Path: csiph.com!eternal-september.org!feeder.eternal-september.org!aioe.org!.POSTED!not-for-mail From: "Rod Pemberton" Newsgroups: comp.lang.forth Subject: Re: New to the group Date: Fri, 02 Oct 2015 00:30:26 -0400 Organization: Aioe.org NNTP Server Lines: 54 Message-ID: References: <4f5b572c-04ae-433e-bed0-9d7b754bc27b@googlegroups.com> <4340f7c0-4267-494e-988f-bdf6d3c8af0f@googlegroups.com> <97f1036b-2ca0-488f-a630-566994f8e58d@googlegroups.com> <-9udnUrFSOV8WJHLnZ2dnUU7-N-dnZ2d@supernews.com> NNTP-Posting-Host: n4wpt9zq8xR26Ttf9mo2BA.user.speranza.aioe.org Mime-Version: 1.0 Content-Type: text/plain; charset=iso-8859-1; format=flowed; delsp=yes Content-Transfer-Encoding: 7bit X-Complaints-To: abuse@aioe.org User-Agent: Opera Mail/12.16 (Linux) X-Notice: Filtered by postfilter v. 0.8.2 Xref: csiph.com comp.lang.forth:42306 On Thu, 01 Oct 2015 08:31:21 -0400, rickman wrote: > On 10/1/2015 2:47 AM, hughaguilar96@gmail.com wrote: >> On Wednesday, September 30, 2015 at 10:34:27 PM UTC-7, Elizabeth D. Rather wrote: >>> Generally, one shouldn't get fussed when reading that a certain >>> condition is "ambiguous." Just take the message as, "don't do that" and >>> (if you care) look at the documentation for the system in question to >>> see what it does. >> >> So, this explains why ticking IF causes gForth to abort --- I should >> have known: "don't do that!" >> >> Perhaps you are explaining why IF does have an xt in VFX, but the xt >> will abort when executed (no matter what STATE is at the time) --- it >> is a non-executable execution-token. >> >> Maybe you are explaining why FIND in gForth returns different xt >> values for IF depending upon what STATE is at the time that FIND executes. >> >> All of this is allowed by the ANS-Forth document --- the bad thing about >> ambiguity is that anything can happen, but whatever happens is legal ANS-Forth. > > I'm sure I'm not the only one who is tired of Hugh's rantings on this > issue. IF does not have defined execution semantics. So why would > anyone expect IF to have an XT and if a value were returned by tick, why > would they expect it to do anything useful when executed? > I only like Hugh's rants when I can make fun of him ... Of course, I also bring up important points which he ignores also. But, all of that still doesn't mean his point was unimportant. ISTM that older Forth standards would return the XT or equivalent (PFA) for ' (tick) if the word was found in the dictionary and/or vocabulary regardless of any execution semantics or immediacy etc. Therefore, *NOT* returning an XT for a word that's in the dictionary because it doesn't have any execution or interpration semantics would seem to be a departure from the prior Forth standards and/or historical Forth behavior. As Hugh noted, code which expects historical behaviors may break with ANS since ANS apparently made little to no effort to preserve such behaviors. I.e., his apparent claim that ANS code is non-portable would seem to be valid in the sense that the code would break on pre-ANS Forths. Although, I don't think he mentioned pre-ANS Forths anywhere in his claims. Rod Pemberton -- Just how many texting and calendar apps does humanity need? Just how many food articles from neurotic millenials do we need?