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<h3 class="unnumberedsec">The ^ operator isn&rsquo;t working</h3>
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<pre class="verbatim">To: Thomas Hadig &lt;hadig@toots.physik.rwth-aachen.de&gt;
Subject: Re: Flex Bug ?
In-reply-to: Your message of Tue, 26 Nov 1996 14:35:01 PST.
Date: Tue, 26 Nov 1996 11:15:05 PST
From: Vern Paxson &lt;vern&gt;

&gt; In my lexer code, i have the line :
&gt; ^\*.*          { }
&gt;
&gt; Thus all lines starting with an astrix (*) are comment lines.
&gt; This does not work !

I can't get this problem to reproduce - it works fine for me.  Note
though that if what you have is slightly different:

	COMMENT	^\*.*
	%%
	{COMMENT}	{ }

then it won't work, because flex pushes back macro definitions enclosed
in ()'s, so the rule becomes

	(^\*.*)		{ }

and now that the '^' operator is not at the immediate beginning of the
line, it's interpreted as just a regular character.  You can avoid this
behavior by using the &quot;-l&quot; lex-compatibility flag, or &quot;%option lex-compat&quot;.

		Vern
</pre></div>




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flex-doc 2.6.4-6 / usr / share / doc / flex-doc / html / The-_005e-operator-isn_0027t-working.html
