[plt-scheme] More PLT Scheme as an Alternative to Matlab

From: Noel Welsh (noelwelsh at gmail.com)
Date: Fri Aug 14 09:32:07 EDT 2009

Certainly there has to be mutation at some level. Immutability at the
user's level means no arrays can alias. Given this a compiler can
reorder array traversals to take advantage of the cache and multiple
cores. This is, AFAIK, the key to high performance on modern machines,
and the key optimisation SAC does on its comprehensions. OTOH it does
require quite some compiler machinery to exploit.


On Fri, Aug 14, 2009 at 1:54 PM, Doug
Williams<m.douglas.williams at gmail.com> wrote:
> You give me more credit for forward thinking than I deserve. I was planning
> on having array-set!. I'm not sure how to avoid it at the primitive level -
> I just won't have enough information at the time I create the underlying
> vectors to make them immutable (and there are no immutable SRFI vectors that
> I'm aware of). Of course, that doesn't mean I have to expose the underlying
> vectors or array-set! in the interface. That would make them logically
> immutable, but not in a manner than helps the GC system, for example.

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