tristate.go 1.3 KB

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  1. // Copyright 2019 Yunion
  2. //
  3. // Licensed under the Apache License, Version 2.0 (the "License");
  4. // you may not use this file except in compliance with the License.
  5. // You may obtain a copy of the License at
  6. //
  7. // http://www.apache.org/licenses/LICENSE-2.0
  8. //
  9. // Unless required by applicable law or agreed to in writing, software
  10. // distributed under the License is distributed on an "AS IS" BASIS,
  11. // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
  12. // See the License for the specific language governing permissions and
  13. // limitations under the License.
  14. package tristate
  15. import "reflect"
  16. type TriState string
  17. const (
  18. True = TriState("true")
  19. False = TriState("false")
  20. None = TriState("")
  21. )
  22. var (
  23. TriStateType = reflect.TypeOf(True)
  24. TriStateTrueValue = reflect.ValueOf(True)
  25. TriStateFalseValue = reflect.ValueOf(False)
  26. TriStateNoneValue = reflect.ValueOf(None)
  27. )
  28. func (r TriState) Bool() bool {
  29. switch r {
  30. case True:
  31. return true
  32. case False:
  33. return false
  34. default:
  35. return false
  36. }
  37. }
  38. func (r TriState) String() string {
  39. return string(r)
  40. }
  41. func (r TriState) IsNone() bool {
  42. return r == None
  43. }
  44. func (r TriState) IsTrue() bool {
  45. return r == True
  46. }
  47. func (r TriState) IsFalse() bool {
  48. return r == False
  49. }
  50. func NewFromBool(b bool) TriState {
  51. if b {
  52. return True
  53. } else {
  54. return False
  55. }
  56. }