Concurrency and channels to walk binary trees

equivalent_trees.go

package main

import (
	"fmt"
	"golang.org/x/tour/tree"
)

func Walk(t *tree.Tree, ch chan int) {
	defer close(ch)
	// using a closure
	var walk func(t *tree.Tree)
	walk = func(t *tree.Tree) {
		if t == nil {
			return
		}
		walk(t.Left)
		ch <- t.Value
		walk(t.Right)
	}
	walk(t)
}

func Same(t1, t2 *tree.Tree) bool {
	ch1, ch2 := make(chan int), make(chan int)
	go Walk(t1, ch1)
	go Walk(t2, ch2)
	for {
		n1, ok1 := <- ch1
		n2, ok2 := <- ch2
		if ok1 != ok2 || n1 != n2 {
			return false
		}
		if !ok1 {
			break
		}
	}
	return true
}

func main() {
	ch := make(chan int)
	go Walk(tree.New(1), ch)
	fmt.Println(Same(tree.New(1), tree.New(2)))
	fmt.Println(Same(tree.New(1), tree.New(1)))
	fmt.Println(Same(tree.New(2), tree.New(1)))
}