Stryng
Stryng
is designed to make it easier to work with strings by using the common and easy to remember subscript syntax and accessing characters and ranges with Int
indices.
Swift's strings management is one of the most painful feature of the language. Sure, it's great to have Unicode correctness and efficiency, but this comes at a cost: too much verbosity and complexity.
Examples
Retrieve a single character at a specific position.
let string = "Example"
// With Stryng
string[1] // "x"
// Without
string[string.index(string.startIndex, offsetBy: 1)] // "x"
Retrieve the substring up to a specific index.
let string = "Example"
// With Stryng
string[..<2] // "Ex"
// Without
string[..<string.index(string.startIndex, offsetBy: 2)] // "Ex"
Retrieve the substring between two indices.
let string = "Example"
// With Stryng
string[1..<6] // "xampl"
// Without
string[string.index(string.startIndex, offsetBy: 1)..<string.index(string.startIndex, offsetBy: 6)] // "Ex"
Retrieve positions of a all substring occurences.
let string = "Example Example"
let occurences = string["xa"] // Returns a [Range<String.Index>] containing all positions of the subtring.
Convert a Substring
to a String
.
let example = "Example"
example[1...5].string // Returns a `String?` instead of a `Substring?`
Usage
This is an up to date list of the supported subscripts. Take a look at StryngTests.swift
if you want to see some more real code examples.
// String[1]
public subscript(index: Int) -> Character?
// String[0..<1]
public subscript(range: Range<Int>) -> Substring?
// String[0...1]
public subscript(range: ClosedRange<Int>) -> Substring?
// String[..<1]
public subscript(value: PartialRangeUpTo<Int>) -> Substring?
// String[...1]
public subscript(value: PartialRangeThrough<Int>) -> Substring?
// String[1...]
public subscript(value: PartialRangeFrom<Int>) -> Substring?
// String["substring"]
public subscript(string: String) -> [Range<String.Index>]
// String["begin"..."end"]
public subscript(range: ClosedRange<String>) -> [ClosedRange<String.Index>]
// String["begin"..<"end"]
public subscript(range: Range<String>) -> [Range<String.Index>]
// String[Character("a")]
public subscript(character: Character) -> [String.Index]
// String["begin"...]
public subscript(range: PartialRangeFrom<String>) -> PartialRangeFrom<String.Index>?
// String[..."end"]
public subscript(range: PartialRangeThrough<String>) -> PartialRangeThrough<String.Index>?
Installation
Cocoapods
To install via Cocoapods, add the following line to your Podfile:
pod 'Stryng'
Swift Package Manager
To install via the Swift Package Manager, add the following line to the dependencies
array in your Package.swift
file:
.package(url: "https://github.com/BalestraPatrick/Stryng.git", from: "0.4.1")
Then, still in your Package.swift
, add "Stryng"
to your target's dependencies
array.
Finally, in your terminal, run the following command to update your dependencies:
$ swift package update
Disclosure
Yes, string traversal in Swift can be slow. The reason why these subscripts don't exist in the standard library is that some people think that it hides the performance implications of traversing a string. Traversing a string from the startIndex
until the endIndex
has complexity O(n).
If you need to get a character at a specific index, in one way or another you will have to traverse the string, but why would you need 3 lines of code instead of 1 to do that if you know what you're doing?
This is why Stryng is here to help you.
Contribute
We'd love your help.
Head over to the issues with your feedback.
Bonus points if you open a Pull request with a failing test for a bug or a new feature!
Author
I'm Patrick Balestra.
Email: [email protected]
Twitter: @BalestraPatrick.
License
Stryng
is available under the MIT license. See the LICENSE file for more info.