[racket-dev] [plt] Push #24906: master branch updated

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Mon Jun 25 22:32:42 EDT 2012

Oh, I see what you mean now. Thanks.

And yes, if you can't "catch" the values passed to the constructor,
then you aren't going to be guaranteeing that the implementation
behaves parametrically anyways!


On Mon, Jun 25, 2012 at 9:27 PM, Asumu Takikawa <asumu at ccs.neu.edu> wrote:
> On 2012-06-25 21:19:33 -0500, Robby Findler wrote:
>> What do you mean by "made opaque by key/c"?
> The prototype I wrote would bind the parameters provided in the
> `#:params` argument to contracts produced by `new-∀/c`. If `key/c` is
> one of the parameters, then `dict-ref` with a key argument wraps it in
> an opaque struct.
> The constructor isn't part of the interface (and can't be in the current
> implementation of `define-generics`), so the initial keys in the
> dictionaries aren't wrapped in opaque structs, causing lookups of the
> initial keys to fail.
> Cheers,
> Asumu

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