kubectl/pkg/framework/predicates/value.go

85 lines
1.9 KiB
Go

/*
Copyright 2018 The Kubernetes Authors.
Licensed under the Apache License, Version 2.0 (the "License");
you may not use this file except in compliance with the License.
You may obtain a copy of the License at
http://www.apache.org/licenses/LICENSE-2.0
Unless required by applicable law or agreed to in writing, software
distributed under the License is distributed on an "AS IS" BASIS,
WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
See the License for the specific language governing permissions and
limitations under the License.
*/
package predicates
import (
"reflect"
)
// Value is a "value predicate". It's a type that decides if a
// value matches or not.
type Value interface {
Match(interface{}) bool
}
// ValueDeepEqual compares the Value data with DeepEqual.
func ValueDeepEqual(v interface{}) Value {
return valueEqual{v: v}
}
type valueEqual struct {
v interface{}
}
func (p valueEqual) Match(v interface{}) bool {
return reflect.DeepEqual(v, p.v)
}
// ValueNot inverses the value of the predicate.
func ValueNot(predicate Value) Value {
return valueNot{vp: predicate}
}
type valueNot struct {
vp Value
}
func (p valueNot) Match(v interface{}) bool {
return !p.vp.Match(v)
}
// ValueAnd returns true if all the sub-predicates are true. If there are
// no sub-predicates, always returns true.
func ValueAnd(predicates ...Value) Value {
return valueAnd{vps: predicates}
}
type valueAnd struct {
vps []Value
}
func (p valueAnd) Match(value interface{}) bool {
for _, vp := range p.vps {
if !vp.Match(value) {
return false
}
}
return true
}
// ValueOr returns true if any sub-predicate is true. If there are no
// sub-predicates, always returns false.
func ValueOr(predicates ...Value) Value {
vps := []Value{}
// Implements "De Morgan's law"
for _, vp := range predicates {
vps = append(vps, ValueNot(vp))
}
return ValueNot(ValueAnd(vps...))
}