Re: One other possible reason for the C predominance

[Robert A Duff <bobduff@shell01.TheWorld.com>]

Keith Thompson <kst-u@mib.org> writes:
> Ludovic Brenta <ludovic@ludovic-brenta.org> writes:
>> In fact, C is bad because it assumes a uniform memory architecture and
>> a flat address space. ...

> No, C doesn't assume this.

Right.  Some C programmers assume it, either by accident or on purpose.
I don't remember K&R C well enough to know whether K and/or R assumed
it.  But the C standard does not assume it.

...
> But all of these operations have undefined behavior if the two
> pointers don't point into the same object (or, as a special case,
> just past the end of the object.)  Since the behavior is undefined,
> an implementation could even check for out-of-bounds accesses,
> though most don't do so.

A C impl could, but it's somewhere between difficult and impossible to
do it efficiently.

> For C implementations on systems with a flat address space, all
> this tends to work as you'd expect (and it makes it very easy to
> shoot yourself in the foot by accidentally going outside the bounds
> of the object you're working with).  But it's entirely possible to
> implement C on a system where distinct objects exist in distinct
> address spaces.

Well, sort of.  C programmers on 8086 found it necessary to sprinkle
their programs with "near" and "far" all over the place -- which means
those programs weren't C.

>... This is by deliberate design.

Deliberate design by whom?  K&R, or later C-standards committees?

- Bob