Let's have some fun for the week-end

[Pascal Bourguignon]

The language provides a programmer with a set of conceptual tools; if these are
inadequate for the task, they will simply be ignored. For example, seriously
restricting the concept of a pointer simply forces the programmer to use a
vector plus integer arithmetic to implement structures, pointer, etc. Good
design and the absence of errors cannot be guaranteed by mere language
features.
-- Bjarne Stroustrup, "The C++ Programming Language"

In how many Lisp program do we implement c-pointers like this (not
counting zeta-C)? Vs. for example displaced arrays which still have
bound checking?

Strange, in 30 years of programming, I never realized that the random
memory pointer was a fundamental data structure.

--
__Pascal Bourguignon__ http://www.informatimago.com/

Voting Democrat or Republican is like choosing a cabin in the Titanic.

[Cesar Rabak]

Pascal Bourguignon escreveu:

> The language provides a programmer with a set of conceptual tools; if these are
> inadequate for the task, they will simply be ignored. For example, seriously
> restricting the concept of a pointer simply forces the programmer to use a
> vector plus integer arithmetic to implement structures, pointer, etc. Good
> design and the absence of errors cannot be guaranteed by mere language
> features.
> -- Bjarne Stroustrup, "The C++ Programming Language"
>
> In how many Lisp program do we implement c-pointers like this (not
> counting zeta-C)? Vs. for example displaced arrays which still have
> bound checking?
>
> Strange, in 30 years of programming, I never realized that the random
> memory pointer was a fundamental data structure.
>

The accurate answer to this question will need we place a problem domain
more thoroughly:

How many device drivers and non hosted applications have been written in
Lisp in the same period of observation?

I think picking one such citation at random takes out it of the context.

--
Cesar Rabak

[Matthew Danish]

Cesar Rabak <cra...@acm.org> writes:
> How many device drivers and non hosted applications have been written
> in Lisp in the same period of observation?

In the past 30 years? That includes the era of Lisp Machines, which
were written in Lisp down to the lowest levels. How about Movix
nowadays? But the larger point is this: ``memory pointers'' are a
hardware-dependent low-level mechanism specific to the von Neumann
machine architecture. That is not the only model for computation,
however, and most high-level languages present a different one. So
there is nothing fundamentally important about ``memory pointers''
that requires them to be part of a programming language. They can be
relegated to a system-specific library, which is the usual case in
modern Lisp implementations (for example, SYSTEM:SAP-REF-32 in CMUCL).

--
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