Swiftで正規表現

Regex.swift

//
//  Regex.swift
//  ha1fRegex
//
//  Created by はるふ on 2016/09/30.
//  Copyright © 2016年 はるふ. All rights reserved.
//

import Foundation

public struct Regex {
    public struct Match {
        public let wholeString: String
        public let groups: [String?]
        
        init(text: NSString, result res: NSTextCheckingResult) {
            let components = (0..<res.numberOfRanges)
                .map { i -> String? in
                    let range = res.range(at: i)
                    guard range.location != NSNotFound else {
                        // ない可能性のある()だとnilのこともある
                        return nil
                    }
                    return text.substring(with: res.range(at: i))
            }
            self.wholeString = components.first.flatMap { $0 } ?? ""
            self.groups = components.dropFirst().map { $0 }
        }
    }
    
    // MARK: Properties
    
    fileprivate let regex: NSRegularExpression
    
    // MARK: Initializers
    
    public init(_ pattern: String, options: NSRegularExpression.Options = []) throws {
        do {
            self.regex = try NSRegularExpression(pattern: pattern, options: options)
        }
    }
    
    // MARK: Public functions
    
    public func matches(_ string: String, range: NSRange? = nil, options: NSRegularExpression.MatchingOptions = []) -> Bool {
        return self.firstMatch(string, range: range, options: options) != nil
    }
    
    public func firstMatch(_ string: String, range: NSRange? = nil, options: NSRegularExpression.MatchingOptions = []) -> Match? {
        let targetRange = range ?? string.wholeNSRange()
        let nsstring = string as NSString
        if let res = self.regex.firstMatch(in: string, options: options, range: targetRange) {
            return Regex.Match(text: nsstring, result: res)
        } else {
            return nil
        }
    }
    
    public func allMatches(_ string: String, range: NSRange? = nil, options: NSRegularExpression.MatchingOptions = []) -> [Match] {
        let targetRange = range ?? string.wholeNSRange()
        let nsstring = string as NSString
        return self.regex.matches(in: string, options: options, range: targetRange).map { res in
            return Regex.Match(text: nsstring, result: res)
        }
    }
}

extension Regex {
    // MARK: Preset regexes
    
    private static let PATTERN_FLOAT = "-*([1-9]\\d*|0)(\\.\\d+)?"
    private static let PATTERN_EMAIL = "^[a-zA-Z0-9.!#$%&'*+/=?^_`{|}~-]+@[a-zA-Z0-9-]+(?:\\.[a-zA-Z0-9-]+)+$"
    
    public static let email = try! Regex(PATTERN_EMAIL)
    public static let float = try! Regex(PATTERN_FLOAT)
}

extension String {
    // MARK: Extensions of String
    
    fileprivate func wholeRange() -> Range<String.Index> {
        return self.startIndex..<self.endIndex
    }
    
    fileprivate func wholeNSRange() -> NSRange {
        return NSRange(location: 0, length: self.count)
    }
    
    public func replace(_ regex: Regex, with template: String, range: NSRange? = nil, options: NSRegularExpression.MatchingOptions = []) -> String {
        let targetRange = range ?? self.wholeNSRange()
        return regex.regex.stringByReplacingMatches(in: self, options: options, range: targetRange, withTemplate: template)
    }
    
    /// (を(?:で置換する
    public func ignoringExtractions() -> String {
        return replace(try! Regex("\\((?!\\?:)"), with: "(?:")
    }
}

MIT License

Copyright (c) 2016 はるふ

Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:

The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.

THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.

http://qiita.com/_ha1f/items/e2eb39be82de09731537