如果不使用NSRegularExpression，我如何獲得我的字符串正則表達式的所有匹配？

Question

斯威夫特3推出String.range(of:options)。然後，利用該功能，能夠匹配字符串的一部分而不創建NSRegularExpression對象，例如：

let text = "it is need #match my both #hashtag!" 
let match = text.range(of: "(?:^#|\\s#)[\\p{L}0-9_]*", options: .regularExpression)! 

print(text[match]) // #math 

但是，是可能的匹配正則表達式的兩次出現（即，#match和#hashtag），而不是隻有第一個？

Answer 1

let text = "it is need #match my both #hashtag!" 
// create an object to store the ranges found 
var ranges: [Range<String.Index>] = [] 
// create an object to store your search position 
var start = text.startIndex 
// create a while loop to find your regex ranges 
while let range = text.range(of: "(?:^#|\\s#)[\\p{L}0-9_]*", options: .regularExpression, range: start..<text.endIndex) { 
    // append your range found 
    ranges.append(range) 
    // and change the startIndex of your string search 
    start = range.lowerBound < range.upperBound ? range.upperBound : text.index(range.lowerBound, offsetBy: 1, limitedBy: text.endIndex) ?? text.endIndex 
} 
ranges.forEach({print(text[$0])}) 

---

這將打印

#match

#hashtag

如果你需要使用它不止在你的代碼，一旦你要這個擴展添加到您的項目：

extension String { 
    func ranges(of string: String, options: CompareOptions = .literal) -> [Range<Index>] { 
     var result: [Range<Index>] = [] 
     var start = startIndex 
     while let range = range(of: string, options: options, range: start..<endIndex) { 
      result.append(range) 
      start = range.lowerBound < range.upperBound ? range.upperBound : index(range.lowerBound, offsetBy: 1, limitedBy: endIndex) ?? endIndex 
     } 
     return result 
    } 
} 

---

用法：

let text = "it is need #match my both #hashtag!" 
let pattern = "(?:^#|\\s#)[\\p{L}0-9_]*" 
let ranges = text.ranges(of: pattern, options: .regularExpression) 
let matches = ranges.map{text[$0]} 
print(matches) // [" #match", " #hashtag"]