github.com/GoogleCloudPlatform/compute-image-tools/cli_tools@v0.0.0-20240516224744-de2dabc4ed1b/common/utils/collections/collections_utils.go (about)

     1  //  Copyright 2020 Google Inc. All Rights Reserved.
     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  
    15  package collections
    16  
    17  // ReverseMap reverses keys and their values.
    18  // The 2nd returned value indicates whether the operation succeeded. A map with
    19  // duplicate values can't be reversed. In that case, a 'false' is returned.
    20  func ReverseMap(m map[string]string) (map[string]string, bool) {
    21  	newMap := make(map[string]string, len(m))
    22  	for k, v := range m {
    23  		if _, ok := newMap[v]; ok {
    24  			return nil, false
    25  		}
    26  		newMap[v] = k
    27  	}
    28  	return newMap, true
    29  }
    30  
    31  // GetKeys gets all keys of the map.
    32  func GetKeys(m map[string]string) []string {
    33  	keys := make([]string, 0, len(m))
    34  	for k := range m {
    35  		keys = append(keys, k)
    36  	}
    37  	return keys
    38  }