/*
* A short example of doing things with subranges of slices
* @authord ggtowell
* Created: July 25, 2021
 */

package main

import "fmt"

func main() {
	// create a slice containing integers and populate it with 1..10
	s := []int{1, 2, 3, 4, 5, 6, 7, 8, 9, 10}
	fmt.Printf("s=%v\n", s)
	// a couple of the item in the slice
	v := s[2:4]
	fmt.Printf("v=%v\n", v)

	// fill w with two separate pieces of slice
	var w []int
	fmt.Printf("w=%v\n", w)
	for _, val := range s[1:3] {
		w = append(w, val)
	}
	// it is a lot easier to use varidic append than writing a loop ... on the other hand I never remember this syntax.
	w = append(w, s[6:8]...)
	fmt.Printf("w=%v\n", w)

	// another way to copy pieces -- note that this way overwrites
	// start by making a slice of length 6
	z := make([]int, 6)
	/** Equivalent to the make
	var z []int
	for i:=0; i<6; i++ {
		z = append(z, 0)
	}
	**/
	fmt.Printf("z=%v\n", z)
	//then use copy function to get the parts into new slice
	// note that this appproach leaves "holes"
	copy(z[0:1], s[2:4])
	copy(z[3:5], s[6:8])
	fmt.Printf("z=%v\n", z)

	ss()
}

// the pointer issue does not really arise unless you are using structs.
func ss() {
	ss := make([]string, 1)
	aa := "asdf"
	ss = append(ss, aa)
	fmt.Println(aa)
	fmt.Println(ss)
	aa = aa[0:2]
	fmt.Println(aa)
	fmt.Println(ss)
}