Relay-Version: version B 2.10 5/3/83; site utzoo.UUCP Posting-Version: Notesfiles $Revision: 1.6.2.17 $; site uiucdcs.UUCP Path: utzoo!watmath!clyde!cbosgd!ihnp4!inuxc!pur-ee!uiucdcs!mccaugh From: mccaugh@uiucdcs.UUCP Newsgroups: net.lang Subject: Re: High-levelity Message-ID: <26400021@uiucdcs.UUCP> Date: Sat, 29-Dec-84 19:47:00 EST Article-I.D.: uiucdcs.26400021 Posted: Sat Dec 29 19:47:00 1984 Date-Received: Thu, 3-Jan-85 00:55:32 EST References: <83@mit-athena.UUCP> Lines: 22 Nf-ID: #R:mit-athena:-8300:uiucdcs:26400021:000:1236 Nf-From: uiucdcs!mccaugh Dec 29 18:47:00 1984 Re: the question of hi-levelity-- It seems to me that what eludes us in the way of definition is that we have yet to define "levelity" itself before we can assess the "hi-ness" of it...It was my understanding that Bell's classic on Computer Struct- ures might be a first resort to the problem: if by "level" we mean some "layer" of abstraction between programmer and bare machine, then per- haps the lowest-level languages are indeed the assembly languages that are (except for macros) in 1-to-1 correspondence with the machine's own language. Alternatively, we might think of "hi-ness" of levels not only in terms of distance from the physical machine but (since they are lay- ers of "abstraction") also in terms of what virtual machine does play host to that language, e.g., the string-oriented machine that one might have in mind to interpret his Snobol program. That is to say, "height" of the language level might pertain to the virtual machine instead of the language, the usefulness of which concept is that then one can be- gin to think of equating languages level-wise if the virtual host can interpret them both. uiucmsl!mccaugh