[plt-scheme] minor glitch in Lazy Scheme?

From: Matthias Felleisen (matthias at ccs.neu.edu)
Date: Sat Jan 13 12:17:49 EST 2007

On Jan 13, 2007, at 12:04 PM, Eli Barzilay wrote:

>> (PS I like Lazy Scheme a lot -- it's going to let me explain lazy
>> evaluation to my students, and let them play with it a bit, without
>> my having to teach them Haskell.)
> Like Matthias said -- that was exactly the point.  I wanted to teach
> lazy evaluation, and the choices were (a) switch to Haskell, (b) use
> lazy streams.  (a) is too strong of a change to make any sense --
> switching the syntax makes everything too confusing, having it
> statically typed doesn't help too.  (b) is the traditional solution,
> but I find it too weak when you want to demonstrate laziness properly.

BTW, for the curious, we will try something similar with types  
(http://www.ccs.neu.edu/home/samth/typed-scheme.html) and we are  
working with OK U on doing program proofs that way (http:// 

And yes, the Lazy Language will soon support the Stepper so that you  
can explain how different the evaluation (reduction) proceeds.

-- Matthias

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