Path: csiph.com!feeder.erje.net!2.us.feeder.erje.net!news.glorb.com!border1.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: "SLK Mail" Newsgroups: comp.compilers Subject: precedences vs. hierarchy Date: Tue, 07 Jun 2016 08:53:41 -0800 Organization: SLK Systems Lines: 11 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <16-06-007@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-15; format=flowed; delsp=yes Content-Transfer-Encoding: 8bit Injection-Info: miucha.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="24426"; mail-complaints-to="abuse@iecc.com" Keywords: parse Posted-Date: 07 Jun 2016 10:55:13 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:1713 Using precedence parsing keeps the grammar, and so the parser smaller and also easier to read. The size was much more important when memory was measured in kilobytes, not in gigabytes. It also eliminates the empty precedence transitions at runtime, though this is easy to do by reducing the parse tree before creating the parser. Languages are generally specified with a hierarchical grammar. This better decouples the specification from the implementation. The SLK Parser Generator: www.slkpg.com