Path: csiph.com!xmission!news.snarked.org!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end
From: Andy <borucki.andrzej@gmail.com>
Newsgroups: comp.compilers
Subject: Re: Reachability of DFA part
Date: Sat, 21 Dec 2019 01:15:58 -0800 (PST)
Organization: Compilers Central
Lines: 26
Sender: news@iecc.com
Approved: comp.compilers@iecc.com
Message-ID: <19-12-012@comp.compilers>
References: <19-12-008@comp.compilers> <19-12-009@comp.compilers>
Mime-Version: 1.0
Content-Type: text/plain; charset="UTF-8"
Content-Transfer-Encoding: 8bit
Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="80896"; mail-complaints-to="abuse@iecc.com"
Keywords: lex
Posted-Date: 21 Dec 2019 13:10:00 EST
X-submission-address: compilers@iecc.com
X-moderator-address: compilers-request@iecc.com
X-FAQ-and-archives: http://compilers.iecc.com
In-Reply-To: <19-12-009@comp.compilers>
Xref: csiph.com comp.compilers:2393

W dniu piątek, 20 grudnia 2019 17:41:04 UTC+1 użytkownik Kaz Kylheku
napisał:
> In the NFA automaton, every time the prefix of the input given so far
> ends in ba, the machine will be in an acceptance state corresponding
> to that trailing ba.

Machine finally accept all strings begin from "ab" but "ba" will unused.
This is similar to definition of comment: in Pascal. comment begin at { and
end of }, careless definition is {*} which mark as comment to rest of file.

Good definition would be {[^}]*}
Complexity of problem increases when comment ends with string len >1, for
example C: */ or Pascal *)
if we renaming : /->a *->b other->c
then bad definition will ab(a|b|b)*ba and good definition is complicated:
ab(b|(a|c)*b*)*a (if I not make mistake)

Commments should maybe be defined in other way, especially comments can be
nested in Object Pascal. Comment nesting can using stack or simply counter. I
see, in Pascal is using counter. Difference: Pascal has two types of multiline
comments { } and (* *)

If we use stack, closing comment type must be equal last open comment type,
for counter - only count comments of type first opening, example
{ { (* } *) }