[plt-scheme] #<undefined>

From: Matthew Flatt (mflatt at cs.utah.edu)
Date: Sat Jun 22 23:29:58 EDT 2002

At Sat, 22 Jun 2002 22:11:54 -0400 (EDT), David Feuer wrote:
> Would it be feasable to have something more useful than #<undefined>? 

Yes. DrScheme's Intermdiate Student language, for example, raises an
exception when an uninitialized variable is accessed.

> I'm kind of curious how you
> decided to use #<undefined>, rather than an optimized true letrec.

I'm not sure what you mean.

Perhaps you mean that a `letrec' binding immediate procedure
expressions should directly generate a set of recursive closures
(without using #<undefined> at any point). MzScheme certainly does


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