[plt-scheme] hash-has-key?

From: Marek Kubica (marek at xivilization.net)
Date: Sat Mar 28 10:11:14 EDT 2009

On Sat, 28 Mar 2009 10:07:50 -0400
Dave Herman <dherman at ccs.neu.edu> wrote:

> Matthias Felleisen:
> > Because Typed Scheme is typed, it's not possible for hash-ref to
> > use one standard "not found" type, so the API ought to provide the  
> > return type.
> I don't know what this means.

I guess Matthias wanted to point out that being untyped or typed does
not help as there is no standard "not found" value/type either way.


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