Question

给出要查找的单词列表（及其复数形式）：

let array = ["\\b(ab+?)(s\\b|\\b)", "\\b(cd+?)(s\\b|\\b)", "\\b(ef+?)(s\\b|\\b)", "\\b(gh+?)(s\\b|\\b)"]

这是以下内容的缩写：

let words = ["ab", "cd", "ef", "gh"]
let array = words + words.map {$0 + "s"}

我想从一个句子中得到所有的单词。从字符串的开头开始， 直到满足正则表达式的最后一个单词 。来自array或其复数形式的每个元素都应匹配（通过添加＆＃34; s＆＃34;， ies 复数不被考虑）：

例如：

let string_1 = "abc ab def cds ghi jkl bs mno" // should get "abc ab def cds"
let string_2 = "abc ghs def" // should get "abc ghs"
let string_3 = "abc ab def bc ghi" // should get "abc ab"
let string_4 = "abc def" // should get "" or nil

我目前的想法是：

let words = string_1.components(separatedBy: CharacterSet.whitespacesAndNewlines)
let lastOccurrence: (Int, String)? = words.enumerated().reversed().first(where: { (index, value) in
    if let _ = restOfSentence.range(of: value, options: .regularExpression) {
        return true
    }
    return false
})

if let l_o = lastOccurrence {
    let matchingWordsArray = words[0...l_o.0]
    let matchingWords = matchingWordsArray.joined(separator: " ")
    print(matchingWords)
}

将句子分成单词然后加入它们对我来说似乎很昂贵有一个更好的方法吗？

Answer 1

你可以使用NSRegularExpression（虽然我发现它的Swift实现充满了旧的NSRange / NSString依赖）：

let string_1 = "abc ab def cds ghi jkl bs mno" // should get "abc ab def cds"
let string_2 = "abc ghs def" // should get "abc ghs"
let string_3 = "abc ab def bc ghi" // should get "abc ab"
let string_4 = "abc def" // should get "" or nil


let array = ["\\b(ab+?)(s\\b|\\b)", "\\b(cd+?)(s\\b|\\b)", "\\b(ef+?)(s\\b|\\b)", "\\b(gh+?)(s\\b|\\b)"]

func matchingWords(_ string:String, patterns:[String]) -> String
{
   let anyPattern = patterns.map{"("+$0+")"}.joined(separator:"|")

   let string = NSString(string:string)
   let fullRange = NSMakeRange(0,string.length)

   if let regEx     = try? NSRegularExpression(pattern:anyPattern, options:.caseInsensitive),
      let lastRange = regEx.matches(in:string as String, range:fullRange).last?.range
   {
     return string.substring(to: lastRange.location + lastRange.length)
   }

   return ""
}

print( matchingWords( string_1, patterns:array) ) // abc ab def cds
print( matchingWords( string_2, patterns:array) ) // abc gh
print( matchingWords( string_3, patterns:array) ) // abc ab
print( matchingWords( string_4, patterns:array) ) // <empty string>

如何获取包含属于数组的单词的字符串的开头？

1 个答案: