swift - 使用谓词自定义排序顺序

Question

我有一个数组

arr = ["A", "B", "a", "b", "1", "2"]

当我排序时使用:

arr.sorted(by: <)

我得到:

["1", "2", "A", "B", "a", "b"]

但我正在寻找结果:

["a", "b", "A", "B", "1", 2"]

一种自定义排序顺序，其中小号按排序顺序排在第一位，然后按排序顺序加盖，最后按排序顺序排列数字。有什么简单的方法可以做到这一点？

Answer 1

我可能是错的，但我认为您需要实现自己的自定义排序方法:

var arr = ["A", "B", "a", "b", "1", "2"]
arr.sort {
    if $0.first?.isLowercase == true && ($1.first?.isUppercase == true || $1.first?.isWholeNumber == true) {
        return true
    }
    if $0.first?.isUppercase == true && $1.first?.isWholeNumber == true {
        return true
    }
    if $0.first?.isWholeNumber == true && ($1.first?.isLowercase == true ||  $1.first?.isUppercase == true) {
        return false
    }
    return $0 < $1
}

print(arr) // "["a", "b", "A", "B", "1", "2"]\n"

---

extension MutableCollection where Element: StringProtocol, Self: RandomAccessCollection {
    mutating func customSort(by areInIncreasingOrder: (Element, Element) throws -> Bool = (<)) rethrows {
        try sort {
            if try areInIncreasingOrder("1","2") {
                if $0.first?.isLowercase == true && ($1.first?.isUppercase == true || $1.first?.isWholeNumber == true) {
                    return true
                }
                if $0.first?.isUppercase == true && $1.first?.isWholeNumber == true {
                    return true
                }
                if $0.first?.isWholeNumber == true && ($1.first?.isLowercase == true ||  $1.first?.isUppercase == true) {
                    return false
                }
            } else {
                if $0.first?.isWholeNumber == true && ($1.first?.isLowercase == true ||  $1.first?.isUppercase == true) {
                    return true
                }
                if $0.first?.isUppercase == true && ($1.first?.isLowercase == true || $1.first?.isWholeNumber == true) {
                    return true
                }
                if $0.first?.isLowercase == true && ($1.first?.isUppercase == true || $1.first?.isWholeNumber == true) {
                    return false
                }
            }
            return try areInIncreasingOrder($0,$1)
        }
    }
}

---

var array =  ["B","A","b", "a", "1", "2"]
do {
    try array.customSort()
    print(array) // "["a", "b", "A", "B", "1", "2"]\n"
} catch {
    print(error)
}