import Foundation
let pattern = #"^[A-Z](([A-Z]{1,2}[a-z0-9]+)+([A-Z]{1,3}[a-z0-9]+)*[A-Z]{0,3}|([a-z0-9]+[A-Z]{0,3})*|[A-Z]{1,2})$"#
let regex = try! NSRegularExpression(pattern: pattern, options: .anchorsMatchLines)
let testString = #"""
ABCD
ABCDE
snake_case
camelCase
2PascalCase
streamIOIO
gREATERDtha
MdeADFAFdsADFads
DeviceSNSD
AabcABCD
AabcABCDabcABCD
ABabcABCD
ABabcABCDabcABCD
ABCabcABCD
ABCabcABCDabcABCDabcABCDabcABCD
ABCDabcABCD
ABCDabcABCDabcABCDabcABCDabcABCD
HTMLParser
ContextHTMLParser
ABabcABCDbcABC
ABCDabcABC
ABCDabcAB
ABCDabcA
CamelCa_1
HELLO
AaABC
PacalCasePacalCasePacalCasePacalCasePacalCasePacalCase
AabcABCabcABC
MoeADFdsADFads
ABCabcABC
ABCabcAB
ABabcABC
ABabcAB
AabcAB
ABCabcABCabcA
ABCabcA
Aabc123
AabcABC
A
AB
ABC
StreamIO
IOStream
DeviceID
DeviceSNS
Context
PascalCase
Pascal2Case
PascalCaseA
Pascal2CaseA
ModeA
Mode2A
Mode2A2
Mode2A2A
CreateAMode
CreateBMode
MadeEasy
WonderFul
AndMe
HtmlParser
H
AaA
Camel01C
Camel01c01
Camel01C01
Camel01CC01
Camel0a1c1
Camel0a1C1
Camel0ac1b1C1
CamelC
CamelC1
CamelCA
CamelCa1
IbsReleaseTestVerificationRegressionSuite
IbsReleaseTestVerificationRegressioNSuite
IbsReleaseTestVerificationRegressioN
XmlHttpRequest
NewCustomerId
InnerStopwatch
SupportsIpv6OnIos
YouTubeImporter
YoutubeImporter
Affine3D
"""#
let stringRange = NSRange(location: 0, length: testString.utf16.count)
let matches = regex.matches(in: testString, range: stringRange)
var result: [[String]] = []
for match in matches {
var groups: [String] = []
for rangeIndex in 1 ..< match.numberOfRanges {
let nsRange = match.range(at: rangeIndex)
guard !NSEqualRanges(nsRange, NSMakeRange(NSNotFound, 0)) else { continue }
let string = (testString as NSString).substring(with: nsRange)
groups.append(string)
}
if !groups.isEmpty {
result.append(groups)
}
}
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