1 /*
2  * Copyright (C) 2020 The Android Open Source Project
3  *
4  * Licensed under the Apache License, Version 2.0 (the "License");
5  * you may not use this file except in compliance with the License.
6  * You may obtain a copy of the License at
7  *
8  *      http://www.apache.org/licenses/LICENSE-2.0
9  *
10  * Unless required by applicable law or agreed to in writing, software
11  * distributed under the License is distributed on an "AS IS" BASIS,
12  * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
13  * See the License for the specific language governing permissions and
14  * limitations under the License.
15  */
16 
17 import java.util.Locale
18 
19 private val camelHumpBoundary = Regex(
20     "-"
21     + "|_"
22     + "|(?<=[0-9])(?=[^0-9])"
23     + "|(?<=[A-Z])(?=[^A-Za-z]|[A-Z][a-z])"
24     + "|(?<=[a-z])(?=[^a-z])"
25 )
26 
27 private fun String.toCamelHumps(): List<String> = split(camelHumpBoundary)
28 
29 fun String.toUpperCamelCase(): String =
30     toCamelHumps().joinToString("") { it.toLowerCase(Locale.ROOT).capitalize(Locale.ROOT) }
31 
32 fun String.toLowerCamelCase(): String = toUpperCamelCase().decapitalize(Locale.ROOT)
33 
34 fun String.toUpperKebabCase(): String =
35     toCamelHumps().joinToString("-") { it.toUpperCase(Locale.ROOT) }
36 
37 fun String.toLowerKebabCase(): String =
38     toCamelHumps().joinToString("-") { it.toLowerCase(Locale.ROOT) }
39 
40 fun String.toUpperSnakeCase(): String =
41     toCamelHumps().joinToString("_") { it.toUpperCase(Locale.ROOT) }
42 
43 fun String.toLowerSnakeCase(): String =
44     toCamelHumps().joinToString("_") { it.toLowerCase(Locale.ROOT) }
45