Path: csiph.com!weretis.net!feeder6.news.weretis.net!news.misty.com!news.iecc.com!.POSTED.news.iecc.com!nerds-end From: Jan Ziak <0xe2.0x9a.0x9b@gmail.com> Newsgroups: comp.compilers Subject: Re: What is the meaning of an expression? Date: Tue, 18 Jan 2022 10:03:06 -0800 (PST) Organization: Compilers Central Lines: 22 Sender: news@iecc.com Approved: comp.compilers@iecc.com Message-ID: <22-01-067@comp.compilers> References: <22-01-052@comp.compilers> <22-01-060@comp.compilers> <22-01-066@comp.compilers> Mime-Version: 1.0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8bit Injection-Info: gal.iecc.com; posting-host="news.iecc.com:2001:470:1f07:1126:0:676f:7373:6970"; logging-data="62251"; mail-complaints-to="abuse@iecc.com" Keywords: semantics, comment Posted-Date: 18 Jan 2022 13:25:09 EST X-submission-address: compilers@iecc.com X-moderator-address: compilers-request@iecc.com X-FAQ-and-archives: http://compilers.iecc.com In-Reply-To: <22-01-066@comp.compilers> Xref: csiph.com comp.compilers:2840 > Now we're even deeper in the tarpit. Is the "meaning" a mathematical statement, > an instruction to a compiler to generate code computing the value of an expression, > something else? I don't know, and it's pretty clear none of the rest of us do either. > -John In my opinion, your comments are moving this discussion in the wrong direction. In the context of compilers: a compiler isn't in control of the meaning of the source code input into the compiler, because the input might be a Universal Turing Machine. The compiler knows for certain that the source code is moving a machine from one state to another state (while not in a terminating state: perform a state transition) while the source code is being executed - a compiler isn't trying to answer the question of what the _final_ meanings of those state transitions are. If the compiler tried to answer such a question, then the compiler might never stop compiling the source code. The set of terminating states is specified by the source code, not by the compiler. -atom [If you go back the the start of the thread, someone asked about a statement that "The meaning of an expression is the value of the expression." I suppose we could ask what it means to a compiler but that seems awfully anthropomorphic. -John]