xyselect

Introduction

Package xyselect defines custom select statements.

Features

The main object in the library is Selector, a custom usage of select statement.

There are two types of Selector, which are R (stand for reflect) and E (stand for exhausted).

E selector uses a center channel to receive all selected channels, so that it doesn't support to wait on a sending channel. Moreover, E selector creates a goroutine to wait on the center channel, and that goroutine only stops when all selected channels closed. For this reason, you should call Select until get an error of ExhaustedError to ensure the goroutine stopped.

R selector uses the built-in library, reflect, to customize select statement. It supports to wait on both receiving and sending channels. It also does not create any goroutine while using.

Each selector has its own advantage, while R selector more flexible, E selector is faster.

Visit pkg.go.dev for more details.

Benchmark

op name	time per op
RSelector	728ns
ESelector	679ns

Example

var c = make(chan int)
go func() { 
    c <- 10
    close(c)
}()

var eselector = xyselect.E()
eselector.Recv(xyselect.C(c))

var _, v, _ = eselector.Select(false)
fmt.Println(v)

// Output:
// 10

var rselector = xyselect.R()
var c = make(chan int)
var rc = xyselect.C(c)

go func() { c <- 10 }()
rselector.Recv(rc)
var _, v, _ = rselector.Select(false)
fmt.Println("receive", v)

rselector.Send(c, 20)
rselector.Select(false)
fmt.Println("send", <-rc)

// Output:
// receive 10
// send 20