class Chronic::TimeZone

def self.scan(tokens)
  tokens.each_index do |i|
    if t = self.scan_for_all(tokens[i]) then tokens[i].tag(t); next end
  end
  tokens
end

def self.scan_for_all(token)
  scanner = {/[PMCE][DS]T/i => :tz,
             /(tzminus)?\d{4}/ => :tz}
  scanner.keys.each do |scanner_item|
    return self.new(scanner[scanner_item]) if scanner_item =~ token.word
  end
  return nil
end

def to_s
  'timezone'
end