From lojban+bncCLr6ktCfBBC8m7HnBBoENflijg@googlegroups.com Tue Nov 23 15:27:10 2010 Received: from mail-gx0-f189.google.com ([209.85.161.189]) by chain.digitalkingdom.org with esmtp (Exim 4.72) (envelope-from ) id 1PL2GM-0005qK-15; Tue, 23 Nov 2010 15:27:10 -0800 Received: by gxk19 with SMTP id 19sf1272888gxk.16 for ; Tue, 23 Nov 2010 15:26:56 -0800 (PST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=googlegroups.com; s=beta; h=domainkey-signature:received:x-beenthere:received:received:received :received:received-spf:received:received:received:date:from:to :subject:message-id:mail-followup-to:references:mime-version :in-reply-to:x-original-sender:x-original-authentication-results :reply-to:precedence:mailing-list:list-id:list-post:list-help :list-archive:sender:list-subscribe:list-unsubscribe:content-type :content-disposition; bh=WYHCDRC4W+KcwE9xQtl67BCLkk2oQ1sNNz9iLHeJNw4=; b=LznqY7OTRmIqW9s9s3zVAGzGrMarRYx34Ru2LqNUIIM/RMYg326njtneifrAkhfKD7 zIunPHZmkMRwE5HjK8Jn+9pwNfll2K8yhlGnvtruFmo/D3uRyXm9mADwJvJ2aPbQrJmN UQdH4zb5L8WS1NXCa/wvnUlfgG8frXrEg8HgQ= DomainKey-Signature: a=rsa-sha1; c=nofws; d=googlegroups.com; s=beta; h=x-beenthere:received-spf:date:from:to:subject:message-id :mail-followup-to:references:mime-version:in-reply-to :x-original-sender:x-original-authentication-results:reply-to :precedence:mailing-list:list-id:list-post:list-help:list-archive :sender:list-subscribe:list-unsubscribe:content-type :content-disposition; b=TrAJNJTSR0Iqe9FknonI7d4KCYC5bizTU4oFZZFmwU+8LGLiPQvaLMS8AF8QKls+jh obCpML+S9r+EIFK9wbNddbxd6nOYgJd8Lh2t5C6FOPE4pn3p6e0CTcRkrYS0W4GsGjXN N/o5SFJuGRvuRdQRpqlO7PI55GOHgkw6xZHG8= Received: by 10.150.174.42 with SMTP id w42mr799626ybe.59.1290554812945; Tue, 23 Nov 2010 15:26:52 -0800 (PST) X-BeenThere: lojban@googlegroups.com Received: by 10.150.1.11 with SMTP id 11ls641043yba.0.p; Tue, 23 Nov 2010 15:26:51 -0800 (PST) Received: by 10.150.96.2 with SMTP id t2mr1911204ybb.12.1290554811106; Tue, 23 Nov 2010 15:26:51 -0800 (PST) Received: by 10.150.96.2 with SMTP id t2mr1911203ybb.12.1290554811056; Tue, 23 Nov 2010 15:26:51 -0800 (PST) Received: from mail-gw0-f46.google.com (mail-gw0-f46.google.com [74.125.83.46]) by gmr-mx.google.com with ESMTP id s48si118320yhc.10.2010.11.23.15.26.50; Tue, 23 Nov 2010 15:26:50 -0800 (PST) Received-SPF: neutral (google.com: 74.125.83.46 is neither permitted nor denied by best guess record for domain of alanpost@sunflowerriver.org) client-ip=74.125.83.46; Received: by gwj20 with SMTP id 20so502615gwj.5 for ; Tue, 23 Nov 2010 15:26:50 -0800 (PST) Received: by 10.150.204.13 with SMTP id b13mr5211969ybg.410.1290554809546; Tue, 23 Nov 2010 15:26:49 -0800 (PST) Received: from sunflowerriver.org (c-68-35-167-179.hsd1.nm.comcast.net [68.35.167.179]) by mx.google.com with ESMTPS id q41sm4354863ybk.13.2010.11.23.15.26.47 (version=TLSv1/SSLv3 cipher=RC4-MD5); Tue, 23 Nov 2010 15:26:48 -0800 (PST) Date: Tue, 23 Nov 2010 16:26:44 -0700 From: ".alyn.post." To: lojban@googlegroups.com Subject: Re: [lojban] rp-expression-tail ordered choice with empty grouping Message-ID: <20101123232644.GJ10838@alice.local> Mail-Followup-To: lojban@googlegroups.com References: <20101123184352.GE10838@alice.local> <20101123185211.GU9301@digitalkingdom.org> <20101123190157.GG10838@alice.local> Mime-Version: 1.0 In-Reply-To: X-Original-Sender: alyn.post@lodockikumazvati.org X-Original-Authentication-Results: gmr-mx.google.com; spf=neutral (google.com: 74.125.83.46 is neither permitted nor denied by best guess record for domain of alanpost@sunflowerriver.org) smtp.mail=alanpost@sunflowerriver.org Reply-To: lojban@googlegroups.com Precedence: list Mailing-list: list lojban@googlegroups.com; contact lojban+owners@googlegroups.com List-ID: List-Post: , List-Help: , List-Archive: Sender: lojban@googlegroups.com List-Subscribe: , List-Unsubscribe: , Content-Type: text/plain; charset=ISO-8859-1 Content-Disposition: inline I'm interested. Is this compatible with the current grammar? What is it that you mean when you say "playing around?" -Alan On Wed, Nov 24, 2010 at 10:17:42AM +1100, Ross Ogilvie wrote: > I've been playing around with the mekso grammar recently. I think I have a > rewrite, but I want to finish coding and check that it works as I want it > to. I'll post tomorrow or the day after if people are interested. > > mi'e ros > > On Wed, Nov 24, 2010 at 6:01 AM, .alyn.post. > <[1]alyn.post@lodockikumazvati.org> wrote: > > On Tue, Nov 23, 2010 at 10:52:11AM -0800, Robin Lee Powell wrote: > > On Tue, Nov 23, 2010 at 11:43:52AM -0700, .alyn.post. wrote: > > > What does the following production in the lojban grammar mean?: > > > > > > rp-expression-tail <- rp-expression operator rp-expression-tail / > > > () > > > > > > Do I understand that to mean 'the sequence of rp-expression, > > > operator, and rp-expression-tail OR nothing?' Could the above > > > also be expressed: > > > > > > rp-expression-tail <- (rp-expression operator rp-expression-tail)? > > > > > > And if so, why the odd way of specifying it? I'm weak on pitfalls > > > of recursive behavior in grammars, am I looking at a workaround > > > related to that? > > > > Yes, and it mostly doesn't work. Lojban's RPN (which, if I have my > > druthers, the next version of the language will not have, by the > > way) is left-recursive, which is problematic. See the peg mailing > > list for various solutions, but IMO since a number of PEG parser > > generators handle this on their own, I think we should just have it > > be left-recursive and say that people have to use such a generator. > > > > If you can figure out how to fix it in in the rules so the right > > behaviour pops out, though, *please* do so. There are links to > > papers on the peg mailing list; it came up just last week; "*[1]* > > *Packrat Parsers Can Support Left Recursion*, Alessandro Warth, > > James R. Douglass, and Todd Millstein (2008)" is the citation I'm > > seeing at a brief glance. > > > > Great. I saw that thread and ignored it as not being relevant in > the moment, but I'm happy to read it and play with it when I get to > that point. > > I've downloaded the paper and cached it with this problem, as I'm a > bit ahead of myself with it. > -Alan > -- > .i ko djuno fi le do sevzi > > -- > You received this message because you are subscribed to the Google > Groups "lojban" group. > To post to this group, send email to [2]lojban@googlegroups.com. > To unsubscribe from this group, send email to > [3]lojban+unsubscribe@googlegroups.com. > For more options, visit this group at > [4]http://groups.google.com/group/lojban?hl=en. > > -- > You received this message because you are subscribed to the Google Groups > "lojban" group. > To post to this group, send email to lojban@googlegroups.com. > To unsubscribe from this group, send email to > lojban+unsubscribe@googlegroups.com. > For more options, visit this group at > http://groups.google.com/group/lojban?hl=en. > > References > > Visible links > 1. mailto:alyn.post@lodockikumazvati.org > 2. mailto:lojban@googlegroups.com > 3. mailto:lojban%2Bunsubscribe@googlegroups.com > 4. http://groups.google.com/group/lojban?hl=en -- .i ko djuno fi le do sevzi -- You received this message because you are subscribed to the Google Groups "lojban" group. To post to this group, send email to lojban@googlegroups.com. To unsubscribe from this group, send email to lojban+unsubscribe@googlegroups.com. For more options, visit this group at http://groups.google.com/group/lojban?hl=en.