RE: Demystifying Continuations

["Anton van Straaten" <address@hidden>]

Dave,

> > Guy really hit the nail on the head here - as an implementor of a
> > certain type of language, you're steeped in ideas like reifiable
> > cloneable contexts, and that's the model that you want to translate
> > continuations into.
>
> Perhaps I misunderstood his humor. I thought he was alluding to the fact
> the the terms I used were, in and of themselves, non-trivial concepts.
> Which in turn meant that my using those terms to explain continuations
> was perhaps no simpler or easier to understand than "explanations" I had
> complained about in my original missive.

Well, I agree with your interpretation, too, and don't think our
descriptions are mutually exclusive.  Both interpretations describe part of
what I've been trying to say.

I'm not sure I disagree with you as much as you think.  I have confused
matters by addressing at least three different points without delineating
them clearly.  My points are:

*  As Guy more succinctly and humorously noted, your explanation of
continuations isn't "much more easily understood" (one of your original
claims).

*  You're interested in implementation strategies, in fact perhaps even more
specifically, in popular and successful strategies, so you need literature
about that specific topic, not about continuations in general.  This might
mean that the literature isn't as bad as you claimed, i.e. "written by
people who were not very good at explaining it in basic terms", but rather
that you've been looking at literature with a different focus.

*  Finally, there's the more nebulous question of whether or not there is a
mystical level of continuation nirvana, and if there is, whether or not you
have attained it (and thus qualify for the Golden Beanie of Continuation
Satori...)  If you always talk about continuations in terms of a possible
implementation mechanism, it can be hard for others to tell whether you've
really understood the point of continuations.  Which may explain why some
people may have given you the impression that there's some mysterious secret
as yet unrevealed to you.  And for all I know, perhaps there is.  It is in
this context that I was suggesting that working in a "continuation-oriented
environment" might be helpful.  At least, it might give some insight as to
why people talk that way about continuations.  And why they're "wonderful".

One area in which we may disagree is on what constitutes "first principles".
As to that, I'd go back to Guy's point: "objects" aren't "first principles",
for example, by any stretch of the imagination.  And if a "cloneable reified
objectification of a stack" is a "first principle", I'd hate to see what the
second principle is...  ;oP

Anton