Earlier quoted context omitted.
> and certainly not by better implementations of familiar constructs. Why not? I sort of took the slides as just that. For a good chunk of the slides he talks about the simple singly-linked list found in LISP. Then shows that implemented as a Tree (conc list), familiar operations still exist, but we get improvements by making operations more parallelizable. Slide 24 starts showing how `first`, `rest`, `append` can be…
Why not? Well, if first and rest are unsuitable for parallelism as Steele says, a programming edifice built on top of better implementations of those might be beside the point. My understanding of the slides is that we don't need better language runtimes to exploit parallelism for us while we continue to write the same kind of code as before; what we need is a new set of primitives (modeled by conc lists in this talk…
Yes, I agree he was saying that, but that doesn't mean we can't change the implementations of what we use now to actually make it easier to do accomplish this.
> another thing - the transformation from cons to conc is nontrivial in the Lisp context because Lisp's code=data is so tied to cons. It might be an interesting to think about what programs would look like if you applied code=data rigorously in a conc model. Would a language whose expressions are represented as concs look or feel significantly different than a cons-based one?
But, you could still implement car and cdr in terms on conc, so this is not really an issue. It might not be the most efficient thing, but that's sort of the benefit of macros. Expand at compile time, and avoid the overhead. So, in summary, write macros in terms of an emulated cons cell, and use conc optimized primitives elsewhere.