stdconnect.go

package mock4std

import (
	"io"
	"os"
	"sync"
)

type RW struct {
	R io.Reader
	W io.WriteCloser
}
type pipePairs = []*RW

func genPipePair() pipePairs {
	r1, w2 := io.Pipe()
	r2, w1 := io.Pipe()
	return pipePairs{
		&RW{r1, w1},
		&RW{r2, w2},
	}
}
func StdConnect(
	solver func(io.Reader, io.Writer) error,
	server func(io.Reader, io.Writer) error,
) {
	var wg *sync.WaitGroup
	var pipes = genPipePair()
	wg.Add(2)
	go loggedIoWorker(solver, wg, pipes[0])
	go loggedIoWorker(server, wg, pipes[1])
	wg.Wait()
}

func loggedIoWorker(
	f func(io.Reader, io.Writer) error,
	wg *sync.WaitGroup,
	RW *RW,
) {
	defer wg.Done()
	defer RW.W.Close()
	var tee = io.TeeReader(RW.R, os.Stdout)
	f(tee, RW.W)
}