StringScanner

StringScanner is a native swift implementation of a string scanner; a replacement of NSScanner.

StringScanner has been built by using swfit standard library only, and it does not depend on libFoundation. In that way it can be built on mac and linux, and can be build with static compilation in mind.

StringScanner is initialized with a string, it has an internal index that get progressed as the string is scanned.

StringScanner has two operations, peek and scan.

• scan returns a string and advances the internal string index.
• peek returns a string but does not progress the internal string index.

The result of scan or peek is a ScannerResult, which has the following values:

• ScannerResult.none: no string was found
• ScannerResult.end: the scanner has reached the end of the string
• ScannerResult.value(str): the string is found

Scanning for a given length

let scanner = StringScanner(string: "Hello my name is omar")
scanner.scan(length: 5)

Returns ScannerResult.("Hello")

Scan the string until a pattern is found

let scanner = StringScanner(string: "Hello my name is omar")
scanner.scan(untilPattern: "my")

Returns ScannerResult.("Hello ")

Scan the string until a string is found

let scanner = StringScanner(string: "Hello my name is omar")
scanner.scan(untilString: "my")

Returns ScannerResult.("Hello ")

Scan the string for a given string. If the search string is found, it gets rerurned and the scanner index is advanced.

let scanner = StringScanner(string: "Hello my name is omar")
scanner.scan(forString: "Hello mymy")

Returns ScannerResult.("Hello my ")

If we scan for a non exsisting string, we will get ScannerResult.none

Scan the string until a character set of strings is found. If the character set is found, it gets rerurned and the scanner index is advanced.

let scanner = StringScanner(string: "This is a test 1234")
scanner.scan(untilCharacterSet: .range("1"..<"4"))

Returns ScannerResult.("This is a test ")

If we scan for a non exsisting string, we will get ScannerResult.none

Scan the string until a character set of strings is found and return the string and the found character set. If the character set is found, it gets rerurned and the scanner index is advanced.

let scanner = StringScanner(string: "This is a test 1234")
scanner.scan(forCharacterSet: .range("1"..<"4"))

Returns ScannerResult.("This is a test 1")

If we scan for a non exsisting string, we will get ScannerResult.none

Peeking for a given length

let scanner = StringScanner(string: "Hello my name is omar")
scanner.peek(length: 5)

Returns ScannerResult.("Hello")

Peek the string until a pattern is found

let scanner = StringScanner(string: "Hello my name is omar")
scanner.peek(untilPattern: "my")

Returns ScannerResult.("Hello ")

Peek the string until a string is found

let scanner = StringScanner(string: "Hello my name is omar")
scanner.peek(untilString: "my")

Returns ScannerResult.("Hello ")

Peek the string for a given string. If the search string is found, it gets rerurned.

let scanner = StringScanner(string: "Hello my name is omar")
scanner.peek(forString: "Hello mymy")

Returns ScannerResult.("Hello my ")

If we scan for a non exsisting string, we will get ScannerResult.none

Peek the string until a character set of strings is found. If the character set is found, it gets rerurned.

let scanner = StringScanner(string: "This is a test 1234")
scanner.peek(untilCharacterSet: .range("1"..<"4"))

Returns ScannerResult.("This is a test ")

If we scan for a non exsisting string, we will get ScannerResult.none

Scan the string until a character set of strings is found and return the string and the found character set. If the character set is found, it gets rerurned.

let scanner = StringScanner(string: "This is a test 1234")
scanner.peek(forCharacterSet: .range("1"..<"4"))

Returns ScannerResult.("This is a test 1")

If we scan for a non exsisting string, we will get ScannerResult.none

CharacterSet provide ready made character sets that represent the most used ones: such as .allLetters, smallLetters, alphaNumeric.

Character set can be joined togther. For example we can search for all numbers + ABC

let scanner = StringScanner(string: "This is a test 1234")
let set = CharacterSet.numbers.join(characterSet: CharacterSet.string("ABC"))

The we can scan until we find that set

scanner.scan(untilCharacerSet: set)

This returns This is a test

scanner.reset() resets the internal index to zero

scanner.reset() resets the internal index to zero

You can install Swiftline using CocoaPods, carthage and Swift package manager

use_frameworks!
pod 'StringScanner'

github 'getGuaka/StringScanner'

Add swiftline as dependency in your Package.swift

  import PackageDescription

  let package = Package(name: "YourPackage",
    dependencies: [
      .Package(url: "https://github.com/getGuaka/StringScanner.git", from: "0.0.0"),
    ]
  )

Tests can be found here.

Run them with

swift test