[r6rs-discuss] Thoughts on Scheme's Future

[Anton van Straaten]

Joe Marshall wrote:
> On Fri, Sep 4, 2009 at 1:21 PM, Anton van
> Straaten<anton at appsolutions.com> wrote:
>> Joe Marshall wrote:
>>> Similarly with threads.  These are a disaster.  It is very hard to program with
>>> concurrency.  It is harder still if your concurrancy mechanism is something
>>> as primitive as a thread.  In nearly every implementation of Common Lisp
>>> I've worked on, they've made major errors in concurrency control.  And these
>>> are the *vendors*.  The users have no hope of getting it right.
>>>
>>> I don't know what the correct solution to concurrency is, but I'm sure we
>>> can do better than a thread library.
>> I don't know what the correct solution to control flow is, but I'm sure
>> we can do better than first-class continuations.
> 
> Agreed.  Although this could be interpreted in two different ways, both of which
> I agree with.
> 
>     1.  Easier to understand user constructs such as structured
> exceptions, non-local
>          exits, co-operative co-routines, etc. should be what users turn to
>          rather than ad-hoc grabbing of continuations.

Right.  But the question is, should it be possible to implement all 
those things in Scheme, without having to resort to coding in some lower 
level or host language?  If the answer is yes, then you still need 
something like first-class continuations.  The same argument applies to 
(something like) threads.

Anton