Example of a Go pipeline

stringer_pipeline.go

package main

import (
	"fmt"
)

type Stringer struct {
	In    chan *string
	Out    chan *string
	Error chan error
	Suffix string
}

func NewStringer(sufx string, errChan chan error) *Stringer {
	return &Stringer{
		In:    make(chan *string, 100),
		Out:   make(chan *string, 100),
		Error: errChan,
		Suffix: sufx,
	}
}

func (s *Stringer) Run() {
	defer close(s.Out)

	for msg := range s.In {
		newMsg := *msg + s.Suffix
		s.Out <- &newMsg
	}
}

func InstantiateStringPipeline(errChan chan error, msg *string) chan *string {

	a := NewStringer("A", errChan)
	go func() {
		a.In <- msg
		close(a.In)
	}()

	b := NewStringer("B", errChan)
	c := NewStringer("C", errChan)

	b.In = a.Out
	c.In = b.Out

	go a.Run()
	go b.Run()
	go c.Run()

	return c.Out
}

func main() {
	errChan := make(chan error)
	msg := "HOLA"
	select {
	case res := <-InstantiateStringPipeline(errChan, &msg):
		fmt.Println(*res)
		return
	case err := <-errChan:
		fmt.Println("Error", err)
		return
	}
}