# .multipart.
class Number

	var _value as int

	cue init(value as int)
		base.init
		_value = value
		
	get value from _value
	
	def fromLetter(le as Letter) as Number?
		is shared
		branch le.value
			on 'a', return Number(1)
			on 'b', return Number(2)
		return nil