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From: andrew@orca.UUCP (Andrew Klossner)
Newsgroups: net.unix
Subject: Re: comments in lex
Message-ID: <1614@orca.UUCP>
Date: Sat, 13-Jul-85 20:52:26 EDT
Article-I.D.: orca.1614
Posted: Sat Jul 13 20:52:26 1985
Date-Received: Wed, 17-Jul-85 04:53:34 EDT
References: <114@emacs.uucp> <193@jendeh.UUCP>
Organization: Tektronix, Wilsonville OR
Lines: 17

>> How do you recognise a PL/1 style comment?
>
> "/*"([^*]|"*"[^/])*"*/"

Two problems:

1) This pattern will incorrectly recognize "/***/ */" as a comment.

2) This approach to comment skipping is a bad idea in lex, because the
   generated lexer will try to accumulate the entire comment in the
   "yytext" buffer, which has a fixed size.  (On our system, the size
   is 1024 bytes.)  If ever a comment with more bytes than the buffer
   size is found, the lex driver will merrily overwrite the memory
   following the buffer and blow away your compile.

  -=- Andrew Klossner   (decvax!tektronix!orca!andrew)       [UUCP]
                        (orca!andrew.tektronix@csnet-relay)  [ARPA]