Kotlin 驼峰 空格 下划线 互相转换

Kotlin 驼峰 空格 下划线 互相转换

案例如下：

convert this to camel case ->
ConvertThisToCamelCase ->
convert_this_to_camel_case

代码如下：

package com.android.learn01

import java.util.*

fun main() {
    println("convert_this_to_camel_case".underlineToCamelCase())
    println("convert_this_to_camel_case".underlineToCamelCase().cameToUnderlineCase())
    println("========================================")
    println("convert this to camel case".spaceToUnderlineCase())
    println("convert_this_to_camel_case".underlineToSpaceCase())
    println("========================================")
    println("convert this to camel case".spaceToCamelCase())
    println("convert this to camel case".spaceToCamelCase().cameToSpaceCase())
}

// 空格转驼峰
fun String.spaceToCamelCase(): String {
    val str = this.trim()
    if (str.isEmpty()) return ""
    return str.split("\\s+".toRegex())
        .joinToString("") { if (it[0] in 'a'..'z') it[0] - 32 + it.substring(1) else it }
}

// 驼峰转空格
fun String.cameToSpaceCase(): String {
    val str = this.trim()
    if (str.isEmpty()) return ""
    val list = mutableListOf<String>()
    var i = 1
    var j = 0
    while (i < str.length) {
        if (str[i] in 'A'..'Z') {
            list.add(str.substring(j, i))
            j = i
        }
        i ++
    }
    list.add(str.substring(j))
    return list.joinToString(" ") { it.lowercase(Locale.getDefault()) }
}

// 下划线转驼峰
fun String.underlineToCamelCase(): String {
    val str = this.trim()
    if (str.isEmpty()) return ""
    return str.split("_")
        .joinToString("") { if (it[0] in 'a'..'z') it[0] - 32 + it.substring(1) else it }
}

// 驼峰转下划线
fun String.cameToUnderlineCase(): String {
    val str = this.trim()
    if (str.isEmpty()) return ""
    val list = mutableListOf<String>()
    var i = 1
    var j = 0
    while (i < str.length) {
        if (str[i] in 'A'..'Z') {
            list.add(str.substring(j, i))
            j = i
        }
        i ++
    }
    list.add(str.substring(j))
    return list.joinToString("_") { it.lowercase(Locale.getDefault()) }
}

// 空格转下划线 使用跳板
fun String.spaceToUnderlineCase(): String {
    return this.spaceToCamelCase().cameToUnderlineCase()
}
// 下划线转空格 使用跳板
fun String.underlineToSpaceCase(): String {
    return this.underlineToCamelCase().cameToSpaceCase()
}

如果各位大佬有比我更好的方法还请分享一下，万分感谢！！！