Path: utzoo!utgpu!news-server.csri.toronto.edu!cs.utexas.edu!samsung!uakari.primate.wisc.edu!dali.cs.montana.edu!ogicse!zephyr.ens.tek.com!tektronix!percy!data!kend From: kend@data.UUCP (Ken Dickey) Newsgroups: comp.lang.misc Subject: Re^8: Some things that pointer-less languages can't do efficiently Message-ID: <423@data.UUCP> Date: 31 Oct 90 17:37:55 GMT References: <26739:Oct1023:44:2690@kramden.acf.nyu.edu> <65450@lanl.gov> <420@data.UUCP> <422@data.UUCP> <35S67X@xds13.ferranti.com> Organization: Microcosm, Beaverton, OR Lines: 55 You should probably hit `N' here... -Ken peter@ficc.ferranti.com (Peter da Silva) writes: >In article <422@data.UUCP> kend@data.UUCP (Ken Dickey) writes: ken>> The definition of "pointer" comes from an extensive body of literature ken>> on computation. You should use a term with a meaning closer to what ken>> you wish to express rather than redefining a term with an established ken>> meaning. CS is already full of overdefined terms. peter>Fine. You want to play name games. THe question at hand is "what is a peter>pointer", or "what is it that makes pointers dangerous". To answer this peter>question you have to ask "what is a pointer" in terms of what we want peter>to know about them. What is wrong with using the standard definition of pointer? I have given a number of references which support my interpretation. I think that it is you who are playing word games by redefining things as you go along. peter>If you think the fact that a pointer points at a peter>machine address (an implementation detail) is significant, then is Sabre-C peter>a pointerless language? If so, what is significantly different between peter>it and conventional C implementations? I know of no programming language called "Sabre-C". You are confusing language with implementation here. ken>> In the context of computer programming languages, "token" has a ken>> meaning in the context of syntax. I did not know you were speaking of ken>> networks. peter>No, the term "token" has a meaning in the larger world of CS: a token is peter>an opaque object that refers to another object. In the context of compilers peter>it's a small easily-handled object that refers to a string of characters. In the context of compilers, a "token" is a (meaningless) unit of syntax. Meanings come into play in the semantics which results from the analysis. I have looked through a number of standard CS texts and have been unable to find a definition of "token" other than an a meaningless (but unique) marker used in token-ring networks or as a syntactic unit in computer language analysis. I ask again, what are the references which support your definition? peter>.. I don't care what peter>the underlying implementation does. It doesn't have to have machine peter>addresses in the implementation anywhere... look at the UNIX file system: peter>a link (either symbolic or hard) is a pointer, but there are no CPU peter>addresses involved at all. Hell, a symbolic link can point into another peter>address space! So where has someone defined pointer == link? Go back and look up "pointer" in a few standard textbooks. -Ken