[plt-scheme] Asynchronous Let

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Thu Jul 5 12:07:28 EDT 2007

On Jul 5, 2007, at 11:25 AM, Erich Rast wrote:

> BTW, is there some implementation of futures for current MzScheme  
> or R5RS that I've missed?

Gambit use to have futures. Cormac and I did futures pre-PLT Scheme,  
around 93~94.

Like laziness, futures require a decision on which positions/ 
primitives you want to make "future strict" (in analogy to "value  
strict"). For example,

  (if *** ... ...)

must force a future in the *** position. For cons/constructors-in- 
general, it depends on what you're willing to accept.

With an #%app expander, you can get a Future language going with Lazy  
Scheme as a starting point.

-- Matthias

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