github.com/elves/elvish@v0.15.0/pkg/eval/vars/blackhole.go (about) 1 package vars 2 3 type blackhole struct{} 4 5 func (blackhole) Set(interface{}) error { 6 return nil 7 } 8 9 func (blackhole) Get() interface{} { 10 return nil 11 } 12 13 // NewBlackhole returns a blackhole variable. Assignments to a blackhole 14 // variable will be discarded, and getting a blackhole variable always returns 15 // nil. 16 func NewBlackhole() Var { 17 return blackhole{} 18 } 19 20 // IsBlackhole returns whether the variable is a blackhole variable. 21 func IsBlackhole(v Var) bool { 22 _, ok := v.(blackhole) 23 return ok 24 }