Path: utzoo!attcan!uunet!ficc!peter From: peter@ficc.uu.net (Peter da Silva) Newsgroups: comp.lang.misc Subject: Re: Pointers as 3-tuples (Re: JLG's flogging of horses (was Re: Relationship between C and C++)) Message-ID: <1BT2FU7ggpc2@ficc.uu.net> Date: 9 Apr 90 11:28:12 GMT References: <14313@lambda.UUCP> Reply-To: peter@ficc.uu.net (Peter da Silva) Organization: Xenix Support, FICC Lines: 37 > Under your proposed 3-tuple > idea, the distinction between pointers and arrays is further narrowed. Not at all. The *semantics* of pointers as addresses, and pointers as 3-tuples, are identical. A legal ANSI C program should operate identically under either implementation. It's just a safety net... not a new concept. [ And it's not my concept, either... much as I'd like to claim authorship, I didn't originate it. ] > In > fact, because of the way you've constructed it, the two concepts are now > nearly identical since the aliasing can only be within the _same_ bounded > object. That was always true, it was just unchecked. > For recursive data structures, either pointers or some other mechanism is > still required. And this is an important point. C can be implemented with a certain set of minimal constructs. It's really a very low-level language. And at this level pointers and arrays are the same... and the internals of recursive data structures are visible. If you don't like that, use a higher-level language. Treat C as a fancy assembler. > (Actually, even recursive data structures may be implemented > with arrays, but it is less elegant in the general case.) Exactly. Pointers are more general than arrays. > The point of this discussion is > that pointers are not, and should not be treated, as a useful method of > implementing arrays. Not at all. Since pointers and arrays are isomorphic, that pointers are a useful method of implementing arrays becomes a tautology. -- _--_|\ `-_-' Peter da Silva. +1 713 274 5180. . / \ 'U` \_.--._/ v