<p>Hi Daniel,</p>

<p>Yes, it works with "isalnum" in my test, but another define, just below: is_char_equal is also using "isalpha" but I don't know if it needs modification:</p>

<div class="highlight highlight-source-c"><pre>#<span class="pl-k">define</span> <span class="pl-en">is_char_equal</span>(<span class="pl-v">_c_,_cs_</span>) \
        ( (isalpha((<span class="pl-k">int</span>)_c_)?(((_c_)|0x20)==(_cs_)):((_c_)==(_cs_)))==<span class="pl-c1">1</span> )</pre></div>

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