Let's hack some code

Alaric B. Williams alaric@abwillms.demon.co.uk
Wed, 30 Apr 1997 18:12:57 +0000

On 29 Apr 97 at 1:15, lispos@math.gatech.edu wrote:

> First-class Continuations would of course trivialize threads,
> as well as being of great help to support the Schemists among LispOSers.

> If you fear about the power of duplicating continuations,

IIRC, it's possible to implement them without efficiency loss.
Is that correct? Either use a linked list instead of a stack
(calls would take longer, but we'll inline many of 'em, right?),
or use a stack, treating the EIP return value in the x86 case
as an implicit continuation parameter, with the actual continuation
reified as the stack pointer, and clone stacks when continuations
are reified - faster calls, slower call/cc. I'd go for the non-stack
approach myself, but I'm not an expert implementer.

> Also, there's a lot to recycle from the Fox project at CMU -- the
> only OS I know (besides the dead OSes of LispMs) written as a set of
> modules and functors in a higher-order functional language.

Yes. The language-research community seems to work like so:

Professor X invents a cool new way of doing something, and
designs a language that does this.

Therefore, we get lots of languages that are really good at a set of
things, but there is no sharing... when somebody writes a language,
they often have a concept to demonstrate in mind. It's no surprise
this is a "commercial failure". Only as these languages persist
and grow (like Lisp) do they become "successful".

It takes a non-academic group to harvest a cropp of REALLY good
ideas, of which there are plenty, and make something that implements
MOST of them!
> == Fare' -- rideau@ens.fr -- Franc,ois-Rene' Rideau -- DDa(.ng-Vu~ Ba^n ==

Alaric B. Williams (alaric@abwillms.demon.co.uk)

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