feat: add ReduceConcurrent

docs/api/packages/random.md

@@ -26,6 +26,7 @@ import (
 -   [RandInt](#RandInt)
 -   [RandString](#RandString)
 -   [RandFromGivenSlice](#RandFromGivenSlice)
+-   [RandSliceFromGivenSlice](#RandSliceFromGivenSlice)
 -   [RandUpper](#RandUpper)
 -   [RandLower](#RandLower)
 -   [RandNumeral](#RandNumeral)
@@ -150,6 +151,33 @@ func main() {
 }
 ```
 
+### <span id="RandSliceFromGivenSlice">RandSliceFromGivenSlice</span>
+
+<p>从给定切片中生成长度为 num 的随机切片</p>
+
+<b>函数签名:</b>
+
+```go
+func RandSliceFromGivenSlice[T any](slice []T, num int, repeatable bool) []T
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[运行]()</span></b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+    	goods := []string{"apple", "banana", "cherry", "elderberry", "fig", "grape", "honeydew", "kiwi", "lemon","mango", "nectarine", "orange"}
+	chosen3goods := random.RandSliceFromGivenSlice(goods, 3, false)
+	fmt.Println(chosen3goods)
+}
+```
+
 ### <span id="RandUpper">RandUpper</span>
 
 <p>生成给定长度的随机大写字母字符串</p>

docs/api/packages/slice.md

@@ -53,6 +53,7 @@ import (
 -   [Flatten](#Flatten)
 -   [FlattenDeep](#FlattenDeep)
 -   [ForEach](#ForEach)
+-   [ForEachConcurrent](#ForEachConcurrent)
 -   [ForEachWithBreak](#ForEachWithBreak)
 -   [GroupBy](#GroupBy)
 -   [GroupWith](#GroupWith)
@@ -69,6 +70,7 @@ import (
 -   [Merge](#Merge)
 -   [Reverse](#Reverse)
 -   [Reduce<sup>deprecated</sup>](#Reduce)
+-   [ReduceConcurrent](#ReduceConcurrent)
 -   [ReduceBy](#ReduceBy)
 -   [ReduceRight](#ReduceRight)
 -   [Replace](#Replace)
@@ -909,7 +911,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func FilterConcurrent[T any](slice []T, numOfThreads int, predicate func(index int, item T) bool) []T
+func FilterConcurrent[T any](slice []T, predicate func(index int, item T) bool, numThreads int) []T
 ```
 
 <b>示例:</b>
@@ -927,7 +929,7 @@ func main() {
         return num%2 == 0
     }
 
-    result := slice.FilterConcurrent(nums, 2, isEven)
+    result := slice.FilterConcurrent(nums, isEven, 2)
 
     fmt.Println(result)
 
@@ -1179,6 +1181,43 @@ func main() {
 }
 ```
 
+### <span id="ForEachConcurrent">ForEachConcurrent</span>
+
+<p>对slice并发执行foreach操作。</p>
+
+<b>函数签名:</b>
+
+```go
+func ForEachConcurrent[T any](slice []T, iteratee func(index int, item T), numThreads int)
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[运行]()</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5, 6, 7, 8}
+
+    result := make([]int, len(nums))
+
+    addOne := func(index int, value int) {
+        result[index] = value + 1
+    }
+
+    slice.ForEachConcurrent(nums, addOne, 4)
+
+    fmt.Println(result)
+
+    // Output:
+    // [2 3 4 5 6 7 8 9]
+}
+```
+
+
 ### <span id="ForEachWithBreak">ForEachWithBreak</span>
 
 <p>遍历切片的元素并为每个元素调用iteratee函数，当iteratee函数返回false时，终止遍历。</p>
@@ -1527,7 +1566,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func MapConcurrent[T any, U any](slice []T, numOfThreads int, iteratee func(index int, item T) U) []U
+func MapConcurrent[T any, U any](slice []T, iteratee func(index int, item T) U, numThreads int) []U
 ```
 
 <b>示例:</b>
@@ -1540,13 +1579,15 @@ import (
 
 func main() {
     nums := []int{1, 2, 3, 4, 5, 6}
-	
-    result := slice.MapConcurrent(nums, 4, func(_, n int) int { return n * n })
+    
+    result := slice.MapConcurrent(nums, func(_, n int) int {     
+        return n * n 
+    }, 4)
 
-	fmt.Println(result)
+    fmt.Println(result)
 
-	// Output:
-	// [1 4 9 16 25 36]
+    // Output:
+    // [1 4 9 16 25 36]
 }
 ```
 
@@ -1719,6 +1760,38 @@ func main() {
 }
 ```
 
+### <span id="ReduceConcurrent">ReduceConcurrent</span>
+
+<p>对切片元素执行并发reduce操作。</p>
+
+<b>函数签名:</b>
+
+```go
+func ReduceConcurrent[T any](slice []T, initial T, reducer func(index int, item T, agg T) T, numThreads int) T
+```
+
+<b>示例:<span style="float:right;display:inline-block;">[运行]()</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+    
+    result := slice.ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+        return agg + item
+    }, 1)
+
+    fmt.Println(result)
+
+    // Output:
+    // 55
+}
+```
+
 ### <span id="ReduceBy">ReduceBy</span>
 
 <p>对切片元素执行reduce操作。</p>
@@ -2439,7 +2512,7 @@ func main() {
 <b>函数签名:</b>
 
 ```go
-func UniqueByConcurrent[T comparable](slice []T, numOfThreads int, comparator func(item T, other T) bool) []T
+func UniqueByConcurrent[T comparable](slice []T, comparator func(item T, other T) bool, numThreads int) []T
 ```
 
 <b>示例:</b>
@@ -2452,10 +2525,9 @@ import (
 
 func main() {
     nums := []int{1, 2, 3, 1, 2, 4, 5, 6, 4, 7}
-    numOfThreads := 4
     comparator := func(item int, other int) bool { return item == other }
 
-    result := slice.UniqueByConcurrent(nums, numOfThreads, comparator)
+    result := slice.UniqueByConcurrent(nums, comparator, 4)
 
     fmt.Println(result)
     // Output:

docs/en/api/packages/random.md

@@ -25,6 +25,8 @@ import (
 -   [RandBytes](#RandBytes)
 -   [RandInt](#RandInt)
 -   [RandString](#RandString)
+-   [RandFromGivenSlice](#RandFromGivenSlice)
+-   [RandSliceFromGivenSlice](#RandSliceFromGivenSlice)
 -   [RandUpper](#RandUpper)
 -   [RandLower](#RandLower)
 -   [RandNumeral](#RandNumeral)
@@ -148,6 +150,33 @@ func main() {
 }
 ```
 
+### <span id="RandSliceFromGivenSlice">RandSliceFromGivenSlice</span>
+
+<p>Generate a random slice of length num from given slice.</p>
+
+<b>Signature:</b>
+
+```go
+func RandSliceFromGivenSlice[T any](slice []T, num int, repeatable bool) []T
+```
+
+<b>Example:<span style="float:right;display:inline-block;">[Run]()</span></b>
+
+```go
+package main
+
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/random"
+)
+
+func main() {
+    	goods := []string{"apple", "banana", "cherry", "elderberry", "fig", "grape", "honeydew", "kiwi", "lemon", "mango", "nectarine", "orange"}
+	chosen3goods := random.RandSliceFromGivenSlice(goods, 3, false)
+	fmt.Println(chosen3goods)
+}
+```
+
 ### <span id="RandUpper">RandUpper</span>
 
 <p>Generate a random upper case string</p>

docs/en/api/packages/slice.md

@@ -53,6 +53,7 @@ import (
 -   [Flatten](#Flatten)
 -   [FlattenDeep](#FlattenDeep)
 -   [ForEach](#ForEach)
+-   [ForEachConcurrent](#ForEachConcurrent)
 -   [ForEachWithBreak](#ForEachWithBreak)
 -   [GroupBy](#GroupBy)
 -   [GroupWith](#GroupWith)
@@ -69,6 +70,7 @@ import (
 -   [Merge](#Merge)
 -   [Reverse](#Reverse)
 -   [Reduce<sup>deprecated</sup>](#Reduce)
+-   [ReduceConcurrent](#ReduceConcurrent)
 -   [ReduceBy](#ReduceBy)
 -   [ReduceRight](#ReduceRight)
 -   [Replace](#Replace)
@@ -907,7 +909,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func FilterConcurrent[T any](slice []T, numOfThreads int, predicate func(index int, item T) bool) []T
+func FilterConcurrent[T any](slice []T, predicate func(index int, item T) bool, numThreads int) []T
 ```
 
 <b>Example:</b>
@@ -925,7 +927,7 @@ func main() {
         return num%2 == 0
     }
 
-    result := slice.FilterConcurrent(nums, 2, isEven)
+    result := slice.FilterConcurrent(nums, isEven, 2)
 
     fmt.Println(result)
 
@@ -1177,6 +1179,42 @@ func main() {
 }
 ```
 
+### <span id="ForEachConcurrent">ForEachConcurrent</span>
+
+<p>Applies the iteratee function to each item in the slice concurrently.</p>
+
+<b>Signature:</b>
+
+```go
+func ForEachConcurrent[T any](slice []T, iteratee func(index int, item T), numThreads int)
+```
+
+<b>Example:<span style="float:right;display:inline-block;">[Run]()</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5, 6, 7, 8}
+
+    result := make([]int, len(nums))
+
+    addOne := func(index int, value int) {
+        result[index] = value + 1
+    }
+
+    slice.ForEachConcurrent(nums, addOne, 4)
+
+    fmt.Println(result)
+
+    // Output:
+    // [2 3 4 5 6 7 8 9]
+}
+```
+
 ### <span id="ForEachWithBreak">ForEachWithBreak</span>
 
 <p>Iterates over elements of slice and invokes function for each element, when iteratee return false, will break the for each loop.</p>
@@ -1525,7 +1563,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func MapConcurrent[T any, U any](slice []T, numOfThreads int, iteratee func(index int, item T) U) []U
+func MapConcurrent[T any, U any](slice []T, iteratee func(index int, item T) U, numThreads int) []U
 ```
 
 <b>Example:</b>
@@ -1539,7 +1577,7 @@ import (
 func main() {
     nums := []int{1, 2, 3, 4, 5, 6}
     
-    result := slice.MapConcurrent(nums, 4, func(_, n int) int { return n * n })
+    result := slice.MapConcurrent(nums, func(_, n int) int { return n * n }, 4)
 
     fmt.Println(result)
 
@@ -1717,6 +1755,39 @@ func main() {
 }
 ```
 
+### <span id="ReduceConcurrent">ReduceConcurrent</span>
+
+<p>Reduces the slice to a single value by applying the reducer function to each item in the slice concurrently.</p>
+
+<b>Signature:</b>
+
+```go
+func ReduceConcurrent[T any](slice []T, initial T, reducer func(index int, item T, agg T) T, numThreads int) T
+```
+
+<b>Example:<span style="float:right;display:inline-block;">[运行]()</span></b>
+
+```go
+import (
+    "fmt"
+    "github.com/duke-git/lancet/v2/slice"
+)
+
+func main() {
+    nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+    
+    result := slice.ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+        return agg + item
+    }, 1)
+
+    fmt.Println(result)
+
+    // Output:
+    // 55
+}
+```
+
+
 ### <span id="ReduceBy">ReduceBy</span>
 
 <p>Produces a value from slice by accumulating the result of each element as passed through the reducer function.</p>
@@ -2437,7 +2508,7 @@ func main() {
 <b>Signature:</b>
 
 ```go
-func UniqueByConcurrent[T comparable](slice []T, numOfThreads int, comparator func(item T, other T) bool) []T
+func UniqueByConcurrent[T comparable](slice []T, comparator func(item T, other T) bool, numThreads int) []T
 ```
 
 <b>Example:</b>
@@ -2450,10 +2521,9 @@ import (
 
 func main() {
     nums := []int{1, 2, 3, 1, 2, 4, 5, 6, 4, 7}
-    numOfThreads := 4
     comparator := func(item int, other int) bool { return item == other }
 
-    result := slice.UniqueByConcurrent(nums, numOfThreads, comparator)
+    result := slice.UniqueByConcurrent(nums,comparator, 4)
 
     fmt.Println(result)
     // Output:

random/random.go

@@ -186,6 +186,7 @@ func RandStringSlice(charset string, sliceLen, strLen int) []string {
 }
 
 // RandFromGivenSlice generate a random element from given slice.
+// Play: todo
 func RandFromGivenSlice[T any](slice []T) T {
 	if len(slice) == 0 {
 		var zero T
@@ -194,6 +195,35 @@ func RandFromGivenSlice[T any](slice []T) T {
 	return slice[rand.Intn(len(slice))]
 }
 
+// RandSliceFromGivenSlice generate a random slice of length num from given slice.
+//   - If repeatable is true, the generated slice may contain duplicate elements.
+//
+// Play: todo
+func RandSliceFromGivenSlice[T any](slice []T, num int, repeatable bool) []T {
+	if num <= 0 || len(slice) == 0 {
+		return slice
+	}
+
+	if !repeatable && num > len(slice) {
+		num = len(slice)
+	}
+
+	result := make([]T, num)
+	if repeatable {
+		for i := range result {
+			result[i] = slice[rand.Intn(len(slice))]
+		}
+	} else {
+		shuffled := make([]T, len(slice))
+		copy(shuffled, slice)
+		rand.Shuffle(len(shuffled), func(i, j int) {
+			shuffled[i], shuffled[j] = shuffled[j], shuffled[i]
+		})
+		result = shuffled[:num]
+	}
+	return result
+}
+
 // RandUpper generate a random upper case string of specified length.
 // Play: https://go.dev/play/p/29QfOh0DVuh
 func RandUpper(length int) string {

random/random_example_test.go

@@ -47,18 +47,15 @@ func ExampleRandFromGivenSlice() {
 	goods := []string{"apple", "banana", "cherry", "elderberry", "fig", "grape", "honeydew", "kiwi", "lemon",
 		"mango", "nectarine", "orange"}
 
-	isInGoods := false
 	result := RandFromGivenSlice(goods)
-	for _, good := range goods {
-		if good == result {
-			isInGoods = true
-			break
-		}
-	}
-	fmt.Println(isInGoods)
+	fmt.Println(result)
+}
 
-	// Output:
-	// true
+func ExampleRandSliceFromGivenSlice() {
+	goods := []string{"apple", "banana", "cherry", "elderberry", "fig", "grape", "honeydew", "kiwi", "lemon",
+		"mango", "nectarine", "orange"}
+	chosen3goods := RandSliceFromGivenSlice(goods, 3, false)
+	fmt.Println(chosen3goods)
 }
 
 func ExampleRandUpper() {

random/random_test.go

@@ -292,6 +292,46 @@ func TestRandFromGivenSlice(t *testing.T) {
 	assert.Equal(0, emtpyIntResult)
 }
 
+func TestRandSliceFromGivenSlice(t *testing.T) {
+	t.Parallel()
+	assert := internal.NewAssert(t, "TestRandSliceFromGivenSlice")
+
+	randomSet := []any{"a", 8, "王", true, 1.1}
+	repeatableResult := RandSliceFromGivenSlice(randomSet, 8, true)
+	assert.Equal(8, len(repeatableResult))
+	unrepeatableResult := RandSliceFromGivenSlice(randomSet, 8, false)
+	assert.Equal(len(randomSet), len(unrepeatableResult))
+
+	var findCount int
+	for _, v := range repeatableResult {
+		for _, vv := range randomSet {
+			if v == vv {
+				findCount++
+			}
+		}
+	}
+	assert.Equal(8, findCount)
+	findCount = 0
+
+	for _, v := range unrepeatableResult {
+		for _, vv := range randomSet {
+			if v == vv {
+				findCount++
+			}
+		}
+	}
+	assert.Equal(len(randomSet), findCount)
+
+	emptyAnyRandomSet := []any{}
+	emptyAnyResult := RandSliceFromGivenSlice(emptyAnyRandomSet, 3, true)
+	assert.Equal([]any{}, emptyAnyResult)
+
+	emptyIntRandomSet := []int{}
+	emtpyIntResult := RandSliceFromGivenSlice(emptyIntRandomSet, 3, true)
+	assert.Equal([]int{}, emtpyIntResult)
+
+}
+
 func TestRandBool(t *testing.T) {
 	t.Parallel()
 	assert := internal.NewAssert(t, "TestRandBool")

slice/slice_concurrent.go

@@ -8,13 +8,54 @@ import (
 	"sync"
 )
 
+// ForEachConcurrent applies the iteratee function to each item in the slice concurrently.
+// Play: todo
+func ForEachConcurrent[T any](slice []T, iteratee func(index int, item T), numThreads int) {
+	sliceLen := len(slice)
+	if sliceLen == 0 {
+		return
+	}
+
+	if numThreads <= 0 {
+		numThreads = 1
+	}
+
+	var wg sync.WaitGroup
+
+	chunkSize := (sliceLen + numThreads - 1) / numThreads
+
+	for i := 0; i < numThreads; i++ {
+		start := i * chunkSize
+		end := start + chunkSize
+
+		if start >= sliceLen {
+			break
+		}
+
+		if end > sliceLen {
+			end = sliceLen
+		}
+
+		wg.Add(1)
+		go func(start, end int) {
+			defer wg.Done()
+
+			for j := start; j < end; j++ {
+				iteratee(j, slice[j])
+			}
+		}(start, end)
+	}
+
+	wg.Wait()
+}
+
 // MapConcurrent applies the iteratee function to each item in the slice concurrently.
 // Play: todo
-func MapConcurrent[T any, U any](slice []T, numOfThreads int, iteratee func(index int, item T) U) []U {
+func MapConcurrent[T any, U any](slice []T, iteratee func(index int, item T) U, numThreads int) []U {
 	result := make([]U, len(slice))
 	var wg sync.WaitGroup
 
-	workerChan := make(chan struct{}, numOfThreads)
+	workerChan := make(chan struct{}, numThreads)
 
 	for index, item := range slice {
 		wg.Add(1)
@@ -35,13 +76,57 @@ func MapConcurrent[T any, U any](slice []T, numOfThreads int, iteratee func(inde
 	return result
 }
 
+// ReduceConcurrent reduces the slice to a single value by applying the reducer function to each item in the slice concurrently.
+// Play: todo
+func ReduceConcurrent[T any](slice []T, initial T, reducer func(index int, item T, agg T) T, numThreads int) T {
+	if numThreads <= 0 {
+		numThreads = 1
+	}
+
+	var wg sync.WaitGroup
+	var mu sync.Mutex
+
+	sliceLen := len(slice)
+	chunkSize := (sliceLen + numThreads - 1) / numThreads
+	results := make([]T, numThreads)
+
+	for i := 0; i < numThreads; i++ {
+		start := i * chunkSize
+		end := start + chunkSize
+		if end > sliceLen {
+			end = sliceLen
+		}
+
+		wg.Add(1)
+		go func(i, start, end int) {
+			defer wg.Done()
+			tempResult := initial
+			for j := start; j < end; j++ {
+				tempResult = reducer(j, slice[j], tempResult)
+			}
+			mu.Lock()
+			results[i] = tempResult
+			mu.Unlock()
+		}(i, start, end)
+	}
+
+	wg.Wait()
+
+	result := initial
+	for i, r := range results {
+		result = reducer(i, result, r)
+	}
+
+	return result
+}
+
 // FilterConcurrent applies the provided filter function `predicate` to each element of the input slice concurrently.
 // Play: todo
-func FilterConcurrent[T any](slice []T, numOfThreads int, predicate func(index int, item T) bool) []T {
+func FilterConcurrent[T any](slice []T, predicate func(index int, item T) bool, numThreads int) []T {
 	result := make([]T, 0)
 	var wg sync.WaitGroup
 
-	workerChan := make(chan struct{}, numOfThreads)
+	workerChan := make(chan struct{}, numThreads)
 
 	for index, item := range slice {
 		wg.Add(1)
@@ -66,20 +151,20 @@ func FilterConcurrent[T any](slice []T, numOfThreads int, predicate func(index i
 
 // UniqueByParallel removes duplicate elements from the slice by parallel
 // The comparator function is used to compare the elements
-// The numOfThreads parameter specifies the number of threads to use
-// If numOfThreads is less than or equal to 0, it will be set to 1
+// The numThreads parameter specifies the number of threads to use
+// If numThreads is less than or equal to 0, it will be set to 1
 // The comparator function should return true if the two elements are equal
 // Play: todo
-func UniqueByConcurrent[T comparable](slice []T, numOfThreads int, comparator func(item T, other T) bool) []T {
-	if numOfThreads <= 0 {
-		numOfThreads = 1
-	} else if numOfThreads > len(slice) {
-		numOfThreads = len(slice)
+func UniqueByConcurrent[T comparable](slice []T, comparator func(item T, other T) bool, numThreads int) []T {
+	if numThreads <= 0 {
+		numThreads = 1
+	} else if numThreads > len(slice) {
+		numThreads = len(slice)
 	}
 
 	maxThreads := runtime.NumCPU()
-	if numOfThreads > maxThreads {
-		numOfThreads = maxThreads
+	if numThreads > maxThreads {
+		numThreads = maxThreads
 	}
 
 	removeDuplicate := func(items []T, comparator func(item T, other T) bool) []T {
@@ -99,9 +184,9 @@ func UniqueByConcurrent[T comparable](slice []T, numOfThreads int, comparator fu
 		return result
 	}
 
-	chunkSize := (len(slice) + numOfThreads - 1) / numOfThreads
+	chunkSize := (len(slice) + numThreads - 1) / numThreads
 
-	chunks := make([][]T, 0, numOfThreads)
+	chunks := make([][]T, 0, numThreads)
 	for i := 0; i < len(slice); i += chunkSize {
 		end := i + chunkSize
 		if end > len(slice) {
@@ -114,7 +199,7 @@ func UniqueByConcurrent[T comparable](slice []T, numOfThreads int, comparator fu
 		index int
 		data  []T
 	}
-	resultCh := make(chan resultChunk, numOfThreads)
+	resultCh := make(chan resultChunk, numThreads)
 	var wg sync.WaitGroup
 
 	for i, chunk := range chunks {

slice/slice_example_test.go

@@ -254,7 +254,7 @@ func ExampleFilterConcurrent() {
 		return num%2 == 0
 	}
 
-	result := FilterConcurrent(nums, 2, isEven)
+	result := FilterConcurrent(nums, isEven, 2)
 
 	fmt.Println(result)
 
@@ -429,6 +429,23 @@ func ExampleForEach() {
 	// [2 3 4]
 }
 
+func ExampleForEachConcurrent() {
+	nums := []int{1, 2, 3, 4, 5, 6, 7, 8}
+
+	result := make([]int, len(nums))
+
+	addOne := func(index int, value int) {
+		result[index] = value + 1
+	}
+
+	ForEachConcurrent(nums, addOne, 4)
+
+	fmt.Println(result)
+
+	// Output:
+	// [2 3 4 5 6 7 8 9]
+}
+
 func ExampleForEachWithBreak() {
 	numbers := []int{1, 2, 3, 4, 5}
 
@@ -510,6 +527,18 @@ func ExampleReduce() {
 	// 6
 }
 
+func ExampleReduceConcurrent() {
+	nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+	result := ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+		return agg + item
+	}, 1)
+
+	fmt.Println(result)
+
+	// Output:
+	// 55
+}
+
 func ExampleReduceBy() {
 	result1 := ReduceBy([]int{1, 2, 3, 4}, 0, func(_ int, item int, agg int) int {
 		return agg + item
@@ -1203,10 +1232,9 @@ func ExampleLeftPadding() {
 
 func ExampleUniqueByConcurrent() {
 	nums := []int{1, 2, 3, 1, 2, 4, 5, 6, 4, 7}
-	numOfThreads := 4
 	comparator := func(item int, other int) bool { return item == other }
 
-	result := UniqueByConcurrent(nums, numOfThreads, comparator)
+	result := UniqueByConcurrent(nums, comparator, 4)
 
 	fmt.Println(result)
 
@@ -1216,7 +1244,7 @@ func ExampleUniqueByConcurrent() {
 
 func ExampleMapConcurrent() {
 	nums := []int{1, 2, 3, 4, 5, 6}
-	result := MapConcurrent(nums, 4, func(_, n int) int { return n * n })
+	result := MapConcurrent(nums, func(_, n int) int { return n * n }, 4)
 
 	fmt.Println(result)
 

slice/slice_test.go

@@ -410,6 +410,73 @@ func TestForEach(t *testing.T) {
 	assert.Equal([]int{3, 4, 5, 6, 7}, result)
 }
 
+func TestForEachConcurrent(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestForEachConcurrent")
+
+	t.Run("single thread", func(t *testing.T) {
+		numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
+		result := make([]int, len(numbers))
+
+		addOne := func(index int, value int) {
+			result[index] = value + 1
+		}
+
+		ForEachConcurrent(numbers, addOne, 1)
+
+		expected := []int{2, 3, 4, 5, 6, 7, 8, 9, 10}
+		assert.Equal(expected, result)
+	})
+
+	t.Run("normal", func(t *testing.T) {
+		numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
+		result := make([]int, len(numbers))
+
+		addOne := func(index int, value int) {
+			result[index] = value + 1
+		}
+
+		ForEachConcurrent(numbers, addOne, 4)
+
+		expected := []int{2, 3, 4, 5, 6, 7, 8, 9, 10}
+		assert.Equal(expected, result)
+	})
+
+	t.Run("negative threads", func(t *testing.T) {
+		numbers := []int{1, 2, 3, 4, 5, 6, 7, 8, 9}
+		result := make([]int, len(numbers))
+
+		addOne := func(index int, value int) {
+			result[index] = value + 1
+		}
+
+		ForEachConcurrent(numbers, addOne, -4)
+
+		expected := []int{2, 3, 4, 5, 6, 7, 8, 9, 10}
+		assert.Equal(expected, result)
+	})
+
+	t.Run("high number threads", func(t *testing.T) {
+		numbers := make([]int, 1000)
+		for i := range numbers {
+			numbers[i] = i
+		}
+
+		result := make([]int, len(numbers))
+
+		addOne := func(index int, value int) {
+			result[index] = value + 1
+		}
+
+		ForEachConcurrent(numbers, addOne, 50)
+
+		for i, item := range numbers {
+			assert.Equal(item+1, result[i])
+		}
+	})
+}
+
 func TestForEachWithBreak(t *testing.T) {
 	t.Parallel()
 
@@ -520,6 +587,44 @@ func TestReduce(t *testing.T) {
 	}
 }
 
+func TestReduceConcurrent(t *testing.T) {
+	t.Parallel()
+
+	assert := internal.NewAssert(t, "TestReduceConcurrent")
+
+	t.Run("basic", func(t *testing.T) {
+		nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+		result := ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+			return agg + item
+		}, 4)
+		assert.Equal(55, result)
+	})
+
+	t.Run("empty slice", func(t *testing.T) {
+		nums := []int{}
+		result := ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+			return agg + item
+		}, 4)
+		assert.Equal(0, result)
+	})
+
+	t.Run("single thread", func(t *testing.T) {
+		nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+		result := ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+			return agg + item
+		}, 1)
+		assert.Equal(55, result)
+	})
+
+	t.Run("negative threads", func(t *testing.T) {
+		nums := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
+		result := ReduceConcurrent(nums, 0, func(_ int, item, agg int) int {
+			return agg + item
+		}, -1)
+		assert.Equal(55, result)
+	})
+}
+
 func TestReduceBy(t *testing.T) {
 	t.Parallel()
 
@@ -1509,10 +1614,9 @@ func TestUniqueByConcurrent(t *testing.T) {
 	assert := internal.NewAssert(t, "TestUniqueByConcurrent")
 
 	nums := []int{1, 2, 3, 1, 2, 4, 5, 6, 4, 7}
-	numOfThreads := 4
 	comparator := func(item int, other int) bool { return item == other }
 
-	result := UniqueByConcurrent(nums, numOfThreads, comparator)
+	result := UniqueByConcurrent(nums, comparator, 4)
 
 	assert.Equal([]int{1, 2, 3, 4, 5, 6, 7}, result)
 }
@@ -1523,21 +1627,21 @@ func TestMapConcurrent(t *testing.T) {
 	assert := internal.NewAssert(t, "TestMapConcurrent")
 
 	t.Run("empty slice", func(t *testing.T) {
-		actual := MapConcurrent([]int{}, 4, func(_, n int) int { return n * n })
+		actual := MapConcurrent([]int{}, func(_, n int) int { return n * n }, 4)
 		assert.Equal([]int{}, actual)
 	})
 
 	t.Run("single thread", func(t *testing.T) {
 		nums := []int{1, 2, 3, 4, 5, 6}
 		expected := []int{1, 4, 9, 16, 25, 36}
-		actual := MapConcurrent(nums, 1, func(_, n int) int { return n * n })
+		actual := MapConcurrent(nums, func(_, n int) int { return n * n }, 1)
 		assert.Equal(expected, actual)
 	})
 
 	t.Run("multiple threads", func(t *testing.T) {
 		nums := []int{1, 2, 3, 4, 5, 6}
 		expected := []int{1, 4, 9, 16, 25, 36}
-		actual := MapConcurrent(nums, 4, func(_, n int) int { return n * n })
+		actual := MapConcurrent(nums, func(_, n int) int { return n * n }, 4)
 		assert.Equal(expected, actual)
 	})
 
@@ -1549,21 +1653,21 @@ func TestFilterConcurrent(t *testing.T) {
 	assert := internal.NewAssert(t, "TestFilterConcurrent")
 
 	t.Run("empty slice", func(t *testing.T) {
-		actual := FilterConcurrent([]int{}, 4, func(_, n int) bool { return n != 0 })
+		actual := FilterConcurrent([]int{}, func(_, n int) bool { return n != 0 }, 4)
 		assert.Equal([]int{}, actual)
 	})
 
 	t.Run("single thread", func(t *testing.T) {
 		nums := []int{1, 2, 3, 4, 5, 6}
 		expected := []int{4, 5, 6}
-		actual := FilterConcurrent(nums, 1, func(_, n int) bool { return n > 3 })
+		actual := FilterConcurrent(nums, func(_, n int) bool { return n > 3 }, 1)
 		assert.Equal(expected, actual)
 	})
 
 	t.Run("multiple threads", func(t *testing.T) {
 		nums := []int{1, 2, 3, 4, 5, 6}
 		expected := []int{4, 5, 6}
-		actual := FilterConcurrent(nums, 4, func(_, n int) bool { return n > 3 })
+		actual := FilterConcurrent(nums, func(_, n int) bool { return n > 3 }, 4)
 		assert.Equal(expected, actual)
 	})