From mboxrd@z Thu Jan 1 00:00:00 1970 X-Spam-Checker-Version: SpamAssassin 3.4.4 (2020-01-24) on polar.synack.me X-Spam-Level: X-Spam-Status: No, score=-1.1 required=5.0 tests=BAYES_00, PP_MIME_FAKE_ASCII_TEXT autolearn=no autolearn_force=no version=3.4.4 Path: border1.nntp.ams3.giganews.com!border1.nntp.ams2.giganews.com!border2.nntp.ams2.giganews.com!border4.nntp.ams.giganews.com!border2.nntp.ams.giganews.com!nntp.giganews.com!weretis.net!feeder4.news.weretis.net!nuzba.szn.dk!news.jacob-sparre.dk!munin.jacob-sparre.dk!pnx.dk!.POSTED!not-for-mail From: "Randy Brukardt" Newsgroups: comp.lang.ada Subject: Re: LALR parser question Date: Thu, 2 May 2013 16:57:20 -0500 Organization: Jacob Sparre Andersen Research & Innovation Message-ID: References: <85sj2aydwi.fsf@stephe-leake.org> NNTP-Posting-Host: static-69-95-181-76.mad.choiceone.net X-Trace: munin.nbi.dk 1367531849 21922 69.95.181.76 (2 May 2013 21:57:29 GMT) X-Complaints-To: news@jacob-sparre.dk NNTP-Posting-Date: Thu, 2 May 2013 21:57:29 +0000 (UTC) X-Priority: 3 X-MSMail-Priority: Normal X-Newsreader: Microsoft Outlook Express 6.00.2900.5931 X-RFC2646: Format=Flowed; Response X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2900.6157 X-Original-Bytes: 2937 Xref: number.nntp.dca.giganews.com comp.lang.ada:181364 Date: 2013-05-02T16:57:20-05:00 List-Id: "Yannick Duchêne (Hibou57)" wrote in message news:op.wwfqzzi0ule2fv@cardamome... Le Thu, 02 May 2013 03:49:53 +0200, Randy Brukardt a écrit: >> I tend to agree that the speed of parsing doesn't matter that much, but >> you >> would be surprised at how slow some compilers were at parsing and syntax >> analysis, especially before GNAT came out. We actually had a pretty >> decent >> business from companies that bought our fast compiler just to do >> pre-compiles on before using their main development slug to build the >> actual >> system. > >More precisely, is there an average picture? What is considered fast and >what is considered slow? Which amount of sample Ada sources parsed in >which amount of time? How slow was their "main development slug"? How fast >is Janus Ada compared to theirs? I couldn't answer these questions numerically; we didn't own those other compilers that were too slow. And it was a long time ago. I'd heard that in some cases it was a factor of 10. But the numbers are hardly relevant today. Obviously, the developers thought that they saved enough time doing check-out compilations using Janus/Ada to justify paying for a license, which was not free. So that suggests that there the main system was pretty slow (probably on the order of hours). After all, in those days it took 4 or so hours to do a full recompile of Janus/Ada. (It's under 5 minutes today.) We spent a lot of effort trying not to make changes to the symboltable in order to avoid those long compiles, which lead to all kinds of misuses of existing components. It's always a pain when one of those turns up (these days, I change them to have meaningful names and fewer tricks, of course, although its not always worth the effort to change). Randy.