NSRegularExpression syntax suger

regularExpression.swift

//
//  main.swift
//  Reg
//
//  Created by KatagiriSo on 2017/10/17.
//  Copyright © 2017年 RodhosSoft. All rights reserved.
//

import Foundation


extension NSString {
    func selfRange() -> NSRange {
        let str = self as String
        if str.isEmpty {
            return NSRange(location: 0, length: 0)
        }
        
        return self.range(of: self as String)
    }
}

extension String {
    func selfRange() -> NSRange {
        return (self as NSString).selfRange()
    }
    
    func firstMatch(pattern:String, options:NSRegularExpression.Options = [], matchOptions:NSRegularExpression.MatchingOptions = [] ) -> NSTextCheckingResult? {
        
        guard let reg = try? NSRegularExpression(pattern: pattern, options:options) else {
            return nil
        }
        return reg.firstMatch(in: self,
                              options: matchOptions,
                              range: self.selfRange() )
    }
    
    func isInteger() -> Bool {
        return firstMatch(pattern: "[0-9]*")?.range.toRange() == self.selfRange().toRange()
    }
}

extension NSTextCheckingResult {
    func show() {
        print("\(self.range.location) - \(self.range.length)")
    }
}

func integerTest(text:String) {
    print(" \(text) ... \(text.isInteger())")
}

"12345".firstMatch(pattern: "[0-9]*")?.show()
"12a345".firstMatch(pattern: "[0-9]*")?.show()
"a12345".firstMatch(pattern: "[0-9]*")?.show()


integerTest(text: "1928491")
integerTest(text: "1934712947239851209452398")
integerTest(text: "1293481209348120934812094a123041203984013294")
integerTest(text: "")
integerTest(text: " 120312903129038210")
integerTest(text: "1293812 2103123")
integerTest(text: "\n23")