Data Set and Concurrency in Go with Channels

dataset_channels.go

// https://play.golang.org/p/b7lYcShM2kC
package main

import (
	"fmt"
	"sync"
)

type Set struct {
	values map[int]interface{}
	mu     sync.Mutex
}

func (s *Set) List() []int {
	s.mu.Lock()
	defer s.mu.Unlock()

	var result []int
	for k := range s.values {
		result = append(result, k)
	}
	return result
}
func (s *Set) Add(item int) {
	s.mu.Lock()
	defer s.mu.Unlock()

	s.values[item] = nil
}

func NewSet() *Set {
	return &Set{
		values: make(map[int]interface{}),
	}
}

func main() {
	s := NewSet()
	
	foo := func(s *Set, c chan int, values ...int) {
		defer close(c)
		
		for i, v := range values {
			s.Add(v)
			c <- i
		}
	}
	
	values := []int{1, 2, 3, 5, 1}
	c := make(chan(int), len(values))
	go foo(s, c, values...)
	
	select {
		case <- c:
	}
	fmt.Println(s.List())
}