25-range-over-iterators.go

package main

import (
  "fmt"
  "iter"
  "slices"
)

type List[T any] struct {
  head, tail *element[T]
}

type element[T any] struct {
  next *element[T]
  val T
}

func (lst *List[T]) Push(v T){
  if lst.tail == nil {
    lst.head = &element[T]{val: v}
    lst.tail = lst.head
  }else {
    lst.tail.next = &element[T]{val:v}
    lst.tail = lst.tail.next
  }
}

func (lst *List[T]) All() iter.Seq[T]{
  return func(yield func(T) bool){
    for e := lst.head; e != nil; e = e.next {
      if !yield(e.val){
        return
      }
    }
  }
}

func genFib() iter.Seq[int] {
  return func(yield func(int) bool){
    a, b := 1, 1

    for {
      if !yield(a){
        return
      }
      a, b = b, a + b
    }
  }
}

func main(){
  lst := List[int]{}
  lst.Push(10)
  lst.Push(13)
  lst.Push(23)

  for e := range lst.All(){
    fmt.Println(e)
  }

  all := slices.Collect(lst.All())
  fmt.Println("all:",all)

  for n := range genFib() {
    if n >= 10 {
      break
    }
    fmt.Println(n)
  }
}