swift regular expression replace matches using transform

swift string replace matches.swift

import Foundation

extension String {
	func replacingOcurrences(ofPattern pattern: String, _ matchTransform: (NSTextCheckingResult) -> String) -> String {

		guard let regex = try? NSRegularExpression(pattern: pattern, options: []) else {
			return self
		}

		var transformedCharacters: [Character] = []
		var formatStringCurrentIndex = 0
		let formatCharacters = [Character](self)

		regex.enumerateMatches(in: self, options: [], range: NSRange(self.startIndex..<self.endIndex, in: self)) { (match, _, _) in
			
			guard let match = match else { return }
			
			let transformedValue = matchTransform(match)
			let charactersRange = match.range.location..<(match.range.location + match.range.length)

			while formatStringCurrentIndex < charactersRange.lowerBound {
				transformedCharacters.append(formatCharacters[formatStringCurrentIndex])
				formatStringCurrentIndex += 1
			}
			transformedCharacters.append(contentsOf: transformedValue)
			formatStringCurrentIndex = charactersRange.upperBound
		}
		
		transformedCharacters.append(contentsOf: formatCharacters[formatStringCurrentIndex...])
		
		return String(transformedCharacters)
	}
}
extension String {
	func replacingOcurrences(ofPattern pattern: String, _ matchValueTransform: (String) -> String) -> String {
		self.replacingOcurrences(ofPattern: pattern) { (match: NSTextCheckingResult) in
			guard let matchRange = Range(match.range, in: self) else {
				return self
			}
			let matchValue = String(self[matchRange])
			return matchValueTransform(matchValue)
		}
	}
}

let dict: [String: Any] = [
	"name": "Danielj7",
	"other": 2231237
]

let start = DispatchTime.now()
print(
	"Me llamo {name}, tengo {other} años".replacingOcurrences(ofPattern: #"\{(\w+)\}"#) { (matchValue: String) in
		String(describing: dict[String(matchValue.dropFirst().dropLast())] ?? matchValue)
	}
)
let end = DispatchTime.now()

let nanoTime = end.uptimeNanoseconds - start.uptimeNanoseconds
let timeInterval = Double(nanoTime) / 1_000_000_000 
print(timeInterval)