package main
import (
"errors"
"fmt"
)
// FmtArgs formats args as a string. First argument should be format string
// and the rest are arguments to the format
func FmtArgs(args ...interface{}) string {
if len(args) == 0 {
return ""
}
format := args[0].(string)
if len(args) == 1 {
return format
}
return fmt.Sprintf(format, args[1:]...)
}
func panicWithMsg(defaultMsg string, args ...interface{}) {
s := FmtArgs(args...)
if s == "" {
s = defaultMsg
}
fmt.Printf("%s\n", s)
panic(s)
}
// PanicIf panics if cond is true
func PanicIf(cond bool, args ...interface{}) {
if !cond {
return
}
panicWithMsg("PanicIf: condition failed", args...)
}
// PanicIfErr panics if err is not nil
func PanicIfErr(err error, args ...interface{}) {
if err == nil {
return
}
panicWithMsg(err.Error(), args...)
}
func main() {
PanicIfErr(nil) // nothing happens
PanicIfErr(errors.New("there was an error")) // will panic
}
