Path: csiph.com!v102.xanadu-bbs.net!xanadu-bbs.net!news.glorb.com!peer02.iad.highwinds-media.com!news.highwinds-media.com!feed-me.highwinds-media.com!border1.nntp.dca1.giganews.com!border2.nntp.dca1.giganews.com!nntp.giganews.com!news.iecc.com!.POSTED!nerds-end From: Ivan Godard Newsgroups: comp.compilers Subject: Re: specifying semantics, was Formatting of Language LRMs Date: Sun, 29 Jun 2014 11:49:00 -0700 Organization: A noiseless patient Spider Lines: 23 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <14-06-031@comp.compilers> References: <14-06-010@comp.compilers> <14-06-023@comp.compilers> <14-06-025@comp.compilers> <14-06-027@comp.compilers> <14-06-030@comp.compilers> NNTP-Posting-Host: news.iecc.com Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Trace: miucha.iecc.com 1404070247 42900 2001:470:1f07:1126:0:676f:7373:6970 (29 Jun 2014 19:30:47 GMT) X-Complaints-To: abuse@iecc.com NNTP-Posting-Date: Sun, 29 Jun 2014 19:30:47 +0000 (UTC) Keywords: semantics Posted-Date: 29 Jun 2014 15:30:46 EDT X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com X-Received-Bytes: 2406 X-Received-Body-CRC: 1813126446 Xref: csiph.com comp.compilers:1286 On 6/29/2014 4:56 AM, George Neuner wrote: > Technically any grammar formalism is a denotational description of the > syntax of the accepted/generated language. But I think what you > really may be asking is whether a vW-grammar also is a semantic > description of the language it describes. > > The only place I have seen a 2 level grammar used was in the original > Algol68 report. Despite the inclusion of semantically meaningful > terms like "inseparable" and "strongly", etc., in actuality the vW > grammar in the report was used only for syntax specification. Language > semantics were not described *using* the formalism but rather were > given by accompanying text and only were *referenced* by the > formalism. Well, conventionally the type system of a language is considered semantics, yet the whole Algol68 type system, including checking all expressions for type validity, is present in the VWG. So while one can say that any language definition mechanism is syntactic by definition, that doesn't seem to be a useful definition to me. BTW, I'm talking about the VWG in the *Revised* Report, which different somewhat from that in the original report before the Great Schism.