Go ??????? Go 1.22, ?? Go 1.23?? ???? ?? ?? ? ???? ????. . ??? ??? ??? ? ??? ????, ?? ???? ??? ?????? ??? ??? ??? ????. ??, ??? ?? ??? ???! Go?? ???? ??? ???? ? ??? ???? ???? ??? ???????.

??? ??: ?? ???? ??

?? ??? ?? ? ??? ? ?? ??? ??? ??? ???. ??? ?? ??? ??? ???? ? ??? ??? ? ????.

package main

import (
    "fmt"
)

func NormalTransform[T1, T2 any](list []T1, transform func(T1) T2) []T2 {
    transformed := make([]T2, len(list))

    for i, t := range list {
        transformed[i] = transform(t)
    }

    return transformed
}

func main() {
    list := []int{1, 2, 3, 4, 5}
    doubleFunc := func(i int) int { return i * 2 }

    for i, num := range NormalTransform(list, doubleFunc) {
        fmt.Println(i, num)
    }
}

? ??? ???? ??? ?? ?? ?????.

0 2
1 4
2 6
3 8
4 10

?? ????? ?? ?? ?? T1? ??? ??? ? ??? ?? ??? ???? ?? ?? T2? ??? ??? ??? ? ??? ???? ?? ?? Go ?????. ?? ???? ?? ???!

??? ???? ???? ?? ??? ? ?? ?? ??? ??? ??? ?????

???? ?????!

?? ??? ??? ???? ???? ??? ???????.

package main

import (
    "fmt"
)

func IteratorTransform[T1, T2 any](list []T1, transform func(T1) T2) iter.Seq2[int, T2] {
    return func(yield func(int, T2) bool) {
        for i, t := range list {
            if !yield(i, transform(t)) {
                return
            }
        }
    }
}

func main() {
    list := []int{1, 2, 3, 4, 5}
    doubleFunc := func(i int) int { return i * 2 }

    for i, num := range NormalTransform(list, doubleFunc) {
        fmt.Println(i, num)
    }
}

???? ?? Go ??? 1.23?? ???? ???. ??? ??? ?????.

0 2
1 4
2 6
3 8
4 10

??? ??? ???? ? ?????? ?? ? ???? ???? ???? ??? ?????.

???? ???? ??? ??????

?? ??? ???? ?? ??? ?? ??? ??? ?? ?? ???? ??? ??? ????. ??? ????? ???? ? ??? ??? ??? ?? ???!

? ??? ?? ?????? ??? ??? ???????.

package main

import (
    "testing"
)

var (
    transform = func(i int) int { return i * 2 }
    list      = []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
)

func BenchmarkNormalTransform(b *testing.B) {
    for i := 0; i < b.N; i++ {
        NormalTransform(list, transform)
    }
}

func BenchmarkIteratorTransform(b *testing.B) {
    for i := 0; i < b.N; i++ {
        IteratorTransform(list, transform)
    }
}

?? ???? ??? ??? ????.

BenchmarkNormalTransform-8      41292933                29.49 ns/op
BenchmarkIteratorTransform-8    1000000000               0.3135 ns/op

?! ??? ? ?????! ??? ????. ???? ??? ????? ????. NormalTransform ??? ??? ??? ??? ???? ??, IteratorTransform ??? ??? ?? ???? ?? ???? ?????.

???? ??? ???? ???? ??? ?????.

func BenchmarkIteratorTransform(b *testing.B) {
    for i := 0; i < b.N; i++ {
        for range IteratorTransform(list, transform) {
        }
    }
}

?? ??? ?? ??????.

BenchmarkNormalTransform-8      40758822                29.16 ns/op
BenchmarkIteratorTransform-8    53967146                22.39 ns/op

?????. ???? ?? ? ????. ?? NormalTransform? ???? ?? ???(?)? ??? ?? ??? ???? ??, ???? ?? ??? ? ??? ???? ??? ???? ?????.

???? ?? ? ?? ?? ??? ?????

???? ??? ??? ?? ??? ??? ??? ?? ? ?????. ??? ??? ? ?? 4? ???? ????? ????? ?????.

func BenchmarkNormalTransform(b *testing.B) {
    for i := 0; i < b.N; i++ {
        for _, num := range NormalTransform(list, transform) {
            if num == 4 {
                break
            }
        }
    }
}

func BenchmarkIteratorTransform(b *testing.B) {
    for i := 0; i < b.N; i++ {
        for _, num := range IteratorTransform(list, transform) {
            if num == 4 {
                break
            }
        }
    }
}

??? ?????:

package main

import (
    "fmt"
)

func NormalTransform[T1, T2 any](list []T1, transform func(T1) T2) []T2 {
    transformed := make([]T2, len(list))

    for i, t := range list {
        transformed[i] = transform(t)
    }

    return transformed
}

func main() {
    list := []int{1, 2, 3, 4, 5}
    doubleFunc := func(i int) int { return i * 2 }

    for i, num := range NormalTransform(list, doubleFunc) {
        fmt.Println(i, num)
    }
}

? ?? iterator? ?? ????! ?? ???? ?? ??? ???? ?? ??? ??? ??? ?? ?? ?????. ??? NormalTransform? ??? ???? ??? ???? ??? ?? ??? ?????.

??: ?? Iterator? ???? ????

?? Go?? ???? ???? ??? ??????

• ???: ???? ???? ?? ?? ?? ??? ???? ????? ??? ???? ?? ??? ? ????.
• ???: ?? ??? ????? ????? ??? ???? ? ? ??? ??? ??? ????? ??? ? ????. ??? ???? ???? ????? ?? ? ???? ? ??? ?? ?????. ???? ?? ??? ??? ?, ?? ?? ??? ?? ??? ??? ?? ?????? ?? ?????.

Iterator: ????? ??? ???? ??????!

? ??? Go? ??? ????: ???? ???!? ?? ?????. ??? ??? PHP ??? ????? ?? ?? ??? ?????!