Path: csiph.com!weretis.net!feeder6.news.weretis.net!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: antispam@math.uni.wroc.pl Newsgroups: comp.compilers Subject: Re: Learning only one lexer made me blind to its hidden assumptions Date: Wed, 13 Jul 2022 19:52:45 -0000 (UTC) Organization: Aioe.org NNTP Server Lines: 23 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <22-07-010@comp.compilers> References: <22-07-006@comp.compilers> Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="30201"; mail-complaints-to="abuse@iecc.com" Keywords: flex Posted-Date: 13 Jul 2022 15:59:03 EDT X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com Xref: csiph.com comp.compilers:3114 Roger L Costello wrote: > Below I have documented some of the differences between Lex/Flex and ScanGen. > Difference: > - Flex deals with individual characters > - ScanGen lumps characters into character classes and deals with classes. Use > of character classes decreases (quite significantly) the size of the > transition table Hmm, from flex manual: : -Ce, --ecs : construct equivalence classes : : -Cm, --meta-ecs : construct meta-equivalence classes If you want smaller tables use options above and flex DFA will work on character classes. -- Waldek Hebisch