(flex.info)The ^ operator isn't working

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The ^ operator isn't working
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     To: Thomas Hadig <hadig@toots.physik.rwth-aachen.de>
     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 <vern>
     
     > In my lexer code, i have the line :
     > ^\*.*          { }
     >
     > Thus all lines starting with an astrix (*) are comment lines.
     > 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 "-l" lex-compatibility flag, or "%option lex-compat".
     
     		Vern