1// Copyright 2018, OpenCensus Authors
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
15package metricdata
16
17// LabelKey represents key of a label. It has optional
18// description attribute.
19type LabelKey struct {
20	Key         string
21	Description string
22}
23
24// LabelValue represents the value of a label.
25// The zero value represents a missing label value, which may be treated
26// differently to an empty string value by some back ends.
27type LabelValue struct {
28	Value   string // string value of the label
29	Present bool   // flag that indicated whether a value is present or not
30}
31
32// NewLabelValue creates a new non-nil LabelValue that represents the given string.
33func NewLabelValue(val string) LabelValue {
34	return LabelValue{Value: val, Present: true}
35}
36