relay

go get github.com/codemodus/relay

Package relay provides a simple mechanism for relaying control flow based upon whether a checked error is nil or not.

Usage

funcCodedFns(handler...func(error)) (CodedCheckFunc, CodedTripFunc)
funcDefaultHandler() func(error)
funcFns(handler...func(error)) (CheckFunc, TripFunc)
funcHandle()
typeCheckFunctypeCodedCheckFunctypeCodedErrorfunc (ce*CodedError) Error() stringfunc (ce*CodedError) ExitCode() inttypeCodedTripFuncfuncCodedTripFn(ckCodedCheckFunc) CodedTripFunctypeExitCodertypeRelayfuncNew(handler...func(error)) *Relayfunc (r*Relay) Check(errerror)
func (r*Relay) CodedCheck(codeint, errerror)
typeTripFuncfuncTripFn(ckCheckFunc) TripFunc

Setup

import (
"github.com/codemodus/relay"
)
funcmain() {
r:=relay.New()
deferrelay.Handle()
err:=fail()
r.Check(err)
// prints "{cmd_name}: {err_msg}" to stderr// calls os.Exit with code set as 1
}

Setup (Custom Handler)

h:=func(errerror) {
fmt.Println(err)
fmt.Println("extra message")
}
r:=relay.New(h)
deferrelay.Handle()
err:=fail()
r.Check(err)
fmt.Println("should not print")
// Output:// always fails// extra message

Setup (Eased Usage)

ck:=relay.New().Checkdeferrelay.Handle()
err:=fail()
ck(err)
// prints "{cmd_name}: {err_msg}" to stderr// calls os.Exit with code set as 1

Setup (Coded Check)

ck:=relay.New().CodedCheckdeferrelay.Handle()
err:=fail()
ck(3, err)
// prints "{cmd_name}: {err_msg}" to stderr// calls os.Exit with code set as first arg to r.CodedCheck ("ck")

Setup (Trip Function)

ck:=relay.New().Checktrip:=relay.TripFn(ck)
deferrelay.Handle()
n:=three()
ifn!=2 {
trip("must receive %v: %v is invalid", 2, n)
}
fmt.Println("should not print")
// prints "{cmd_name}: {trip_msg}" to stderr// calls os.Exit with code set as 1

Setup (Eased Usage - Check and Trip)

ck, trip:=relay.Fns()
deferrelay.Handle()
err:=mightFail()
ck(err)
n:=three()
ifn!=2 {
trip("must receive %v: %v is invalid", 2, n)
}
fmt.Println("should not print")
// prints "{cmd_name}: {trip_msg}" to stderr// calls os.Exit with code set as 1

More Info

Background

golang/go#32437 (comment)

Documentation

View the GoDoc

Benchmarks

N/A