LLRegex 1.3.0

Maintained by Rock Young.

You want to add pod 'LLRegex', '~> 1.3' similar to the following to your Podfile:

target 'MyApp' do
  pod 'LLRegex', '~> 1.3'
end

Then run a pod install inside your terminal, or from CocoaPods.app.

Alternatively to give it a test run, run the command:

pod try LLRegex

LLRegex 1.3.0

By
Rocke Young

LLRegex

Regular expression library in Swift, wrapping NSRegularExpression. Don’t hesitate to try out on playground.

Features

Value Semantics
Enumerates matches with Sequence
Named capture group
Range supported (NSRange eliminated)
Regex Options, Match Options
Find & Replace with flexibility
String matching, replacing, splitting

Communication

If you found a bug, open an issue, typically with related pattern.
If you have a feature request, open an issue.

Requirements

iOS 8.0+ / macOS 10.10+ / tvOS 9.0+ / watchOS 2.0+
Xcode 8.1+
Swift 3.0+

Installation

Swift Package Manager

dependencies: [
    .Package(url: "https://github.com/LittleRockInGitHub/LLRegex.git", majorVersion: 1)
]

Usage

Making a Regex

let numbers = Regex("(\\d)(\\d+)(\\d)")

let insensitive = Regex("LLRegex", options: [.caseInsensitive])

let runtimeError = Regex("")    // Runtime error would be raised

let invalid = try? Regex(pattern: "")   // nil returned

Searching

Method matches(in:options:range:) returns a sequence producing matches lazily, which is the only one for searching. All other variants were dropped thanks to the power of Sequence.

let s = "123-45-6789-0-123-45-6789-01234"
let subrange = s.characters.dropFirst(3).startIndex..<s.endIndex

for match in numbers.matches(in: s) {
    // enumerating
    match.matched
}

if let first = numbers.matches(in: s).first {
    // first match
    first.matched
}

let allMatches: [Match] = numbers.matches(in: s).all // all matches

let subrangeMatches = numbers.matches(in: s, options: [.withTransparentBounds], range: subrange)

for case let match in subrangeMatches.dropFirst(1) where match.matched != "6789" {
    match.matched
}

Important: If the matched range is unable to be converted to Range<String.Index>, the match is ignored . Try searching “\r” in “\r\n”.

Match & Capture Groups

if let first = numbers.matches(in: s).first {
    
    first.matched
    first.range
    first.groups.count
    first.groups[1].matched
    first.groups[1].range
    
    let replacement = first.replacement(withTemplate: "$3$2$1")     // Replacement with template
}

Named Capture Group

Named capture group feature is enabled when .namedCaptureGroups is set.

let named = Regex("(?<year>\\d+)-(?<month>\\d+)-(?<day>\\d+)", options: .namedCaptureGroups)
let s = "Today is 2017-06-23."

for m in named.matches(in: s) {
    m.groups["year"]?.matched
}

named.replacingAllMatches(in: s, replacement: .replaceWithTemplate("${month}/${day}/${year}")) // Today is 06/23/2017.

Note: If the comment in pattern contains the notation of capture group, the detection for named capture group will fail.

Replacing

numbers.replacingFirstMatch(in: s, replacement: .remove)

numbers.replacingAllMatches(in: s, range: subrange, replacement: .replaceWithTemplate("$3$2$1"))

Flexible Find & Replace is offered by replacingMatches(in:options:range:replacing:).

numbers.replacingMatches(in: s) { (idx, match) -> Match.Replacing in
    
    switch idx {
    case 0:
        return .keep    // Keeps unchanged
    case 1:
        return .remove  // Removes the matched string
    case 2:
        return .replaceWithTemplate("($1-$3)")    // Replaces with template
    case 3:
        return .replaceWithString(String(match.matched.characters.reversed()))   // Replaces with string
    default:
        return .stop    // Stops replacing
    }
}

String Matching

"123".isMatching("\\d+")
"llregex".isMatching(insensitive)   // Regex is accepted
"123-456".isMatching("\\d+")    // isMatching(_:) checks whether matches entirely

String Replacing

Note: Two variants - one with pattern and template label, the other is not.

"123".replacingAll("1", with: "$0")
"123-321".replacingAll(pattern: "(\\d)(\\d)", withTemplate: "$2$1")

s.replacingFirst(pattern: numbers, in: subrange, withTemplate: "!")

String Splitting

s.split(seperator: "\\d")
s.split(seperator: numbers, maxSplits: 2, omittingEmptyString: false)