Xref: news-dnh.mv.net comp.os.msdos.djgpp:1259 Path: news-dnh.mv.net!mv!news.sprintlink.net!newsfeed.internetmci.com!news.mathworks.com!fu-berlin.de!news.dfn.de!gs.dfn.de!news.gwdg.de!grotheer From: grotheer AT PROBLEM_WITH_INEWS_DOMAIN_FILE (Olaf Grotheer) Newsgroups: comp.os.msdos.djgpp Subject: Re: Bison/Flex Date: 28 Jul 1995 13:26:08 GMT Organization: MPI fuer Festkoerperforschung, Stuttgart Lines: 21 References: Nntp-Posting-Host: physix.mpi-stuttgart.mpg.de To: djgpp AT sun DOT soe DOT clarkson DOT edu Dj-Gateway: from newsgroup comp.os.msdos.djgpp George C. Moschovitis (gmoscho AT alexander DOT cc DOT ece DOT ntua DOT gr) wrote: : What exactly are the bison ond flex utilities ? They are the Gnuish versions of the programs lex and yacc (yet another compiler compiler) respectively. lex (or flex) takes a description of what should be considered as a 'token' and produces C-source code that will compile into a program that seperates a sequence of characters, say an input file into a sequence of tokens. yacc takes a description of a 'grammar', rules explaining what sequence of tokens should be considered meaningful and again produces C-source code now for a compiler that will interprete the sequence of tokens. : Are they usefull? Yes, I think so. For a simple problem, its easier to write code by hand, but for a problem of moderate size, lex and yacc are quite valuable. (I haven't tried really big problems yet :-) ) : Where can I find info? Where are many books out explaining lex and yacc. They are really compatible with flex and bison. Hope that helps. Olaf.