import Foundation
let pattern = #"\[pause[^]]*"(\d+)"]"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"I am [pitch = "high"]Rudratosh Shastri[endpitch]. what is your name ? how are you? sorry [pause ="3000"] i can not hear you ?[rate="-70.00%"] i still can't hear you[endrate] ? [rate="+50.00%"]why i can't hear you[endrate] ?"#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let substitutionString = #"<break time="$1ms"/>"#
let result = regex.stringByReplacingMatches(in: testString, range: stringRange, withTemplate: substitutionString)
print(result)
Please keep in mind that these code samples are automatically generated and are not guaranteed to work. If you find any syntax errors, feel free to submit a bug report. For a full regex reference for Swift 5.2, please visit: https://developer.apple.com/documentation/foundation/nsregularexpression