Question

我正在使用 Regex规则检查一些动态文本，对每个switch的正则表达式模式index使用array。一切正常，但在最后一个case中，我希望地图停止映射并尽早返回！但似乎我无法在地图函数中return！还有更好的方法或解决方案吗？

fileprivate func regexMatch(pattern regex: [String], in text: String) -> Dictionary<String, Any>
{
    do
    {
        for (index, string) in regex.enumerated()
        {
            let regex = try NSRegularExpression(pattern: string, options: .caseInsensitive)
            let results: [NSTextCheckingResult] = regex.matches(in: text, range: NSRange(text.startIndex..., in: text))

            _ = results.compactMap
            {
                /* If i put a guard check to see if result is filled 
                 * then return, works fine but iterates again for the next index and keeps returning till it’s over!
                */
                switch index
                {
                case 0:
                    // Does something
                case 1:
                    // Does something else
                case 2:
                    // Does the last thing
                    // If succeed finding the match! Just return or exit the map!
                    let carNames = String(Range($0.range, in: text).map { String(text[$0]) }!).lowercased()

                    for case let car as Car in carsList!
                    {
                        if spottedCarNamesInReceipt.contains(car.name!.lowercased())
                        {
                            result["car"] = car
                            return  // This does work though, but the map starts iterating again over the next index!
                        }
                    }

                default:
                    break;
                }
            }
        }

        return result

    } catch let error
    {
        print("Invalid regex: \(error.localizedDescription)")
        return [:]
    }

Answer 1

如果不使用结果，则无需使用compactMap。而且没有办法退出compactMap。用于周期内。

Answer 2

使用return语句forEach循环或任何类型的Maps，仅针对闭包中的当前调用退出，而for...in循环也退出所有后续的后续调用。因此for...in解决了需要提前退出的问题。

从compactMap返回和退出

2 个答案: