chans_example.go

package main

import (
    "fmt"
)

func write(input chan int) {
    for i := 0; i < 4; i++ {
        fmt.Printf("sending i: %d to input channel\n", i)
        input <- i
    }
}

func read(input, err chan int) {
    for {
        i := <-input
        fmt.Printf("read i: %d from input channel\n", i)
        if i%3 == 0 {
            fmt.Printf("send i: %d to err channel\n", i)
            err <- i
        }
        if i == -1 {
            defer close(input)
            defer close(err)
            return
        }
    }
}

func main() {
    ch := make(chan int, 3)
    err := make(chan int, 1)

    go read(ch, err)
    go write(ch)
    i := 0
    for value, ok := <- err; ok; value, ok = <- err {
        fmt.Printf("read value: %d from err\n", value)
        i += 1
        if i >= 3 {
            ch <- value * 1000
            break
        }
        ch <- value
    }
}