&gt; Regex is just the wrong tool for lexing and parsing<p>Funny; I recently wrote an Island parser that extends Regex to create a token stream: <a href="https:&#x2F;&#x2F;github.com&#x2F;musesum&#x2F;Par" rel="nofollow">https:&#x2F;&#x2F;github.com&#x2F;musesum&#x2F;Par</a><p>Quoting the link to Rob Pike&#x27;s post:<p>&gt; Consider finding alphanumeric identifiers. It&#x27;s not too hard to write the regexp (something like &quot;[a-ZA-Z_][a-ZA-Z_0-9]*&quot;), but really not much harder to write as a simple loop<p>Maybe I&#x27;m missing something, but does this suggest replacing a declaration with a procedure? Oh the horror!