class Samovar::One

def initialize(key, description, pattern: //, default: nil)
	@key = key
	@description = description
	@pattern = pattern
	@default = default
end

def parse(input, default = @default)
	if input.first =~ @pattern
		input.shift
	end || default
end

def to_a
	usage = [to_s, @description]
	
	if @default
		usage << "Default: #{@default.inspect}"
	end
	
	return usage
end

def to_s
	"<#{@key}>"
end