tendermint/libs/common/nil.go

30 lines
763 B
Go

package common
import "reflect"
// Go lacks a simple and safe way to see if something is a typed nil.
// See:
// - https://dave.cheney.net/2017/08/09/typed-nils-in-go-2
// - https://groups.google.com/forum/#!topic/golang-nuts/wnH302gBa4I/discussion
// - https://github.com/golang/go/issues/21538
func IsTypedNil(o interface{}) bool {
rv := reflect.ValueOf(o)
switch rv.Kind() {
case reflect.Chan, reflect.Func, reflect.Map, reflect.Ptr, reflect.Slice:
return rv.IsNil()
default:
return false
}
}
// Returns true if it has zero length.
func IsEmpty(o interface{}) bool {
rv := reflect.ValueOf(o)
switch rv.Kind() {
case reflect.Array, reflect.Chan, reflect.Map, reflect.Slice, reflect.String:
return rv.Len() == 0
default:
return false
}
}