Thanks for looking at it. Digesting your feedback ... <div class="gmail_quote">On Fri, Aug 3, 2012 at 12:02 PM, Sam Tobin-Hochstadt <<a href="mailto:samth@ccs.neu.edu" target="_blank">samth@ccs.neu.edu</a>> wrote: <blockquote class="gmail_quote" style="margin:0 0 0 .8ex;border-left:1px #ccc solid;padding-left:1ex">On Tue, Jul 31, 2012 at 5:04 PM, Ray Racine <<a href="mailto:ray.racine@gmail.com">ray.racine@gmail.com</a>> wrote: > Hi, > > I created a github repo which has a few small files which I think > demonstrate 0, 1 or 3 bugs in Typed Racket. I finally got a chance to take a look at this, sorry for the delay. > The three potential bugs. > 1. The show stopper is found at the very bottom of samples.rkt. This is not a bug in Typed Racket; you aren't creating enough streams. I don't fully understand how iteratees are supposed to work, but roughly, you're trying to produce and (Iteratee A (Iteratee A D)). For a `Continue` structure to match this, its `step` function has to take `(Stream A)` as input, and produce `(Iteratee A (Iteratee A D))`. However, the `iter` value that you're producing is of type `(Iteratee A D)`, which isn't what you want. Your `tee` function produces an iteratee that, I think, always stays at the beginning of its argument, which isn't what you want. > 2. There is a something, I think, not quite right just above #1 also in > samples.rkt. The inferencer appears to rashly and prematurely assume > (Enumerator Integer A) here is (Enumerator Integer Integer). What would `A` be bound to here? Do you want the result to be (All (A) (Enumerator Integer A))? If so, you'll need to change the type of `enumerator/list` to: (: enumerator/list (All (D) (Listof D) -> (All (A) (Enumerator D A)))) That will require some other changes in the rest of the `samples.rkt` file, it looks like. -- sam th <a href="mailto:samth@ccs.neu.edu">samth@ccs.neu.edu</a> </blockquote></div>