groupbyunichar.swift

func groupByFirstLetter(strings: [String]) -> [String : [String]] {
	let A = ("A" as NSString).characterAtIndex(0)
	let Z = ("Z" as NSString).characterAtIndex(0)
	
	let dictionaries: [[String : [String]]] = (A...Z).map {
		Character(UnicodeScalar($0))
	}.map { (character) -> [String : [String]] in
		let values = strings.filter {
			$0.uppercaseString.hasPrefix(String(character))
		}
		return [String(character) : values]
	}.filter { $0.values.first!.count > 0 }
	
	return dictionaries.reduce([:]) { (collector: [String : [String]], dictionary) -> [String : [String]] in
		var returnCollector = collector
		for (key, value) in dictionary {
			returnCollector.updateValue(value, forKey: key)
		}
		return returnCollector
	}
}