Scanner+Swift.swift

// Scanner+Swift.swift
//
// A set of idiomatic swift extensions to Scanner
//
// Based on https://gist.github.com/natecook1000/59bb0c9117b555f5d40d
// Converted to Swift 3
//


import Foundation

extension Scanner {
    
    /// Returns a string scanned as long as characters from a given character set are encountered, or `nil` if none are found.
    public func scanCharacters(from set: CharacterSet) -> String? {
        var value: NSString?
        guard scanCharacters(from: set, into: &value) else { return nil }
        return value as? String
    }
    
    /// Returns a string scanned until a character from the given character set is encountered, or the remainder of the scanner's string. Returns `nil` if the scanner is already `atEnd`.
    public func scanUpToCharacters(from set: CharacterSet) -> String? {
        var value: NSString?
        guard scanUpToCharacters(from: set, into: &value) else { return nil }
        return value as? String
    }
    
    /// Returns the given string if scanned, or `nil` if not found.
    public func scan(string: String) -> String? {
        var value: NSString?
        guard scanString(string, into: &value) else { return nil }
        return value as? String
    }
    
    /// Returns a string, scanned until the given string is found, or the remainder of the scanner's string. Returns `nil` if the scanner is already `atEnd`
    public func scanUpTo(string: String) -> String? {
        var value: NSString?
        guard scanUpTo(string, into: &value) else { return nil }
        return value as? String
    }
    
    /// Returns a Double if scanned, or `nil` if not found.
    public func scanDouble() -> Double? {
        var value = Double(0)
        guard scanDouble(&value) else { return nil }
        return value
    }
    
    /// Returns a Float if scanned, or `nil` if not found.
    public func scanFloat() -> Float? {
        var value = Float(0)
        guard scanFloat(&value) else { return nil }
        return value
    }
    
    /// Returns an Int if scanned, or `nil` if not found.
    public func scanInt() -> Int? {
        var value = Int(0)
        guard scanInt(&value) else { return nil }
        return value
    }
    
    /// Returns an Int32 if scanned, or `nil` if not found.
    public func scanInt32() -> Int32? {
        var value = Int32(0)
        guard scanInt32(&value) else { return nil }
        return value
    }
    
    /// Returns an Int64 if scanned, or `nil` if not found.
    public func scanInt64() -> Int64? {
        var value = Int64(0)
        guard scanInt64(&value) else { return nil }
        return value
    }
    
    /// Returns a UInt64 if scanned or `nil` if not found.
    public func scanUInt64() -> UInt64? {
        var value = UInt64(0)
        guard scanUnsignedLongLong(&value) else { return nil }
        return value
    }
    
    /// Returns a Decimal if scanned, or `nil` if not found.
    public func scanDecimal() -> Decimal? {
        var value = Decimal(0)
        guard scanDecimal(&value) else { return nil }
        return value
    }
    
    /// Returns a Float if scanned in hexadecimal, or `nil` if not found.
    public func scanHexFloat() -> Float? {
        var value = Float(0)
        guard scanHexFloat(&value) else { return nil }
        return value
    }

    /// Returns a Double if scanned in hexadecimal, or `nil` if not found.
    public func scanHexDouble() -> Double? {
        var value = Double(0)
        guard scanHexDouble(&value) else { return nil }
        return value
    }

    /// Returns a UInt32 if scanned in hexadecimal, or `nil` if not found.
    public func scanHexUInt32() -> UInt32? {
        var value = UInt32(0)
        guard scanHexInt32(&value) else { return nil }
        return value
    }

    /// Returns a UInt64 if scanned in hexadecimal, or `nil` if not found.
    public func scanHexUInt64() -> UInt64? {
        var value = UInt64(0)
        guard scanHexInt64(&value) else { return nil }
        return value
    }
}