[From nobody Wed Oct 28 23:33:00 2009
Subject: Re: [r6rs-discuss] Implicitly Concurrent Scheme
From: Ray Dillinger <bear@sonic.net>
To: Marc Feeley <feeley@iro.umontreal.ca>
In-Reply-To: <25221400-C3DC-4750-888E-56A9C43233C3@iro.umontreal.ca>
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	<25221400-C3DC-4750-888E-56A9C43233C3@iro.umontreal.ca>
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Date: Wed, 28 Oct 2009 20:27:39 -0700
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On Wed, 2009-10-28 at 21:54 -0400, Marc Feeley wrote:
> On 2009-10-28, at 4:53 PM, John Cowan wrote:
> 
> > Marc Feeley scripsit:
> >
> >> Not true.  Lazy-task creation will do a very good job dynamically.
> >> Read my PhD thesis for details:
> >
> > I confess to not having read it yet, but it appears to be about  
> > futures,
> > which are directly inserted into code by the programmer, not inferred
> > by the implementation for *every* argument of *every* call.
> 
> The overhead is so low that a compiler could automatically insert them  
> for every formal parameter of procedure calls (except when they are  
> trivial expressions like constants, variable references, or calls to  
> primitives with trivial expression arguments).

Variable references are not "trivial" expressions w/r/t lazy 
evaluation, unless they are immutable.  The time of evaluation
can make a difference.

			Bear



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