Golang sending sending multiple values through channel

multivalChSample.go

package main

import "fmt"

func f(c chan func() (int, string)) {
	c <- (func() (int, string) { return 0, "s" })
}

func main() {
	c := make(chan func() (int, string))
	go f(c)
	y, z := (<-c)()
	fmt.Println(y)
	fmt.Println(z)
}

Hi, Slav,
thanks for the trick. I tried it and found that the two values are not handled atomically, so they get screwed when the pairs are sent in a rapid sequence. Fernand Galiana @derailed suggested to fix it with the following trick that seems to work:

c <- ( func (i int, s string) func() (int, string) {
              return func() (int, string) {
                              return i, s
                          }
           } (intCode, dataString) )

The rationale is that (unlike function arguments) values for externally defined variables in function body are sampled asynchronously. Therefore, shielding them with an additional function taking variables as arguments makes sampling synchronous.

Cool, thanks for sharing the idea.

@akhilo Although I understand the explanation alright. But I'm really not sure how can it be non-atomic when the channel is returning a func and variable are inside the func body.

Can you please show me how did you test it.