[racket] TR: unwrapping from <#Typed Value: ... > ??

In the works Sam would say -- Matthias


On Nov 24, 2011, at 4:46 PM, Ismael Figueroa Palet wrote:

> Thanks Robby for your answer,
> 
> When I create an annotated-proc (as in http://docs.racket-lang.org/reference/procedures.html)
> 
> Unfortunately it seems that I lose type information:
> 
> > (annotated-proc (lambda (x) x) (gensym))
> 
> - : annotated-proc
> #<procedure>
> > (lambda (x) x)
> 
> - : (Any -> Any : ((! False @ 0) | (False @ 0)) (0))
> #<procedure>
> > 
> 
> So it seems in Typed Racket applicable structs cannot replace closures?
> 
> 
> 2011/11/24 Robby Findler <robby at eecs.northwestern.edu>
> Not a direct answer to your question, but comparing procedures for
> equality using eq? can be fragile (contracts will break the equality,
> depending on how you use them, for example).
> 
> You might instead use applicable structs to implement the equality by
> putting some token you use for equality into a second field.
> 
> Robby
> 
> On Thu, Nov 24, 2011 at 2:14 PM, Ismael Figueroa Palet
> <ifigueroap at gmail.com> wrote:
> > I need to compare to procedures for equality. In the untyped version of the
> > code I used eq? and it worked for my purposes.
> > Now, in the Typed Racket version I'm having the problem that somehow one of
> > the procedures is wrapped in a "typed value" struct while the other is not.
> >
> > When I display the values I get:
> >
> > #<Typed Value: #<procedure:A>> #<procedure:A>
> >
> > is there any way to unwrap the value?
> >
> > Thanks
> > --
> > Ismael
> >
> >
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> 
> 
> 
> -- 
> Ismael
> 
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