replacePlus.swift

let patternEmail = "[\\w0-9\\.]+@[\\w.]+"
let raw = "1 2 [email protected], [email protected]"
let replaceWith = "xxx"
let text = raw.replace(pattern: patternEmail, with: replaceWith) // example

struct ReplacerPlusResult {
    let textReplaced: String
    var rangesApplied: [Range<String.Index>]
}

func replacerPlus(text: String, pattern: String, with: String, savedRanges: [Range<String.Index>] = []) -> ReplacerPlusResult? {
    var ranges: [Range<String.Index>] = savedRanges ?? []
    var mutableText = text
    if let range = text.range(of: pattern, options: .regularExpression) {
        mutableText = mutableText.replacingCharacters(in: range, with: with)
        ranges.append(range)
        return replacerPlus(text: mutableText, pattern: pattern, with: with, savedRanges: ranges)
    }
    return ReplacerPlusResult(textReplaced: mutableText, rangesApplied: ranges)
}

let result = replacerPlus(text: raw, pattern: patternEmail, with: replaceWith)
print(result?.textReplaced)
result?.rangesApplied.forEach({ print($0.lowerBound.encodedOffset) })