Copyright 2017, OpenCensus 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 tag

import 

const (
	maxKeyLength = 255
valid are restricted to US-ASCII subset (range 0x20 (' ') to 0x7e ('~')).
	validKeyValueMin = 32
	validKeyValueMax = 126
)

var (
	errInvalidKeyName = errors.New("invalid key name: only ASCII characters accepted; max length must be 255 characters")
	errInvalidValue   = errors.New("invalid value: only ASCII characters accepted; max length must be 255 characters")
)

func ( string) bool {
	if len() == 0 {
		return false
	}
	if len() > maxKeyLength {
		return false
	}
	return isASCII()
}

func ( string) bool {
	for ,  := range  {
		if ( < validKeyValueMin) || ( > validKeyValueMax) {
			return false
		}
	}
	return true
}

func ( string) bool {
	if len() > maxKeyLength {
		return false
	}
	return isASCII()