Path: utzoo!attcan!uunet!ficc!peter From: peter@ficc.uu.net (Peter da Silva) Newsgroups: comp.lang.misc Subject: Cheap implementations of languages (Re: Pointers and poor implementations (was: Re: JLG's flogging ...)) Message-ID: Date: 9 Apr 90 11:19:43 GMT References: <14312@lambda.UUCP> Reply-To: peter@ficc.uu.net (Peter da Silva) Organization: Xenix Support, FICC Lines: 35 In article <14312@lambda.UUCP> jlg@lambda.UUCP (Jim Giles) writes: > Non-segmented byte-addressible machine don't exhibit the failing that you > give as the reason for limiting pointer values to only lie within the > allocated object! Apparently, you are willing to reinterpret the context > of this discussion to fit your preconceptions any time you feel like it. Nah, I'm not *in* this discussion. I'm just sitting on the side pointing out things you guys miss. Like, the fact that C can run at all in such a minimal implementation has proven to be one of it's strengths. How many PD Fortran compilers are there? > You imply that many implementations actually > allocate an extra element at the end for the 'dispensation' on pointer > values at one past the end. No, that was someone else. But, yes, many low-end implementations on machines like the IBM-PC have done so. And the IBM-PC is probably the major C user base right now... and it's a segmented byte-addressible machine. C doesn't fit so well into it, but it's easy enough to make it look like a flat address space, subject to some limitations, so long as you allocate those extra bytes for breathing room. > Are you saying that this implementation should be regarded as anything but > poor? No. But it's also cheap. And look at what it's got to work with. > By the way, pascal doesn't _have_ pointer arithmetic. So this whole issue > doesn't arise there. Pascal is also such a limited language that it's heavily fragmanted. Portability between compilers... let along machines... is practically non- existent. Because to do much of anything interesting in it you need to use extensions. You don't write in "Pascal". You write in Turbo-pascal, or Oregon pascal/2, or UCSD Pascal, or JRT Pascal, or Alice, or whatever... -- _--_|\ `-_-' Peter da Silva. +1 713 274 5180. . / \ 'U` \_.--._/ v