[plt-scheme] What is the role of promise and force?

From: Danny Yoo (dyoo at cs.wpi.edu)
Date: Sun May 6 18:21:54 EDT 2007

On Sun, 6 May 2007, Grant Rettke wrote:

> What is the role of promise and force?
> This weekend I read the R5RS spec. Before then I hadn't heard anything 
> about promise and force, in other words, they don't get blogged about or 
> written up much. Why not? Are they important? For what kinds of things 
> are they used?

Hi Grant,

Maybe this might help?


It's all about streams, which tries to deal with modeling the state of a 
system without doing explicit mutation.  A little of the way through the 
chapter, it will discuss how we might implement streams by using DELAY and 
FORCE as our primitives for implementing streams.

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