[racket-dev] syntax-local-inferred-name, keyword functions, and syntax properties

From: Robby Findler (robby at eecs.northwestern.edu)
Date: Mon Dec 9 16:16:49 EST 2013

Is it possible that that name can leak out in an error message?


On Mon, Dec 9, 2013 at 3:10 PM, Sam Tobin-Hochstadt <samth at cs.indiana.edu>wrote:

> Currently, this program fails with a somewhat bizarre type error:
>     #lang typed/racket
>     (: foo ([#:k Any] -> Integer))
>     (define (foo #:k [s #f]) 0)
>     (let: ([i : Integer (foo #:k #t)]) i)
> The reason is that the expansion of keyword applications generates a
> name to use for the function (here `foo`), and it uses
> `syntax-local-infer-name` to get the name to use. Unfortunately, in
> this case, it produces `i`, an identifier which has an extra syntax
> property saying that `i` is an `Integer`.  Of course, `foo` isn't an
> integer, it's a function, and so we get a type error.
> I don't see why the inferred name is the right choice here -- there's
> no connection between `i` and the name of the function. I can just
> change this to use a fresh name, but I thought I'd ask first.
> Sam
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