Creates a stream whose elements are the specified values.
+ +Signature: + +```go +func Of[T any](elems ...T) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.Of(1, 2, 3) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### FromSlice + +Creates a stream from slice.
+ +Signature: + +```go +func FromSlice[T any](source []T) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.FromSlice([]int{1, 2, 3}) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### FromChannel + +Creates a stream from channel.
+ +Signature: + +```go +func FromChannel[T any](source <-chan T) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + ch := make(chan int) + go func() { + for i := 1; i < 4; i++ { + ch <- i + } + close(ch) + }() + + s := stream.FromChannel(ch) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### FromRange + +Creates a number stream from start to end. both start and end are included. [start, end]
+ +Signature: + +```go +func FromRange[T constraints.Integer | constraints.Float](start, end, step T) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.FromRange(1, 5, 1) + + data := s.ToSlice() + fmt.Println(data) + + // Output: + // [1 2 3 4 5] +} +``` + +### Generate + +Creates a stream where each element is generated by the provided generater function.
+ +Signature: + +```go +func Generate[T any](generator func() func() (item T, ok bool)) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + n := 0 + max := 4 + + generator := func() func() (int, bool) { + return func() (int, bool) { + n++ + return n, n < max + } + } + + s := stream.Generate(generator) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### Concat + +Creates a lazily concatenated stream whose elements are all the elements of the first stream followed by all the elements of the second stream.
+ +Signature: + +```go +func Concat[T any](a, b stream[T]) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s1 := stream.FromSlice([]int{1, 2, 3}) + s2 := stream.FromSlice([]int{4, 5, 6}) + + s := Concat(s1, s2) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3 4 5 6] +} +``` + +### Distinct + +Creates returns a stream that removes the duplicated items. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Distinct() stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 2, 3, 3, 3}) + distinct := original.Distinct() + + data1 := original.ToSlice() + data2 := distinct.ToSlice() + + fmt.Println(data1) + fmt.Println(data2) + + // Output: + // [1 2 2 3 3 3] + // [1 2 3] +} +``` + +### Filter + +Returns a stream consisting of the elements of this stream that match the given predicate. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Filter(predicate func(item T) bool) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3, 4, 5}) + + isEven := func(n int) bool { + return n%2 == 0 + } + + even := original.Filter(isEven) + + fmt.Println(even.ToSlice()) + + // Output: + // [2 4] +} +``` + +### Map + +Returns a stream consisting of the elements of this stream that apply the given function to elements of stream. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Map(mapper func(item T) T) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + addOne := func(n int) int { + return n + 1 + } + + increament := original.Map(addOne) + + fmt.Println(increament.ToSlice()) + + // Output: + // [2 3 4] +} +``` + +### Peek + +Returns a stream consisting of the elements of this stream, additionally performing the provided action on each element as elements are consumed from the resulting stream. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Peek(consumer func(item T)) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + data := []string{} + peekStream := original.Peek(func(n int) { + data = append(data, fmt.Sprint("value", n)) + }) + + fmt.Println(original.ToSlice()) + fmt.Println(peekStream.ToSlice()) + fmt.Println(data) + + // Output: + // [1 2 3] + // [1 2 3] + // [value1 value2 value3] +} +``` + +### Skip + +Returns a stream consisting of the remaining elements of this stream after discarding the first n elements of the stream. If this stream contains fewer than n elements then an empty stream will be returned. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Skip(n int) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3, 4}) + + s1 := original.Skip(-1) + s2 := original.Skip(0) + s3 := original.Skip(1) + s4 := original.Skip(5) + + fmt.Println(s1.ToSlice()) + fmt.Println(s2.ToSlice()) + fmt.Println(s3.ToSlice()) + fmt.Println(s4.ToSlice()) + + // Output: + // [1 2 3 4] + // [1 2 3 4] + // [2 3 4] + // [] +} +``` + +### Limit + +Returns a stream consisting of the elements of this stream, truncated to be no longer than maxSize in length. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Limit(maxSize int) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3, 4}) + + s1 := original.Limit(-1) + s2 := original.Limit(0) + s3 := original.Limit(1) + s4 := original.Limit(5) + + fmt.Println(s1.ToSlice()) + fmt.Println(s2.ToSlice()) + fmt.Println(s3.ToSlice()) + fmt.Println(s4.ToSlice()) + + // Output: + // [] + // [] + // [1] + // [1 2 3 4] +} +``` + +### Reverse + +Returns a stream whose elements are reverse order of given stream. Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Reverse() stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + reverse := original.Reverse() + + fmt.Println(reverse.ToSlice()) + + // Output: + // [3 2 1] +} +``` + +### Range + +Returns a stream whose elements are in the range from start(included) to end(excluded) original stream.Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Range(start, end int) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + s1 := original.Range(0, 0) + s2 := original.Range(0, 1) + s3 := original.Range(0, 3) + s4 := original.Range(1, 2) + + fmt.Println(s1.ToSlice()) + fmt.Println(s2.ToSlice()) + fmt.Println(s3.ToSlice()) + fmt.Println(s4.ToSlice()) + + // Output: + // [] + // [1] + // [1 2 3] + // [2] +} +``` + +### Sorted + +Returns a stream consisting of the elements of this stream, sorted according to the provided less function.Support chainable operation
+ +Signature: + +```go +func (s stream[T]) Sorted(less func(a, b T) bool) stream[T] +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{4, 2, 1, 3}) + + sorted := original.Sorted(func(a, b int) bool { return a < b }) + + fmt.Println(original.ToSlice()) + fmt.Println(sorted.ToSlice()) + + // Output: + // [4 2 1 3] + // [1 2 3 4] +} +``` + +### ForEach + +Performs an action for each element of this stream.
+ +Signature: + +```go +func (s stream[T]) ForEach(action func(item T)) +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result := 0 + original.ForEach(func(item int) { + result += item + }) + + fmt.Println(result) + + // Output: + // 6 +} +``` + +### Reduce + +Performs a reduction on the elements of this stream, using an associative accumulation function, and returns an Optional describing the reduced value, if any.
+ +Signature: + +```go +func (s stream[T]) Reduce(initial T, accumulator func(a, b T) T) T +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result := original.Reduce(0, func(a, b int) int { + return a + b + }) + + fmt.Println(result) + + // Output: + // 6 +} +``` + +### FindFirst + +Returns the first element of this stream and true, or zero value and false if the stream is empty.
+ +Signature: + +```go +func (s stream[T]) FindFirst() (T, bool) +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result, ok := original.FindFirst() + + fmt.Println(result) + fmt.Println(ok) + + // Output: + // 1 + // true +} +``` + +### Max + +Returns the maximum element of this stream according to the provided less function. less fuction: a > b
+ +Signature: + +```go +func (s stream[T]) Max(less func(a, b T) bool) (T, bool) +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{4, 2, 1, 3}) + + max, ok := original.Max(func(a, b int) bool { return a > b }) + + fmt.Println(max) + fmt.Println(ok) + + // Output: + // 4 + // true +} +``` + +### Min + +Returns the minimum element of this stream according to the provided less function. less fuction: a < b
+ +Signature: + +```go +func (s stream[T]) Min(less func(a, b T) bool) (T, bool) +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{4, 2, 1, 3}) + + min, ok := original.Min(func(a, b int) bool { return a < b }) + + fmt.Println(min) + fmt.Println(ok) + + // Output: + // 1 + // true +} +``` + +### AllMatch + +Returns whether all elements of this stream match the provided predicate.
+ +Signature: + +```go +func (s stream[T]) AllMatch(predicate func(item T) bool) bool +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result1 := original.AllMatch(func(item int) bool { + return item > 0 + }) + + result2 := original.AllMatch(func(item int) bool { + return item > 1 + }) + + fmt.Println(result1) + fmt.Println(result2) + + // Output: + // true + // false +} +``` + +### AnyMatch + +Returns whether any elements of this stream match the provided predicate.
+ +Signature: + +```go +func (s stream[T]) AnyMatch(predicate func(item T) bool) bool +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result1 := original.AnyMatch(func(item int) bool { + return item > 1 + }) + + result2 := original.AnyMatch(func(item int) bool { + return item > 3 + }) + + fmt.Println(result1) + fmt.Println(result2) + + // Output: + // true + // false +} +``` + +### NoneMatch + +Returns whether no elements of this stream match the provided predicate.
+ +Signature: + +```go +func (s stream[T]) NoneMatch(predicate func(item T) bool) bool +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result1 := original.NoneMatch(func(item int) bool { + return item > 3 + }) + + result2 := original.NoneMatch(func(item int) bool { + return item > 1 + }) + + fmt.Println(result1) + fmt.Println(result2) + + // Output: + // true + // false +} +``` + +### Count + +Returns the count of elements in the stream.
+ +Signature: + +```go +func (s stream[T]) Count() int +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s1 := stream.FromSlice([]int{1, 2, 3}) + s2 := stream.FromSlice([]int{}) + + fmt.Println(s1.Count()) + fmt.Println(s2.Count()) + + // Output: + // 3 + // 0 +} +``` + +### ToSlice + +Returns the elements in the stream.
+ +Signature: + +```go +func (s stream[T]) ToSlice() []T +``` + +Example: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.Of(1, 2, 3) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` diff --git a/docs/stream_zh-CN.md b/docs/stream_zh-CN.md new file mode 100644 index 0000000..8d8d1d0 --- /dev/null +++ b/docs/stream_zh-CN.md @@ -0,0 +1,907 @@ +# Strutil + +Stream 实现，该包仅验证简单 go stream 实现，功能有限。 + + + +## 源码: + +- [https://github.com/duke-git/lancet/blob/main/stream/stream.go](https://github.com/duke-git/lancet/blob/main/stream/stream.go) + + + +## 用法: + +```go +import ( + "github.com/duke-git/lancet/v2/stream" +) +``` + + + +## 目录 + +- [Of](#Of) +- [FromSlice](#FromSlice) +- [FromChannel](#FromChannel) +- [FromRange](#FromRange) +- [Generate](#Generate) +- [Concat](#Concat) +- [Distinct](#Distinct) +- [Filter](#Filter) +- [Map](#Map) +- [Peek](#Peek) +- [Skip](#Skip) +- [Limit](#Limit) +- [Reverse](#Reverse) +- [Range](#Range) +- [Sorted](#Sorted) +- [ForEach](#ForEach) +- [Reduce](#Reduce) +- [FindFirst](#FindFirst) +- [Max](#Max) +- [Min](#Min) +- [AllMatch](#AllMatch) +- [AnyMatch](#AnyMatch) +- [NoneMatch](#NoneMatch) +- [Count](#Count) +- [ToSlice](#ToSlice) + + + +## 文档 + +### Of + +创建元素为指定值的stream。
+ +函数签名: + +```go +func Of[T any](elems ...T) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.Of(1, 2, 3) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### FromSlice + +从切片创建stream。
+ +函数签名: + +```go +func FromSlice[T any](source []T) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.FromSlice([]int{1, 2, 3}) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### FromChannel + +从通道创建stream。
+ +函数签名: + +```go +func FromChannel[T any](source <-chan T) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + ch := make(chan int) + go func() { + for i := 1; i < 4; i++ { + ch <- i + } + close(ch) + }() + + s := stream.FromChannel(ch) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### FromRange + +指定一个范围创建stream, 范围两端点值都包括在内。
+ +函数签名: + +```go +func FromRange[T constraints.Integer | constraints.Float](start, end, step T) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.FromRange(1, 5, 1) + + data := s.ToSlice() + fmt.Println(data) + + // Output: + // [1 2 3 4 5] +} +``` + +### Generate + +创建一个stream，其中每个元素都由提供的生成器函数生成
+ +函数签名: + +```go +func Generate[T any](generator func() func() (item T, ok bool)) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + n := 0 + max := 4 + + generator := func() func() (int, bool) { + return func() (int, bool) { + n++ + return n, n < max + } + } + + s := stream.Generate(generator) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` + +### Concat + +创建一个延迟连接stream，其元素是第一个stream的所有元素，后跟第二个stream的全部元素。
+ +函数签名: + +```go +func Concat[T any](a, b stream[T]) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s1 := stream.FromSlice([]int{1, 2, 3}) + s2 := stream.FromSlice([]int{4, 5, 6}) + + s := Concat(s1, s2) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3 4 5 6] +} +``` + +### Distinct + +创建并返回一个stream，用于删除重复的项。 支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Distinct() stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 2, 3, 3, 3}) + distinct := original.Distinct() + + data1 := original.ToSlice() + data2 := distinct.ToSlice() + + fmt.Println(data1) + fmt.Println(data2) + + // Output: + // [1 2 2 3 3 3] + // [1 2 3] +} +``` + +### Filter + +返回一个通过判定函数的stream 支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Filter(predicate func(item T) bool) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3, 4, 5}) + + isEven := func(n int) bool { + return n%2 == 0 + } + + even := original.Filter(isEven) + + fmt.Println(even.ToSlice()) + + // Output: + // [2 4] +} +``` + +### Map + +返回一个stream，该stream由将给定函数应用于源stream元素的元素组成。支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Map(mapper func(item T) T) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + addOne := func(n int) int { + return n + 1 + } + + increament := original.Map(addOne) + + fmt.Println(increament.ToSlice()) + + // Output: + // [2 3 4] +} +``` + +### Peek + +返回一个由源stream的元素组成的stream，并在从生成的stream中消耗元素时对每个元素执行所提供的操作。 支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Peek(consumer func(item T)) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + data := []string{} + peekStream := original.Peek(func(n int) { + data = append(data, fmt.Sprint("value", n)) + }) + + fmt.Println(original.ToSlice()) + fmt.Println(peekStream.ToSlice()) + fmt.Println(data) + + // Output: + // [1 2 3] + // [1 2 3] + // [value1 value2 value3] +} +``` + +### Skip + +在丢弃stream的前n个元素后，返回由源stream的其余元素组成的stream。如果此stream包含的元素少于n个，则将返回一个空stream。支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Skip(n int) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3, 4}) + + s1 := original.Skip(-1) + s2 := original.Skip(0) + s3 := original.Skip(1) + s4 := original.Skip(5) + + fmt.Println(s1.ToSlice()) + fmt.Println(s2.ToSlice()) + fmt.Println(s3.ToSlice()) + fmt.Println(s4.ToSlice()) + + // Output: + // [1 2 3 4] + // [1 2 3 4] + // [2 3 4] + // [] +} +``` + +### Limit + +返回由源stream的元素组成的stream，该stream被截断为长度不超过maxSize。支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Limit(maxSize int) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3, 4}) + + s1 := original.Limit(-1) + s2 := original.Limit(0) + s3 := original.Limit(1) + s4 := original.Limit(5) + + fmt.Println(s1.ToSlice()) + fmt.Println(s2.ToSlice()) + fmt.Println(s3.ToSlice()) + fmt.Println(s4.ToSlice()) + + // Output: + // [] + // [] + // [1] + // [1 2 3 4] +} +``` + +### Reverse + +返回元素与源stream的顺序相反的stream。支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Reverse() stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + reverse := original.Reverse() + + fmt.Println(reverse.ToSlice()) + + // Output: + // [3 2 1] +} +``` + +### Range + +返回一个stream，该stream的元素在从源stream的开始（包含）到结束（排除）的范围内。支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Range(start, end int) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + s1 := original.Range(0, 0) + s2 := original.Range(0, 1) + s3 := original.Range(0, 3) + s4 := original.Range(1, 2) + + fmt.Println(s1.ToSlice()) + fmt.Println(s2.ToSlice()) + fmt.Println(s3.ToSlice()) + fmt.Println(s4.ToSlice()) + + // Output: + // [] + // [1] + // [1 2 3] + // [2] +} +``` + +### Sorted + +返回一个stream，该stream由源stream的元素组成，并根据提供的less函数进行排序。支持链式操作
+ +函数签名: + +```go +func (s stream[T]) Sorted(less func(a, b T) bool) stream[T] +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{4, 2, 1, 3}) + + sorted := original.Sorted(func(a, b int) bool { return a < b }) + + fmt.Println(original.ToSlice()) + fmt.Println(sorted.ToSlice()) + + // Output: + // [4 2 1 3] + // [1 2 3 4] +} +``` + +### ForEach + +对stream的每个元素执行一个操作。
+ +函数签名: + +```go +func (s stream[T]) ForEach(action func(item T)) +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result := 0 + original.ForEach(func(item int) { + result += item + }) + + fmt.Println(result) + + // Output: + // 6 +} +``` + +### Reduce + +使用关联累加函数对stream的元素执行reduce操作，并reduce操作结果（如果有）。
+ +函数签名: + +```go +func (s stream[T]) Reduce(initial T, accumulator func(a, b T) T) T +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result := original.Reduce(0, func(a, b int) int { + return a + b + }) + + fmt.Println(result) + + // Output: + // 6 +} +``` + +### FindFirst + +返回此stream的第一个元素和true，如果stream为空，则返回零值和false。
+ +函数签名: + +```go +func (s stream[T]) FindFirst() (T, bool) +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result, ok := original.FindFirst() + + fmt.Println(result) + fmt.Println(ok) + + // Output: + // 1 + // true +} +``` + +### Max + +根据提供的less函数返回stream的最大元素。less 函数: a > b
+ +函数签名: + +```go +func (s stream[T]) Max(less func(a, b T) bool) (T, bool) +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{4, 2, 1, 3}) + + max, ok := original.Max(func(a, b int) bool { return a > b }) + + fmt.Println(max) + fmt.Println(ok) + + // Output: + // 4 + // true +} +``` + +### Min + +根据提供的less函数返回stream的最小元素。less函数: a < b
+ +函数签名: + +```go +func (s stream[T]) Min(less func(a, b T) bool) (T, bool) +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{4, 2, 1, 3}) + + min, ok := original.Min(func(a, b int) bool { return a < b }) + + fmt.Println(min) + fmt.Println(ok) + + // Output: + // 1 + // true +} +``` + +### AllMatch + +判断stream的所有元素是否全部匹配指定判定函数。
+ +函数签名: + +```go +func (s stream[T]) AllMatch(predicate func(item T) bool) bool +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result1 := original.AllMatch(func(item int) bool { + return item > 0 + }) + + result2 := original.AllMatch(func(item int) bool { + return item > 1 + }) + + fmt.Println(result1) + fmt.Println(result2) + + // Output: + // true + // false +} +``` + +### AnyMatch + +判断stream是否包含匹配指定判定函数的元素。
+ +函数签名: + +```go +func (s stream[T]) AnyMatch(predicate func(item T) bool) bool +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result1 := original.AnyMatch(func(item int) bool { + return item > 1 + }) + + result2 := original.AnyMatch(func(item int) bool { + return item > 3 + }) + + fmt.Println(result1) + fmt.Println(result2) + + // Output: + // true + // false +} +``` + +### NoneMatch + +判断stream的元素是否全部不匹配指定的判定函数。
+ +函数签名: + +```go +func (s stream[T]) NoneMatch(predicate func(item T) bool) bool +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + original := stream.FromSlice([]int{1, 2, 3}) + + result1 := original.NoneMatch(func(item int) bool { + return item > 3 + }) + + result2 := original.NoneMatch(func(item int) bool { + return item > 1 + }) + + fmt.Println(result1) + fmt.Println(result2) + + // Output: + // true + // false +} +``` + +### Count + +返回stream中元素的数量。
+ +函数签名: + +```go +func (s stream[T]) Count() int +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s1 := stream.FromSlice([]int{1, 2, 3}) + s2 := stream.FromSlice([]int{}) + + fmt.Println(s1.Count()) + fmt.Println(s2.Count()) + + // Output: + // 3 + // 0 +} +``` + +### ToSlice + +返回stream中的元素切片。
+ +函数签名: + +```go +func (s stream[T]) ToSlice() []T +``` + +示例: + +```go +import ( + "fmt" + "github.com/duke-git/lancet/v2/stream" +) + +func main() { + s := stream.Of(1, 2, 3) + + data := s.ToSlice() + + fmt.Println(data) + + // Output: + // [1 2 3] +} +``` diff --git a/stream/stream.go b/stream/stream.go index 464c8b0..39197d8 100644 --- a/stream/stream.go +++ b/stream/stream.go @@ -51,7 +51,7 @@ type stream[T any] struct { source []T } -// Of creates a stream stream whose elements are the specified values. +// Of creates a stream whose elements are the specified values. // Play: https://go.dev/play/p/jI6_iZZuVFE func Of[T any](elems ...T) stream[T] { return FromSlice(elems) @@ -268,7 +268,7 @@ func (s stream[T]) ForEach(action func(item T)) { } // Reduce performs a reduction on the elements of this stream, using an associative accumulation function, and returns an Optional describing the reduced value, if any. -// Play: https://go.dev/play/p/g-xkHiuIpTi +// Play: https://go.dev/play/p/6uzZjq_DJLU func (s stream[T]) Reduce(initial T, accumulator func(a, b T) T) T { for _, v := range s.source { initial = accumulator(initial, v) diff --git a/stream/stream_example_test.go b/stream/stream_example_test.go index 3dc8474..4842071 100644 --- a/stream/stream_example_test.go +++ b/stream/stream_example_test.go @@ -91,11 +91,11 @@ func ExampleConcat() { } func ExampleStream_Distinct() { - originalStream := FromSlice([]int{1, 2, 2, 3, 3, 3}) - distinctStream := originalStream.Distinct() + original := FromSlice([]int{1, 2, 2, 3, 3, 3}) + distinct := original.Distinct() - data1 := originalStream.ToSlice() - data2 := distinctStream.ToSlice() + data1 := original.ToSlice() + data2 := distinct.ToSlice() fmt.Println(data1) fmt.Println(data2) @@ -267,10 +267,8 @@ func ExampleStream_ForEach() { func ExampleStream_Reduce() { original := FromSlice([]int{1, 2, 3}) - result := 0 - - original.ForEach(func(item int) { - result += item + result := original.Reduce(0, func(a, b int) int { + return a + b }) fmt.Println(result)