class Chronic::Ordinal

def self.scan(tokens, options)

Returns an Array of tokens.

options - The Hash of options specified in Chronic::parse.
tokens - An Array of tokens to scan.

tags to each token.
Scan an Array of Token objects and apply any necessary Ordinal 
def self.scan(tokens, options)
  tokens.each_index do |i|
    if tokens[i].word =~ /^(\d+)(st|nd|rd|th|\.)$/
        ordinal = $1.to_i
        tokens[i].tag(Ordinal.new(ordinal))
        tokens[i].tag(OrdinalDay.new(ordinal)) if Chronic::Date::could_be_day?(ordinal)
        tokens[i].tag(OrdinalMonth.new(ordinal)) if Chronic::Date::could_be_month?(ordinal)
        if Chronic::Date::could_be_year?(ordinal)
            year = Chronic::Date::make_year(ordinal, options[:ambiguous_year_future_bias])
            tokens[i].tag(OrdinalYear.new(year.to_i))
        end
    end
  end
end

def to_s 

def to_s
  'ordinal'
end