我更喜欢实际接收Set中的实际捕获。我添加了一个名为captureGroups()的方法，它以字符串而不是范围的形式返回捕获。
import Foundation
extension String {
func matchingStrings(regex: String) -> [[String]] {
guard let regex = try? NSRegularExpression(pattern: regex, options: []) else { return [] }
let nsString = self as NSString
let results = regex.matches(in: self, options: [], range: NSMakeRange(0, nsString.length))
return results.map { result in
(0..<result.numberOfRanges).map { result.rangeAt($0).location != NSNotFound
? nsString.substring(with: result.rangeAt($0))
: ""
}
}
}
func range(from nsRange: NSRange) -> Range<String.Index>? {
guard
let from16 = utf16.index(utf16.startIndex, offsetBy: nsRange.location, limitedBy: utf16.endIndex),
let to16 = utf16.index(utf16.startIndex, offsetBy: nsRange.location + nsRange.length, limitedBy: utf16.endIndex),
let from = from16.samePosition(in: self),
let to = to16.samePosition(in: self)
else { return nil }
return from ..< to
}
}
extension NSRegularExpression {
typealias GroupNamesSearchResult = (NSTextCheckingResult, NSTextCheckingResult, Int)
private func textCheckingResultsOfNamedCaptureGroups() -> [String:GroupNamesSearchResult] {
var groupnames = [String:GroupNamesSearchResult]()
guard let greg = try? NSRegularExpression(pattern: "^\\(\\?<([\\w\\a_-]*)>$", options: NSRegularExpression.Options.dotMatchesLineSeparators) else {
// This never happens but the alternative is to make this method throwing
return groupnames
}
guard let reg = try? NSRegularExpression(pattern: "\\(.*?>", options: NSRegularExpression.Options.dotMatchesLineSeparators) else {
// This never happens but the alternative is to make this method throwing
return groupnames
}
let m = reg.matches(in: self.pattern, options: NSRegularExpression.MatchingOptions.withTransparentBounds, range: NSRange(location: 0, length: self.pattern.utf16.count))
for (n,g) in m.enumerated() {
let r = self.pattern.range(from: g.rangeAt(0))
let gstring = self.pattern.substring(with: r!)
let gmatch = greg.matches(in: gstring, options: NSRegularExpression.MatchingOptions.anchored, range: NSRange(location: 0, length: gstring.utf16.count))
if gmatch.count > 0{
let r2 = gstring.range(from: gmatch[0].rangeAt(1))!
groupnames[gstring.substring(with: r2)] = (g, gmatch[0],n)
}
}
return groupnames
}
func indexOfNamedCaptureGroups() throws -> [String:Int] {
var groupnames = [String:Int]()
for (name,(_,_,n)) in try self.textCheckingResultsOfNamedCaptureGroups() {
groupnames[name] = n + 1
}
return groupnames
}
func rangesOfNamedCaptureGroups(match:NSTextCheckingResult) throws -> [String:Range<Int>] {
var ranges = [String:Range<Int>]()
for (name,(_,_,n)) in try self.textCheckingResultsOfNamedCaptureGroups() {
ranges[name] = match.rangeAt(n+1).toRange()
}
return ranges
}
private func nameForIndex(_ index: Int, from: [String:GroupNamesSearchResult]) -> String? {
for (name,(_,_,n)) in from {
if (n + 1) == index {
return name
}
}
return nil
}
func captureGroups(string: String, options: NSRegularExpression.MatchingOptions = []) -> [String:String] {
return captureGroups(string: string, options: options, range: NSRange(location: 0, length: string.utf16.count))
}
func captureGroups(string: String, options: NSRegularExpression.MatchingOptions = [], range: NSRange) -> [String:String] {
var dict = [String:String]()
let matchResult = matches(in: string, options: options, range: range)
let names = try self.textCheckingResultsOfNamedCaptureGroups()
for (n,m) in matchResult.enumerated() {
for i in (0..<m.numberOfRanges) {
let r2 = string.range(from: m.rangeAt(i))!
let g = string.substring(with: r2)
if let name = nameForIndex(i, from: names) {
dict[name] = g
}
}
}
return dict
}
}
您是否看过[用NSRegularExpression命名捕获组]（http://stackoverflow.com/questions/24814974/named-capture-groups-with-nsregularexpression）？ –
@Thomas @Thomas我确实看到了，但是从2014年开始，讨论都说不支持命名捕获组 - 但是（至少在iOS 9和OS X 10.11上）确实支持 - 并且它们正在工作至少在我的机器上，我不能将结果范围映射回他们来自的组。 – Dai
* iOS 4.0及更高版本*中提供的Apple文档状态... –