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From: kend@data.UUCP (Ken Dickey)
Newsgroups: comp.lang.misc
Subject: Re^2: Some things that pointer-less languages can't do efficiently
Message-ID: <416@data.UUCP>
Date: 17 Oct 90 20:06:00 GMT
Organization: Microcosm, Beaverton, OR
Lines: 28


ok@goanna.cs.rmit.oz.au (Richard A. O'Keefe) writes:

>(Since Lisp has rplaca/rplacd -- or, in Scheme, set-car!/set-cdr! -- Lisp
>is a very poor example of a "pointerless: language...)


I fear I have missed most of the discussion (our news feed is not the
most robust), so my comments may be somewhat random, but here goes...

There are a number of programming languages, Scheme and ML among them,
which do not have a pointer abstraction.  This is not to say that
pointers are not used in their implementations.  Typically, such
languages concentrate on values.  Whether or not a value is small
enough to fit in a register is the concern of the implementation.
Such languages support rapid, reliable code development by eliding a
whole class of user errors. [After programming in Scheme for a few
days, no one ever "falls off the end of a pointer chain" or
"defererences a bogus pointer"].

Such languages tend to be more abstract and hence more portable across
machine/os architectures than languages like C.  Sure, there are
people who prefer to write device drivers, etc. in C.  But trying to
scale up a device driver level development technology is an expensive
and error prone way to build software systems.


-Ken Dickey				kend@data.uucp