<code>P('keyword_</code><em><code>n</code></em><code>')</code> ordered
    choices, use another convenience function: <a href="#lexer.word_match"><code>lexer.word_match()</code></a>. It is
    much easier and more efficient to write word matches like:</p>

    <pre><code>
    local keyword = token(lexer.KEYWORD, lexer.word_match[[
      keyword_1 keyword_2 ... keyword_n
    ]])

    local case_insensitive_keyword = token(lexer.KEYWORD, lexer.word_match([[
      KEYWORD_1 keyword_2 ... KEYword_n
    ]], true