package main

/**
* A tail recursive and not tail recursive function in Go
* Since the Go compiler does not implement tail call optimization, tail recursion
* is irrelevant
* Created: Sep 20, 2023
* gtowell
**/

//a function that is NOT tail recursive
// just compute the sum of some numbers
// this will stack overflow
func notTail(p int64) int64 {
	return p + notTail(p+1)
}

// internal tail recursive implementation of summer
// Still stack overflow since GO does not do tail call optimization

// just calls the TR version of summing, adding the extra param required for
// tail recursion.
func tail(p int64) int64 {
	var iTail func(int64, int64) int64
	// internal tail recursive implementation of summer
	// Still stack overflow since GO does not do tail call optimization
	iTail = func(pp int64, aa int64) int64 {
		if pp>10000000 {
			return aa
		}	
		return iTail(pp+1, aa+pp)
	}
	return iTail(p, 0)
}

func main() {
	//notTail(0)
	println(tail(0))
}