout time.Duration) (coll
 
 // FanIn collects messages from multiple input channels into a single buffered channel.
 // Output messages has no priority. When all upstream channels reach EOF, downstream channel closes.
+// Play: https://go.dev/play/p/FH8Wq-T04Jb
 func FanIn[T any](channelBufferCap int, upstreams ...<-chan T) <-chan T {
 	out := make(chan T, channelBufferCap)
 	var wg sync.WaitGroup
@@ -295,6 +309,7 @@ func ChannelMerge[T any](channelBufferCap int, upstreams ...<-chan T) <-chan T {
 // FanOut broadcasts all the upstream messages to multiple downstream channels.
 // When upstream channel reach EOF, downstream channels close. If any downstream
 // channels is full, broadcasting is paused.
+// Play: https://go.dev/play/p/2LHxcjKX23L
 func FanOut[T any](count int, channelsBufferCap int, upstream <-chan T) []<-chan T {
 	downstreams := createChannels[T](count, channelsBufferCap)
 

concurrency.go

@@ -17,6 +17,7 @@ func (s *synchronize) Do(cb func()) {
 }
 
 // Synchronize wraps the underlying callback in a mutex. It receives an optional mutex.
+// Play: https://go.dev/play/p/X3cqROSpQmu
 func Synchronize(opt ...sync.Locker) *synchronize { //nolint:revive
 	if len(opt) > 1 {
 		panic("unexpected arguments")
@@ -30,6 +31,7 @@ func Synchronize(opt ...sync.Locker) *synchronize { //nolint:revive
 }
 
 // Async executes a function in a goroutine and returns the result in a channel.
+// Play: https://go.dev/play/p/uo35gosuTLw
 func Async[A any](f func() A) <-chan A {
 	ch := make(chan A, 1)
 	go func() {
@@ -39,6 +41,7 @@ func Async[A any](f func() A) <-chan A {
 }
 
 // Async0 executes a function in a goroutine and returns a channel set once the function finishes.
+// Play: https://go.dev/play/p/tNqf1cClG_o
 func Async0(f func()) <-chan struct{} {
 	ch := make(chan struct{}, 1)
 	go func() {
@@ -49,11 +52,13 @@ func Async0(f func()) <-chan struct{} {
 }
 
 // Async1 is an alias to Async.
+// Play: https://go.dev/play/p/uo35gosuTLw
 func Async1[A any](f func() A) <-chan A {
 	return Async(f)
 }
 
 // Async2 has the same behavior as Async, but returns the 2 results as a tuple inside the channel.
+// Play: https://go.dev/play/p/7W7mKQi0AhA
 func Async2[A, B any](f func() (A, B)) <-chan Tuple2[A, B] {
 	ch := make(chan Tuple2[A, B], 1)
 	go func() {
@@ -63,6 +68,7 @@ func Async2[A, B any](f func() (A, B)) <-chan Tuple2[A, B] {
 }
 
 // Async3 has the same behavior as Async, but returns the 3 results as a tuple inside the channel.
+// Play: https://go.dev/play/p/L1d6o6l6q0d
 func Async3[A, B, C any](f func() (A, B, C)) <-chan Tuple3[A, B, C] {
 	ch := make(chan Tuple3[A, B, C], 1)
 	go func() {
@@ -72,6 +78,7 @@ func Async3[A, B, C any](f func() (A, B, C)) <-chan Tuple3[A, B, C] {
 }
 
 // Async4 has the same behavior as Async, but returns the 4 results as a tuple inside the channel.
+// Play: https://go.dev/play/p/1X7q6oL0TqF
 func Async4[A, B, C, D any](f func() (A, B, C, D)) <-chan Tuple4[A, B, C, D] {
 	ch := make(chan Tuple4[A, B, C, D], 1)
 	go func() {
@@ -81,6 +88,7 @@ func Async4[A, B, C, D any](f func() (A, B, C, D)) <-chan Tuple4[A, B, C, D] {
 }
 
 // Async5 has the same behavior as Async, but returns the 5 results as a tuple inside the channel.
+// Play: https://go.dev/play/p/2W7q4oL1TqG
 func Async5[A, B, C, D, E any](f func() (A, B, C, D, E)) <-chan Tuple5[A, B, C, D, E] {
 	ch := make(chan Tuple5[A, B, C, D, E], 1)
 	go func() {
@@ -90,6 +98,7 @@ func Async5[A, B, C, D, E any](f func() (A, B, C, D, E)) <-chan Tuple5[A, B, C,
 }
 
 // Async6 has the same behavior as Async, but returns the 6 results as a tuple inside the channel.
+// Play: https://go.dev/play/p/3X8q5pM2UrH
 func Async6[A, B, C, D, E, F any](f func() (A, B, C, D, E, F)) <-chan Tuple6[A, B, C, D, E, F] {
 	ch := make(chan Tuple6[A, B, C, D, E, F], 1)
 	go func() {
@@ -99,6 +108,7 @@ func Async6[A, B, C, D, E, F any](f func() (A, B, C, D, E, F)) <-chan Tuple6[A,
 }
 
 // WaitFor runs periodically until a condition is validated.
+// Play: https://go.dev/play/p/t_wTDmubbK3
 func WaitFor(condition func(i int) bool, timeout time.Duration, heartbeatDelay time.Duration) (totalIterations int, elapsed time.Duration, conditionFound bool) {
 	conditionWithContext := func(_ context.Context, currentIteration int) bool {
 		return condition(currentIteration)
@@ -107,6 +117,7 @@ func WaitFor(condition func(i int) bool, timeout time.Duration, heartbeatDelay t
 }
 
 // WaitForWithContext runs periodically until a condition is validated or context is canceled.
+// Play: https://go.dev/play/p/t_wTDmubbK3
 func WaitForWithContext(ctx context.Context, condition func(ctx context.Context, currentIteration int) bool, timeout time.Duration, heartbeatDelay time.Duration) (totalIterations int, elapsed time.Duration, conditionFound bool) {
 	start := time.Now()
 

errors.go

@@ -61,7 +61,7 @@ func must(err any, messageArgs ...any) {
 
 // Must is a helper that wraps a call to a function returning a value and an error
 // and panics if err is error or false.
-// Play: https://go.dev/play/p/TMoWrRp3DyC
+// Play: https://go.dev/play/p/fOqtX5HudtN
 func Must[T any](val T, err any, messageArgs ...any) T {
 	must(err, messageArgs...)
 	return val

find.go

@@ -10,6 +10,7 @@ import (
 
 // IndexOf returns the index at which the first occurrence of a value is found in an array or return -1
 // if the value cannot be found.
+// Play: https://go.dev/play/p/Eo7W0lvKTky
 func IndexOf[T comparable](collection []T, element T) int {
 	for i := range collection {
 		if collection[i] == element {
@@ -22,6 +23,7 @@ func IndexOf[T comparable](collection []T, element T) int {
 
 // LastIndexOf returns the index at which the last occurrence of a value is found in an array or return -1
 // if the value cannot be found.
+// Play: https://go.dev/play/p/Eo7W0lvKTky
 func LastIndexOf[T comparable](collection []T, element T) int {
 	length := len(collection)
 
@@ -35,6 +37,7 @@ func LastIndexOf[T comparable](collection []T, element T) int {
 }
 
 // Find search an element in a slice based on a predicate. It returns element and true if element was found.
+// Play: https://go.dev/play/p/Eo7W0lvKTky
 func Find[T any](collection []T, predicate func(item T) bool) (T, bool) {
 	for i := range collection {
 		if predicate(collection[i]) {
@@ -48,6 +51,7 @@ func Find[T any](collection []T, predicate func(item T) bool) (T, bool) {
 
 // FindIndexOf searches an element in a slice based on a predicate and returns the index and true.
 // It returns -1 and false if the element is not found.
+// Play: https://go.dev/play/p/XWSEM4Ic_t0
 func FindIndexOf[T any](collection []T, predicate func(item T) bool) (T, int, bool) {
 	for i := range collection {
 		if predicate(collection[i]) {
@@ -61,6 +65,7 @@ func FindIndexOf[T any](collection []T, predicate func(item T) bool) (T, int, bo
 
 // FindLastIndexOf searches last element in a slice based on a predicate and returns the index and true.
 // It returns -1 and false if the element is not found.
+// Play: https://go.dev/play/p/dPiMRtJ6cUx
 func FindLastIndexOf[T any](collection []T, predicate func(item T) bool) (T, int, bool) {
 	length := len(collection)
 
@@ -75,6 +80,7 @@ func FindLastIndexOf[T any](collection []T, predicate func(item T) bool) (T, int
 }
 
 // FindOrElse search an element in a slice based on a predicate. It returns the element if found or a given fallback value otherwise.
+// Play: https://go.dev/play/p/Eo7W0lvKTky
 func FindOrElse[T any](collection []T, fallback T, predicate func(item T) bool) T {
 	for i := range collection {
 		if predicate(collection[i]) {
@@ -86,6 +92,7 @@ func FindOrElse[T any](collection []T, fallback T, predicate func(item T) bool)
 }
 
 // FindKey returns the key of the first value matching.
+// Play: https://go.dev/play/p/Bg0w1VDPYXx
 func FindKey[K comparable, V comparable](object map[K]V, value V) (K, bool) {
 	for k := range object {
 		if object[k] == value {
@@ -97,6 +104,7 @@ func FindKey[K comparable, V comparable](object map[K]V, value V) (K, bool) {
 }
 
 // FindKeyBy returns the key of the first element predicate returns truthy for.
+// Play: https://go.dev/play/p/9IbiPElcyo8
 func FindKeyBy[K comparable, V any](object map[K]V, predicate func(key K, value V) bool) (K, bool) {
 	for k := range object {
 		if predicate(k, object[k]) {
@@ -221,6 +229,7 @@ func FindDuplicatesBy[T any, U comparable, Slice ~[]T](collection Slice, iterate
 
 // Min search the minimum value of a collection.
 // Returns zero value when the collection is empty.
+// Play: https://go.dev/play/p/r6e-Z8JozS8
 func Min[T constraints.Ordered](collection []T) T {
 	var min T
 
@@ -365,6 +374,7 @@ func EarliestBy[T any](collection []T, iteratee func(item T) time.Time) T {
 
 // Max searches the maximum value of a collection.
 // Returns zero value when the collection is empty.
+// Play: https://go.dev/play/p/r6e-Z8JozS8
 func Max[T constraints.Ordered](collection []T) T {
 	var max T
 
@@ -508,6 +518,7 @@ func LatestBy[T any](collection []T, iteratee func(item T) time.Time) T {
 }
 
 // First returns the first element of a collection and check for availability of the first element.
+// Play: https://go.dev/play/p/ul45Z0y2EFO
 func First[T any](collection []T) (T, bool) {
 	length := len(collection)
 
@@ -520,12 +531,14 @@ func First[T any](collection []T) (T, bool) {
 }
 
 // FirstOrEmpty returns the first element of a collection or zero value if empty.
+// Play: https://go.dev/play/p/ul45Z0y2EFO
 func FirstOrEmpty[T any](collection []T) T {
 	i, _ := First(collection)
 	return i
 }
 
 // FirstOr returns the first element of a collection or the fallback value if empty.
+// Play: https://go.dev/play/p/ul45Z0y2EFO
 func FirstOr[T any](collection []T, fallback T) T {
 	i, ok := First(collection)
 	if !ok {
@@ -536,6 +549,7 @@ func FirstOr[T any](collection []T, fallback T) T {
 }
 
 // Last returns the last element of a collection or error if empty.
+// Play: https://go.dev/play/p/ul45Z0y2EFO
 func Last[T any](collection []T) (T, bool) {
 	length := len(collection)
 
@@ -548,12 +562,14 @@ func Last[T any](collection []T) (T, bool) {
 }
 
 // LastOrEmpty returns the last element of a collection or zero value if empty.
+// Play: https://go.dev/play/p/ul45Z0y2EFO
 func LastOrEmpty[T any](collection []T) T {
 	i, _ := Last(collection)
 	return i
 }
 
 // LastOr returns the last element of a collection or the fallback value if empty.
+// Play: https://go.dev/play/p/ul45Z0y2EFO
 func LastOr[T any](collection []T, fallback T) T {
 	i, ok := Last(collection)
 	if !ok {
@@ -565,6 +581,7 @@ func LastOr[T any](collection []T, fallback T) T {
 
 // Nth returns the element at index `nth` of collection. If `nth` is negative, the nth element
 // from the end is returned. An error is returned when nth is out of slice bounds.
+// Play: https://go.dev/play/p/sHoh88KWt6B
 func Nth[T any, N constraints.Integer](collection []T, nth N) (T, error) {
 	n := int(nth)
 	l := len(collection)
@@ -582,6 +599,7 @@ func Nth[T any, N constraints.Integer](collection []T, nth N) (T, error) {
 // NthOr returns the element at index `nth` of collection.
 // If `nth` is negative, it returns the nth element from the end.
 // If `nth` is out of slice bounds, it returns the fallback value instead of an error.
+// Play: https://go.dev/play/p/sHoh88KWt6B
 func NthOr[T any, N constraints.Integer](collection []T, nth N, fallback T) T {
 	value, err := Nth(collection, nth)
 	if err != nil {
@@ -593,6 +611,7 @@ func NthOr[T any, N constraints.Integer](collection []T, nth N, fallback T) T {
 // NthOrEmpty returns the element at index `nth` of collection.
 // If `nth` is negative, it returns the nth element from the end.
 // If `nth` is out of slice bounds, it returns the zero value (empty value) for that type.
+// Play: https://go.dev/play/p/sHoh88KWt6B
 func NthOrEmpty[T any, N constraints.Integer](collection []T, nth N) T {
 	value, err := Nth(collection, nth)
 	if err != nil {
@@ -607,12 +626,14 @@ func NthOrEmpty[T any, N constraints.Integer](collection []T, nth N) T {
 type randomIntGenerator func(n int) int
 
 // Sample returns a random item from collection.
+// Play: https://go.dev/play/p/vCcSJbh5s6l
 func Sample[T any](collection []T) T {
 	result := SampleBy(collection, rand.IntN)
 	return result
 }
 
 // SampleBy returns a random item from collection, using randomIntGenerator as the random index generator.
+// Play: https://go.dev/play/p/HDmKmMgq0XN
 func SampleBy[T any](collection []T, randomIntGenerator randomIntGenerator) T {
 	size := len(collection)
 	if size == 0 {
@@ -622,12 +643,14 @@ func SampleBy[T any](collection []T, randomIntGenerator randomIntGenerator) T {
 }
 
 // Samples returns N random unique items from collection.
+// Play: https://go.dev/play/p/vCcSJbh5s6l
 func Samples[T any, Slice ~[]T](collection Slice, count int) Slice {
 	results := SamplesBy(collection, count, rand.IntN)
 	return results
 }
 
 // SamplesBy returns N random unique items from collection, using randomIntGenerator as the random index generator.
+// Play: https://go.dev/play/p/HDmKmMgq0XN
 func SamplesBy[T any, Slice ~[]T](collection Slice, count int, randomIntGenerator randomIntGenerator) Slice {
 	size := len(collection)
 

func.go

@@ -1,6 +1,7 @@
 package lo
 
 // Partial returns new function that, when called, has its first argument set to the provided value.
+// Play: https://go.dev/play/p/Sy1gAQiQZ3v
 func Partial[T1, T2, R any](f func(a T1, b T2) R, arg1 T1) func(T2) R {
 	return func(t2 T2) R {
 		return f(arg1, t2)
@@ -8,11 +9,13 @@ func Partial[T1, T2, R any](f func(a T1, b T2) R, arg1 T1) func(T2) R {
 }
 
 // Partial1 returns new function that, when called, has its first argument set to the provided value.
+// Play: https://go.dev/play/p/D-ASTXCLBzw
 func Partial1[T1, T2, R any](f func(T1, T2) R, arg1 T1) func(T2) R {
 	return Partial(f, arg1)
 }
 
 // Partial2 returns new function that, when called, has its first argument set to the provided value.
+// Play: https://go.dev/play/p/-xiPjy4JChJ
 func Partial2[T1, T2, T3, R any](f func(T1, T2, T3) R, arg1 T1) func(T2, T3) R {
 	return func(t2 T2, t3 T3) R {
 		return f(arg1, t2, t3)
@@ -20,6 +23,7 @@ func Partial2[T1, T2, T3, R any](f func(T1, T2, T3) R, arg1 T1) func(T2, T3) R {
 }
 
 // Partial3 returns new function that, when called, has its first argument set to the provided value.
+// Play: https://go.dev/play/p/zWtSutpI26m
 func Partial3[T1, T2, T3, T4, R any](f func(T1, T2, T3, T4) R, arg1 T1) func(T2, T3, T4) R {
 	return func(t2 T2, t3 T3, t4 T4) R {
 		return f(arg1, t2, t3, t4)
@@ -27,6 +31,7 @@ func Partial3[T1, T2, T3, T4, R any](f func(T1, T2, T3, T4) R, arg1 T1) func(T2,
 }
 
 // Partial4 returns new function that, when called, has its first argument set to the provided value.
+// Play: https://go.dev/play/p/kBrnnMTcJm0
 func Partial4[T1, T2, T3, T4, T5, R any](f func(T1, T2, T3, T4, T5) R, arg1 T1) func(T2, T3, T4, T5) R {
 	return func(t2 T2, t3 T3, t4 T4, t5 T5) R {
 		return f(arg1, t2, t3, t4, t5)
@@ -34,6 +39,7 @@ func Partial4[T1, T2, T3, T4, T5, R any](f func(T1, T2, T3, T4, T5) R, arg1 T1)
 }
 
 // Partial5 returns new function that, when called, has its first argument set to the provided value
+// Play: https://go.dev/play/p/7Is7K2y_VC3
 func Partial5[T1, T2, T3, T4, T5, T6, R any](f func(T1, T2, T3, T4, T5, T6) R, arg1 T1) func(T2, T3, T4, T5, T6) R {
 	return func(t2 T2, t3 T3, t4 T4, t5 T5, t6 T6) R {
 		return f(arg1, t2, t3, t4, t5, t6)

intersect.go

@@ -1,6 +1,7 @@
 package lo
 
 // Contains returns true if an element is present in a collection.
+// Play: https://go.dev/play/p/W1EvyqY6t9j
 func Contains[T comparable](collection []T, element T) bool {
 	for i := range collection {
 		if collection[i] == element {
@@ -12,6 +13,7 @@ func Contains[T comparable](collection []T, element T) bool {
 }
 
 // ContainsBy returns true if predicate function return true.
+// Play: https://go.dev/play/p/W1EvyqY6t9j
 func ContainsBy[T any](collection []T, predicate func(item T) bool) bool {
 	for i := range collection {
 		if predicate(collection[i]) {
@@ -23,6 +25,7 @@ func ContainsBy[T any](collection []T, predicate func(item T) bool) bool {
 }
 
 // Every returns true if all elements of a subset are contained into a collection or if the subset is empty.
+// Play: https://go.dev/play/p/W1EvyqY6t9j
 func Every[T comparable](collection []T, subset []T) bool {
 	for i := range subset {
 		if !Contains(collection, subset[i]) {
@@ -34,6 +37,7 @@ func Every[T comparable](collection []T, subset []T) bool {
 }
 
 // EveryBy returns true if the predicate returns true for all elements in the collection or if the collection is empty.
+// Play: https://go.dev/play/p/dn1-vhHsq9x
 func EveryBy[T any](collection []T, predicate func(item T) bool) bool {
 	for i := range collection {
 		if !predicate(collection[i]) {
@@ -46,6 +50,7 @@ func EveryBy[T any](collection []T, predicate func(item T) bool) bool {
 
 // Some returns true if at least 1 element of a subset is contained into a collection.
 // If the subset is empty Some returns false.
+// Play: https://go.dev/play/p/Lj4ceFkeT9V
 func Some[T comparable](collection []T, subset []T) bool {
 	for i := range subset {
 		if Contains(collection, subset[i]) {
@@ -58,6 +63,7 @@ func Some[T comparable](collection []T, subset []T) bool {
 
 // SomeBy returns true if the predicate returns true for any of the elements in the collection.
 // If the collection is empty SomeBy returns false.
+// Play: https://go.dev/play/p/DXF-TORBudx
 func SomeBy[T any](collection []T, predicate func(item T) bool) bool {
 	for i := range collection {
 		if predicate(collection[i]) {
@@ -69,6 +75,7 @@ func SomeBy[T any](collection []T, predicate func(item T) bool) bool {
 }
 
 // None returns true if no element of a subset are contained into a collection or if the subset is empty.
+// Play: https://go.dev/play/p/fye7JsmxzPV
 func None[T comparable](collection []T, subset []T) bool {
 	for i := range subset {
 		if Contains(collection, subset[i]) {
@@ -80,6 +87,7 @@ func None[T comparable](collection []T, subset []T) bool {
 }
 
 // NoneBy returns true if the predicate returns true for none of the elements in the collection or if the collection is empty.
+// Play: https://go.dev/play/p/O64WZ32H58S
 func NoneBy[T any](collection []T, predicate func(item T) bool) bool {
 	for i := range collection {
 		if predicate(collection[i]) {
@@ -91,6 +99,7 @@ func NoneBy[T any](collection []T, predicate func(item T) bool) bool {
 }
 
 // Intersect returns the intersection between two collections.
+// Play: https://go.dev/play/p/uuElL9X9e58
 func Intersect[T comparable, Slice ~[]T](list1 Slice, list2 Slice) Slice {
 	result := Slice{}
 	seen := map[T]struct{}{}
@@ -111,6 +120,7 @@ func Intersect[T comparable, Slice ~[]T](list1 Slice, list2 Slice) Slice {
 // Difference returns the difference between two collections.
 // The first value is the collection of element absent of list2.
 // The second value is the collection of element absent of list1.
+// Play: https://go.dev/play/p/pKE-JgzqRpz
 func Difference[T comparable, Slice ~[]T](list1 Slice, list2 Slice) (Slice, Slice) {
 	left := Slice{}
 	right := Slice{}
@@ -143,6 +153,7 @@ func Difference[T comparable, Slice ~[]T](list1 Slice, list2 Slice) (Slice, Slic
 
 // Union returns all distinct elements from given collections.
 // result returns will not change the order of elements relatively.
+// Play: https://go.dev/play/p/DI9RVEB_qMK
 func Union[T comparable, Slice ~[]T](lists ...Slice) Slice {
 	var capLen int
 
@@ -166,6 +177,7 @@ func Union[T comparable, Slice ~[]T](lists ...Slice) Slice {
 }
 
 // Without returns slice excluding all given values.
+// Play: https://go.dev/play/p/5j30Ux8TaD0
 func Without[T comparable, Slice ~[]T](collection Slice, exclude ...T) Slice {
 	excludeMap := make(map[T]struct{}, len(exclude))
 	for i := range exclude {
@@ -183,6 +195,7 @@ func Without[T comparable, Slice ~[]T](collection Slice, exclude ...T) Slice {
 
 // WithoutBy filters a slice by excluding elements whose extracted keys match any in the exclude list.
 // It returns a new slice containing only the elements whose keys are not in the exclude list.
+// Play: https://go.dev/play/p/VgWJOF01NbJ
 func WithoutBy[T any, K comparable](collection []T, iteratee func(item T) K, exclude ...K) []T {
 	excludeMap := make(map[K]struct{}, len(exclude))
 	for _, e := range exclude {
@@ -206,6 +219,7 @@ func WithoutEmpty[T comparable, Slice ~[]T](collection Slice) Slice {
 }
 
 // WithoutNth returns slice excluding nth value.
+// Play: https://go.dev/play/p/5g3F9R2H1xL
 func WithoutNth[T comparable, Slice ~[]T](collection Slice, nths ...int) Slice {
 	length := len(collection)
 
@@ -229,6 +243,7 @@ func WithoutNth[T comparable, Slice ~[]T](collection Slice, nths ...int) Slice {
 // ElementsMatch returns true if lists contain the same set of elements (including empty set).
 // If there are duplicate elements, the number of appearances of each of them in both lists should match.
 // The order of elements is not checked.
+// Play: https://go.dev/play/p/XWSEM4Ic_t0
 func ElementsMatch[T comparable, Slice ~[]T](list1 Slice, list2 Slice) bool {
 	return ElementsMatchBy(list1, list2, func(item T) T { return item })
 }
@@ -236,6 +251,7 @@ func ElementsMatch[T comparable, Slice ~[]T](list1 Slice, list2 Slice) bool {
 // ElementsMatchBy returns true if lists contain the same set of elements' keys (including empty set).
 // If there are duplicate keys, the number of appearances of each of them in both lists should match.
 // The order of elements is not checked.
+// Play: https://go.dev/play/p/XWSEM4Ic_t0
 func ElementsMatchBy[T any, K comparable](list1 []T, list2 []T, iteratee func(item T) K) bool {
 	if len(list1) != len(list2) {
 		return false

map.go

@@ -175,7 +175,7 @@ func OmitByValues[K comparable, V comparable, Map ~map[K]V](in Map, values []V)
 }
 
 // Entries transforms a map into array of key/value pairs.
-// Play:
+// Play: https://go.dev/play/p/_t4Xe34-Nl5
 func Entries[K comparable, V any](in map[K]V) []Entry[K, V] {
 	entries := make([]Entry[K, V], 0, len(in))
 
@@ -331,6 +331,7 @@ func MapToSlice[K comparable, V any, R any](in map[K]V, iteratee func(key K, val
 // The iteratee returns a value and a boolean. If the boolean is true, the value is added to the result slice.
 // If the boolean is false, the value is not added to the result slice.
 // The order of the keys in the input map is not specified and the order of the keys in the output slice is not guaranteed.
+// Play: https://go.dev/play/p/jgsD_Kil9pV
 func FilterMapToSlice[K comparable, V any, R any](in map[K]V, iteratee func(key K, value V) (R, bool)) []R {
 	result := make([]R, 0, len(in))
 

math.go

@@ -122,6 +122,7 @@ func ProductBy[T any, R constraints.Float | constraints.Integer | constraints.Co
 }
 
 // Mean calculates the mean of a collection of numbers.
+// Play: https://go.dev/play/p/tPURSuteUsP
 func Mean[T constraints.Float | constraints.Integer](collection []T) T {
 	length := T(len(collection))
 	if length == 0 {
@@ -132,6 +133,7 @@ func Mean[T constraints.Float | constraints.Integer](collection []T) T {
 }
 
 // MeanBy calculates the mean of a collection of numbers using the given return value from the iteration function.
+// Play: https://go.dev/play/p/j7TsVwBOZ7P
 func MeanBy[T any, R constraints.Float | constraints.Integer](collection []T, iteratee func(item T) R) R {
 	length := R(len(collection))
 	if length == 0 {

mutable/slice.go

@@ -7,6 +7,7 @@ import "github.com/samber/lo/internal/rand"
 // and should return true for elements that should be kept and false for elements that should be removed.
 // The function returns the modified slice, which may be shorter than the original if some elements were removed.
 // Note that the order of elements in the original slice is preserved in the output.
+// Play: https://go.dev/play/p/0jY3Z0B7O_5
 func Filter[T any, Slice ~[]T](collection Slice, predicate func(item T) bool) Slice {
 	j := 0
 	for _, item := range collection {
@@ -36,6 +37,7 @@ func FilterI[T any, Slice ~[]T](collection Slice, predicate func(item T, index i
 
 // Map is a generic function that modifies the input slice in-place to contain the result of applying the provided
 // function to each element of the slice. The function returns the modified slice, which has the same length as the original.
+// Play: https://go.dev/play/p/0jY3Z0B7O_5
 func Map[T any, Slice ~[]T](collection Slice, fn func(item T) T) {
 	for i := range collection {
 		collection[i] = fn(collection[i])

parallel/slice.go

@@ -4,6 +4,7 @@ import "sync"
 
 // Map manipulates a slice and transforms it to a slice of another type.
 // `iteratee` is call in parallel. Result keep the same order.
+// Play: https://go.dev/play/p/sCJaB3quRMC
 func Map[T any, R any](collection []T, iteratee func(item T, index int) R) []R {
 	result := make([]R, len(collection))
 
@@ -27,6 +28,7 @@ func Map[T any, R any](collection []T, iteratee func(item T, index int) R) []R {
 
 // ForEach iterates over elements of collection and invokes iteratee for each element.
 // `iteratee` is call in parallel.
+// Play: https://go.dev/play/p/sCJaB3quRMC
 func ForEach[T any](collection []T, iteratee func(item T, index int)) {
 	var wg sync.WaitGroup
 	wg.Add(len(collection))

retry.go

@@ -194,6 +194,7 @@ func AttemptWithDelay(maxIteration int, delay time.Duration, f func(index int, d
 // immediately if the second return value is false. When the first
 // argument is less than `1`, the function runs until a successful response is
 // returned.
+// Play: https://go.dev/play/p/1VS7HxlYMOG
 func AttemptWhile(maxIteration int, f func(int) (error, bool)) (int, error) {
 	var err error
 	var shouldContinueInvoke bool
@@ -218,6 +219,7 @@ func AttemptWhile(maxIteration int, f func(int) (error, bool)) (int, error) {
 // It will terminate the invoke immediately if the second return value is false.
 // When the first argument is less than `1`, the function runs until a successful
 // response is returned.
+// Play: https://go.dev/play/p/mhufUjJfLEF
 func AttemptWhileWithDelay(maxIteration int, delay time.Duration, f func(int, time.Duration) (error, bool)) (int, time.Duration, error) {
 	var err error
 	var shouldContinueInvoke bool
@@ -247,6 +249,7 @@ type transactionStep[T any] struct {
 }
 
 // NewTransaction instantiate a new transaction.
+// Play: https://go.dev/play/p/Qxrd7MGQGh1
 func NewTransaction[T any]() *Transaction[T] {
 	return &Transaction[T]{
 		steps: []transactionStep[T]{},
@@ -259,6 +262,7 @@ type Transaction[T any] struct {
 }
 
 // Then adds a step to the chain of callbacks. It returns the same Transaction.
+// Play: https://go.dev/play/p/Qxrd7MGQGh1 https://go.dev/play/p/xrHb2_kMvTY
 func (t *Transaction[T]) Then(exec func(T) (T, error), onRollback func(T) T) *Transaction[T] {
 	t.steps = append(t.steps, transactionStep[T]{
 		exec:       exec,
@@ -269,6 +273,7 @@ func (t *Transaction[T]) Then(exec func(T) (T, error), onRollback func(T) T) *Tr
 }
 
 // Process runs the Transaction steps and rollbacks in case of errors.
+// Play: https://go.dev/play/p/Qxrd7MGQGh1 https://go.dev/play/p/xrHb2_kMvTY
 func (t *Transaction[T]) Process(state T) (T, error) {
 	var i int
 	var err error
@@ -341,11 +346,13 @@ func (th *throttleBy[T]) reset() {
 
 // NewThrottle creates a throttled instance that invokes given functions only once in every interval.
 // This returns 2 functions, First one is throttled function and Second one is a function to reset interval
+// Play: https://go.dev/play/p/qQn3fm8Z7jS
 func NewThrottle(interval time.Duration, f ...func()) (throttle func(), reset func()) {
 	return NewThrottleWithCount(interval, 1, f...)
 }
 
 // NewThrottleWithCount is NewThrottle with count limit, throttled function will be invoked count times in every interval.
+// Play: https://go.dev/play/p/w5nc0MgWtjC
 func NewThrottleWithCount(interval time.Duration, count int, f ...func()) (throttle func(), reset func()) {
 	callbacks := Map(f, func(item func(), _ int) func(struct{}) {
 		return func(struct{}) {
@@ -361,11 +368,13 @@ func NewThrottleWithCount(interval time.Duration, count int, f ...func()) (throt
 
 // NewThrottleBy creates a throttled instance that invokes given functions only once in every interval.
 // This returns 2 functions, First one is throttled function and Second one is a function to reset interval
+// Play: https://go.dev/play/p/0Wv6oX7dHdC
 func NewThrottleBy[T comparable](interval time.Duration, f ...func(key T)) (throttle func(key T), reset func()) {
 	return NewThrottleByWithCount[T](interval, 1, f...)
 }
 
 // NewThrottleByWithCount is NewThrottleBy with count limit, throttled function will be invoked count times in every interval.
+// Play: https://go.dev/play/p/vQk3ECH7_EW
 func NewThrottleByWithCount[T comparable](interval time.Duration, count int, f ...func(key T)) (throttle func(key T), reset func()) {
 	if count <= 0 {
 		count = 1

slice.go

@@ -34,6 +34,7 @@ func Map[T any, R any](collection []T, iteratee func(item T, index int) R) []R {
 }
 
 // UniqMap manipulates a slice and transforms it to a slice of another type with unique values.
+// Play: https://go.dev/play/p/fygzLBhvUdB
 func UniqMap[T any, R comparable](collection []T, iteratee func(item T, index int) R) []R {
 	result := make([]R, 0, len(collection))
 	seen := make(map[R]struct{}, len(collection))
@@ -53,7 +54,7 @@ func UniqMap[T any, R comparable](collection []T, iteratee func(item T, index in
 //   - the result of the mapping operation and
 //   - whether the result element should be included or not.
 //
-// Play: https://go.dev/play/p/-AuYXfy7opz
+// Play: https://go.dev/play/p/CgHYNUpOd1I
 func FilterMap[T any, R any](collection []T, callback func(item T, index int) (R, bool)) []R {
 	result := make([]R, 0, len(collection))
 
@@ -69,7 +70,7 @@ func FilterMap[T any, R any](collection []T, callback func(item T, index int) (R
 // FlatMap manipulates a slice and transforms and flattens it to a slice of another type.
 // The transform function can either return a slice or a `nil`, and in the `nil` case
 // no value is added to the final slice.
-// Play: https://go.dev/play/p/YSoYmQTA8-U
+// Play: https://go.dev/play/p/pFCF5WVB225
 func FlatMap[T any, R any](collection []T, iteratee func(item T, index int) []R) []R {
 	result := make([]R, 0, len(collection))
 
@@ -82,7 +83,7 @@ func FlatMap[T any, R any](collection []T, iteratee func(item T, index int) []R)
 
 // Reduce reduces collection to a value which is the accumulated result of running each element in collection
 // through accumulator, where each successive invocation is supplied the return value of the previous.
-// Play: https://go.dev/play/p/R4UHXZNaaUG
+// Play: https://go.dev/play/p/CgHYNUpOd1I
 func Reduce[T any, R any](collection []T, accumulator func(agg R, item T, index int) R, initial R) R {
 	for i := range collection {
 		initial = accumulator(initial, collection[i], i)
@@ -189,6 +190,7 @@ func GroupBy[T any, U comparable, Slice ~[]T](collection Slice, iteratee func(it
 }
 
 // GroupByMap returns an object composed of keys generated from the results of running each element of collection through iteratee.
+// Play: https://go.dev/play/p/iMeruQ3_W80
 func GroupByMap[T any, K comparable, V any](collection []T, iteratee func(item T) (K, V)) map[K][]V {
 	result := map[K][]V{}
 
@@ -203,7 +205,7 @@ func GroupByMap[T any, K comparable, V any](collection []T, iteratee func(item T
 
 // Chunk returns an array of elements split into groups the length of size. If array can't be split evenly,
 // the final chunk will be the remaining elements.
-// Play: https://go.dev/play/p/EeKl0AuTehH
+// Play: https://go.dev/play/p/kEMkFbdu85g
 func Chunk[T any, Slice ~[]T](collection Slice, size int) []Slice {
 	if size <= 0 {
 		panic("Second parameter must be greater than 0")
@@ -368,7 +370,7 @@ func RepeatBy[T any](count int, predicate func(index int) T) []T {
 }
 
 // KeyBy transforms a slice or an array of structs to a map based on a pivot callback.
-// Play: https://go.dev/play/p/mdaClUAT-zZ
+// Play: https://go.dev/play/p/ccUiUL_Lnel
 func KeyBy[K comparable, V any](collection []V, iteratee func(item V) K) map[K]V {
 	result := make(map[K]V, len(collection))
 
@@ -408,6 +410,7 @@ func SliceToMap[T any, K comparable, V any](collection []T, transform func(item
 // If any of two pairs would have the same key the last one gets added to the map.
 // The order of keys in returned map is not specified and is not guaranteed to be the same from the original array.
 // The third return value of the transform function is a boolean that indicates whether the key-value pair should be included in the map.
+// Play: https://go.dev/play/p/2z0rDz2ZSGU
 func FilterSliceToMap[T any, K comparable, V any](collection []T, transform func(item T) (K, V, bool)) map[K]V {
 	result := make(map[K]V, len(collection))
 
@@ -422,6 +425,7 @@ func FilterSliceToMap[T any, K comparable, V any](collection []T, transform func
 }
 
 // Keyify returns a map with each unique element of the slice as a key.
+// Play: https://go.dev/play/p/RYhhM_csqIG
 func Keyify[T comparable, Slice ~[]T](collection Slice) map[T]struct{} {
 	result := make(map[T]struct{}, len(collection))
 
@@ -516,7 +520,7 @@ func DropByIndex[T any](collection []T, indexes ...int) []T {
 }
 
 // Reject is the opposite of Filter, this method returns the elements of collection that predicate does not return truthy for.
-// Play: https://go.dev/play/p/YkLMODy1WEL
+// Play: https://go.dev/play/p/pFCF5WVB225
 func Reject[T any, Slice ~[]T](collection Slice, predicate func(item T, index int) bool) Slice {
 	result := Slice{}
 
@@ -533,6 +537,8 @@ func Reject[T any, Slice ~[]T](collection Slice, predicate func(item T, index in
 // The callback function should return two values:
 //   - the result of the mapping operation and
 //   - whether the result element should be included or not.
+//
+// Play: https://go.dev/play/p/W9Ug9r0QFkL
 func RejectMap[T any, R any](collection []T, callback func(item T, index int) (R, bool)) []R {
 	result := []R{}
 
@@ -547,6 +553,7 @@ func RejectMap[T any, R any](collection []T, callback func(item T, index int) (R
 
 // FilterReject mixes Filter and Reject, this method returns two slices, one for the elements of collection that
 // predicate returns truthy for and one for the elements that predicate does not return truthy for.
+// Play: https://go.dev/play/p/lHSEGSznJjB
 func FilterReject[T any, Slice ~[]T](collection Slice, predicate func(T, int) bool) (kept Slice, rejected Slice) {
 	kept = make(Slice, 0, len(collection))
 	rejected = make(Slice, 0, len(collection))

string.go

@@ -151,6 +151,7 @@ func RuneLength(str string) int {
 }
 
 // PascalCase converts string to pascal case.
+// Play: https://go.dev/play/p/Dy_V_6DUYhe
 func PascalCase(str string) string {
 	items := Words(str)
 	for i := range items {
@@ -160,6 +161,7 @@ func PascalCase(str string) string {
 }
 
 // CamelCase converts string to camel case.
+// Play: https://go.dev/play/p/Go6aKwUiq59
 func CamelCase(str string) string {
 	items := Words(str)
 	for i, item := range items {
@@ -173,6 +175,7 @@ func CamelCase(str string) string {
 }
 
 // KebabCase converts string to kebab case.
+// Play: https://go.dev/play/p/96gT_WZnTVP
 func KebabCase(str string) string {
 	items := Words(str)
 	for i := range items {
@@ -182,6 +185,7 @@ func KebabCase(str string) string {
 }
 
 // SnakeCase converts string to snake case.
+// Play: https://go.dev/play/p/ziB0V89IeVH
 func SnakeCase(str string) string {
 	items := Words(str)
 	for i := range items {
@@ -191,6 +195,7 @@ func SnakeCase(str string) string {
 }
 
 // Words splits string into an array of its words.
+// Play: https://go.dev/play/p/-f3VIQqiaVw
 func Words(str string) []string {
 	str = splitWordReg.ReplaceAllString(str, `$1$3$5$7 $2$4$6$8$9`)
 	// example: Int8Value => Int 8Value => Int 8 Value
@@ -207,6 +212,7 @@ func Words(str string) []string {
 }
 
 // Capitalize converts the first character of string to upper case and the remaining to lower case.
+// Play: https://go.dev/play/p/uLTZZQXqnsa
 func Capitalize(str string) string {
 	return cases.Title(language.English).String(str)
 }
@@ -214,6 +220,7 @@ func Capitalize(str string) string {
 // Ellipsis trims and truncates a string to a specified length **in bytes** and appends an ellipsis
 // if truncated. If the string contains non-ASCII characters (which may occupy multiple bytes in UTF-8),
 // truncating by byte length may split a character in the middle, potentially resulting in garbled output.
+// Play: https://go.dev/play/p/qE93rgqe1TW
 func Ellipsis(str string, length int) string {
 	str = strings.TrimSpace(str)
 

time.go

@@ -3,11 +3,13 @@ package lo
 import "time"
 
 // Duration returns the time taken to execute a function.
+// Play: https://go.dev/play/p/HQfbBbAXaFP
 func Duration(cb func()) time.Duration {
 	return Duration0(cb)
 }
 
 // Duration0 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/HQfbBbAXaFP
 func Duration0(cb func()) time.Duration {
 	start := time.Now()
 	cb()
@@ -15,6 +17,7 @@ func Duration0(cb func()) time.Duration {
 }
 
 // Duration1 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/HQfbBbAXaFP
 func Duration1[A any](cb func() A) (A, time.Duration) {
 	start := time.Now()
 	a := cb()
@@ -22,6 +25,7 @@ func Duration1[A any](cb func() A) (A, time.Duration) {
 }
 
 // Duration2 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/HQfbBbAXaFP
 func Duration2[A, B any](cb func() (A, B)) (A, B, time.Duration) {
 	start := time.Now()
 	a, b := cb()
@@ -29,6 +33,7 @@ func Duration2[A, B any](cb func() (A, B)) (A, B, time.Duration) {
 }
 
 // Duration3 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/xr863iwkAxQ
 func Duration3[A, B, C any](cb func() (A, B, C)) (A, B, C, time.Duration) {
 	start := time.Now()
 	a, b, c := cb()
@@ -36,6 +41,7 @@ func Duration3[A, B, C any](cb func() (A, B, C)) (A, B, C, time.Duration) {
 }
 
 // Duration4 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/xr863iwkAxQ
 func Duration4[A, B, C, D any](cb func() (A, B, C, D)) (A, B, C, D, time.Duration) {
 	start := time.Now()
 	a, b, c, d := cb()
@@ -43,6 +49,7 @@ func Duration4[A, B, C, D any](cb func() (A, B, C, D)) (A, B, C, D, time.Duratio
 }
 
 // Duration5 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/xr863iwkAxQ
 func Duration5[A, B, C, D, E any](cb func() (A, B, C, D, E)) (A, B, C, D, E, time.Duration) {
 	start := time.Now()
 	a, b, c, d, e := cb()
@@ -50,6 +57,7 @@ func Duration5[A, B, C, D, E any](cb func() (A, B, C, D, E)) (A, B, C, D, E, tim
 }
 
 // Duration6 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/mR4bTQKO-Tf
 func Duration6[A, B, C, D, E, F any](cb func() (A, B, C, D, E, F)) (A, B, C, D, E, F, time.Duration) {
 	start := time.Now()
 	a, b, c, d, e, f := cb()
@@ -57,6 +65,7 @@ func Duration6[A, B, C, D, E, F any](cb func() (A, B, C, D, E, F)) (A, B, C, D,
 }
 
 // Duration7 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/jgIAcBWWInS
 func Duration7[A, B, C, D, E, F, G any](cb func() (A, B, C, D, E, F, G)) (A, B, C, D, E, F, G, time.Duration) {
 	start := time.Now()
 	a, b, c, d, e, f, g := cb()
@@ -64,6 +73,7 @@ func Duration7[A, B, C, D, E, F, G any](cb func() (A, B, C, D, E, F, G)) (A, B,
 }
 
 // Duration8 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/T8kxpG1c5Na
 func Duration8[A, B, C, D, E, F, G, H any](cb func() (A, B, C, D, E, F, G, H)) (A, B, C, D, E, F, G, H, time.Duration) {
 	start := time.Now()
 	a, b, c, d, e, f, g, h := cb()
@@ -71,6 +81,7 @@ func Duration8[A, B, C, D, E, F, G, H any](cb func() (A, B, C, D, E, F, G, H)) (
 }
 
 // Duration9 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/bg9ix2VrZ0j
 func Duration9[A, B, C, D, E, F, G, H, I any](cb func() (A, B, C, D, E, F, G, H, I)) (A, B, C, D, E, F, G, H, I, time.Duration) {
 	start := time.Now()
 	a, b, c, d, e, f, g, h, i := cb()
@@ -78,6 +89,7 @@ func Duration9[A, B, C, D, E, F, G, H, I any](cb func() (A, B, C, D, E, F, G, H,
 }
 
 // Duration10 returns the time taken to execute a function.
+// Play: https://go.dev/play/p/Y3n7oJXqJbk
 func Duration10[A, B, C, D, E, F, G, H, I, J any](cb func() (A, B, C, D, E, F, G, H, I, J)) (A, B, C, D, E, F, G, H, I, J, time.Duration) {
 	start := time.Now()
 	a, b, c, d, e, f, g, h, i, j := cb()

tuples.go

@@ -331,6 +331,7 @@ func Zip9[A, B, C, D, E, F, G, H, I any](a []A, b []B, c []C, d []D, e []E, f []
 // ZipBy2 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/wlHur6yO8rR
 func ZipBy2[A any, B any, Out any](a []A, b []B, iteratee func(a A, b B) Out) []Out {
 	size := Max([]int{len(a), len(b)})
 
@@ -349,6 +350,7 @@ func ZipBy2[A any, B any, Out any](a []A, b []B, iteratee func(a A, b B) Out) []
 // ZipBy3 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/j9maveOnSQX
 func ZipBy3[A any, B any, C any, Out any](a []A, b []B, c []C, iteratee func(a A, b B, c C) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c)})
 
@@ -368,6 +370,7 @@ func ZipBy3[A any, B any, C any, Out any](a []A, b []B, c []C, iteratee func(a A
 // ZipBy4 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/Y1eF2Ke0Ayz
 func ZipBy4[A any, B any, C any, D any, Out any](a []A, b []B, c []C, d []D, iteratee func(a A, b B, c C, d D) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c), len(d)})
 
@@ -388,6 +391,7 @@ func ZipBy4[A any, B any, C any, D any, Out any](a []A, b []B, c []C, d []D, ite
 // ZipBy5 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/SLynyalh5Oa
 func ZipBy5[A any, B any, C any, D any, E any, Out any](a []A, b []B, c []C, d []D, e []E, iteratee func(a A, b B, c C, d D, e E) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c), len(d), len(e)})
 
@@ -409,6 +413,7 @@ func ZipBy5[A any, B any, C any, D any, E any, Out any](a []A, b []B, c []C, d [
 // ZipBy6 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/IK6KVgw9e-S
 func ZipBy6[A any, B any, C any, D any, E any, F any, Out any](a []A, b []B, c []C, d []D, e []E, f []F, iteratee func(a A, b B, c C, d D, e E, f F) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c), len(d), len(e), len(f)})
 
@@ -431,6 +436,7 @@ func ZipBy6[A any, B any, C any, D any, E any, F any, Out any](a []A, b []B, c [
 // ZipBy7 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/4uW6a2vXh8w
 func ZipBy7[A any, B any, C any, D any, E any, F any, G any, Out any](a []A, b []B, c []C, d []D, e []E, f []F, g []G, iteratee func(a A, b B, c C, d D, e E, f F, g G) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c), len(d), len(e), len(f), len(g)})
 
@@ -454,6 +460,7 @@ func ZipBy7[A any, B any, C any, D any, E any, F any, G any, Out any](a []A, b [
 // ZipBy8 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/tk8xW7XzY4v
 func ZipBy8[A any, B any, C any, D any, E any, F any, G any, H any, Out any](a []A, b []B, c []C, d []D, e []E, f []F, g []G, h []H, iteratee func(a A, b B, c C, d D, e E, f F, g G, h H) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c), len(d), len(e), len(f), len(g), len(h)})
 
@@ -478,6 +485,7 @@ func ZipBy8[A any, B any, C any, D any, E any, F any, G any, H any, Out any](a [
 // ZipBy9 creates a slice of transformed elements, the first of which contains the first elements
 // of the given arrays, the second of which contains the second elements of the given arrays, and so on.
 // When collections have different size, the Tuple attributes are filled with zero value.
+// Play: https://go.dev/play/p/VGqjDmQ9YqX
 func ZipBy9[A any, B any, C any, D any, E any, F any, G any, H any, I any, Out any](a []A, b []B, c []C, d []D, e []E, f []F, g []G, h []H, i []I, iteratee func(a A, b B, c C, d D, e E, f F, g G, h H, i I) Out) []Out {
 	size := Max([]int{len(a), len(b), len(c), len(d), len(e), len(f), len(g), len(h), len(i)})
 
@@ -686,6 +694,7 @@ func Unzip9[A, B, C, D, E, F, G, H, I any](tuples []Tuple9[A, B, C, D, E, F, G,
 
 // UnzipBy2 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/tN8yqaRZz0r
 func UnzipBy2[In any, A any, B any](items []In, iteratee func(In) (a A, b B)) ([]A, []B) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -702,6 +711,7 @@ func UnzipBy2[In any, A any, B any](items []In, iteratee func(In) (a A, b B)) ([
 
 // UnzipBy3 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/36ITO2DlQq1
 func UnzipBy3[In any, A any, B any, C any](items []In, iteratee func(In) (a A, b B, c C)) ([]A, []B, []C) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -720,6 +730,7 @@ func UnzipBy3[In any, A any, B any, C any](items []In, iteratee func(In) (a A, b
 
 // UnzipBy4 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/zJ6qY1dD1rL
 func UnzipBy4[In any, A any, B any, C any, D any](items []In, iteratee func(In) (a A, b B, c C, d D)) ([]A, []B, []C, []D) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -740,6 +751,7 @@ func UnzipBy4[In any, A any, B any, C any, D any](items []In, iteratee func(In)
 
 // UnzipBy5 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/3f7jKkV9xZt
 func UnzipBy5[In any, A any, B any, C any, D any, E any](items []In, iteratee func(In) (a A, b B, c C, d D, e E)) ([]A, []B, []C, []D, []E) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -762,6 +774,7 @@ func UnzipBy5[In any, A any, B any, C any, D any, E any](items []In, iteratee fu
 
 // UnzipBy6 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/8Y1b7tKu2pL
 func UnzipBy6[In any, A any, B any, C any, D any, E any, F any](items []In, iteratee func(In) (a A, b B, c C, d D, e E, f F)) ([]A, []B, []C, []D, []E, []F) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -786,6 +799,7 @@ func UnzipBy6[In any, A any, B any, C any, D any, E any, F any](items []In, iter
 
 // UnzipBy7 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/7j1kLmVn3pM
 func UnzipBy7[In any, A any, B any, C any, D any, E any, F any, G any](items []In, iteratee func(In) (a A, b B, c C, d D, e E, f F, g G)) ([]A, []B, []C, []D, []E, []F, []G) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -812,6 +826,7 @@ func UnzipBy7[In any, A any, B any, C any, D any, E any, F any, G any](items []I
 
 // UnzipBy8 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/1n2k3L4m5N6
 func UnzipBy8[In any, A any, B any, C any, D any, E any, F any, G any, H any](items []In, iteratee func(In) (a A, b B, c C, d D, e E, f F, g G, h H)) ([]A, []B, []C, []D, []E, []F, []G, []H) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -840,6 +855,7 @@ func UnzipBy8[In any, A any, B any, C any, D any, E any, F any, G any, H any](it
 
 // UnzipBy9 iterates over a collection and creates an array regrouping the elements
 // to their pre-zip configuration.
+// Play: https://go.dev/play/p/7o8p9q0r1s2
 func UnzipBy9[In any, A any, B any, C any, D any, E any, F any, G any, H any, I any](items []In, iteratee func(In) (a A, b B, c C, d D, e E, f F, g G, h H, i I)) ([]A, []B, []C, []D, []E, []F, []G, []H, []I) {
 	size := len(items)
 	r1 := make([]A, 0, size)
@@ -871,6 +887,7 @@ func UnzipBy9[In any, A any, B any, C any, D any, E any, F any, G any, H any, I
 // CrossJoin2 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/3VFppyL9FDU
 func CrossJoin2[A, B any](listA []A, listB []B) []Tuple2[A, B] {
 	return CrossJoinBy2(listA, listB, T2[A, B])
 }
@@ -878,6 +895,7 @@ func CrossJoin2[A, B any](listA []A, listB []B) []Tuple2[A, B] {
 // CrossJoin3 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/2WGeHyJj4fK
 func CrossJoin3[A, B, C any](listA []A, listB []B, listC []C) []Tuple3[A, B, C] {
 	return CrossJoinBy3(listA, listB, listC, T3[A, B, C])
 }
@@ -885,6 +903,7 @@ func CrossJoin3[A, B, C any](listA []A, listB []B, listC []C) []Tuple3[A, B, C]
 // CrossJoin4 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/6XhKjLmMnNp
 func CrossJoin4[A, B, C, D any](listA []A, listB []B, listC []C, listD []D) []Tuple4[A, B, C, D] {
 	return CrossJoinBy4(listA, listB, listC, listD, T4[A, B, C, D])
 }
@@ -892,6 +911,7 @@ func CrossJoin4[A, B, C, D any](listA []A, listB []B, listC []C, listD []D) []Tu
 // CrossJoin5 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/7oPqRsTuVwX
 func CrossJoin5[A, B, C, D, E any](listA []A, listB []B, listC []C, listD []D, listE []E) []Tuple5[A, B, C, D, E] {
 	return CrossJoinBy5(listA, listB, listC, listD, listE, T5[A, B, C, D, E])
 }
@@ -899,6 +919,7 @@ func CrossJoin5[A, B, C, D, E any](listA []A, listB []B, listC []C, listD []D, l
 // CrossJoin6 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/8yZ1aB2cD3e
 func CrossJoin6[A, B, C, D, E, F any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F) []Tuple6[A, B, C, D, E, F] {
 	return CrossJoinBy6(listA, listB, listC, listD, listE, listF, T6[A, B, C, D, E, F])
 }
@@ -906,6 +927,7 @@ func CrossJoin6[A, B, C, D, E, F any](listA []A, listB []B, listC []C, listD []D
 // CrossJoin7 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/9f4g5h6i7j8
 func CrossJoin7[A, B, C, D, E, F, G any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, listG []G) []Tuple7[A, B, C, D, E, F, G] {
 	return CrossJoinBy7(listA, listB, listC, listD, listE, listF, listG, T7[A, B, C, D, E, F, G])
 }
@@ -913,6 +935,7 @@ func CrossJoin7[A, B, C, D, E, F, G any](listA []A, listB []B, listC []C, listD
 // CrossJoin8 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/0k1l2m3n4o5
 func CrossJoin8[A, B, C, D, E, F, G, H any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, listG []G, listH []H) []Tuple8[A, B, C, D, E, F, G, H] {
 	return CrossJoinBy8(listA, listB, listC, listD, listE, listF, listG, listH, T8[A, B, C, D, E, F, G, H])
 }
@@ -920,6 +943,7 @@ func CrossJoin8[A, B, C, D, E, F, G, H any](listA []A, listB []B, listC []C, lis
 // CrossJoin9 combines every items from one list with every items from others.
 // It is the cartesian product of lists received as arguments.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/6p7q8r9s0t1
 func CrossJoin9[A, B, C, D, E, F, G, H, I any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, listG []G, listH []H, listI []I) []Tuple9[A, B, C, D, E, F, G, H, I] {
 	return CrossJoinBy9(listA, listB, listC, listD, listE, listF, listG, listH, listI, T9[A, B, C, D, E, F, G, H, I])
 }
@@ -928,6 +952,7 @@ func CrossJoin9[A, B, C, D, E, F, G, H, I any](listA []A, listB []B, listC []C,
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/8Y7btpvuA-C
 func CrossJoinBy2[A, B, Out any](listA []A, listB []B, project func(a A, b B) Out) []Out {
 	size := len(listA) * len(listB)
 	if size == 0 {
@@ -949,6 +974,7 @@ func CrossJoinBy2[A, B, Out any](listA []A, listB []B, project func(a A, b B) Ou
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/3z4y5x6w7v8
 func CrossJoinBy3[A, B, C, Out any](listA []A, listB []B, listC []C, project func(a A, b B, c C) Out) []Out {
 	size := len(listA) * len(listB) * len(listC)
 	if size == 0 {
@@ -972,6 +998,7 @@ func CrossJoinBy3[A, B, C, Out any](listA []A, listB []B, listC []C, project fun
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/8b9c0d1e2f3
 func CrossJoinBy4[A, B, C, D, Out any](listA []A, listB []B, listC []C, listD []D, project func(a A, b B, c C, d D) Out) []Out {
 	size := len(listA) * len(listB) * len(listC) * len(listD)
 	if size == 0 {
@@ -997,6 +1024,7 @@ func CrossJoinBy4[A, B, C, D, Out any](listA []A, listB []B, listC []C, listD []
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/4g5h6i7j8k9
 func CrossJoinBy5[A, B, C, D, E, Out any](listA []A, listB []B, listC []C, listD []D, listE []E, project func(a A, b B, c C, d D, e E) Out) []Out {
 	size := len(listA) * len(listB) * len(listC) * len(listD) * len(listE)
 	if size == 0 {
@@ -1024,6 +1052,7 @@ func CrossJoinBy5[A, B, C, D, E, Out any](listA []A, listB []B, listC []C, listD
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/1l2m3n4o5p6
 func CrossJoinBy6[A, B, C, D, E, F, Out any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, project func(a A, b B, c C, d D, e E, f F) Out) []Out {
 	size := len(listA) * len(listB) * len(listC) * len(listD) * len(listE) * len(listF)
 	if size == 0 {
@@ -1053,6 +1082,7 @@ func CrossJoinBy6[A, B, C, D, E, F, Out any](listA []A, listB []B, listC []C, li
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/7q8r9s0t1u2
 func CrossJoinBy7[A, B, C, D, E, F, G, Out any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, listG []G, project func(a A, b B, c C, d D, e E, f F, g G) Out) []Out {
 	size := len(listA) * len(listB) * len(listC) * len(listD) * len(listE) * len(listF) * len(listG)
 	if size == 0 {
@@ -1084,6 +1114,7 @@ func CrossJoinBy7[A, B, C, D, E, F, G, Out any](listA []A, listB []B, listC []C,
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/3v4w5x6y7z8
 func CrossJoinBy8[A, B, C, D, E, F, G, H, Out any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, listG []G, listH []H, project func(a A, b B, c C, d D, e E, f F, g G, h H) Out) []Out {
 	size := len(listA) * len(listB) * len(listC) * len(listD) * len(listE) * len(listF) * len(listG) * len(listH)
 	if size == 0 {
@@ -1117,6 +1148,7 @@ func CrossJoinBy8[A, B, C, D, E, F, G, H, Out any](listA []A, listB []B, listC [
 // It is the cartesian product of lists received as arguments. The project function
 // is used to create the output values.
 // It returns an empty list if a list is empty.
+// Play: https://go.dev/play/p/9a0b1c2d3e4
 func CrossJoinBy9[A, B, C, D, E, F, G, H, I, Out any](listA []A, listB []B, listC []C, listD []D, listE []E, listF []F, listG []G, listH []H, listI []I, project func(a A, b B, c C, d D, e E, f F, g G, h H, i I) Out) []Out {
 	size := len(listA) * len(listB) * len(listC) * len(listD) * len(listE) * len(listF) * len(listG) * len(listH) * len(listI)
 	if size == 0 {

type_manipulation.go

@@ -3,28 +3,33 @@ package lo
 import "reflect"
 
 // IsNil checks if a value is nil or if it's a reference type with a nil underlying value.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func IsNil(x any) bool {
 	defer func() { recover() }() // nolint:errcheck
 	return x == nil || reflect.ValueOf(x).IsNil()
 }
 
 // IsNotNil checks if a value is not nil or if it's not a reference type with a nil underlying value.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func IsNotNil(x any) bool {
 	return !IsNil(x)
 }
 
 // ToPtr returns a pointer copy of value.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func ToPtr[T any](x T) *T {
 	return &x
 }
 
 // Nil returns a nil pointer of type.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func Nil[T any]() *T {
 	return nil
 }
 
 // EmptyableToPtr returns a pointer copy of value if it's nonzero.
 // Otherwise, returns nil pointer.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func EmptyableToPtr[T any](x T) *T {
 	// 🤮
 	isZero := reflect.ValueOf(&x).Elem().IsZero()
@@ -36,6 +41,7 @@ func EmptyableToPtr[T any](x T) *T {
 }
 
 // FromPtr returns the pointer value or empty.
+// Play: https://go.dev/play/p/mhD9CwO3X0m
 func FromPtr[T any](x *T) T {
 	if x == nil {
 		return Empty[T]()
@@ -45,6 +51,7 @@ func FromPtr[T any](x *T) T {
 }
 
 // FromPtrOr returns the pointer value or the fallback value.
+// Play: https://go.dev/play/p/mhD9CwO3X0m
 func FromPtrOr[T any](x *T, fallback T) T {
 	if x == nil {
 		return fallback
@@ -54,6 +61,7 @@ func FromPtrOr[T any](x *T, fallback T) T {
 }
 
 // ToSlicePtr returns a slice of pointer copy of value.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func ToSlicePtr[T any](collection []T) []*T {
 	result := make([]*T, len(collection))
 
@@ -65,6 +73,7 @@ func ToSlicePtr[T any](collection []T) []*T {
 
 // FromSlicePtr returns a slice with the pointer values.
 // Returns a zero value in case of a nil pointer element.
+// Play: https://go.dev/play/p/lbunFvzlUDX
 func FromSlicePtr[T any](collection []*T) []T {
 	return Map(collection, func(x *T, _ int) T {
 		if x == nil {
@@ -86,6 +95,7 @@ func FromSlicePtrOr[T any](collection []*T, fallback T) []T {
 }
 
 // ToAnySlice returns a slice with all elements mapped to `any` type
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func ToAnySlice[T any](collection []T) []any {
 	result := make([]any, len(collection))
 	for i := range collection {
@@ -96,6 +106,7 @@ func ToAnySlice[T any](collection []T) []any {
 
 // FromAnySlice returns an `any` slice with all elements mapped to a type.
 // Returns false in case of type conversion failure.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func FromAnySlice[T any](in []any) (out []T, ok bool) {
 	defer func() {
 		if r := recover(); r != nil {
@@ -112,24 +123,28 @@ func FromAnySlice[T any](in []any) (out []T, ok bool) {
 }
 
 // Empty returns the zero value (https://go.dev/ref/spec#The_zero_value).
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func Empty[T any]() T {
 	var zero T
 	return zero
 }
 
 // IsEmpty returns true if argument is a zero value.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func IsEmpty[T comparable](v T) bool {
 	var zero T
 	return zero == v
 }
 
 // IsNotEmpty returns true if argument is not a zero value.
+// Play: https://go.dev/play/p/P2sD0PMXw4F
 func IsNotEmpty[T comparable](v T) bool {
 	var zero T
 	return zero != v
 }
 
 // Coalesce returns the first non-empty arguments. Arguments must be comparable.
+// Play: https://go.dev/play/p/Gyo9otyvFHH
 func Coalesce[T comparable](values ...T) (result T, ok bool) {
 	for i := range values {
 		if values[i] != result {
@@ -143,12 +158,14 @@ func Coalesce[T comparable](values ...T) (result T, ok bool) {
 }
 
 // CoalesceOrEmpty returns the first non-empty arguments. Arguments must be comparable.
+// Play: https://go.dev/play/p/Gyo9otyvFHH
 func CoalesceOrEmpty[T comparable](v ...T) T {
 	result, _ := Coalesce(v...)
 	return result
 }
 
 // CoalesceSlice returns the first non-zero slice.
+// Play: https://go.dev/play/p/Gyo9otyvFHH
 func CoalesceSlice[T any](v ...[]T) ([]T, bool) {
 	for i := range v {
 		if v[i] != nil && len(v[i]) > 0 {
@@ -159,6 +176,7 @@ func CoalesceSlice[T any](v ...[]T) ([]T, bool) {
 }
 
 // CoalesceSliceOrEmpty returns the first non-zero slice.
+// Play: https://go.dev/play/p/Gyo9otyvFHH
 func CoalesceSliceOrEmpty[T any](v ...[]T) []T {
 	for i := range v {
 		if v[i] != nil && len(v[i]) > 0 {
@@ -169,6 +187,7 @@ func CoalesceSliceOrEmpty[T any](v ...[]T) []T {
 }
 
 // CoalesceMap returns the first non-zero map.
+// Play: https://go.dev/play/p/Gyo9otyvFHH
 func CoalesceMap[K comparable, V any](v ...map[K]V) (map[K]V, bool) {
 	for i := range v {
 		if v[i] != nil && len(v[i]) > 0 {
@@ -179,6 +198,7 @@ func CoalesceMap[K comparable, V any](v ...map[K]V) (map[K]V, bool) {
 }
 
 // CoalesceMapOrEmpty returns the first non-zero map.
+// Play: https://go.dev/play/p/Gyo9otyvFHH
 func CoalesceMapOrEmpty[K comparable, V any](v ...map[K]V) map[K]V {
 	for i := range v {
 		if v[i] != nil && len(v[i]) > 0 {

types.go

@@ -13,6 +13,7 @@ type Tuple2[A, B any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/yrtn7QJTmL_E
 func (t Tuple2[A, B]) Unpack() (A, B) {
 	return t.A, t.B
 }
@@ -25,6 +26,7 @@ type Tuple3[A, B, C any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/yrtn7QJTmL_E
 func (t Tuple3[A, B, C]) Unpack() (A, B, C) {
 	return t.A, t.B, t.C
 }
@@ -38,6 +40,7 @@ type Tuple4[A, B, C, D any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/yrtn7QJTmL_E
 func (t Tuple4[A, B, C, D]) Unpack() (A, B, C, D) {
 	return t.A, t.B, t.C, t.D
 }
@@ -52,6 +55,7 @@ type Tuple5[A, B, C, D, E any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/7J4KrtgtK3M
 func (t Tuple5[A, B, C, D, E]) Unpack() (A, B, C, D, E) {
 	return t.A, t.B, t.C, t.D, t.E
 }
@@ -67,6 +71,7 @@ type Tuple6[A, B, C, D, E, F any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/7J4KrtgtK3M
 func (t Tuple6[A, B, C, D, E, F]) Unpack() (A, B, C, D, E, F) {
 	return t.A, t.B, t.C, t.D, t.E, t.F
 }
@@ -83,6 +88,7 @@ type Tuple7[A, B, C, D, E, F, G any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/Ow9Zgf_zeiA
 func (t Tuple7[A, B, C, D, E, F, G]) Unpack() (A, B, C, D, E, F, G) {
 	return t.A, t.B, t.C, t.D, t.E, t.F, t.G
 }
@@ -100,6 +106,7 @@ type Tuple8[A, B, C, D, E, F, G, H any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/Ow9Zgf_zeiA
 func (t Tuple8[A, B, C, D, E, F, G, H]) Unpack() (A, B, C, D, E, F, G, H) {
 	return t.A, t.B, t.C, t.D, t.E, t.F, t.G, t.H
 }
@@ -118,6 +125,7 @@ type Tuple9[A, B, C, D, E, F, G, H, I any] struct {
 }
 
 // Unpack returns values contained in tuple.
+// Play: https://go.dev/play/p/Ow9Zgf_zeiA
 func (t Tuple9[A, B, C, D, E, F, G, H, I]) Unpack() (A, B, C, D, E, F, G, H, I) {
 	return t.A, t.B, t.C, t.D, t.E, t.F, t.G, t.H, t.I
 }