/*
* Using a closure to simulate an iterator.  If you language does not have an
* iterator, but does do closures.   Really a useless thing in Go 
* as iterators work fine
* @author gtowell
* created: July 30, 2021
 */

package main

import "fmt"

// the type of the iterator function
// note the use of two return values.
// The first gives the next value of the slice
// The second indicates where that value should actually be
// used (i.e., the slice actually had another value)
type CIter func() (int,bool)

// the function to generator the closure containing function
func makeClo(slic []int) CIter {
	idx:=0
	fun := func() (int,bool) {
		if idx>=len(slic) {
			return 0,false
		}
		x := slic[idx]
		idx++
		return x,true
		}
	return fun
}

func main() {
	var islic []int
	// fill a slice with things
	for i:=5; i<25; i++ {
		islic = append(islic, i)
	}
	clo := makeClo(islic) // the function
	// a while loop over the closure
	for {
		c,more:=clo()
		if !more {
			break;
		}
		fmt.Printf("CLO: %v\n", c)
	}
}