Panic & Recover for long fail-fast methods

panic-recover.go

package main

import (
	"errors"
	"fmt"
	"math/rand"
	"runtime"
	"time"
)

func main() {
	rand.Seed(time.Now().Unix())

	err := doStuff()

	if err != nil {
		fmt.Println(err)
	}
}

func doStuff() (err error) {
	defer func() {
		if r := recover(); r != nil {
			if _, ok := r.(runtime.Error); ok {
				panic(ok)
			}
			err = r.(error)
		}
	}()
	p := func(status string, err error) {
		if err != nil {
			panic(errors.New("Error " + status + ": " + err.Error()))
		}
	}

	p("reticulating splines", reticulateSplines())
	p("reticulating more splines", reticulateSplines())

	spline1, err := getReticulatedSplines()
	p("getting reticulated splines", err)

	spline2, err := getReticulatedSplines()
	p("getting more reticulated splines", err)

	fmt.Println("Finished! Splines returned:", spline1, "and", spline2)
	return nil
}

func reticulateSplines() error {
	if rand.Intn(10) > 7 {
		return errors.New("Not enough splines to reticulate!")
	}
	return nil
}

func getReticulatedSplines() (spline string, err error) {
	if rand.Intn(10) > 7 {
		return "", errors.New("No splines left to eat!")
	}
	return fmt.Sprint("spline number ", rand.Intn(10)), nil
}

Note: Running this on the playground will always create the same result, because time is frozen there.