class Chronic::Pointer

def self.scan(tokens)
  # for each token
  tokens.each_index do |i|
    if t = self.scan_for_all(tokens[i]) then tokens[i].tag(t) end
  end
  tokens
end

def self.scan_for_all(token)
  scanner = {/\bpast\b/ => :past,
             /\bfuture\b/ => :future,
             /\bin\b/ => :future}
  scanner.keys.each do |scanner_item|
    return self.new(scanner[scanner_item]) if scanner_item =~ token.word
  end
  return nil
end

def to_s
  'pointer-' << @type.to_s
end