ZScanner

ZScanner aims enhancement or replacement of Scanner in Foundation framework.

Basic Usage

let scanner = ZScanner(string: "1.25e+5,125000,1024,512")
let a = scanner.scanFloatinPoint() // 1.25e+5
scanner.scan(string: ",")
let b = scanner.scanFloatinPoint() // 125000
scanner.scan(string: ",")
let x = scanner.scanInteger() // 1024
scanner.scan(string: ",")
let y = scanner.scanInteger() // 512

When you are expecting one of some keyword, you may use array of strings to scan.

let scanner = ZScanner(token: "true")
let a = scanner.scan(tokens: ["true", "false"]) 
a // true

If you like to scan associated indirect value, you may use dictionary to scan, and it returns its associated value instad of direct keyword.

let scanner = ZScanner(string: "JST 15:00")
if let offset = scanner.scan(dictionary: ["JST": 9, "EST": -5, "MST": -6, "PST": -8, "GMT": 0]) {
	scanner.scanWhitespaces()
	if let hour: Int = scanner.scanInteger(), let _ = scanner.scan(string: ":"), let minute: Int = scanner.scanInteger() {
		// offset: 9
		// hour: 15
		// minute: 0
	}
}

If you like to more sophisticated things to scan, you may provide a class or a struct confoms to ZScannable.

protocol ZScannable {
	init?(_ scanner: ZScanner)
}

Here is an example of providing extension of Bool.

extension Bool {
	init?(_ scanner: ZScanner) {
		scanner.scanWhitespaces()
		if let value: Bool = scanner.scan(dictionary: ["true": true, "false": false]) { self = value }
		else { return nil }
	}
}

Then you may scan boolean value.

let scanner = ZScanner(string: "false")
let value: Bool? = Bool(scanner) // false

You may scan an identifier.

let scanner = ZScanner(string: "not_found_404")
let value = scanner.scanIdentifier() // "not_found_404"

Be aware that when you scan a keyword, it won't scan that keyword partially.

let scanner = ZScanner(string: "helloworld")
let hello = scanner.scan(string: "hello") // nil
let world = scanner.scan(string: "helloworld") // "helloworld"

let scanner = ZScanner(string: "hello world")
let hello = scanner.scan(string: "hello") // "hello"
let world = scanner.scan(string: "world") // "world"

You may have to pay attension to whitespaces to scan.

let scanner = ZScanner(string: "  hello")
let hello1 = scanner.scan(string: "hello") // nil
scanner.scanWhitespaces()
let hello2 = scanner.scan(string: "hello") // "hello"

To ignore whitespaces for scanning a token, use scan(token:) whereas scan(string:) do not ignore any whitespaces to go on.

let scanner = ZScanner(string: "    func hello ( )")
let t1 = scanner.scan(token: "func") // "func"
let t2 = scanner.scanIdentifier() // "hello"
let t3 = scanner.scan(token: "(")
let t4 = scanner.scan(token: ")")

You may use options to scan case insensitive keyword.

let scanner = ZScanner(string: "hElLo")
let hello = scanner.scan(string: "hello", options: [.caseInsensitive]) // "hElLo"

License

MIT License