This code is a simple example of range over function and iterators in Go

iterator-range.go

package main

import (
	"fmt"
	"iter"
)

type Employee struct {
	Name   string
	Salary int
}

var Employees = []Employee{
	{Name: "Elliot", Salary: 4},
	{Name: "Donna", Salary: 5},
}

func main() {
	fmt.Println("Slice")
	for k, v := range []int{2, 2, 2, 2} {
		fmt.Printf("%d: %+v\n", k, v)
	}

	fmt.Println("Map")
	m := map[int]string{
		23: "lais",
		13: "luana",
		21: "luiz",
	}
	for k, v := range m {
		fmt.Printf("%d: %+v\n", k, v)
	}

	fmt.Println("Function")
	for i, employee := range Iterate(Employees) {
		fmt.Printf("%d: %+v\n", i, employee)
	}
}

func Iterate[Employee any](e []Employee) iter.Seq2[int, Employee] {
	return func(yield func(int, Employee) bool) {
		for i := 0; i <= len(e)-1; i++ {
			if !yield(i, e[i]) {
				return
			}
		}
	}
}